Download the Full Ebook and Access More Features - ebooknice.

com

(Ebook) Cardiopulmonary Bypass, 3rd Edition by

Florian Falter, Albert C. Perrino, Robert A. Baker
ISBN 9781009009621, 1009009621

https://ebooknice.com/product/cardiopulmonary-bypass-3rd-
edition-46820242

OR CLICK HERE

DOWLOAD EBOOK

Download more ebook instantly today at https://ebooknice.com

 Instant digital products (PDF, ePub, MOBI) ready for you
Download now and discover formats that fit your needs...

Start reading on any device today!

(Ebook) Biota Grow 2C gather 2C cook by Loucas, Jason;

Viles, James ISBN 9781459699816, 9781743365571,
9781925268492, 1459699815, 1743365578, 1925268497
https://ebooknice.com/product/biota-grow-2c-gather-2c-cook-6661374

ebooknice.com

(Ebook) Matematik 5000+ Kurs 2c Lärobok by Lena

Alfredsson, Hans Heikne, Sanna Bodemyr ISBN 9789127456600,
9127456609
https://ebooknice.com/product/matematik-5000-kurs-2c-larobok-23848312

ebooknice.com

(Ebook) SAT II Success MATH 1C and 2C 2002 (Peterson's SAT

II Success) by Peterson's ISBN 9780768906677, 0768906679

https://ebooknice.com/product/sat-ii-success-
math-1c-and-2c-2002-peterson-s-sat-ii-success-1722018

ebooknice.com

(Ebook) Cardiopulmonary Bypass by Sunit Ghosh, Florian

Falter, David J. Cook ISBN 9780521721998, 0521721997

https://ebooknice.com/product/cardiopulmonary-bypass-6731056

ebooknice.com
(Ebook) Cardiopulmonary Bypass by Sunit Ghosh, Florian
Falter, David J. Cook ISBN 9780521721998, 0521721997

https://ebooknice.com/product/cardiopulmonary-bypass-1461118

ebooknice.com

(Ebook) Cambridge IGCSE and O Level History Workbook 2C -

Depth Study: the United States, 1919-41 2nd Edition by
Benjamin Harrison ISBN 9781398375147, 9781398375048,
1398375144, 1398375047
https://ebooknice.com/product/cambridge-igcse-and-o-level-history-
workbook-2c-depth-study-the-united-states-1919-41-2nd-edition-53538044

ebooknice.com

(Ebook) Master SAT II Math 1c and 2c 4th ed (Arco Master

the SAT Subject Test: Math Levels 1 & 2) by Arco ISBN
9780768923049, 0768923042
https://ebooknice.com/product/master-sat-ii-math-1c-and-2c-4th-ed-
arco-master-the-sat-subject-test-math-levels-1-2-2326094

ebooknice.com

(Ebook) Perfusion for Congenital Heart Surgery: Notes on

Cardiopulmonary Bypass for a Complex Patient Population by
Gregory S. Matte ISBN 9781118900796, 1118900790
https://ebooknice.com/product/perfusion-for-congenital-heart-surgery-
notes-on-cardiopulmonary-bypass-for-a-complex-patient-
population-5031228
ebooknice.com

(Ebook) The Crazy Quilt Handbook, Revised 3rd Edition by

Judith Baker Montano

https://ebooknice.com/product/the-crazy-quilt-handbook-revised-3rd-
edition-53513944

ebooknice.com
 Cardiopulmonary Bypass
Third Edition

P bli h d li b C b id i i P
P bli h d li b C b id i i P
 Cardiopulmonary Bypass

Edited by
Florian Falter
Royal Papworth Hospital, Cambridge

Albert C Perrino
Yale University Medical Center, New Haven, CT

Robert A. Baker
Flinders Medical Centre and Flinders University, Adelaide

The editors are very grateful to Dr Ghosh, who started this project and led the first two editions
from idea to printed book

P bli h d li b C b id i i P
 Shaftesbury Road, Cambridge CB2 8BS, United Kingdom
One Liberty Plaza, 20th Floor, New York, NY 10006, USA
477 Williamstown Road, Port Melbourne, VIC 3207, Australia
314–321, 3rd Floor, Plot 3, Splendor Forum, Jasola District Centre,
New Delhi – 110025, India
103 Penang Road, #05–06/07, Visioncrest Commercial, Singapore 238467

Cambridge University Press is part of Cambridge University Press & Assessment,

a department of the University of Cambridge.

We share the University’s mission to contribute to society through the pursuit of

education, learning and research at the highest international levels of excellence.

www.cambridge.org
Information on this title: www.cambridge.org/9781009009621
DOI: 10.1017/9781009008143
© Cambridge University Press & Assessment 2022
This publication is in copyright. Subject to statutory exception and to the provisions
of relevant collective licensing agreements, no reproduction of any part may take
place without the written permission of Cambridge University Press & Assessment.
First published 2009
Second edition 2015
Third edition 2022
Printed in the United Kingdom by TJ Books Limited, Padstow Cornwall
A catalogue record for this publication is available from the British Library.
Library of Congress Cataloging-in-Publication Data
Names: Falter, Florian, editor. | Perrino, Albert C., Jr. editor. | Baker, Robert A,
1960- editor.
Title: Cardiopulmonary bypass / edited by Florian Falter, Albert C. Perrino,
Robert A. Baker.
Other titles: Cardiopulmonary bypass (Ghosh)
Description: Third edition. | Cambridge, United Kingdom ; New York, NY :
Cambridge University Press, [2022] | Preceded by Cardiopulmonary
bypass / edited by Sunit Ghosh, Florian Falter, Albert C. Perrino, Jr.
Second edition. 2015 | Includes bibliographical references and index.
Identifiers: LCCN 2022010263 (print) | LCCN 2022010264 (ebook) |
ISBN 9781009009621 (paperback) | ISBN 9781009008143 (epub)
Subjects: MESH: Cardiopulmonary Bypass–methods | Cardiac Surgical
Procedures–methods
Classification: LCC RD598 (print) | LCC RD598 (ebook) | NLM WG 168.5 |
DDC 617.4/120592–dc23/eng/20220511
LC record available at https://lccn.loc.gov/2022010263
LC ebook record available at https://lccn.loc.gov/2022010264
ISBN 978-1-009-00962-1 Paperback
Cambridge University Press & Assessment has no responsibility for the
persistence or accuracy of URLs for external or third-party internet websites
referred to in this publication and does not guarantee that any content on
such websites is, or will remain, accurate or appropriate.
..................................................................
Every effort has been made in preparing this book to provide accurate and up-to-
date information that is in accord with accepted standards and practice at the time
of publication. Although case histories are drawn from actual cases, every effort has
been made to disguise the identities of the individuals involved. Nevertheless, the
authors, editors, and publishers can make no warranties that the information
contained herein is totally free from error, not least because clinical standards are
constantly changing through research and regulation. The authors, editors, and
publishers therefore disclaim all liability for direct or consequential damages
resulting from the use of material contained in this book. Readers are strongly
advised to pay careful attention to information provided by the manufacturer of
any drugs or equipment that they plan to use.
P bli h d li b C b id i i P
 Contents
List of Contributors vi
Foreword ix
Alan Merry 11 Myocardial Preservation during
Cardiopulmonary Bypass 102
Gudrun Kunst, Luc Puis and Tom Gilbey
1 Human Factors and Teamwork in 12 Weaning from Cardiopulmonary Bypass 112
Cardiac Surgery 1 Joanne F Irons, Kenneth G Shann
Lindsay Wetzel, David Fitzgerald, Thoralf M and Michael Poullis
Sundt and James H Abernathy III
13 Intraoperative Mechanical Circulatory
2 Equipment for Cardiopulmonary Bypass 9 Support and Other Uses of
Simon Anderson and Amanda Crosby Cardiopulmonary Bypass 123
Mark Buckland and Jessica Underwood
3 Monitoring during
Cardiopulmonary Bypass 25 14 Mechanical Circulatory Support 138
Richard F Newland and Pascal Starinieri Jason M Ali, Ayyaz Ali and Yasir Abu-Omar
4 Cardiopulmonary Bypass Circuit Setup and 15 Cardiopulmonary Bypass for Pediatric
Safety Checks 34 Cardiac Surgery 150
Victoria Molyneux and Shahna Helmick Joseph J Sistino and Timothy J Jones
5 Priming Solutions for Cardiopulmonary 16 Coagulopathy and Hematological Disorders
Bypass Circuits 42 Associated with
Filip De Somer and Robert Young Cardiopulmonary Bypass 156
Bruce D Spiess and Erik Ortmann
6 Anticoagulation for
Cardiopulmonary Bypass 49 17 Inflammation and Organ Damage during
Martin Besser and Linda Shore-Lesserson Cardiopulmonary Bypass 166
R Clive Landis and Sherif Assaad
7 Conduct of Cardiopulmonary Bypass 57
Christiana Burt, Timothy A Dickinson, Narain 18 Neuromonitoring and Cerebral Morbidity
Moorjani and Caitlin Blau Associated with
Cardiopulmonary Bypass 175
8 Minimal Invasive Etienne J Couture, Stéphanie Jarry and André
Extracorporeal Circulation 71 Y Denault
Kyriakos Anastasiadis, Polychronis Antonitsis,
Helena Argiriadou and Apostolos 19 Renal Morbidity Associated with
Deliopoulos Cardiopulmonary Bypass 184
Juan Pablo Domecq and Robert C Albright
9 Considerations for Operations Involving Deep
Hypothermic Circulatory Arrest 80 20 Common and Uncommon Disasters during
Pingping Song and Joseph E Arrowsmith Cardiopulmonary Bypass 194
Gregory M Janelle, Jane Ottens and Michael Franklin
10 Metabolic Management during
Cardiopulmonary Bypass 92
Jonathan Brand and Edward M Darling
Index 205 v

P bli h d li b C b id i i P
 Contributors

James H. Abernathy III Helena Argiriadou

Associate Professor, Interim Executive Vice Chair, Cardiac Anesthesiologist, Assistant Professor,
ACCM Chief, Division of Cardiac Anesthesiology Aristotle University of Thessaloniki
Core Faculty, Armstrong Institute of Patient Safety,
Department of Anesthesiology & Critical Care Joseph E. Arrowsmith
Medicine, Johns Hopkins University Consultant Anaesthetist, Department of Anaesthesia
& Intensive Care Medicine, Royal Papworth
Yasir Abu-Omar Hospital
Director, Cardiothoracic Transplantation and
Mechanical Circulatory Support, University Hospitals Sherif Assaad
Cleveland Medical Center Associate Professor, Cleveland Clinic Lerner College
of Medicine | Case Western Reserve University, and
Robert C. Albright Jr Staff Anesthesiologist, Department of Cardiothoracic
Consultant, Division of Nephrology and HTN Mayo Anesthesiology | Anesthesiology Institute, Cleveland
Clinic Rochester; Professor of Medicine, Division of Clinic
Nephrology and HTN, Mayo Clinic College of
Medicine, Mayo Clinic, Rochester; Regional Vice Martin Besser
President, Mayo Clinic Health System Southeast; Consultant Haematologist, Royal Papworth
Professor of Medicine; Consultant, Division of Hospital
Nephrology and Hypertension Caitlin Blau
Ayyaz Ali Perfusion Supervisor, Mayo Clinic
Vice Chairman of Cardiac Surgery and Surgical Jonathan Brand
Director of Heart Transplantation and Mechanical
Clinical Director and Consultant in Cardiothoracic
Circulatory Support, Hartford Hospital
Anaesthesia and Critical Care, James Cook University
Jason M. Ali Hospital, Middlesbrough
Locum Consultant in Cardiothoracic and Transplant Mark Buckland
Surgery, Royal Papworth Hospital
Deputy Director, Head of Cardiothoracic
Kyriakos Anastasiadis Anaesthesia, Department of Anaesthesiology &
Professor, Department of Cardiothoracic Surgery, Perioperative Medicine, Alfred Hospital and Monash
Aristotle University of Thessaloniki University

Simon Anderson Christiana Burt

Clinical Perfusion Team Leader, Cambridge Consultant Anaesthetist, Royal Papworth Hospital
Perfusion Services, Royal Papworth Hospital Etienne J. Couture
Polychronis Antonitsis Anesthesiologist & Intensivist, Institut universitaire
Associate Professor, Department of Cardiothoracic de cardiologie et de pneumologie de Québec –
Surgery, Aristotle University of Thessaloniki Université Laval (IUCPQ-UL)
vi

P bli h d li b C b id i i P
 List of Contributors

Amanda Crosby Joanne F. Irons

Staff Perfusionist, University of Tennessee Medical Senior Lecturer, University of Sydney; Staff Specialist
Center Anaesthetist, Royal Prince Alfred Hospital
Edward M. Darling Gregory M. Janelle
Associate Professor, College of Health Professions, Professor of Anesthesiology and Surgery and Associate
Department of Cardiovascular Perfusion, SUNY Chair for Clinical Affairs, Department of Anesthesiology,
Upstate Medical University; Faculty/Clinical University of Florida College of Medicine
Coordinator
Stéphanie Jarry
Filip De Somer PhD candidate, Department of Anesthesiology,
Professor in Perfusion Technology, University Ghent, Montreal Heart Institute, Université de Montréal
Chief Perfusionist, University Hospital Ghent
Timothy J. Jones
Apostolos Deliopoulo Consultant Congenital Cardiac Surgeon, Birmingham
Perfusionist, Cardiothoracic Department, Aristotle Women’s and Children’s Hospital, University
University of Thessaloniki Hospitals Birmingham; Honorary Senior Lecturer,
Institute of Cardiovascular Science, University of
André Y. Denault Birmingham
Professor, and Anesthesiologist & Intensivist,
Montreal Heart Institute, Université de Montréal Gudrun Kunst
Professor of Cardiovascular Anaesthesia, Department
Timothy A. Dickinson of Anaesthetics and Pain Medicine, King’s College
Assistant Professor of Surgery, CCP, Mayo Clinic; Hospital NHS Foundation Trust & School of
Director, Perfusion Services Cardiovascular Medicine and Sciences, King’s College
Juan Pablo Domecq London; Consultant Anaesthetist and Professor of
Cardiovascular Anaesthesia, British Heart
Senior Associate Consultant, Division of Nephrology,
Foundation Centre of Research Excellence
Hypertension and Critical Care Medicine, Mayo Clinic,
Rochester, and Mayo Clinic, Mankato; Assistant R. Clive Landis
Professor of Medicine, Mayo Clinic College of Medicine Professor of Cardiovascular Research, and Pro Vice
David Fitzgerald Chancellor and Principal, The University of the West
Indies, Cave Hill Campus
Assistant Professor, Division Director, CVP Program,
Medical University of South Carolina Victoria Molyneux
Michael Franklin Senior Clinical Perfusionist, Great Ormond Street
Hospital for Children NHS Foundation Trust
Clinical Assistant Professor – Cardiothoracic
Anesthesiology, University of Florida Narain Moorjani
Tom Gilbey Consultant Cardiac Surgeon & Clinical Lead for
Cardiac Surgery, Royal Papworth Hospital; Affiliated
Anaesthetic Registrar and NIHR Academic Clinical
Assistant Professor, University of Cambridge;
Fellow, Department of Anaesthetics and Pain
President, Society for Cardiothoracic Surgery in Great
Medicine, King’s College Hospital NHS Foundation
Britain & Ireland
Trust
Richard F. Newland
Shahna Helmick
Senior Perfusionist & Clinical Lead for Perfusion,
Program Director of Perfusion Education, University
Flinders Medical Centre and Lecturer, Flinders
of Iowa Hospitals and Clinics
University

vii

P bli h d li b C b id i i P
 List of Contributors

Erik Ortmann Center; Medical Director, Cardiothoracic Intensive

Chair, Department of Anaesthesiology, Care Unit
Schüchtermann-Heart-Centre
Bruce D. Spiess
Jane Ottens Professor and Associate Chair (Research), University
Chief Perfusionist, Ashford Hospital of Florida College of Medicine

Michael Poullis Pascal Starinieri

Senior Fellow Cardiothoracic Surgery, Manchester Clinical Perfusionist, JESSA Hospital
Royal Infirmary
Thoralf M. Sundt
Luc Puis Chief, Division of Cardiac Surgery, Director of
Senior Perfusionist, University Hospital Brussels, Cardiac Surgery Clinical Service, and Edward D.
Center for Heart and Vascular Diseases Churchill Professor of Surgery, Harvard
Medical School, Massachusetts General
Kenneth G. Shann Hospital
Director, Perfusion Services, Massachusetts General
Hospital Jessica Underwood
Perfusionist, Alfred Hospital; Director, Victorian
Linda Shore-Lesserson Perfusion Specialists
Professor of Anesthesiology, Zucker School of
Medicine at Hofstra Northwell; Vice Chair Academic Lindsay Wetzel
Affairs; Director, Cardiovascular Anesthesiology Cardiac Anesthesiologist, TriHealth Heart Institute -
Seven Hills Anesthesia
Joseph J. Sistino
Professor Emeritus, Medical University of South Robert Young
Carolina College of Health Professions Specialist Cardiothoracic Anaesthetist, Department of
Anaesthesia, Flinders Medical Centre
Pingping Song
Assistant Professor, Department of Anesthesiology &
Pain Medicine, University of Washington Medical

viii

P bli h d li b C b id i i P
 Foreword

Six years after the publication of the second edition of edition, the editors have achieved a consistency of
Cardiopulmonary Bypass, Florian Falter, Robert style and message with a minimum of repetition.
Baker and Albert C Perrino have produced a substan- Thus, the book feels coherent and has a logical flow
tial revision of this highly regarded text. Success in of ideas. As before, there is effective use of illustra-
cardiac surgery requires each member of the team to tions and tables and a good bibliography of selected
be expert in the theory and capable in the practice of references for each chapter. The book will continue to
their individual discipline, but it also requires them to provide an outstanding introduction to this field of
work together effectively as a team, often for long practice, both for surgeons and anesthetists, who pri-
hours under considerable stress. It is thus very pleas- marily need to understand and contribute to the
ing to see a strong new emphasis on teamwork, com- management of cardiopulmonary bypass or mechan-
munication and human factors added to this already ical circulatory support, and for perfusionists who
excellent book. This emphasis is reflected in the also have to set up and run the equipment. For those
renewed authorship of each chapter, which (in most already expert in this field, it will provide a technically
cases) now includes all three of the disciplines key to up-to-date source for revision of the relevant topics
the management of cardiopulmonary bypass – anes- from a highly contemporary perspective.
thesia, perfusion and surgery. The list of editors and The editors work in leading institutions in their
authors is a “Who’s Who” of this field and reflects not respective countries (England, Australia and the
only deep expertise in the relevant topics but also United States). Each is known for leadership and
established ability to disseminate knowledge through innovation within their discipline. The same can be
lecturing and writing. The result, as one might expect, said for the chapter authors. It is unsurprising that the
is a scientifically sound, clearly written and highly book carries a tone of authority that will leave readers
accessible text. It is a text that will (like the previous confident in the reliability of the information and the
edition) be an excellent source of practical hands-on soundness of the perspectives within it.
advice on how to apply the underpinning principles I offer the editors and the authors my hearty
to the everyday practice of cardiopulmonary bypass congratulations.
within the dynamic context of cardiac surgery.
The number of chapters has increased from 16 to Alan Merry FANZCA, FFPMANZCA, FRSNZ
20, but new material has been incorporated through- Professor of Anaesthesiology, University of
out. The themes of teamwork, communication, Auckland,
checklists and safety (both Safety-I and Safety-II) Specialist in Anaesthesia, Auckland City Hospital,
run through the entire book. As with the previous New Zealand.

ix

P bli h d li b C b id i i P
P bli h d li b C b id i i P
 Chapter
Human Factors and Teamwork in

1 Cardiac Surgery
Lindsay Wetzel, David Fitzgerald, Thoralf M Sundt and James H Abernathy III

Teams are especially critical for avoiding errors

Today we face many problems. Some are created and for responding to unexpected events that can
essentially by ourselves based on divisions due to result in catastrophic complications if not managed
ideology, religion, race, economic status, or other appropriately. The elite cardiac operating room rep-
factors. Therefore, the time has come for us to think resents a delicate symphony of quick decision-
on a deeper level, on the human level, and from that making, refined technical skill and sound judgment
level we should appreciate and respect the sameness of by each member of a large multidisciplinary team
others as human beings. consisting of perfusionists, surgeons, anesthesiolo-
—Dalai Lama gists, fellows, residents, nurses, surgical technologists
and other highly trained, capable healthcare
In the current healthcare environment, there is an providers.
increasing focus on providing high quality patient A hallmark feature of successful teams is effective
care at ever lower costs while patients rightly expect and open communication. The cardiac operating
excellent outcomes. Cardiac surgery in particular is room is a high stakes environment where small break-
dependent on several disciplines working together downs in communication and teamwork can have
closely and having a good appreciation of the chal- significant consequences on safe patient care and
lenges facing each one. High quality outcomes are outcome. With that in mind, organizations that
dependent upon a wide array of factors, ranging from accredit healthcare providers, such as The Joint
patient specific issues, to provider acumen and tech- Commission in the United States, have pinpointed
nical skills, to ancillary support systems and increas- teamwork as being critical to thriving healthcare
ingly to organizational factors. organizations that provide optimal patient care and
Successful healthcare organizations understand minimize medical error.
the importance of using teams efficiently to accom-
plish difficult and complex tasks. Teams are assem-
bled with a central, unifying objective in mind and
Error
specific roles are assigned to each member in order to Before we understand teams, we must understand the
achieve this goal. This allows members to play to their root cause of error. It is increasingly recognized that
individual skill set and operate within their comfort most medical errors are avoidable. Rather than being
zone. Advanced technology, streamlined techniques, related to a lapse of technical skill, poor medical
and improved science, much of which is outlined in decision-making, inadequate knowledge or subopti-
the chapters of this text, have no doubt improved mal training, they are more commonly the result of a
practitioner skills and enhanced care. Importantly, a breakdown in effective communication, in teamwork
shared mental model gives what would otherwise be a or during transition of care. Addressing system-based
group of skilled individuals working in isolation the issues, breakdowns in cognitive networks and advan-
ability to successfully tackle increasingly complex cing team-based approaches are essential to high
tasks together. Teams generally provide a purpose quality care.
and a broader sense of meaning to each member, The famous human factors engineer, James
creating a sense of mutual support which can bind Reason, described all systems as containing both
individuals together. active and latent failures. Active failures represent
1

h //d i /10 1017/9781009008143 001 P bli h d li b C b id i i P

 Lindsay Wetzel, David Fitzgerald, Thoralf M Sundt and James H Abernathy III

Table 1.1. Overview of Safety 1 and 2

Safety 1 Safety 2
Definition of That as few things as possible go wrong. That as many things as possible go right.
Safety
Safety Reactive, respond when something happens or Proactive, continuously trying to anticipate
management is categorized as an unacceptable risk. developments and events.
principle
View of the Humans are predominantly seen as a liability or Humans are seen as a resource necessary for
human factor hazard. They are a problem to be fixed. system flexibility and resilience. They provide
in safety flexible solutions to many potential
management problems.
Accident Accidents are caused by failures and Things basically happen in the same way,
investigation malfunctions. The purpose of an investigation regardless of the outcome. The purpose of
is to identify the causes. an investigation is to understand how things
usually go right as a basis for explaining how
things occasionally go wrong.
Risk assessment Accidents are caused by failures and To understand the conditions where
malfunctions. The purpose of an investigation performance variability can become difficult
is to identify causes and contributory factors. or impossible to monitor and control.
Reprinted from, From Safety-I to Safety-II: A White Paper, Hollnagel E et al. Retrieved from www.england.nhs.uk/signuptosafety/wp-content/
uploads/sites/16/2015/10/safety-1-safety-2-whte-papr.pdf. Copyright 2015 by Erik Hollnagel, Robert L Wears, Jeffrey Braithwaite.

errors made by individuals at the service delivery end 2 embraces the variability in the healthcare delivery
(the operating room team); latent failures are organ- system and seeks to understand it. For example: Sally,
izational deficiencies (hospital wide, governmental, a perfusionist, is sought-after for complicated cases.
manufacturers, etc.) that are lurking in the back- She is talented clinically, communicates well, shares
ground contributing to active failures. Latent failures what she is thinking, makes good decisions and is
can be thought of as the holes in the Swiss cheese. steady under pressure. Sally’s resilience serves the
When errors occur, the majority of healthcare team well and, when Sally is there, it performs better.
organizations focus on the active failures, the most Rather than punishing people for making poor deci-
obvious of failures, through investigations like root sions (Safety 1), Safety 2 seeks to understand what
cause analyses or Morbidity & Mortality conferences. Sally does well and how this can be transferred to
Questions typically asked are: “who made mistakes?” other situations.
or “who didn’t follow the rules?.” This type of think- The two different perspectives are best summar-
ing with an emphasis on the negative has been coined ized in Table 1.1.
“Safety 1.” Safety 1 seeks to find the errors, the flaws,
the vulnerabilities. An alternative perspective, how-
ever, has emerged called “Safety 2.” In delivering The Human Factors Perspective
complex, complicated healthcare we do a lot of good Catchpole and McCulloch define human factors as:
and most times, we do it correctly. We manage to do “Enhancing clinical performance through an under-
this despite operating in increasingly complex standing of the effects of teamwork, tasks, equipment,
systems, with ever changing providers and more and workspace, culture and organization on human behav-
more demanding patients. The reason things go right ior and abilities and application of the knowledge in
is not that people behave as they are supposed to but clinical settings.” Or, stated more simply, “The science
because people adapt to the conditions they work in of improving human performance and well-being by
to make outcomes better. Understanding how people examining all the effectors of human performance.”
and the systems they work in adjust in order to Insights into the human factors perspective show
2
provide great care is how “Safety 2” is framed. Safety us that stress and fatigue, shortcomings in human

h //d i /10 1017/9781009008143 001 P bli h d li b C b id i i P

 Chapter 1: Human Factors and Teamwork in Cardiac Surgery

Figure 1.1 Systems Engineering Initiative for Patient Safety (SEIPS) 2.0: A model of work system and patient safety. (Reprinted from Holden RJ,
Carayon P, Gurses AP et al. SEIPS 2.0: A human factors framework for studying and improving the work of healthcare professionals and patients. Ergonomics.
2013;56(11):1669–1686.)

memory, interruptions and distractions, overesti- healthcare performance and outcomes. It celebrates
mation of ability and overreliance on multi-tasking measures which foster quality patient care and pin-
can make even the most seasoned healthcare pro- points interventions which can help healthcare organ-
viders commit medical errors. One of the first frame- izations achieve and maintain surgical excellence. It is
works by which we can understand these complex juxtaposed to individual-centered approaches which
interactions is the Systems Engineering Initiative for contend that human error is due to deficiencies on a
Patient Safety (SEIPS) (see Figure 1.1). personal level and remedies that are focused on discip-
The SEIPS model provides a framework through linary, punitive and litigious means.
which we can identify and addresses modifiable
factors in the interaction of people and their environ-
ments with regard to patient safety events. For Teamwork
instance, the perfusionist (person) operating the car- Salas and coworkers have described teamwork as “a
diopulmonary bypass machine (tool) requires correct distinguishable set of two or more people who inter-
ergonomics, visual and auditory feedback. The com- act dynamically, interdependently, and adaptively
plex machine the person operates should be situated towards a common and valued goal, who have each
in a location that provides short tubing length, is not been assigned specific roles or functions to perform
at risk of being hit by opening OR doors and provides and who have a limited life-span membership.”
the perfusionist with clear lines of sight to the Teams share a common mission and must adapt to
anesthesiologist, the surgeon and the monitor so that the dynamics and demands of various tasks in order
communication is unencumbered (environment). to achieve their end goal. Teams collaborate, they
Outcomes are not only affected by technical skill, synthesize and integrate information and coordinate
but by the intersection of healthcare environment, among members to share responsibilities in a way
team ethos, workload, team member morale, technol- that makes best use of the strengths of each individ-
ogy, effective communication and organizational vari- ual. Successful teamwork is characterized by mutual
ables. The SEIPS model contends that medical error trust, effective communication, realistic goal setting,
can be a natural consequence of system wide break- fair division of tasks, desire to achieve a common goal 3
downs in the vast array of factors which influence and a shared passion for excellence.

h //d i /10 1017/9781009008143 001 P bli h d li b C b id i i P

 Lindsay Wetzel, David Fitzgerald, Thoralf M Sundt and James H Abernathy III

Figure 1.2 Mental workload in the cardiac surgery operating room varies across the cardiac surgery procedure for individual providers
depending on task complexity and responsibilities. CRNA indicates certified registered nurse anesthetist; CST, certified surgical technologist;
NASA, National Aeronautics and Space Administration; Postop, postoperative; Prep, surgical preparation; RN, registered nurse; and TLX, Task
Load Index. (Reprinted from The Journal of Thoracic and Cardiovascular Surgery, Volume 139, Issue 2, RK Wadhera et al., Is the “sterile cockpit” concept applicable
to cardiovascular surgery critical intervals or critical events? The impact of protocol-driven communication during cardiopulmonary bypass, Pages 312–319.
Copyright © 2010, with permission from Elsevier.)

The Joint Commission recognizes communication during takeoff and landing or in unusual or stressful
as one of the top three contributing factors to sentinel situations. This principle is equally applicable to pro-
events. Broadly speaking, communication is “the ceedings in the cardiac operating room – going on
exchange of information between a sender and a and coming off bypass, as an example, are treated
receiver.” Effective communication is characterized similar to starting and landing. Some healthcare
by clarity, comprehensiveness and confirming that organizations have implemented the rule that when
the message has been relayed effectively. It contrib- one member of the team spots trouble they call out
utes to a shared mental awareness, clarifies what team “10,000 feet” to get attention and change the mood
members are worried about, identifies any issues that and focus in the room to problem-solving mode.
have arisen previously during similar moments and Closed-loop communication or “call back,” whereby
establishes an understanding of how to successfully the speaker’s message is repeated or paraphrased by
navigate these scenarios. Fostering an environment the receiver, is an effective way to reduce communi-
which cultivates open, truthful, adaptable, succinct cation ambiguity, miscues, and non-verbalized critical
and constructive communication is critical to any actions.
successful team. We must recognize that at no point during a case
Clear communication is vital during times of is the mental workload the same for all providers
stress. Critical situations don’t need bystanders, they (Figure 1.2). While the patient is on bypass the per-
require the key team members to be in the room and fusionist is working hard while the anesthesiologist
rely on them adhering to their assigned roles. The might have less to concentrate on; during the induc-
“sterile cockpit” concept, widely in use in military and tion of anesthesia, the surgeon will usually be doing
commercial aviation, describes the banning of non- something unrelated; during the vitally important
essential communication during critical periods asso- instrument count the scrub and circulating nurses
4 ciated with high-risk and high mental workload. In are ensuring nothing will be left behind while the rest
aviation, chatting is not allowed below 10,000 feet of the room is congratulating themselves on a job well

h //d i /10 1017/9781009008143 001 P bli h d li b C b id i i P

 Chapter 1: Human Factors and Teamwork in Cardiac Surgery

done. Understanding when different members find hand, overcome challenges in such a way that both
themselves in a period of increased mental workload performance and cohesion are at least sustained, if
helps the entire team to identify the times where we not improved, eventually leading to improved out-
can help our colleagues. comes. The underpinnings of resilience are a shared
Transition of care is an especially high-risk period vision and mission, healthy relationships and invested
for communication breakdown. Handoff of a patient team members. Resilient teams
when OR staff change shift or from operating room to – support each other and encourage recovery after
ICU staff are particularly vulnerable times. In the difficult situations,
absence of standardized clinical practice guidelines, – don’t lay blame on individuals after such
handoffs between providers may be highly variable situations but engage in learning through effective
and unstructured, missing important content items communication and constructive criticism to
during transfer. Poor information transfers also lead facilitate a different outcome in the future.
to incomplete clinical tasks and disruptions in care.
A team which can band together during times of
Standardized handoffs, such as the recently published
duress and lean on one another for support will
AmSECT perfusion handoff tool or the Formula
invariably arise from challenging situations stronger
1 type OR to ICU handoff tool proposed by
and better equipped to deal with future problems.
Catchpole, greatly improve the accuracy of informa-
This is particularly true for the cardiac operating
tion transfer (see Figure 1.3).
room.

Leadership
Leadership style in the cardiac operating room can Practical Solutions
have a significant impact on the function of the entire Breakdown in teamwork is commonly attributed to a
team. Transactional leaders focus more on individual lack of role clarity among team members or ineffect-
tasks, responsibilities and blame. They rarely see the ive communication. Proposals to improve communi-
big picture and engage in unilateral communication cation and to reduce the possibility of error include,
which is not conducive to a team focused environ- but are not limited to, standardized intraoperative
ment. Transformational leaders foster an environ- communication, preoperative briefings, and post-
ment of enthusiasm, learning, cooperation and a operative debriefings.
collective mission. Studies have shown a higher level
of teamwork and information sharing with trans- Standardized Conversations
formational leadership styles. Within a culture of
Standardizing communication practices facilitates
excellence, there must also be a commitment to
stronger team communication and helps all
respect. Professionalism and courtesy are not negoti-
team members “speak the same language.”
able. Effective leaders aim to flatten the hierarchy,
Communicating in a closed-loop, or read-back, fash-
create familiarity and foster an environment where
ion ensures that the entire team is aware of what is
everyone feels safe to speak up and participate. If
occurring and helps in retaining the shared mental
there was an easy button for establishing a culture of
model. Operating rooms can be chaotic places
excellence and effective leadership, we might not have
where background noise makes hearing difficult.
a need for this chapter. Personal and institutional
Acknowledging comments and questions ensures that
willingness to embrace tools such as Just Culture are
communications have been heard and understood.
important to tilt behavior toward personal account-
Repeating back essential information confirms that
ability and adaptability.
the sender’s message has been received. It is import-
ant to foster an environment where closed-loop com-
Repair, Recovery and Resilience munication is encouraged and not looked at as
Resilience alludes to the capacity of individuals and of disengagement (i.e. the individual repeating the mes-
teams to withstand and recover from pressures, stres- sage was not paying attention and hence needs clari-
sors and challenges. Failure to recover from an unex- fication.) Knowing team members by name helps to
pected event is a characteristic of poor performing make communications more direct and removes 5
perioperative programs. Resilient teams, on the other ambiguity as to who is being addressed.

h //d i /10 1017/9781009008143 001 P bli h d li b C b id i i P

 Lindsay Wetzel, David Fitzgerald, Thoralf M Sundt and James H Abernathy III

Figure 1.3 AmSECT perfusionist handoff checklist. (Reproduced with kind permission of the AmSECT Safety Committee.)
6

h //d i /10 1017/9781009008143 001 P bli h d li b C b id i i P

 Chapter 1: Human Factors and Teamwork in Cardiac Surgery

Briefing and Debriefing providing recognized programs to integrate team-

work into clinical practice. Many of these programs
Briefings, both preoperative and postoperative, have
have drawn on decades worth of evidence-based
been implemented to promote information exchange
research pertaining to team building, culture change
and team cohesion. They originated in the aviation
and teamwork in organizations such as the military,
and nuclear power industries to ensure that important
nuclear power and aviation. Their goal is to help
information was communicated to every team
improve teamwork and communication skills. They
member. Preoperative briefings are an opportunity
offer open and accessible training programs in com-
for all operating room personnel to introduce them-
munication, leadership, situation monitoring and
selves with name and role and identify any concerns.
mutual support (see Figure 1.4).
Introduction of team members encourages team
Providing this training to OR teams has been
familiarity which has been linked to improved team-
shown to improve teamwork, communication, reduce
work. The operative plan needs to be discussed and
surgical mortality and morbidity, increase efficiency,
anticipated difficulties are communicated to develop
and improve patient satisfaction. However, sustain-
strategies as to how to deal with them. Any equipment
ability remains a challenge and often comes with the
requirements or lack of certain pieces of kit need to be
need for repeat training.
highlighted. If everybody is on the same page the
team is able to develop a shared mental model of the
work ahead, creating a sense of teamwork and collab- Non-Technical Skill Assessment Tools
oration. Conducting team briefings before every case Several non-technical skill (NTS) taxonomies aimed
is especially important for newer surgical teams or for at rating behavior in the operating department have
teams with new members who may not be aware of been reported in the literature. These instruments are
the unwritten or unspoken traditions. Open commu- designed to measure performance of multidisciplin-
nication before the case establishes a road map for ary team interactions, such as decision-making, situ-
conducting the case and helps minimize disruptions ational awareness, leadership, communication and
during the surgery (i.e. leaving the room to obtain teamwork. Several of the taxonomies have been pre-
equipment and supplies). viously adapted for the cardiac surgical arena and
The briefing, as described here, is distinct and beyond, including NOTSS (Non-Technical Skills
separate from a “time-out.” The “time-out” pause is for Surgeons), Oxford Non-Technical Skills
intended to ensure the right patient, right side, and (NOTECHS), and ANTS (Anaesthetists’ Non-
right operation. Technical Skills). Rating systems assess individual
Postoperative debriefings are equally critical as practitioner’s non-technical skills and team behavior.
they provide an opportunity for the team to under- They should be used as a metric and an incentive for
stand what went well during the case and identify individuals as well as institutions to improve their
areas for improvement in coming procedures. It is performance. While conventional wisdom may sug-
important to make postoperative briefings an arena gest that enhancing NTS performance will confer
for constructive feedback and not for blaming and significant improvements in the safety and the effi-
finger-pointing. When executed effectively, debrief- ciency of patient care, the implementation across
ings improve teamwork, communication and unity. medical education and healthcare institutions is
As teams gain experience together, debriefings will patchy. Unfortunately, there is no silver bullet to
help solve problems encountered during the case, accomplishing perfect team-based performance.
address “near misses” and hopefully prevent these Change often starts small and propagates. Start small,
issues from reoccurring in the future. build a well-functioning unit. Then, through good
outcomes and happy staff, demonstrate what
Creating the Team works for the broader organization. If you live and
Implementing formalized team training in the cardiac work in an organization whose leadership does not
operating room is a vital measure in decreasing value these concepts, press on anyway. Create the
surgical morbidity and mortality. There are numer- culture you want, where you work. Change starts
ous organizations, nationally and internationally, with you. 7

h //d i /10 1017/9781009008143 001 P bli h d li b C b id i i P

 Lindsay Wetzel, David Fitzgerald, Thoralf M Sundt and James H Abernathy III

PROFESSIONAL TEAM BEHAVIOUR

• Inclusivity • Humility
• Enthusiasm • Honesty
• Equality • Integrity
• Clear communication • Civility
• Authenticity

Teamwork
& Leadership
Cooperation

COMMUNICATION

Situation Decision
Awareness Making
• Frequent updates • Decisions clearly
• Announces changes of plan communicated
• Clarifying confusion • Responsibility clear
• Input encouraged • Regular reviews

Figure 1.4 A visual model with the basic but critical concepts enabling teams to work together effectively. (Reproduced with kind permission
from Atrainability, https://atrainability.co.uk)

Suggested Further Reading statement from the American

Heart Association. Circulation.
patient outcomes. Am J Surg.
2009;197(5):678–685.
1. Wiegmann DA, Eggman AA, 2013;128:1139–1169.
Elbardissi AW, Parker SH, Sundt 7. Neily J, Mills PD, Young-Xu Y et al.
TM 3rd. Improving cardiac surgical 4. El Bardissi AW, Wiegmann DA, Association between
care: A work systems approach. Dearani JA, Daly RC, Sundt TM implementation of a medical team
Appl Ergon. 2010;41(5):701–712. 3rd. Application of the human training program and surgical
factors analysis and classification mortality. JAMA. 2010;304
2. Wahr JA, Abernathy JH. system methodology to the (15):1693–1700.
Improving patient safety in the cardiovascular surgery operating
cardiac operating room: Doing 8. Jung JJ, Yule S, Boet S, Szasz P,
room. Ann Thorac Surg. 2007;83 Schulthess P, Grantcharov T.
the right thing the right way, every (4):1412–1419.
time. Curr Anesthesiol Nontechnical skills assessment of
Rep. 2014;4:113–123. 5. Wadhera RK, Parker SH, the collective surgical team using
Burkhart HM et al. Is the “sterile the Non-Technical Skills for
3. Wahr JA, Prager RL, Abernathy cockpit” concept applicable to Surgeons (NOTSS) system. Ann
JH 3rd et al. On behalf of the cardiovascular surgery critical Surg. February 21, 2019.
American Heart Association intervals or critical events? The
Council on Cardiovascular 9. Gillespie BM, Harbeck E, Kang E,
impact of protocol-driven Steel C, Fairweather N, Chaboyer
Surgery and Anesthesia, Council communication during
on Cardiovascular and Stroke W. Correlates of non-technical skills
cardiopulmonary bypass. J Thorac in surgery: A prospective study. BMJ
Nursing, and Council on Quality Cardiovasc Surg. 2010;139
of Care and Outcomes Research. Open. 2017;7(1):e014480.
(2):312–319.
Patient safety in the cardiac 10. Flin R, Patey R, Glavin R, Maran N.
8 operating room: Human factors 6. Mazzocco K, Petitti DB, Fong KT Anaesthetists’ non-technical skills.
and teamwork: A scientific et al. Surgical team behaviors and Br J Anaesth. 2010;105(1):38–44.

h //d i /10 1017/9781009008143 001 P bli h d li b C b id i i P

 Chapter
Equipment for Cardiopulmonary Bypass

2 Simon Anderson and Amanda Crosby

Cardiopulmonary bypass (CPB) provides optimum The heart lung machine and circuitry used in
conditions for cardiothoracic surgery by combining procedures today has advanced significantly since
a pump to substitute for the function of the heart and the advent of extracorporeal circulation and the first
a gas exchange device, the “oxygenator,” to act as an attempts at its use. The basic principles, however,
artificial lung. CPB therefore allows the heart and remain the same to this day:
lungs to be temporarily suspended, to facilitate car-  Venous blood is drained by gravity or assistance
diac, vascular or thoracic surgery in a safe, still, blood- into a reservoir via a cannula placed in a large
less and controlled environment. vein, most typically the right atrium or vena cava.
 Blood is then pumped through the oxygenating
History device and an arterial filter. Transit through the
The first successful open procedures were performed oxygenator reduces the partial pressure of carbon
in 1954 by Dr. Clarence Walton Lillehei using a cross- dioxide in the blood and raises oxygen content.
circulation technique, acting as an extracorporeal cir- Current models have the oxygenator, heat
cuit. This approach worked by circulating the parent’s exchanger and filter incorporated in one
arterial blood into the recipient and controlling the component (Figure 2.1 a and b)
amount of venous blood being returned, giving the  It is next returned into the patient’s arterial system
surgeon up to an hour to perform cardiac surgery. through a cannula in a large artery, most typically
The concept of the heart lung machine (HLM) and the aorta.
cardiopulmonary bypass circuit arose from this tech- Older technology and bypass circuits consisted of
nique of “cross-circulation.” large components that required manual cleaning,
The development of the heart lung machine in were reused after sterilization, and were primed with
1953 was preceded by a number of perfusion pumps. up to 14 units of blood. Due to the advances in
The design of the first such pump originated in technology and techniques, CPB circuits today are
1935 by Charles Lindbergh in collaboration with Dr. more reliable, have more safety devices and are
Alex Carrel. The pump was used to keep organs disposable.
functioning outside of the body with a solution
developed by Carrel to perfuse organs, only limited
by the eventual failure of the organ itself or the Tubing
breakdown of the constituents in the perfusate. In The cardiopulmonary bypass circuit is created with
1953 Dr. John Gibbon used the first total CPB system. tubing connected to the various components required
Gibbon operated on four patients with congenital to support the circulatory system and allow close
heart disease with only one survivor, and considered monitoring. Table 2.1 provides an overview of the
this series of work a failure, however his efforts were main components of a HLM. Different types of
an inspiration to researchers around the world. The tubing may be used throughout the circuit depending
emergence of the DeWall-Lillehei helix reservoir with on what function it serves, for example, tubing used
a bubble oxygenator in 1955 was the first disposable, to monitor pressure is different to tubing for the
efficient, and inexpensive bypass circuit, this innov- actual circulatory support. Tubing should be pos-
ation fueled the rapid expansion into open-heart sur- itioned in an orientation that avoids kinks and allows
gery after 1956. for smooth curves to limit areas of high velocity or 9

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Simon Anderson and Amanda Crosby

(a) Venous
Femoral Vent return
catheters Sucker catheter catheter

Venous
HCT/SAT Cardioplegia
Venous cannula
cardiotomy reservoir
Venous
BGM Arterial
Cardioplegia cannula
Arterial BGM Arterial Bubble
detector solution
• Bubble trap
• Temperature
• Pressure
To cardioplegia Centrifugal Blood from Heat exchange
pump (or Roller oxygenator
Oxygenator with
roller pump) pump
reservoir and
heat exchange

Dual
Arterial Suction Vent Cardioplegia cooler/heater
Temperature
control and Perfusion system (heart-lung machine)
monitoring
system

Figure 2.1 (a) Typical configuration of a basic cardiopulmonary bypass circuit. BGM = blood gas monitor; SAT = oxygen saturation. (b) Full HLM in use.

10

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Chapter 2: Equipment for Cardiopulmonary Bypass

Table 2.1. Components of the CPB machine and the Table 2.2. Commonly used biocompatible tubing coatings
extracorporeal circuit
Manufacturer and Description of Coating
Equipment Function Coating Properties
Oxygenator system, Oxygenate, remove carbon Gore – Carmeda Covalent bonding of heparin
venous reservoir, dioxide and cool/ molecules
oxygenator, heat rewarm blood
exchanger Baxter - Duraflo II Heparin ionically joined with
ammonium and attached to
Gas line and FiO2 blender Delivers fresh gas to the surface
oxygenator in a
controlled mixture Terumo – Xcoating Biopassive polymer creates
hydrophobic and hydrophilic
Arterial pump Pumps blood at a set flow properties without heparin
rate to the patient
Maquet – Bioline Heparin and albumin attached
Cardiotomy suckers and Scavenges blood from the to polypeptides on tubing
vents operative field and vents surface
the heart
LivaNova – P.H.I.S.O. Phosphorylcholine
Arterial line filter Removes microaggregates Coating
and particulate matter
>40 μm Medtronic – Cortiva Endpoint-attached heparin
BioActive Surface coating
Cardioplegia systems Deliver high-dose
potassium solutions to
arrest the heart and
preserve the
myocardium PVC when the tubing is occluded but can release
more particles. Silicone rubber is sometimes utilized
Cannulae Connect the patient to the
extracorporeal circuit in the arterial pump roller head as an alternative to
commonly used PVC tubing.
Tubing used during CPB is subject to repeated
compression in pump roller heads. This intermittent
stagnation. Any junctions or connections between compression can degrade the integrity of the walls of
components have to be secured tightly to prevent the tubing and may cause plastic micro particles to be
leaks or air ingress. Clinicians must consider the released, this is called spallation.
intended use of the tubing when choosing materials Tubing can be made with a biocompatible coating
to create the circuit. (see Table 2.2), which may help reduce the inflamma-
Polyvinylchloride (PVC) is the predominant tory response to foreign material. Sequelae from the
tubing material used today in cardiopulmonary inflammatory response include platelet activation, ini-
bypass, but latex rubber and silicone rubber are other tiation of the coagulation cascade, decreased levels of
options. PVC is made up of polymer chains with circulating coagulation factors, activation of endothe-
polar carbon-chloride (C-Cl) bonds. These bonds lial cells and leukocytes, releasing mediators that may
result in considerable intermolecular attraction between contribute to capillary leakage and tissue edema. This
the polymer chains, making PVC a fairly strong material. is discussed in more detail in Chapter 17.
On its own, PVC is a rigid plastic, but plasticizers are There are a number of surface coatings available
added to the type of tubing used in a circuit, which make on the market today. One type of circuit coating uses
it malleable and easier to manipulate. both hydrophobic and hydrophilic properties to form
Silicone rubber is a semi organic synthetic. Its a new layer on top of the tubing that reduces protein
structure consists of a chain of silicon and oxygen denaturation and platelet adhesion. Since this coating
atoms rather than carbon and hydrogen atoms, as is is made from a non-heparin-based biopassive poly-
the case with other types of rubber. The molecular mer Poly(2-methoxyethylacrylate) (PMEA), this
structure of silicone rubber results in a very flexible tubing can be used on heparin sensitive or intolerant 11
but weak chain. Silicone produces less hemolysis than patients. Another type of biocompatible tubing is

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Simon Anderson and Amanda Crosby

Table 2.3. Tubing sizes commonly used in different parts of the extracorporeal circuit (adults only)

Tubing size Prime Max flow (l/min) Max flow (l/ Function
volume (To keep min)
(cc/ft/ml/ pressure (To keep
30cm) gradient <10 Reynolds
mmH*) number
<1000*)
3/16” (4.5 mm) 5.4 /4.7 0.2 1.8 Cardioplegia section of the blood
cardioplegia delivery system
1/4” (6.0 mm) 9.84/8.5 0.9 2.1 Suction tubing, blood section of the blood
cardioplegia delivery system
3/8” (9.0 mm) 21.6 /19.1 4.0 3.7 Arterial pump line for flow rates <6.7 l/
minute, majority of the arterial tubing in
the extracorporeal circuit
1/2” (12.0 mm) 42/33.9 7.0 5.0 Venous line, larger tubing is required to
gravity drain blood from the patient
*
Source: Hessel EA II, Hill AG in Gravlee GP et al.: Cardiopulmonary Bypass: Principles and Practice. Lippincott Williams & Wilkins, 2000,
Table 5.4

made from phosphorylcholine that mimics the nat- to crystalloid needed, and the type of delivery device.
ural endothelium to reduce platelet activation and cell When choosing tubing for scavenging blood from the
adhesion to the tubing surface. Some tubing contains surgical field and venting of the heart or aorta, the
heparin, which should be noted when providing care decision is usually based on institutional protocol, but
to a heparin intolerant patient. Some institutions will take into account the volume of the tubing length
maintain a small stock of non-coated circuits for these and the displacement per revolution of the pump
patients. Regardless of the type or manufacturer head.
selected, biocompatible tubing can improve platelet
preservation and reduce the inflammatory response
to foreign surfaces. Arterial Cannulae
Selecting the appropriate tubing size is based on The arterial cannula is used to deliver oxygenated,
the application. Larger bore tubing requires less pressurized blood from the HLM directly into the
pump head revolutions needed to displace the same patient’s arterial system. The size of the vessel that is
amount of volume as smaller tubing, meaning less being cannulated and the patient’s required blood
mechanical stress from repeated compression. The flow are considered in selecting the appropriately
internal diameter as well as the length should be sized cannula.
carefully considered as both will affect the priming The ascending aorta is most used as the site of
volume. While a larger internal diameter allows for arterial cannulation for routine cardiovascular sur-
greater flow at lower pressures, it has a higher prime gery allowing antegrade flow to the cerebral and body
volume, increased contact activation, less resistance, circulation. The asceding aorta is large caliber, has a
and a larger pressure gradient. There are many low associated incidence of aortic dissection
factors to consider when selecting the best fit for the (0.01–0.09%), and is easy access when using a median
application required (see Table 2.3). When deciding sternotomy approach. After sternotomy and expos-
upon the size of arterial and venous tubing, the ure, the surgeon can assess the size of the aorta before
patient’s body surface area (BSA) and calculated car- choosing the most appropriate caliber cannula (see
diac index can help guide the appropriate size of Figure 2.2).
tubing. Tubing for cardioplegia administration is Developments in cannula design allow the use of
12 based on the solution being used, the ratio of blood thin wall cannulae. By having a larger effective

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Chapter 2: Equipment for Cardiopulmonary Bypass

DLP® Flexible Arch Cannulae EOPA® Arterial Cannulae

200 200

18 Fr
160 160
Pressure Loss (mm Hg)

Pressure Loss (mm Hg)

22 Fr
20 Fr

120 120 20 Fr
24 Fr

80 80

22 Fr
40 40
24 Fr

0 0
0 1 2 3 4 5 6 0 1 2 3 4 5 6
Flow Rate (L/min of water) Flow Rate (L/min of water)

Select Series® Straight Tip Arterial Cannulae Edwards Soft flow/EZ glide)
200
100

20 Fr 21 Fr. Straight
160
80
Pressure Loss (mm Hg)

Pressure Drop (mm Hg)

140
60 22 Fr

21 Fr. Curved
80 24 Fr. Straight
40 24 Fr
24 Fr. Curved

20 40

0 0
0 1 2 3 4 5 6
0 1 2 3 4 5 6
Flow Rate (L/min of water) Flow Rate (L/min), H2O at Room Temperature

Figure 2.2 Cannula flow profiles.

internal diameter, they achieve lower resistance to

Rings
flow. Subsequently, within the extracorporeal circuit, Straight tip
this leads to a reduction in arterial line pressure and
allows an increase in blood flow. Further develop-
ments come in the form of angled tip arterial cannu-
lae. These manipulate the flow characteristics of blood
leaving the cannula to produce a spray effect, disper-
Bump
sing blood into the aorta. This design not only min-
imizes damage to the vessel wall by directing blood Curved tip
flow toward the aortic arch rather than toward the
vessel wall, but also reduces the pressure drop at the
tip of the cannula. Figure 2.3 shows several designs of
aortic cannulae. Suture
Axillary, subclavian and femoral arteries are
Flange
examples of alternative arterial peripheral cannulation
sites, typically during complex or redo surgery. The
femoral cannulae are longer than conventional ones
and incorporate a spirally wound wire within their Figure 2.3 Commonly used arterial cannulae. (Reproduced with kind 13
wall to prevent “kinking” (see Figure 2.4). X-ray permission from Edwards Lifesciences.)

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Simon Anderson and Amanda Crosby

Figure 2.4 Femoral reinforced cannula. Biomedicus Life SupportTM 21Fr. (Reproduced with ©2020 Medtronic. All rights reserved. Used with the
permission of Medtronic.)

imaging or transesophageal echocardiography (TEE) a bloodless field for the surgeon. Figure 2.5 shows
is used to confirm correct cannula position. Axillary commonly used venous cannulae.
and subclavian cannulation is most commonly Femoral cannulation can be utilized for more
achieved by suturing a dacron graft end-to-side onto complex surgery. In this instance, a long cannula,
the vessel and a 3/8  3/8 inch connector to connect which is in essence an elongated single-stage cannula,
to the HLM arterial line. is typically passed over a guide wire up the femoral
vein into the IVC and RA to achieve venous drainage.
These cannulae are generally placed under TEE
Venous Cannulae guidance. As with arterial cannulation sites, the size
Venous cannulation provides the means to drain and length of the venous cannulae are patient specific
deoxygenated blood from the patient’s venous system and are determined by body surface area (BSA),
into the extracorporeal circuit. It is important to use required full flow and vessel size. In an average height
appropriately sized cannulae in order to obtain max- adult (170 cm, 80 kg), a 25 Fr/55 cm cannula provides
imum venous drainage from the patient so that full sufficient venous drainage from the IVC. However, in
flow can be achieved when CPB is commenced. The smaller patients, a 38cm length cannula may be a
type of venous cannulation used depends on the better option to ensure the cannula is short enough
operation being undertaken. For cardiac surgery not to be positioned in the IVC and not too long to
involving opening chambers of the right heart, for potentially perforate the right atrium or SVC during
example, coronary artery bypass grafts (CABG) or cannulation.
aortic valve replacement (AVR), a two-stage venous
cannula is often used. The tip of this type of cannula Perfusion Pumps
sits in the inferior vena cava (IVC) and drains blood
Perfusion pumps, in the arterial position, propel
from the IVC through holes around the tip; a second
blood forward through the circuit. There are two
series of holes a few centimeters above the tip is sited
main types: positive displacement roller pumps and
in the right atrium to drain venous blood from the
the impeller centrifugal pumps.
superior vena cava (SVC).
During procedures that require the right atrium
(RA) to be opened, bicaval cannulation, where a Roller Pumps
single-stage cannula sits in each of the inferior and A peristaltic pump or “roller pump” is a positive
superior vena cava, is necessary. The two single-stage displacement pump used for moving fluid. Initial
cannulae are connected to the venous line of the CPB HLM technology in the 1950s used a similar peristal-
circuit using a Y-connector. This approach avoids air tic pump, and the technology has not greatly changed
entry into the CPB circuit from the distal series of from its inception. The raceway or the pump header
holes of a two-stage cannula, as they would be sitting accepts a length of tubing, the rotor and roller com-
in the open RA. Air entry would impede venous bination inside the middle of the pump housing
14 drainage – or stop it completely in case of an “air rotate in a clockwise or counterclockwise direction.
lock” – leading to the patient’s calculated full flow Typically, there will be two or more rollers that com-
becoming unachievable in addition to not providing press the tubing and a clutch mechanism to set the

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Chapter 2: Equipment for Cardiopulmonary Bypass

Figure 2.5 Commonly used venous cannulae (a) DLPTM single-stage cannula (b) Bi-caval cannulation technique (c) MC2TM two-stage cannula. 15
(Reproduced with ©2020 Medtronic. All rights reserved. Used with the permission of Medtronic.)

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Simon Anderson and Amanda Crosby

Blood leaves Figure 2.6 Line drawing of a

roller pump.
pump
Blood enters
pump

Rollers force blood

through tubing in
a peristal motion

Omega, or
horseshoe raceway

degree of tubing occlusion, regulating the amount of pressure. As they operate independently of resistance
compression applied to the tubing. Under-occlusive, or pressure, pressures within the circuit must be
or too loose, tubing may result in retrograde flow or monitored. It is essential to limit the pump flow if
inaccurate flow calculations, while over-occlusion, or system pressure becomes excessive. Sudden occlusion
too tight, may increase hemolysis, spallation, and of the inlet of the roller head can create extreme
inaccurate flow calculations. The roller head occlu- negative pressure to the point where the tubing may
sion should be measured before each case to ensure it cavitate and create air bubbles in the circuit.
has the desired setting for the operation. The methods Very similar to the heart, output of a roller pump
to test occlusions are described in detail in Chapter 4. is determined by the internal diameter of the tubing
As the rollers compress and occlude the tubing, the (= stroke volume) and the number of revolutions of
fluid is moved in the corresponding direction(see the pump head (= beats per minute). The larger the
Figure 2.6). The tubing inside the raceway is held in a tubing in the raceway, the less rpms are needed to
fixed position by brackets or a locking mechanism and maintain the same output of smaller tubing. Note that
returns to its natural state once the roller passes over it. reading or recording blood flow directly from the
This intermittent occlusion creates positive and negative arterial roller head does not account for any shunts
pressures on either side of the occlusion point, which is that may be present downstream in the circuit, and
the driving force for the movement of fluid. Positive thus the actual flow reaching the patient may be less.
pressure created by the roller propels fluid and the recoil
of the tubing creates negative pressure refilling the tube.
Roller pumps can be used in any position. They Centrifugal Pumps
can be belt driven or have direct drive systems and are Centrifugal pumps are non-occlusive pumps and utilize
16
not affected by circuit resistance or hydrostatic a magnet and impeller combination to propel blood

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Chapter 2: Equipment for Cardiopulmonary Bypass

(b)

3/8” Blood inlet with two barbs for Durable bearing

gentle flow of blood into pump

Durable, chemical resistant

3/8” Blood outlet with two polycarbonate housing
barbs is compatible with
adult perfusion circuits

Ceramic pivot shaft

for low friction and
low heat generation

Six low-profile impeller fins for Smooth cone for

low turbulence low shear on red blood cells

Internal molded magnet for torque

coupling with external motor Sweeper to prevent blood
stagnation on bottom of pump

Figure 2.7 Centrifugal pump head (a) Medtronic AffinityTM. (b) Schematic cut through of AffinityTM centrifugal pump. (Reproduced with ©2020
Medtronic. All rights reserved. Used with the permission of Medtronic.)

through the CPB circuit. The pump consists of a hard amount of forward flow will decrease, unless the rpms
outer shell which incorporates an impeller design are altered to counter this. For this reason, centrifugal
coupled magnetically with an electric motor and shaft pumps have the potential to allow retrograde flow,
or pin. When the console is turned on and the rpms are however most flow meters will alert the user if this
increased, the cones or fins spin rapidly, creating posi- occurs. Unlike roller pumps whose flow is calculated
tive pressure that propels fluid forward (see Figure 2.7). based on tubing diameter and rpm (stroke volume and
Centrifugal pumps, much like the heart, are after- beats per minute), centrifugal heads require ultrasonic 17
load sensitive. If the post-pump resistance increases, the or electromagnetic meters to accurately determine

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Simon Anderson and Amanda Crosby

blood flow. Unlike rollers, centrifugal pumps do not Table 2.4. Common centrifugal heads, adult sizes
need to be pressure regulated because they will not be Manufacturer Centrifugal Brief Description
able to generate forward flow if the tubing is kinked, Head
clamped, or suddenly occluded. When used for CPB, a
special centrifugal head motor that can be manually LivaNova Revolution Open impeller design,
with impregnated
operated must be available as backup.
nylon magnet and
The perceived benefits of the centrifugal pump are
seal-less low friction
its low prime volume and, because of its non- bearings – 57 ml
occlusive nature, less hemolysis. Despite extensive prime volume
research, there is little clinical evidence to show any
Terumo CAPIOX SP Polycarbonate housing,
benefit of CPB with centrifugal over CPB with roller
impeller design, lip
pumps. Centrifugal pumps may produce less hemoly-
seal – 45 ml prime
sis and platelet activation than roller pumps, but this volume
does not correlate with any difference in clinical out-
come. Centrifugal pumps are less likely to create air Medtronic Affinity CP Low profile fins,
ceramic pivot
embolism situations because as air is introduced to
bearings, no stasis
the cone, the pump will deprime and cease forward
zones – 40 ml prime
flow. Clinicians should remain vigilant, though, as volume
there have been reports of air ingress into circuits
using centrifugal pumps. Centrifugal pumpheads are Abbott - Centrimag Free-floating
Thoratec magnetically
expensive, adding a signficant additional cost to the
levitated rotor, has
CPB circuit. Clinicians favoring centrifugal systems
no bearings or seals
have argued that the ability to create smaller circuits creating minimal
due to remote drive capabilities, allows the circuit to stasis zones – 31 ml
be closer to the surgical field unlike the fixed console prime volume
based roller head position. The new generation roller
Gettinge - Rotaflow RF- Peg-top, one-point
pumps have largely overcome this issue and tubing
Maquet 32 sapphire bearing –
length has decreased significantly in recent years. The 32 ml prime volume
decision to use centrifugal pumps or roller pumps for
CPB is largely determined by institutional factors
rather than clinical indication. Table 2.4 summarizes
commonly used adult centrifugal pump heads. The reservoir acts as a chamber for the venous blood
Centrifugal head technology is not only used in to drain into before it is pumped through the oxygen-
cardiopulmonary bypass cases but also in extracor- ator and permits ready access for the addition of fluids
poreal membrane oxygenation (ECMO) and ven- and drugs. To reduce the risk of perfusion accidents, the
tricular assist devices (VADs). Certain models level of fluid is monitored for the duration of CPB to
possess fins or channels to help avoid areas of stagna- prevent the reservoir from emptying and air entering
tion, while others have magnetically levitated bearing- the circuit. Each manufacturer details the minimum
less motors to reduce heat generation. Each has a set safe fluid level necessary to achieve the rated flow of
rpm needed to generate forward flow, this minimum their device. Low level alarms (see also Chapter 3), often
number will be different with blood viscosity (hemo- coupled to automatic cessation of pump flow when
globin) and patients’ vascular resistance pressure. triggered, add additional safety. Gross air embolism
incidents can still occur if arterial flow exceeds venous
drainage, subsequently emptying the reservoir.
Reservoirs Vacuum-assisted venous drainage may be used to
Cardiotomy reservoirs may be hardshell or softshell optimize venous drainage during CPB. Using vacuum
(collapsible). Hardshell reservoirs usually comprise of assistance can reduce hemodilution and subsequent
a durable polycarbonate housing, a high-efficiency transfusion requirements because improved drainage
18 polyester depth filter and a polyurethane defoamer requires fewer “top-ups” with crystalloids or colloids.
(see Figure 2.8). With the top of the cardiotomy reservoir positioned

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Chapter 2: Equipment for Cardiopulmonary Bypass

which can occur if the suckers are left running at a

high level for prolonged periods. The blood returned
from the intracardiac “vent” suckers is also returned
to the reservoir.
Collapsible reservoirs are used mainly for pediat-
ric or mini bypass cases and are dicussed in more
detail in Chapters 8 and 15.

Oxygenators
The evolution of the oxygenator has been critical to
the success of cardiac surgery and advanced patient
care. Oxygenators are most often described as artifi-
cial lungs as they provide an alveolar capillary system
for gas transfer. The general design goals are efficient
gas exchange, low prime volume, minimized trauma
to blood and efficient cooling and heating capabilities.
Figure 2.8 Fusion reservoir. (Reproduced with ©2020 Medtronic. All
TM
There are two main types of oxygenators com-
rights reserved. Used with the permission of Medtronic.)
monly used in adult cases today, microporous poly-
propylene (PPL) and non-porous polymethylpentene
(PMP). Both are hollow fiber membrane oxygenators,
which are named for the membrane that separates the
at the level of the patient’s atrium, a negative pressure gas and blood phases. The main difference is their
of approximately 60 mmHg is applied when max- duration of use – the PMP type oxygenators typically
imal gravity drainage is reached. The negative pres- maintain gas exchange longer. While PPL oxygen-
sure can be increased by small amounts during CPB, ators are more common, extended use can cause
when the fluid in the reservoir decreases to the safety plasma leaks across the membrane from the blood
limit level. For weaning from bypass, the negative phase into the gas phase, resulting in decreased gas
pressure is gradually decreased to zero, the reservoir exchange efficiency. The non-porous fibers of the
is opened, and the venous line progressively closed. PMP oxygenator make them more durable than
Blood scavenged from the operative field via PPL, and they are typically used for longer term
suckers is also returned to the reservoir. Suction relies applications such as ECMO. The lack of pores does
on the “Venturi” effect, which is the change in pres- not allow exchange of volatile anesthetics, making
sure and fluid velocity through a narrowing in a tube. PMP oxygenators unsuitable for use with CPB.
Suctioning blood from the operative field causes Oxygenators are regulated by federal guidelines,
damage to blood cells and also results in concomitant allowing their use for periods of time usually up to six
entrainment of high volumes of air. The salvaged hours. While using them longer is designated as off
blood may contain tissue and other debris and is label, it is a widespread and acceptable application of
highly activated with inflammatory cells. It is vital the technology to facilitate bridging to recovery or
that this blood is filtered through the reservoir before transplantation when other advanced treatments
being pumped to the patient. Advances in technology have failed.
have seen a more widespread use of reservoirs con- Once entering the device, blood first passes over
taining separate chambers for venous blood and car- the integrated heat exchanger before moving into the
diotomy suction, allowing the suction blood only to oxygenator compartment, where gas exchange takes
be added into the circuit when required. Segregating place (see Figure 2.9). O2 concentration and flow of
suction blood that way has the advantage that it can the sweep gas, which drives gas exchange, are regu-
be passed through a specific filter that absorbs lipid lated with a gas blender and a flow meter integrated
cells, which have been shown to impair oxygenator into the HLM. The sweep is piped into the oxygenator
effectiveness. The reservoir is constantly vented to inlet port, its distribution throughout the membrane’s 19
prevent the entrained air causing a pressure buildup, capillary system varies with the oxygenator used and

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Simon Anderson and Amanda Crosby

the patient’s size. Typically the flow is 2–4 l/min for Cooling the blood, and thus cooling the patient,
adults, depending on blood flow and the desired CO2 results in a lower metabolic demand that helps ensure
removal rate. Volatile anesthetics can be added all tissues are being adequately perfused while on
depending on oxygenator type and HLM in use. bypass. Chapters 9 and 10 discuss temperature man-
Gas scavenging can be attached to the exhaust port. agement and rewarming strategies in more detail.
Gas sampling to determine O2 consumption and end- Intended duration of use, requirement for volatile
tidal CO2 can be attached at this point as well. anesthetics, prime volume, biocompatible coating, gas
Integrating the heat exchanger and arterial line exchange capacity, and the heat exchanger’s efficiency
filter into the oxygenator has decreased circuit size are the main determinants that inform the choice of
and reducted prime volume. The heat exchanger is oxygenator used for a case.
separated from the blood phase by a highly thermal
conductive material and is biologically inert. An Gas Supply System
external heater cooler is connected with thick water
The gas supply is connected to the blender, which
lines, usually made of antimicrobial-coated tubing.
mixes oxygen and air to provide the desired FiO2
Fine control of the water bath temperature allows
and to a flow meter to regulate sweep gas flow (see
precise regulation of the patient temperature.
Figure 2.10). CO2 may be added to the sweep when
pH-stat blood gas management is desired during
hypothermia or cases requiring deep hypothermic
circulatory arrest (DHCA, see Chapter 9). Blending
units and flow meters may be mechanical, but are
now mostly digitally controlled via the HLM.
Continuous inspired O2 analysis is mandatory to
prevent the inadvertent administration of a hypoxic
mixture.

Filters and Bubble Traps

Air entrainment through the venous return line, fluid,
drug and blood administration through the cardiot-
omy reservoir, as well as ingress of air and particulate
matter from cardiotomy suckers and vents, all con-
Figure 2.9 FusionTM oxygenator combined with and a heat tribute to the embolic load patients may be exposed
exchanger in a single unit. (Reproduced with ©2020 Jose Canamares. All
rights reserved. Used with the permission of Jose Canamares.) to. While it is not possible to eliminate the embolic
load in its entirety, the use of arterial filters and

Figure 2.10 LivaNova S5W Electronic Gas Blender,

courtesy of LivaNova PLC. (Reproduced with kind permission
from LivaNova.) Photograph by Jose Canamares used with
permission.

20

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Chapter 2: Equipment for Cardiopulmonary Bypass

Table 2.5. Filtration devices used within the cardiopulmonary Depth filters create a tortuous path between fibers
bypass circuit
and retain particles mechanically. Screen filters are
Filter type Application and specification the most common type and are typically made of a
woven polyester mesh. They are usually pleated to
Gas line Removes 99.999% of bacteria found in
allow for a larger surface area in a confined space
the gas stream minimizing cross-
contamination between the patient
and trap particulates or emboli that are larger than
and the equipment their particular pore size. Filters come in a size range
from 0.2 μm for gas line filters to 40μm for arterial
Pre-CPB 0.2 μm filter is used during the priming
line filters.
and recirculation phase. It is
0.2μm pre-bypass filters are meant to capture any
designed for the removal of
inadvertent particulate debris and particles left from the manufacturing process and are
microbial contaminants and their removed after priming and before initiating bypass.
associated endotoxins Separate arterial line filters are indicated for use in
all CPB procedures where the oxygenator does not
Arterial line Designed to remove microemboli
have an integrated filter. The main goal of an arterial
>20 μm in size from the perfusate
during extracorporeal circulation. filter, whether integrated into the oxygenator or not,
This includes gas emboli, fat emboli is to stop gaseous macro-emboli from entering the
and aggregates composed of circulation, although there is some debate about
platelets, red blood cells and other their effectiveness. Several arterial filters with varying
debris. Pore size depends on characteristics are commercially available (see
manufacturer Table 2.6).
Venous Designed to remove debris and gross The US Food and Drug Administration (FDA)
reservoir air, some models may contain a have outlined key areas of importance pertaining to
defoamer to reduce bubbles from arterial line filters (FDA, 2000). The following list sets
incoming suction or ports forth the risks to health associated with this device
Cardioplegia Blood cardioplegia: >40 μm filter. that were identified in the proposed classification
Crystalloid cardioplegia: >0.2 μm ruling (dated February 26, 1979), as well as additional
filter. Low priming volume filter for adverse event reporting since the classification ruling:
cell-free solutions. Removes  Amount of damage to formed blood elements,
inadvertent particulate debris and clotting and hemolysis
microbial contaminants and their  Degree of pressure drop resulting in inadequate
associated endotoxins
blood flow, damage to the device or structural
Leukodepletion Reduces the levels of leukocytes, integrity and damage to the arterial line
either from the arterial line or  Structural integrity of the product
cardioplegia system, and excludes
 Excessive pressure gradients, for example, blood
microemboli >40 μm
damage and inadequate blood flow
Blood Designed to reduce the levels of  Filtration efficiency and gas emboli-handling
transfusion leukocytes and microaggregates capacities
from one unit of packed red blood
 User error
cells or whole blood, used when
giving blood products to the  Blood incompatibility and the requirements of
patient ISO 10993: Biological Evaluation of Medical
Devices
Cell salvage Designed for the filtration of salvaged
blood, to remove potentially
 Compatibility of the product when exposed to
harmful microaggregates,
circulating blood and infections
leukocytes and lipid particles  Shelf life
These stringent criteria aim to ensure the production
bubble traps can reduce this significantly. Table 2.5 of high-quality arterial line filters that will not
gives an overview of the filters most commonly used have any deleterious effects on the CPB circuit or 21
in CPB circuits. patient.

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Simon Anderson and Amanda Crosby

Table 2.6. Different commercially available arterial line filters, both external and integrated

Manufacturer Filter type Fiber material Filter size (μm)

LivaNova Screen, External Phosphorylcholine-coated polyester net 27, 40, 120
Screen, Integrated Phosphorylcholine-coated polyester net 38
Medtronic Screen, External Cortiva Bioactive surface coating or uncoated 20 or 38
Screen, Integrated Cortiva Bioactive surface coating or uncoated 25
Terumo Screen, External Polyester, X-coating 37
Screen, Integrated Polyester, X-coating 32
Pall Screen, External Heparin-coated polyester 40
Lifeline-Delhi Screen, External Polyester 40, 20
Membrane solutions Screen, External Woven Polyester 40

Suckers and Vents (LV) apex can be associated with particularly serious
consequences including:
The suckers allow spilled blood from the operative
field to be returned to the circuit via the reservoir, but  LV wall rupture if inadequately closed
they can also be used to help salvage emergency  Damage to the LV wall due to excessive suction
situations. In case of life-threatening, excessive bleed-  Embolization through air entrained into the LV
ing before venous cannulation has been established, through the vent site.
the suckers can be used to scavenge blood to the
venous reservoir and subsequently be transfused back Cardioplegia Delivery Systems
into the patient via the arterial line. This is commonly One of the major concerns during cardiac surgery is
known as “sucker bypass” and grants the surgeon protection of the myocardium during procedures.
time to attempt to fix the problem at least Cardioplegia solution is administered to maintain
temporarily. controlled and protected electrical arrest of the myo-
“Vent” suckers are used to drain blood from the cardium during the ischemic period. Chapter 11 is
left ventricular cavity, typically via these sites: dedicated to myocardial protection techniques.
 Aortic root Regardless of the type of cardioplegia delivery
 Right superior pulmonary vein device, monitoring of temperature, appropriate deliv-
 Left atrium or pulmonary artery ery pressure, and time intervals between doses are
 Left ventricle critical to the success of the operation.
 Left ventricular apex Cardioplegia delivery systems typically include a
line for pressure monitoring, an over-pressure relief
The main reasons for venting the heart during CPB
valve, and a recirculation line for easy priming or de-
are to:
airing. Pressure monitoring is essential when deliver-
 prevent distension of the heart ing cardioplegia into small vessels and the coronary
 evacuate air from the cardiac chambers during the sinus to prevent damage. An air detection device is
de-airing phase of the procedure often added to the infusion line for additional protec-
 improve surgical exposure tion against microemboli. Most cardioplegia delivery
 reduce myocardial rewarming systems today have their own dedicated integrated
 create a dry surgical field. heat exchanger. This heat exchanger and accompany-
There are complications associated with all sites used ing water lines are separate from the oxygenator since
for venting, most commonly relating to injury to cardioplegia is typically delivered at temperatures
22 much colder than the patient’s core temperature.
tissues at the site. Venting via the left ventricular

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Chapter 2: Equipment for Cardiopulmonary Bypass

Table 2.7. Cardioplegia delivery systems

Manufacturer Integrated Air Delivery System

Heat Trap
Exchanger
LivaNova Yes Yes Dual roller head or
dual shims
adapter for two
sizes of tubing
for different
ratio options
Medtronic Yes Yes Blood
cardioplegia 4:1
ratio via roller
pump (can also
be used with a
syringe driver
for the
potassium
solutions)
Figure 2.11 Cardioplegia delivery system allows mixing of blood
and cardioplegia solution and warming or cooling of solution by Getinge Yes Yes Blood or
MyothermTM. (Reproduced with ©2020 Jose Canamares. All rights reserved. crystalloid
Used with the permission of Jose Canamares.) Photograph by Jose cardioplegia
Canamares used with permission.
ratio via roller
pump
Cardioplegia delivery systems vary from simple to depending on
complex. Administration in early procedures was accom- tubing set
plished by either using a pressure bag at the head of the
Quest Medical Yes Yes Piston pump
surgical field or elevating glass bottles to the operating for microplegia
theater ceiling via a pulley system and a needle inserted or compatible
directly into the cross-clamped aorta. More complex for numerous
microplegia systems require hardware to be added to the ratios including
heart lung machine and deliver specific aliquot measure- all crystalloid
ments of medications to arrest and protect the myocar-
dium. Standard blood cardioplegia delivery systems use
venous side (low pressure port) to provide a driving
roller pumps and specific tubing sizes to deliver a set ratio
force for blood through the membrane.
of blood to clear cardioplegic solutions (see Figure 2.11).
Hemofilters are used to concentrate blood in
Table 2.7 summarizes the characteristics of some
order to maintain or increase hematocrit (HCT) levels
of the most commonly used cardioplegia systems.
in the presence of excess fluid and can to a degree help
While many designs are available, every system
avoid blood transfusion. They may also be used to
should be capable of changing the ratio of blood to
manage electrolyte or acid/base derangements.
crystalloid, control flow to administer through differ-
The rate of filtration is dependent on the trans-
ent routes of the heart, and be temperature controlled
membrane pressure and the surface area of the filter
to allow cold, warm, or tepid doses of cardioplegia.
and is typically 30–50 ml/minute. The Sieving coeffi-
cient denotes whether a substance will be retained or
Hemofilters passed through the membrane to be filtered out.
Ultrafilters or hemoconcentrators contain semi- Sieving coefficients are based on molecular weight
permeable, hollow fiber membranes that permit pas- and the pore size on the filter. Depending on the
sage of water and electrolytes out of the blood. They membrane used, molecules of up to 50,000 Daltons
are normally connected to the CPB circuit at the are removed. It is important to note that molecules 23
arterial side (high pressure port) and returned to the like heparin or sodium bicarbonate are partially

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Simon Anderson and Amanda Crosby

filtered and their level should be monitored when caused by CPB, mainly through minimizing circuit
using a hemoconcentrator. size, introducing biocompatible surfaces where
possible and reducing prime volume to as little
Miniaturized Extracorporeal as 500 ml. As promising as the concept sounds, it
has not yet found its way into mainstream
Circulation (MiECC) clinical practice. MiECC is discussed in detail in
There has been increasing interest in miniaturized Chapter 8.
bypass circuits. Their aim is to decrease the trauma

Suggested Further Reading Circulation. 2000;102: Iv-87–Iv-93

0
8. Dickinson TA, Riley JB, Crowley JC,
Zabetakis PM. In vitro evaluation of
1. Gourlay T. Biomaterial the air separation ability of four
development for cardiopulmonary 5. Black S, Bolman RM III. C.
Walton Lillehei and the birth of cardiovascular manufacturer
bypass. Perfusion. 2001 extracorporeal circuit designs.
September; 16(5): 381–90. open heart surgery. J Card Surg
2006; 21: 205–208. Journal of Extra Corporeal
2. Kim WG, Yoon CJ. Roller pump Technology 2006; 38: 206–213.
induced tubing wear of 6. Johagen D, Appelblad M,
Svenmarker S. Can the oxygenator 9. Durandy Y.Vacuum-assisted
polyvinylchloride and silicone venous drainage, angel or demon:
rubber tubing: Phase contrast and screen filter reduce gaseous
microemboli? The Journal of PRO? Journal of Extra Corporeal
scanning electron microscopic Technology 2013; 45: 122–127.
studies. Artif Organs. 1998 Extra-corporeal Technology 2014;
October; 22(10): 892–897. 46: 60–66. 10. Potger KC, McMillan D, Ambrose
7. Saczkowski R, Maklin M, Mesana M. Microbubble generation and
3. Rodney F Patterson, Silicones. in transmission of Medtronic’s
Handbook of Thermoset Plastics T, Boodhwani M, Ruel M.
Centrifugal pump and roller affinity hardshell venous reservoir
(Second Edition), 1998. and collapsible venous reservoir
pump in adult cardiac surgery:
4. Denton A Cooley and O H A meta-analysis of randomized bag: An in-vitro comparison.
Frazier. The Past 50 Years of controlled trials. Artificial Organs Journal of Extra Corporeal
Cardiovascular Surgery. 2012; 36: 668–676. Technology 2011; 43: 115–122.

24

h //d i /10 1017/9781009008143 002 P bli h d li b C b id i i P

 Chapter
Monitoring during Cardiopulmonary Bypass

3 Richard F Newland and Pascal Starinieri

A fundamental area of responsibility for the perfusio- Heart Lung Machine

nist during cardiopulmonary bypass (CPB) is to
monitor, respond to, and document heart lung The complexity and extreme invasiveness of CPB
machine (HLM) parameters as well as physiological demands that strict attention is paid to all aspects of
variables obtained from the anesthetic monitor and extracorporeal flow, with importance placed on pro-
other physiological monitoring devices. The heart viding a safe environment for both the patient and
lung machine typically provides monitoring of blood personnel. Technological advancements, together
flow and circuit pressures (e.g., arterial, cardioplegia), with an increased understanding of the pathophysio-
temperatures (e.g., arterial, venous, cardioplegia, oxy- logical effects of extracorporeal flow, have made the
genator inflow and outflow), oxygen and air supply conduct of CPB both safe and reliable. An essential
and timers (e.g., CPB time, myocardial ischemia, cir- part of this success has been the development of
culatory arrest). Patient physiological parameters are monitoring devices that measure the combination of
monitored via the anesthetic monitor (e.g., arterial both physiological and mechanical functions that are
and central venous blood pressure, heart rate and unique to CPB.
ECG, core body temperature, oxygen saturation, cap-
nography). Blood gas parameters may be monitored Blood and Gas Flow
using devices that provide continuous measurements The HLM typically measures systemic blood flow
and/or intermittently using point of care or labora- continuously and in real time either via
tory blood gas analyzers. Non-invasive methods  the rpm of a roller pump and with knowledge of
may be used for cerebral monitoring, such as the tubing size placed through the raceway or
regional cerebral tissue oxygenation and electroen-  an ultrasonic flow probe.
cephalography (EEG) based depth of anesthesia.
Blood flow may also be monitored using continuous
Anticoagulation is monitored using point of care
blood gas monitoring systems (see below).
devices that measure the activated clotting time.
A measurement of blood flow distal to any circuit
These parameters together with procedural events
shunts is important to provide an accurate under-
and CPB interventions should be accurately recorded
standing of actual blood flow to the patient.
to provide documentation of the CPB period. CPB
A continuous supply of oxygen and air is delivered
monitoring recommendations published in the 2019
to the oxygenator during CPB while some specialist
EACTS/EACTA/EBCP guidelines on cardiopulmon-
procedures might require adding CO2 into the gas
ary bypass in adult cardiac surgery are summarized
mix. Modern heart lung machines are equipped with
in Table 3.1. Combined recommendations of the
digital flowmeters rather than the older style rota-
Society of Clinical Perfusion Scientists of Great
meters. Electronic gas blenders are generally con-
Britain and Ireland for Standards of Monitoring
trolled from the HLM work panel, while manual
and Safety during CPB and the American Society
blenders have a ball or cylinder rotameter which is
of ExtraCorporeal Technology Standards and
read against a scale and therefore cannot be continu-
Guidelines for Perfusion Practice are summarized in
ously monitored electronically. Monitoring gas
Table 3.2.

25

h //d i /10 1017/9781009008143 003 P bli h d li b C b id i i P

 Richard F Newland and Pascal Starinieri

Table 3.1. Summary of Class I recommendations CPB Table 3.2. Recommended extracorporeal circuit parameters for
monitoring parameters from the 2019 EACTS/EACTA/ Standards of Monitoring and Safety during CPB by the Society of
EBCP guidelines Clinical Perfusion Scientists of Great Britain and Ireland and the
American Society of ExtraCorporeal Technology Standards and
It is recommended that pressure monitoring devices are Guidelines for Perfusion Practice.
used on the arterial line and cardioplegia delivery
systems during CPB. Oxygen saturation of the blood in the arterial line

A bubble detector is recommended during CPB Oxygen saturation of the blood in the venous return line
procedures on all inflow lines. The flow of the blood to the patient (best measured
It is recommended to use a level sensor during CPB after shunt lines with a separate flow meter)
procedures utilizing a (hard-shell) reservoir. Arterial line pressure (preferably before AND after the
Continuous arterial line pressure monitoring oxygenator)
(preoxygenator and postoxygenator) in the CPB Gas flow and oxygen fraction to the oxygenator
circuit is recommended.
Venous occlusion percentage
Continuous oxygenator arterial outlet temperature
Oxygen concentration in the gas to the oxygenator
monitoring is recommended.
Level sensor during CPB procedures utilizing (hard-shell)
It is recommended to continuously monitor SvO2 and
reservoir
HCT levels during CPB.
Cardioplegia dose, delivery method, line pressure
Monitoring of blood gas analyses through regular
(antegrade), coronary sinus pressure (retrograde), and
intervals or continuous observation is recommended
ischemic intervals
during CPB.
Blood temperature at the arterial outlet and venous inlet
It is recommended to objectively report, adequately
of the oxygenator
record and properly analyse all adverse events related
to CPB practice in an efficient and timely manner. Water temperature in the heater-cooler system
It is recommended that the perfusionist collect data Anticoagulation – Activated Clotting Time (ACT)
concerning the conduct of perfusion via a clinical
Arterial blood gases (regularly or continuously)
registry or database and use such data to actively
containing the following measurements:
participate in institutional and departmental quality
assurance and improvement programmes. pH
It is recommended that the venous line pressure be pCO2
monitored when using assisted venous drainage. pO2
SaO2
HCO3
supply and exchange, together with an oxygen analyzer Base excess
to display the O2 concentration delivered at any point in
Haemoglobin (Hb)
time, is mandatory. Volatile anesthetics may also be used
via the heart lung machine gas delivery system during Haematocrit (HCT)
CPB to maintain anesthesia and/or as an adjunct to Potassium
blood pressure control. A scavenging system for waste
Sodium
anesthetic gases is recommended as being mandatory in
many countries, as volatile anesthetic agent waste is a Glucose (or other point-of-care device)
risk to staff. The end-tidal anesthetic gas concentration Lactate
can be monitored at the oxygenator exhaust port.

Temperature rate and oxygen consumption reduce by 50% for

The purpose of using hypothermia is to provide a every 7°C of temperature drop.
26 degree of organ protection and safety margin during Core temperature monitoring sites include naso-
cardiopulmonary bypass. As a general rule, metabolic pharynx, tympanic membrane, bladder, esophagus,

h //d i /10 1017/9781009008143 003 P bli h d li b C b id i i P

 Chapter 3: Monitoring during Cardiopulmonary Bypass

rectum, pulmonary artery, jugular bulb, arterial Table 3.3. 2015 STS/SCA/AmSect Clinical Practice Guidelines on
temperature monitoring during CPB
inflow, and venous return. Nasopharyngeal, jugular
bulb and arterial inflow temperature give an estimate CLASS I RECOMMENDATIONS
of cerebral temperature. Due to its invasive nature
The oxygenator arterial outlet blood temperature is
and cumbersome placement, jugular bulb probes are recommended to be utilized as a surrogate for
rarely used and the oxygenator arterial outlet blood cerebral temperature measurement during CPB. (Class
temperature is recommended as the surrogate for I, Level C)
cerebral temperature. Oxygenator inlet and outlet
To monitor cerebral perfusate temperature during
temperatures are measured using thermistors.
warming, it should be assumed that the oxygenator
Monitoring the temperature of the arterial blood arterial outlet blood temperature under-estimates
delivered to the body and of venous return blood cerebral perfusate temperature. (Class I, Level C)
helps to protect sensitive organs such as the brain
and to confirm adequacy of cooling and rewarming. Surgical teams should limit arterial outlet blood
temperature to <37°C to avoid cerebral
A temperature gradient of less than 10°C between
hyperthermia. (Class 1, Level C)
arterial outlet and venous inlet is recommended
during cooling to avoid cerebral injury, generation Temperature gradients between the arterial outlet and
of gaseous emboli or outgassing when blood is venous inflow on the oxygenator during CPB cooling
returned to the patient. Maintaining a low gradient should not exceed 10°C to avoid generation of
gaseous emboli. (Class 1, Level C)
between inflow and outflow temperature is equally
important during rewarming from hypothermia as a CLASS IIa RECOMMENDATIONS
fast temperature rise is associated with poor neuro- Pulmonary artery or nasopharyngeal temperature recording
logical outcomes. The perfusate temperature to the is reasonable for weaning and immediate post-bypass
body should not exceed 37°C. temperature measurement. (Class IIa, Level C)
The measurement accuracy of the thermistors is Rewarming when arterial blood outlet temperature 30°C:
affected by their immersion depth. The recommenda- i. To achieve the desired temperature for separation from
tions with regard to temperature monitoring during bypass, it is reasonable to maintain a temperature
CPB published in the 2015 STS/SCA/AMSECT gradient between arterial outlet temperature and the
Clinical Practice Guidelines are summarized in venous inflow of 4°C. (Class IIa, Level B)
Table 3.3. ii. To achieve the desired temperature for separation from
bypass, it is reasonable to maintain a rewarming rate of
0.5°C/min. (Class IIa, Level B)
Pressure Rewarming when arterial blood outlet temperature
Adequate blood pressure is one of the factors neces- <30°C: To achieve the desired temperature for
sary for adequate perfusion of vital organs. It is gen- separation from bypass, it is reasonable to maintain a
erally agreed that in most cases a mean systemic maximal gradient of 10°C between arterial outlet
arterial pressure (MAP) of 50–80 mmHg provides temperature and venous inflow. (Class IIa, Level C)
sufficient end-organ perfusion while cerebral autore-
gulation is preserved.
Circuit pressures are monitored primarily for safety
reasons, in order to avoid over-pressurization and the vasculature, coronary ostia or coronary sinus,
potential for circuit disconnection, cannula dislodge- depending on the route of delivery. The most com-
ment or vascular and tissue injury. Monitoring of cir- monly used mode of giving cardioplegia is antegrade,
cuit line pressure can also provide an indication of directly into the aortic root proximal to the aortic cross-
adequate positioning of cannulae, in particular ensuring clamp or into the coronary ostia at a line pressure of
that the aortic cannula is correctly positioned to avoid 80–150 mmHg. Retrograde cardioplegia is adminis-
dissection. Both pre- and post-oxygenator monitoring tered via a catheter in the coronary sinus, using a flow
is recommended to detect changes in transmembrane of 200–400 ml/min to a coronary sinus pressure of
pressure, as rises may indicate platelet deposition/aggre- between 30 and 80 mmHg.
gation within the oxygenator. Cardioplegia line pres- Servo regulation of pump flow rate coupled to 27
sure monitoring may avoid injury to the coronary pressure limits is an important safety feature of the

h //d i /10 1017/9781009008143 003 P bli h d li b C b id i i P

 Richard F Newland and Pascal Starinieri

(a) Low level detector (b) Bubble detector

Figure 3.1 Detectors for low reservoir blood level (a) and air emboli (b). (Livanova, UK.)

HLM. The higher limit has to be set in a way that Low Level and Air Bubble Detection
stops the pump causing injury at the cannulation site,
Heart lung machines have alarm systems embedded
generally at <250 mmHg. Cardioplegia pressure is
within monitoring on the display panel of the HLM.
typically limited at lower pressures, depending on
Alarms either provide an audible and/or visual indi-
the route of delivery (<150 mmHg antegrade and
cation to the perfusionist or, more critically, can
<80 mmHg retrograde).
adjust or entirely stop pump flow if necessary when
The negative pressure inside the venous reservoir
servo-regulated. Checking alarm levels and function-
is monitored when either vacuum-assisted venous
ality is part of the pre CPB checklist; alarms must be
drainage (VAVD) or kinetic-assisted venous drainage
engaged prior to the initiation of CPB.
(KAVD) is used. The vacuum is typically adjusted in a
The low level alarm is a critical safety feature on
way that the negative pressure does not exceed
the HLM. A sensor on the venous reservoir is placed
30mmHg in order to reduce hemolysis and the risk
at a level below which there is the danger of emptying
of air entrainment into the venous line or across the
the reservoir and entraining air into the arterial cir-
membrane oxygenator. The latter can potentially lead
culation (see Figure 3.1a). If triggered, the servo regu-
to serious harm to the patient through gaseous arter-
lation will stop or significantly reduce the flow rate of
ial micro emboli or massive arterial embolization.
the arterial pump in addition to sounding an acoustic
Negative pressure in the venous line during kinetic-
alarm. The pump will only resume flow once the fluid
assisted venous drainage should not exceed ‒80
level is above the sensor again. Ultrasonic air bubble
mmHg to avoid cavitation and hemolysis. Other cir-
detectors on the arterial side of the HLM operate in
cuit pressures monitored may include antegrade or
the same way to protect against gross air embolism
retrograde cerebral perfusion with servo regulation
(see Figure 3.1b). Both alarm systems received a Class
limits around 150 mmHg for antegrade and
I recommendation in the 2019 EACTS/EACTA/
80 mmHg retrograde.
EBCP guidelines.
Circuit pressures are usually monitored using
Bubble detectors may also be used in the cardio-
reusable electronic transducers, where the fluid is
plegia line, and the venous line in minimized
28 isolated from the transducer by a dedicated disposable
CPB circuits. Although contemporary equipment,
circuit component.

h //d i /10 1017/9781009008143 003 P bli h d li b C b id i i P

 Chapter 3: Monitoring during Cardiopulmonary Bypass

technology, and perfusion techniques have reduced

the potential for massive air embolism, arterial gas-
eous microemboli still remain a concern. Integrated
air bubble detectors can provide quantification of
microbubbles during CPB, yet the values they report
have been found to be less reliable than those gener-
ated by specifically designed microemboli detectors.
This suggests that that microbubble counts from air
bubble detectors integrated in the circuit should not
be reported. However, any events where the low level
and/or air bubble alarms have been triggered should
be included in the perfusion record.

Calibration of Heart Lung Machine

Monitoring Systems Figure 3.2 Terumo CDI550 in-line blood gas analyzer. (Terumo
Cardiovascular Systems Corp., Ann Arbor, MI.)
All monitors and alarms used should be calibrated
and maintained regularly according to the manufac-
turer’s instructions and the recommended service limb and HCO3 and K+ using direct blood contact,
schedule. All equipment must be checked before use while SO2, Hct and Hb are measured using optical
(see Chapter 4 for more detail). reflectance (see Figure 3.2). The cost of the disposable
sensors associated with this technology has led to the
CDI technology not always being routinely adopted.
Gas Exchange In some centers it is used for complex or prolonged
The primary function of the respiratory system is to cases – such as when blood gas management strategy
take in oxygen and eliminate carbon dioxide. Inhaled is changed from α-stat to pH-stat during cooling or
oxygen enters the lungs and reaches the alveoli where rewarming in procedures involving deep hypothermic
it passes through the air-blood barrier and into the circulatory arrest (DHCA).
blood in the capillaries. Similarly, carbon dioxide The System M (Spectrum Medical, Gloucester,
passes from the blood into the alveoli and is then UK) is an example of a diagnostic monitor which
exhaled. Oxygenators on the HLM function using provides continuous non-invasive measurement of
exactly the same principle. blood gases (pCO2, pO2), SO2, flow and bubble/
emboli detection and ventilation parameters (sweep,
In-line Blood Gas Analysis, Venous Saturation oxygenator inlet O2 and outlet CO2) as well as Hb,
however no electrolyte measurements are provided.
and Hematocrit Monitors The reusable sensors are attached to the circuit, neg-
The theoretical advantages of using continuous in- ating the requirement of ongoing disposable costs (see
line blood gas and electrolyte monitoring during Figure 3.3).
CPB are well established; however, the clinical impact The 95% limits of agreement both devices have
remains controversial. The available devices may be with laboratory or point of care blood gas analysis do
divided into those using electrochemical electrodes not allow complete substitution and they should be
and cuvettes, which are placed in the circuit, and considered as trending devices only. The few random-
those that use light absorbance or reflectance, which ized studies that have evaluated the efficacy of these
require sensors placed external to the circuit tubing. devices found that they lead to improved adherence to
The Terumo CDI550 in-line blood gas analyzer institutional perfusion protocols, which did not trans-
(Terumo Cardiovascular Systems Corp., Ann Arbor, late into improved patient outcomes.
MI) is an optical fluorescence and reflectance based More basic forms of in-line monitoring, using
in-line system that continuously monitors 12 key absorbance or reflectance of infrared light signals,
blood gas parameters. Fluorescence sensors measure are commonly used to continuously monitor venous
pH, pCO2, pO2 on both the arterial and the venous and arterial blood oxygen saturations during CPB. 29

h //d i /10 1017/9781009008143 003 P bli h d li b C b id i i P

 Richard F Newland and Pascal Starinieri

Figure 3.3 M4 monitor. (Spectrum Medical, UK.)

Similar to the more advanced devices above, they lack improved neurocognitive function in patients under-
in accuracy but are valuable tools for observing and going NIRS based algorithms to improve oxygen
recording trends. supply/demand ratio, recent randomized trials and a
As a minimum, it is recommended to continu- recently published meta-analysis and systematic
ously monitor SvO2 and Hct and perform full blood review showed no clinical benefit. Cerebral saturation
gas analyses at regular intervals throughout the dur- monitoring is discussed in more detail in Chapter 18
ation of CPB (Class I recommendation, 2019 EACTS/ and its clinical application in Chapter 9.
EACTA/EBCP guidelines).
Oxygen Delivery and Carbon
Cerebral Oxygen Saturation Dioxide Extraction
Adverse cerebral outcomes after cardiac surgery are Oxygen delivery (DO2) is determined by hemoglobin,
associated with increased mortality, prolonged ICU
arterial blood flow, oxygen saturation and PaO2.
and hospital stay and the use of additional healthcare
Many current HLM monitors are able to continuously
resources. Continuous monitoring of cerebral oxygen
calculate and display DO2 during CPB. Alternatively
saturation may provide a tool to detect an imbalance
it can be calculated manually from reference charts.
between cerebral oxygen demand and supply and may
Evidence from a randomized trial and multicenter
decrease the likelihood of intraoperative cerebral injury.
registry data shows that a goal-directed perfusion
Near-infrared spectroscopy (NIRS) can be used to
strategy to maintain oxygen delivery index (DO2i)
monitor cerebral oxygen saturation during cardiac sur- during CPB > 280 mL/min/m2 reduces the incidence
gery. Self-adhesive sensors containing the infrared light of acute kidney injury following cardiac surgery.
source and detectors are placed on one or both sides of the
forehead. Cerebral desaturation is defined as a 20% reduc-
tion from baseline values or an absolute decrease below Anticoagulation Monitoring
50% taking the duration of desaturation into account. Systemic heparinization is required for CPB to avoid
The evidence regarding its clinical benefit is how- coagulation due to contact activation and stasis in the
30
ever contradictory. Although early studies showed reservoir or the operating field. Safe anticoagulation is

h //d i /10 1017/9781009008143 003 P bli h d li b C b id i i P

 Chapter 3: Monitoring during Cardiopulmonary Bypass

ascertained by measuring the activated clotting time  need for temporary atrial or ventricular pacing.
(ACT), which is generally done in the operating Pulmonary artery catheter – although not used rou-
theater. The ACT is a highly unspecific whole blood tinely in many parts of the world, the PAC may be
coagulation assay and is influenced by factors such as used to provide assessments of cardiac output and
temperature, hematocrit, fibrinogen level and platelet pulmonary artery pressure, which may help guide
count or function. The majority of centers around the inotropic support during separation from CPB.
world target ACT values between 450 and 550 Transesophageal echocardiography – TEE is
seconds. The ACT is typically measured every 20–30 widely used in cardiac surgery. Recent guidelines by
minutes and recorded in the perfusion record. the American Society of Anesthesiologists and the
The 2018 STS/SCA/AMSECT Clinical Practice Society of Cardiovascular Anesthesiologists recom-
Guidelines recommend as Class 1 evidence that “a mend that, in the absence of contraindications,
functional whole blood test of anticoagulation, in the intraoperative TEE be performed in all cardiac valve
form of a clotting time, should be measured and should and thoracic aortic procedures (Class 1) and is rea-
demonstrate adequate anticoagulation before initi- sonable for CABG operations (Class IIa). The advan-
ation of, and at regular intervals during cardiopul- tages in the use of TEE prior to CPB include
monary bypass. (Level of Evidence C)”
 confirming the preoperative diagnosis,
Furthermore, a Class IIa recommendation in the
same publication states “it is reasonable to maintain  detecting undiagnosed pathologies,
activated clotting time above 480 seconds during CPB.  confirming the success of surgical intervention,
However, this minimum threshold value is an approxi- particularly in valve repairs and replacements,
mation and may vary based upon the bias of the  confirming appropriate de-airing after open
instrument being used. For instruments using ‘max- chamber surgery and
imal activation’ of whole blood or microcuvette tech-  guiding inotrope management by continuous
nology, values above 400 seconds are frequently assessment of left and right ventricular function.
considered therapeutic. (Level of Evidence C)”
It is important to note that ACT devices from
different manufacturers must not be used inter- Documentation of Intraoperative
changeably. Anticoagulation during cardiopulmonary Monitoring Data: The Cardiopulmonary
bypass is discussed in detail in Chapter 6.
Bypass Record
The CPB or perfusion record is a legal record and
Hemodynamic Monitoring should therefore be accurate and legible. Historically,
Assessment of myocardial function is important both the perfusion record had been handwritten, with the
pre CPB and during separation from CPB. perfusionist documenting physiological parameters
Hemodynamic monitoring includes the electrocar- and heart lung machine values. Typically, this
diogram (ECG), pulmonary artery catheter (PAC) happened every 5–10 minutes, when changes
and transesophageal echocardiography (TEE). occurred or when events or interventions (e.g., drug
Electrocardiogram – ECG monitoring is one of administration) required documentation. A manual
the minimum monitoring requirements during anes- record will always be a snapshot of what occurs
thesia. Although native cardiac function is unneces- during bypass and may be incomplete or inaccurate,
sary during CPB, the ECG can provide important with errors able to be introduced in a number of ways.
clues to These inadequacies include missing data, biased
 efficacy of initial cardioplegia delivery by recording, transcription error and subjectivity of
broadening QRS complexes and the appearance of observation. There are a number of systems that are
towering T waves, able to generate an electronic record with the aid of
 adequacy of myocardial protection by showing data collection software. They provide automatic data
signs of electrical activity, acquisition and integrate data from the HLM and
 early signs of ischemia (ST segment changes or other monitoring systems in the operating room,
ventricular tachyarrhythmias) after cross-clamp most importantly the anesthetic, hemodynamic
removal or before weaning off CPB and
31
monitoring (Figure 3.4). As the number of monitors

h //d i /10 1017/9781009008143 003 P bli h d li b C b id i i P

 Richard F Newland and Pascal Starinieri

(a) Connect Datapad (b) Quantum Workstation

Figure 3.4 Examples of automatic data acquisition and monitoring systems for cardiopulmonary bypass; (a) Connect Datapad (Livanova, UK), (b)
Quantum Workstation. (Spectrum Medical, UK.)

in the operating room increases, the operating team Scientists of Great Britain and Ireland for Standards
needs to observe, record, and respond to more and of Monitoring and Safety during CPB and is a Class
more data. Where this is recorded automatically, the IIa recommendation in the 2019 EACTS/EACTA/
perfusionist and the anesthesiologist are less dis- EBCP guidelines. Comprehensive records also pro-
tracted and more able to concentrate on the patient vide individual departments with the ability to define
rather than on documenting the procedure. The CPB quality metrics based on institutional guidelines.
integrity of the data from automatic data acquisition
removes the bias that is inherent in the manual
record. Application of Electronic Perfusion Data
Apart from creating a record of the patient and Generating an accurate perfusion record is only one
heart lung machine physiological parameters, these component of the value that can be gained from
products provide documentation of CPB equipment, automated electronic perfusion data collection
priming solutions, fluid balance, coagulation and systems. The data provide an enormous resource for
blood gas values, cardioplegia and drug administra- ongoing research activities and quality management.
tion. Electronic perfusion data collection, including The importance and benefits of quality assurance and
32 the ability to produce a printout, is a general recom- quality improvement in healthcare delivery are well
mendation of the Society of Clinical Perfusion recognized. The collected data can be used to monitor

h //d i /10 1017/9781009008143 003 P bli h d li b C b id i i P

 Chapter 3: Monitoring during Cardiopulmonary Bypass

and improve quality of care processes and to report glucose, arterial outlet temperature, and blood gas
practices at an individual or institutional level, or to management during CPB utilizing electronic data.
facilitate multicenter reporting through participation These benchmarks provide a baseline for the imple-
in a CPB registry. mentation of multicenter continuous quality
improvement processes for perfusion practice. By
Registry examining CPB data and related outcomes, registries
have been able to define risk factors associated with
Some examples of CPB registries include the
adverse outcomes.
Northern New England Cardiovascular Disease
One of the problems inherent in determining
Study Group, the Australian and New Zealand
relationships between CPB parameters and the clin-
Collaborative Perfusion Registry (ANZCPR) and the
ical measures of outcomes is the low rate of adverse
PERFORM registry (USA), which is an integral part
events, resulting in the requirement of large cohorts
of the Michigan Society of Thoracic and
to achieve adequate and statistically well powered
Cardiovascular Surgeon Quality Collaborative’s pro-
studies. Amalgamation of collected data provides a
gram. Electronic data collection meets the needs of
means to increase cohort size and therefore reduce
registry endeavors because it provides a method of
the confounding effects of variations in patient risk
transferring de-identified data from multiple sites,
factors and practice changes over time. Registry data
integration of this data into a central database, and a
also play an important role in confirming the gener-
means to generate calculated CPB parameters and
alizability of results of clinical studies and in recom-
perform complex data analysis. The ANZCPR has a
mending them for implementation into clinical
defined process of core metrics and uses these to
practice.
calculate benchmarks for the management of blood

Suggested Further Reading Perfusion Practice: 2013. Baker

RA, Bronson SL, Dickinson TA
during cardiopulmonary bypass.
J Extra Corpor Technol.
1. Puis L, Milojevic M, Boer C et al. et al, on behalf of the International 2018;50:1–14.
2019. 2019 EACTS/EACTA/EBCP Consortium for Evidence-Based
Guidelines on cardiopulmonary 6. Ranucci M, Johnson I, Willcox T
Perfusion for the American et al. Goal-directed perfusion to
bypass in adult cardiac surgery. Society of ExtraCorporeal
Interact Cardiovasc Thorac Surg. reduce acute kidney injury:
Technology. JECT. A randomized trial. J Thorac
February 1, 2020;30(2):161–202. 2013;45:156–166. Cardiovasc Surg. November,
2. Recommendations for Standards 4. Engelman, R, Baker, RA, Likosky 2018;156(5):1918–1927.
of Monitoring during DS et al. The Society of Thoracic
Cardiopulmonary Bypass. The 7. Newland RF, Baker RA,
Surgeons, The Society of Woodman RJ et al. Australian and
Society of Clinical Perfusion Cardiovascular Anesthesiologists,
Scientists of Great Britain and New Zealand Collaborative
and The American Society of Perfusion Registry. Predictive
Ireland, Association of ExtraCorporeal Technology:
Cardiothoracic Anaesthetists, capacity of oxygen delivery during
Clinical practice guidelines for cardiopulmonary bypass on acute
Society for Cardiothoracic cardiopulmonary bypass –
Surgery in Great Britain and kidney injury. Ann Thorac Surg.
Temperature management during June 22, 2019.
Ireland, August 2016. cardiopulmonary bypass. JECT.
3. Report from AmSECT’s 2015;47:145–154. 8. Ottens J, Tuble SC, Sanderson AJ
International Consortium for et al. Improving cardiopulmonary
5. Shore-Lesserson L, Baker RA, bypass: Does continuous blood
Evidence-Based Perfusion: Ferraris V et al. STS/SCA/
American Society of gas monitoring have a role to
AmSECT Clinical practice play? J Extra Corpor Technol.
ExtraCorporeal Technology guidelines: Anticoagulation
Standards and Guidelines for September, 2010;42(3):191–198.

33

h //d i /10 1017/9781009008143 003 P bli h d li b C b id i i P

 Chapter
Cardiopulmonary Bypass Circuit

4 Setup and Safety Checks

Victoria Molyneux and Shahna Helmick

Introduction circuit components should ritualistically follow a rou-

tine dictated by institutional protocols and the process
Assembling the cardiopulmonary bypass (CPB) cir- confirmed by following a recognized, institutionally
cuit and checking the heart lung machine (HLM) for agreed pre-CPB checklist.
faults prior to clinical use is an essential and integral
part of the provision of clinical perfusion. This chap-
ter describes the procedure for setting up the extra- CPB Machine Preparation and Setup
corporeal circuit and the safety checks that should be
undertaken before embarking on a case.
CPB Components
The evolution of CPB has been marked on one Cardiopulmonary bypass circuits are comprised of a
side by sophistication and complexity and on the number of disposable components supported by the
other side by an increased requirement for safety. HLM. We consider four essential elements of the CPB
The death of a pediatric cardiac surgical patient and system that remain the same, despite different manu-
the subsequent Gritten Report of 2007 marked a facturers and different component designs. Principally
turning point for perfusion safety. This led to the these are as follows:
implementation of minimum standards and practice  Membrane oxygenator and venous reservoir
recommendations within the United Kingdom. The  Cardioplegia system
medical communities in many countries have issued  Custom tubing pack
recommendations concerning the training of clinical  Arterial line filter (unless integrated in
perfusionists and the use of monitoring and safety oxygenator/reservoir).
devices for CPB. Although studies have not estab-
lished a cause-to-effect relationship, the decrease in
CPB-related mortality may be partly attributed to
CPB Setup
these measures. Vigilance is paramount to the safety These components can be assembled in a myriad of
of CPB. Modern perfusion systems are designed to configurations, depending on institutional and clin-
optimize safety. Technological advances have seen the ician preference and specific patient requirements.
incorporation of automatic, servo-regulated alarms Although there is no universally agreed or commonly
and fail-safe devices; however, the clinical perfusio- used sequence for setting up and priming a standard
nist’s attention to detail, as well as performance of CPB system, the following list provides a general
pre-CPB checklists and protocols, underpins safe routine to ensure a safe setup:
practice. Investigations around the world have repeat-  All components are checked for sterility,
edly pointed to medical errors that could have been cleanliness, integrity, and expiration date.
prevented as an important cause of morbidity and  The heat exchanger on both the oxygenator and
mortality; human error is a far greater cause of acci- the cardioplegia delivery system (if present) must
dents than mechanical mishap. be leak-tested either upon opening the sterile
Preparing the CPB circuit and HLM, attending to packaging or once the CPB circuit has been set up
the patient’s clinical details and to the surgical but prior to the initiation of priming. In practice
requirements for the procedure all form part of the this is usually done once the CPB circuit has been
process of safe provision of CPB. By necessity, the set up dry. The integrity of the heat exchanger
34 preparation of the HLM and assembly of the CPB may be tested using a pressure occlusion device

h //d i /10 1017/9781009008143 004 P bli h d li b C b id i i P

Other documents randomly have
different content
sind erledigt, nicht? ... Du weißt, daß du Exzellenz übermorgen
triffst? ...«
Frau Erika nickte.
»Bis auf eine,« sagte sie tonlos ... »Du bist sehr gut, daran zu
denken.«
Er strich leicht über ihr Haar und zog mit spitzen Fingern die weiße
Locke tiefer in die Stirn.
»Abends werde ich dann allein etwas unternehmen, wenn du
einverstanden bist ... Die Philharmonie lasse ich auch ...«
Natürlich war Frau Erika einverstanden, und die treue Lina
telephonierte einen zusagenden Bescheid des Herrn Doktor nach der
Eichstädter Straße.
... Als der Abend gekommen war und eine fast fühlbare Stille über
den Räumen lag, in denen eine feingestimmte Beleuchtung die
Farbenzauber des Tages geheimnisvoll vertiefte oder verschwimmen
ließ, ging Frau Erika, das ungewohnte abendliche Alleinsein
unbewußt genießend, in der Zimmerflucht hin und her.
Ihre Gedanken wanderten erst in den gewohnten Geleisen:
... Bazar für das Säuglingsheim ... Toilette dazu ... Anprobe ... Sie
sah in ihrem Notizbüchelchen nach, wann? ... zwei five o'clocks ...
die Erkundigung nach dem lahmen Mädchen für Exzellenz Berens ...
Neue Franzosen bei Cassirer ... Zwölf-Personen-Diner im Hause ...
Das alles tauchte kraus durcheinander in ihren Überlegungen auf.
Aber sie war dabei voller Unruhe, und wahrscheinlich fieberte sie,
– denn mitten in diesen notwendigen und auch wichtigen
Tageseinteilungen glaubte sie beständig die Stimme ihres
Vormittagsgastes zu hören, die sehr laut geklungen haben mußte ...
Daher wohl auch die Eindringlichkeit der Worte, die schließlich doch
nichts anderes gewesen waren, als der Ausdruck erwartungsvoller
Lebensfreude, – wie sie selbst sie vor Jahren hätte aussprechen
können ...
Damals ... als sie das Studentenlied von dem lustigen Musikanten
gesungen hatte ... wenn sie das wirklich gewesen war ...
Sie versank in Grübeln und Brüten, und verscheuchte
Erinnerungen rangen sich zaghaft wieder hervor.
... Jetzt ein Bild ... ein Brief mit guten Worten aus längst
vergangenen Zeiten ... oder etwas von den kleinen Heiligtümern, die
ihr als Reste von dem jauchzenden Leben des Kindes übrig
geblieben waren.
Ihr Mann nannte das Ballast, und alle Dinge, die nicht in den Stil
des neuen Lebens paßten, hatten wohlverpackt auf dem großen
Boden des Saalfelder Hauses zurückgelassen werden müssen.
Aber eine kleine Kiste fiel ihr ein, die irrtümlicherweise mit nach
Berlin gekommen war, und die sie nicht hatte öffnen lassen, weil sie
wußte, daß sie nur Wertloses enthalten konnte.
Heute hatte sie Sehnsucht, irgendeinen Gegenstand aus jenen
vergangenen Zeiten vor sich zu sehen.
Sie klingelte und gab den Befehl, die kleine Kiste
herbeizuschaffen.
Die treue Lina zog die Augenbrauen in die Höhe. Das Kistchen
stünde wohl auf einer Bodenkammer, aber da wäre doch, soviel sie
wüßte, nur ein Porzellankopf drin ...
Ob sie es denn geöffnet hätte? ...
Jawohl, die gnädige Frau würde sich doch erinnern, daß sie es
selbst befohlen hätte ...
Nein, – sie erinnerte sich nicht, wiederholte aber den Wunsch, die
Kiste bei sich zu haben.
 Die treue Lina holte es also und setzte es mit einem leidenden
Seufzer auf den perlmuttereingelegten Hocker, wo es plump und
frech in der zarten Umgebung dastand.
Frau Erika konnte es kaum erwarten, den darin verpackten
Gegenstand zu enthüllen.
Nun sie ihn in der Hand hielt, gab es eine große Enttäuschung.
Es war ein häßlicher Matrosenkopf in grell bemaltem Porzellan, wie
ihn vor vielen Jahren, vielleicht zu Anfang des vorigen Jahrhunderts,
die Seefahrer aus England herübergebracht hatten. Die großen,
hervortretenden Augen starrten. Blanke Goldringe steckten in den
Ohren und eine Pfeife hing aus dem breiten, roten Mund. Den
Schädel verdeckte ein schwarzer Lackhut, den man abnehmen
mußte, wenn man zu dem Tabak gelangen wollte, der in dem hohlen
Innern aufbewahrt wurde. Man spürte jetzt noch den schwachen
Geruch, – – und wie lange mochte wohl nichts mehr darin gewesen
sein? ...
Frau Erika schloß die Augen, und dann riefen die Erlebnisse aus
den Kindheitstagen sie an, in die dieser Kopf von seiner Ecke her,
oben auf dem eintürigen Schrank, hineingeschaut hatte.
Und wie sie den verödeten Gedankenwegen nachging, tauchten
von Neuem lang vergessene Bilder in ihr auf. Einfache und
bedeutungslose, – aber sie hauchten ein wunderlich starkes Leben
aus ...
... Da war in dem kleinen Haus in der ostpreußischen Hafenstadt
ein Stübchen, wie eine Schiffskabine ausgestattet ... Auf dem
schwarzen Ledersofa sah sie den alten Großohm mit dem breiten,
roten Gesicht und dem schneeweißen Bartkranz drum herum. Neben
ihm, zart und fein, die kleine Großtante im schwarzen Kopftuch,
lange, schmale Fidibusstreifen aus weißem Papier faltend.
Sie selbst auf kleinem Schemel neben dem Tisch. Es wurde stark
duftender Tee aus hohen, goldenen Tassen getrunken, und kleine
Gewürzkuchen gab es dazu, die die Großtante aus einer Blechbüchse
hervorholte.
Und dann erzählte der alte Mann Geschichten. Wunderliche
Geschichten ... von Seestürmen, ... von lachenden Küsten, wo die
Menschen nackt gingen, – von Meerungeheuern, die die langen
Arme aus dem Wasser reckten und sich mit tellergroßen Saugnäpfen
am Schiffe festsogen, von den wilden Späßen, wenn man die Linie
passierte ... und auch von dem Schattenschiff, das in der Meerenge
Bab-el-Mandeb sein grausiges Wesen trieb.
Von den siebzehn Menschen, denen er dann hier in seiner
Tätigkeit als Oberlotse das Leben gerettet hatte, erzählte wieder
seine alte Frau, – und zuweilen kam auch ihre, Erikas eigene schöne,
junge Mutter dazu und streichelte mit ihren weißen Händen die
knotigen Gichtfinger des Alten und lachte so leise und lustig, wie nur
sie lachen konnte, wenn er sie dran erinnerte, daß sie oben im Sund
auf einem Heringsschiff zur Welt gekommen war. Und die Sonne
funkelte in die Fenster des Puppenhäuschens, und abends kam der
Mond und schimmerte auf den weißen Tauen und Segeln des
Schiffes, das in der Mitte des Zimmers von der Decke hing – oder er
glitzerte auf dem Matrosenkopf, der so lebendig zu werden schien,
daß man sich ordentlich vor ihm fürchte.
Wie fluteten diese Bilder aus goldenen Kinder- und Ferientagen,
einfach und doch so vielsagend, durch das Van-de-Velde-Zimmer!
Mit welch ergreifend rauher Stimme rief jenes Leben die weiche
Existenz von heute an. Aber nun nicht weiter ... Nichts von
Elternhaus, nichts von lustigen Ritten und tränenschwerem Abschied
– nichts von alledem, was dann kam ... In Gedanken an der See
bleiben – – bei den lieben, alten Leuten.
Frau Erika legte die heiße Stirn an den häßlichen Matrosenkopf –
man konnte schon sagen »zärtlich«, meinte die treue Lina an ihrer
Türspalte – dann setzte sie ihn behutsam auf die Schreibtischecke
neben ein spiegeltragendes Tanagrafigürchen, dessen ausgestreckter
zarter Arm sich gegen die gemeine Nachbarschaft zu wehren
schien ...
Es war schon spät, und Frau Erika schlief unter dumpfem Brausen
ein, das von irgendwoher kam. Sie wußte nicht, rauschte das
fiebernde Blut in ihr, oder schlug die Ostsee mit langen,
schäumenden Wellen an den Strand, den sie damals von den kleinen
Fenstern des Lotsenhäuschens in Pillau hatte sehen können ...
Am nächsten Morgen wunderte sie sich über die Stimmungen des
vergangenen Tages und glaubte, sie geträumt zu haben. Das
Aufstehen wurde ihr schwer, die Glieder wollten ihr nicht gehorchen,
und die Brust schmerzte sie beim Atmen noch mehr als gestern.
Aber es ließ sich überwinden, und so saß sie beim Frühstück mit
ihrem gewohnten Lächeln dem Gatten gegenüber, der, in seine
Zeitungen vertieft, nicht auf sie achtete.
Schwindlig ging sie dann in ihr grünes Zimmer und legte sich auf
die Chaiselongue unter die großen Latanie.
Der Matrosenkopf, den sie gestern mit so viel wehmütiger
Zärtlichkeit auf den Eckplatz gestellt hatte, war heute in seiner rohen
Häßlichkeit geradezu eine Verunstaltung des schönen Raumes. Und
doch konnte sie die Augen nicht von ihm lassen und glaubte sogar,
den schwachen Tabakgeruch zu verspüren, der doch nur in nächster
Nähe zu merken war.
»Ich muß ihn fortsetzen, ehe Lovis kommt,« dachte sie, aber sie
rührte sich nicht.
Und da trat Doktor Lohrer schon ein. Gedämpft fröhlich und mit
aufmerksamem Lächeln um den spitzen Mund.
»Nun,« sagte er – »dir geht's also besser? ...«
Sie mußte jetzt »ja« sagen. Sie wußte, das erwartete er. Aber
plötzlich regte sich der Wunsch in ihr, bedauert und gepflegt zu
werden, und so sagte sie statt dessen:
 »Nein, ich möchte mich am liebsten wieder zu Bett legen.«
»Wegen einer kleinen Erkältung, mit der du sonst die
anstrengendsten Dinge unternimmst? Wenn du dich jetzt legst,
bricht unfehlbar der Schnupfen los, der dich für morgen unmöglich
macht.«
Sie schwieg.
»Hast du etwa die fade Absicht, die Sitzung und den Tee im
Ministerium abzusagen?«
»Ich weiß nicht,« sagte sie ängstlich, »ob ich hinkann.«
Jetzt hatte er sich umgewendet und den Matrosenkopf gesehen.
»Erika« ... rief er ganz fassungslos vor Entsetzen ... »Bist du von
Sinnen? ... Wie kannst du das Monstrum da vor dir dulden? ... Ist
das etwa ein Geschenk von deiner neuen Freundin?«
Frau Erika bemerkte, wie aufgebracht er war. Sie lenkte ein.
»Verzeih ... ich ließ mich vielleicht wirklich etwas gehen ... das
Scheusal da ist aus Versehen stehen geblieben ... Ein Überbleibsel
aus meiner Kinderzeit ... ich will mir's aufbewahren« ...
»Aber möglichst unsichtbar, wenn ich bitten darf ... Und, – daß du
dich auf deine Verpflichtungen besinnst und dich nicht hängen läßt,
liebes Kind, freut mich, – ist aber wohl selbstverständlich.«
»Und du bist überzeugt, daß es sehr wichtig ist?« fragte Frau
Erika, ohne Ton in der Stimme.
»Das ist doch keine Frage! ... Es hat Mühe genug gekostet, dich
dahin zu lanzieren ... Da wir leider keine Kinder haben, will ich
wenigstens für meine Person und für deine natürlich ... aber warum
das immer wiederholen. Wir sind ja einer Meinung und haben uns
oft genug darüber ausgesprochen ...«
 Dieser in bösen Stunden immer wiederkehrende Hinweis auf ihre
Kinderlosigkeit, vereint mit dem Vorwurf über ihren Mangel an
Vorsicht bei jenem schrecklichen Unfall, der ihnen das Kind geraubt
hatte, wirkte jedesmal auf Frau Erika, als ob sie zu Boden
geschlagen würde. Wenn sie sich dann erhoben hatte, ging sie
wieder gehorsam den gemeinsamen Weg.
Er war übrigens in ihren eigenen, wie den Augen der Welt weit
entfernt davon, ein Dornenweg zu sein ...
Nach dem Lunch, als Herr Doktor Lohrer längst fortgegangen war,
hatte Frau Erika noch ein paar Schwächeanfälle, Frost- und
Hitzeschauer. Wenn sie dann die Augen zumachte, wollte sie sich
von neuem die beruhigenden Bilder vergegenwärtigen, die sich
gestern beim Anblick des alten Porzellankopfes eingefunden hatten.
Sie holte ihn auch wieder aus dem Schränkchen hervor, in dem sie
ihn verborgen hatte, aber heute stand er einfach in seiner
kulturlosen Häßlichkeit da und wollte ihr nichts Schönes erzählen.
Im Gegenteil – die Gedanken irrten von ihm ab zu verbotenen
Wegen, auf denen einstmals alle Schrecknisse des Menschenlebens,
Unglück, Sorge, Schande und Verlassenheit über sie hatten herfallen
wollen ...
Und das waren Töne, die hier nicht anklingen durften ... Mit
Gewalt mußten sie vertrieben werden ... Ein ander Bild ... ein frohes
... Galopp, Menuett und Walzer ... Nein, d a s war ja nicht jenes Lied,
das sie als Kind mitgesungen hatte, wenn in den Sommerferien alt
und jung vor der Tür des Lotsenhäuschens zusammensaß ... Das
hieß doch: »Morgen, da geht's in die brausende See ... morgen, da
geht's in die brau ... au ... sende See ...«
Sie fuhr auf ... Was war das? ... Sie phantasierte ja am hellen Tage
... Sie wollte vielleicht doch den Arzt kommen lassen.
Sie stand auf, um zu ihrem Telephon an den Schreibtisch zu
gehen.
 Da trat die treue Lina ein.
»Herr Doktor telephonieren eben, gnädige Frau möchte nicht
vergessen, die Erkundigung Eichstädter Straße 9 einzuziehen ...«
»Eichstädter Straße 9?« fragte Frau Erika. Die treue Lina senkte
bestürzt die gefärbte Tolle. Sie hatte den Auftrag eben von der
Eichstädter Straße aus bekommen und, in Gedanken noch dort,
diese vielgebrauchte Adresse versehentlich ausgesprochen.
»Ach nein ... nicht Eichstädter – Heilbronner Straße.«
»Ja gut, Heilbronner, ich hab's ja notiert,« sagte Frau Lohrer.
»Bringen Sie meine Sachen, ich will dann gleich hin ...«
Sie mußte sich zusammennehmen ... Der Doktor hatte bis morgen
abend Zeit ... nach dem Tee bei der Ministerin.
Es war schwer, mit den stechenden Schmerzen in der Brust, gegen
den Wind anzukämpfen, und in den Gliedern lag's ihr wie Blei.
Alle melancholischen Schauer eines grauen Novembernachmittags
gingen um ... Der erste Schnee war in losen Flocken gefallen und
auf dem Pflaster zu schmutzigem Wasser geworden. Schwere,
bleifarbene Wolken drückten sich immer tiefer in die Straße hinein,
und ein leise winselnder, müder Wind versuchte hier und da
vergebens, sie aufzujagen.
Es war noch früh, aber trübe Dämmerung verwischte die Umrisse
der Häuser und Bäume. Menschen und Gefährte bewegten sich wie
Schatten.
Von aufspringenden und wieder verschwindenden Gedanken
gequält, ging Frau Erika ihres Weges, und weiter, als sie beabsichtigt
hatte. Mitten in der Potsdamer Straße fiel ihr ein, daß sie mit ihren
Brustschmerzen eigentlich gar nicht gehen durfte, und sie stieg in
ein Auto.
 Die zuletzt gehörte Adresse klang noch in ihren Ohren, und sie
nannte sie: »Eichstädter Straße 9.«
Die Gegend, in die sie kam, war ihr fremd.
Phantastische Formen sprangen aus dem zitternden Nebel auf.
Hier glitzerte ein Goldbeschlag aus massigen Steinen heraus – da
grüßte eine fratzenhafte Maske mit aufgerissenem Rachen von
einem hohen Torpfeiler herunter ... dort hob sich eine schwere
schmiedeeiserne Einzäunung, hinter der Zypressen wuchsen, und
nun ein Goldgitter ...
Wo war sie? ... Das Auto hielt. Sie zahlte mechanisch.
Aus dem Eingangstor des Hauses, vor dem sie stand, fiel ein
breiter, blutroter Schein auf das nasse Pflaster und rang mit dem
blendenden Lichte einer großen elektrischen Kugellaterne, die eben
aufflammte.
»Alles Neubauten,« sagte ein Gedanke in dem fiebernden Hirn der
kranken Frau. Und weiter:
»Wie bin ich hierher gekommen, so weit ab von meiner Wohnung
... und was will ich hier? ... Ach, das steht in meinem Notizbuch.« ...
Und Frau Erika drückte auf die Glocke.
Die Tür öffnete sich. Sie stand in einem roterleuchteten Vorraum,
an dessen Wänden ein Gewirr von weißen Arabesken, Früchten,
Masken und Putten lebendig zu werden schien ...
Und dann, während Frau Erika in ihrer Handtasche nach dem
Notizbuch kramte, kam ein Wunder: Die weiße Tür links wurde
aufgerissen – ein paar tappende Schritte ... und auf der obersten
Stufe der Treppe die herunterführte, stand ein Bübchen in weißem,
zottigem Mantel, die weiße Kappe aus dem blühenden Gesicht mit
dem blonden Kraushaar geschoben, die dicken Händchen gespreizt
... und mit Augen, die ganz weit vor Verwunderung hinunterblickten
... mit Augen!!
 Wie kam ihr toter Junge hierher?!?
»Mein Kind ... mein Bub' ... mein alles ... wo warst du so lange? ...
wo haben sie dich versteckt? ... liebes ... liebes ...«
Sie war oben und riß das Bürschchen an sich.
Das war einen Augenblick stumm vor Schreck. Dann fing es zu
strampeln und zu schreien an.
»Loslassen ... loslassen ... Mutti ... Mutti!«
»Was gibt's denn?«
In der offenen Tür stand eine schöne, lebenstrotzende Frau, im
eng anliegenden Schneiderkleid, zum Ausgehen fertig.
Das blühende, breite Gesicht unter dicken, rotbraunen Haarwellen
leuchtete vor Gesundheit. Jeder Muskel des starken Körpers schien
von Kraft gespannt und geschwellt.
»Setzen Sie mal sofort den Jungen hin,« rief sie laut und grell.
»Was bedeutet denn das? ... Ah ... Sie?!! ... Sie?!! ...«
Ihre Stimme überschlug sich. In den schmalen, glitzernden,
grauen Augen brannte eine vernichtende Feindseligkeit auf ... das
ganze junge Weib wand sich in Verlegenheit und giftigem Haß.
Frau Lohrer achtete nicht darauf.
Sie hatte den Buben zur Erde gleiten lassen und stand weiß und
stumm da.
»Verzeihung,« sagte sie dann. »Er gleicht zum Verwechseln
meinem verstorbenen Kinde« ...
Die schöne, kraftvolle Person hob das Bürschchen hoch, drückte
es an sich und lachte laut und höhnisch auf.
Dann trat sie hastig in die Wohnung zurück und schloß die Tür
hinter sich zu.
 Frau Erika stand noch einige Sekunden da und starrte den
Verschwundenen nach.
Der Portier öffnete sein Fenster und kam dann heraus.
»Zu wem wünschen gnädige Frau?« fragte er höflich.
Frau Erika schüttelte den Kopf und sagte nur: »Nach Hause.«
»Soll ich Auto besorgen?«
Sie nickte, achtete nicht darauf, wie lange sie wartete, und
bemerkte auch das verwunderte Kopfschütteln des Portiers nicht, als
sie ihre Adresse angab.
Die Augen fielen ihr zu, und sie fuhr aus dem Dämmerzustand erst
auf, als der Wagen vor dem Hause in der Bendlerstraße hielt.
Wie im Schlaf ging sie hinauf, vorbei an der treuen Lina, die ihr
beim Ablegen helfen wollte, und in ihr grünes Zimmer.
Eine beklemmende Angst nahm ihr den Atem. Sie wußte nicht
mehr, wo sie war. Sie konnte nicht mehr Traum und Wirklichkeit
unterscheiden – nicht mehr Leben und Sterben ...
Ja ... das blühende Leben hatte die Tür vor ihr zugeschlagen und
ihr Kind im Arm davongetragen, und sie ... sie stand hier ganz allein,
ganz fremd. Sie brauchte etwas, um sich daran zu halten ... denn sie
fiel um ... irgendwohin in die Finsternis ... Aber da war nichts ... kein
Mensch ... kein Ton ... kein Bild ... Nur Schönheit, bunter
Farbenzauber, fremdes Gerät, an das sich kein Erleben knüpft ...
... Doch! ... Der Matrosenkopf stand noch von vorhin auf dem
kleinen Tischchen neben der Chaiselongue und grinste ...
Nach ihm streckte sich ihre Hand aus.
Da fiel er zur Erde, gegen ein bauchiges Bronzegefäß, und
zerbrach in ein paar große Stücke ... Frau Erika griff voll Entsetzen
nach dem einen – es war ein Ohr, mit dem blanken Ohrring darin –,
dann warf sie sich auf die Chaiselongue und fing fassungslos zu
weinen an.
Nicht, wie ein Mensch weint, dem ein großer Kummer das Herz
getroffen hat. Es war ein Winseln, wie das des müden Windes
draußen, der die grauen Wolken nicht verjagen konnte. Ein
jammervolles, grauenhaftes Weinen.
Die treue Lina beugte sich verständnislos zu der Liegenden.
»Fehlt der gnädigen Frau etwas?«
»Mein einziges, ... mein letztes« ...
Nur eine matte Handbewegung nach den Scherben am Boden.
Achselzuckend sah die Jungfer darauf nieder.
»Beruhigen sich gnädige Frau doch ... gnädige Frau schaden sich.
Herr Doktor ist auch schon zu Hause und kann jeden Augenblick
hereinkommen« ... Das jammernde Weinen hörte nicht auf. Leise
und eintönig klagte es weiter.
Die treue Lina stand ratlos daneben und ließ in Gedanken die im
Hause verkehrenden Herren an sich vorübergehen.
So irgendeine heimliche Geschichte mußte doch dahinter stecken!
... Was konnte nur geschehen sein? ... Sie hatte schon immer
gedacht ... diese Stillen ... Ob sie nun nicht doch den Herrn rief?
Da schlug matt draußen das Telephon an.
Sie ging schnell hinaus und nahm mit überraschtem Aufschrei die
Meldung entgegen.
Dann klopfte sie, nachdem sie die Bluse zurechtgerückt und den
Rock über den Hüften heruntergestrichen hatte, an die
Arbeitszimmertür des Herrn Dr. Lohrer.
 Diese Stunde nun war die, in der er durchaus ungestört zu sein
wünschte, – in der er die Geschäftsdispositionen für den
übernächsten Tag ausarbeitete, – in der allein er auch vor sich selbst
alle ästhetischen und gesellschaftlichen Rücksichten wegwarf und
seiner eigentlichen Natur die Zügel schießen ließ.
Sogar die treue Lina hatte um diese Tageszeit doppelt tadellos zu
sein, wenn sie, im Notfall, ihn an seinem Schreibtisch aufsuchen
mußte.
Heute trat sie etwas hastiger ein als sonst.
»Darf ich Herrn Doktor stören?«
»Zum Kuckuck ... nein! Was gibt's? ...«
»Gnädige Frau liegt auf der Chaiselongue und weint ganz
furchtbar.«
Doktor Lohrer drehte sich auf seinem Stuhl um. »Und?« ... fragte
er eisig.
»Sie sagt, weil sie den gräßlichen Puppenkopf zerschlagen hat ...
Aber ...«
»Aber? Nun? ...«
Die treue Lina trat einen Schritt näher:
»Aus der Eichstädter Straße telephoniert man eben ... die gnädige
Frau ist in der Wohnung gewesen, – und es scheint, – sie hat den
Bubi fortnehmen wollen ...«
Doktor Lohrer sprang auf.
Seine hohe, schlaffe Gestalt streckte sich, und sein schmales
Fuchsgesicht bekam den gefürchteten Raubtierausdruck.
»Hallo!!«
Und er ging unverwandt in das Zimmer seiner Frau.
 Der Anblick, der sich ihm bot, war nicht geeignet, seine Empörung
über die verbrecherische Geschmacklosigkeit, von der er eben
erfahren hatte, zu besänftigen.
Frau Erika lag mit verschobenen Kleidern, noch in Hut und Mantel,
mit niedergesunkenem Kopf über der Chaiselongue und winselte wie
ein gepeinigtes Tier.
»Erika,« ... rief Doktor Lohrer in fassungslosem Zorn.
Sie rührte sich nicht.
Er rüttelte sie an den Schultern. Der Körper gab nach, aber sie
öffnete die Augen nicht, aus denen unaufhörlich die Tränen
hervorquollen.
Er griff nach der herabhängenden Hand. Sie war behandschuht,
aber er fühlte die Glut durch das Leder. –
Es war keine Frage, – seine Frau fieberte. Sie war krank, kränker
leider, als sie es in Anbetracht der morgigen Sitzung im
Unterrichtsministerium und der gesellschaftlichen Aussichten, die
sich für den Winter daran knüpften, sein durfte. Und es war auch
nicht an der Zeit, um Taktlosigkeiten, die in solchem Zustande
begangen worden waren, zu rechten.
Mit Hilfe der treuen Lina wurde Frau Erika der Straßenkleidung
entledigt. Eine sanfte Gewalt mußte angewandt werden, als die
Hand, die den Scherben des Matrosenkopfes fest umklammert hielt,
von dem Handschuh befreit werden sollte.
Dann erst durfte nach dem Arzt telephoniert werden.
»Wie konnten Sie die gnädige Frau in einem solchen Zustande
ausgehen lassen?« ... schrie Doktor Lohrer die treue Lina an.
Sie wollte aufbegehren. Aber ein Blick in das verbissen grübelnde
Gesicht und die zornigen Augen belehrten sie, daß dies im
Augenblick unangebracht war.
 »Gnädige Frau ist doch nicht leicht zu beeinflussen ... bei aller
Güte ...« wagte sie zu bemerken. »Auch mit dem häßlichen
Porzellankopf ...«
Er winkte abwehrend.
»Telephonieren Sie sofort nach der Eichstädter Straße, daß das,
was Sie vorhin sagten, unbedingt ein Irrtum sein müsse ... die
gnädige Frau läge mit hohem Fieber zu Bett ... Ich lasse das sagen
... verstehen Sie? ...«
Natürlich verstand die treue Lina und richtete die Bestellung aus,
während Doktor Lohrer, peinlich erregt, neben seiner
zusammenhanglos murmelnden Gattin den Arzt erwartete. – – – – –
Es war eine doppelseitige Lungenentzündung, bei dem schwachen
Herzen und der zarten Konstitution der Kranken von vornherein eine
böse, fast aussichtslose Sache.
Herr Doktor Lohrer stand anfangs ungeduldig und voller
Erbitterung und Staunen an dem Bette seiner Frau und spielte in
Gedanken mit allen Möglichkeiten – aber er spielte.
Daß das Äußerste in Wirklichkeit eintreten könnte, fiel ihm noch
nicht ein zu glauben. Noch empfand er, was geschah, als eine ihm
zugefügte Beleidigung, sogar als die Lage schon fast hoffnungslos
war.
Der harte Kampf dauerte länger, als man gedacht hatte. Der ganze
Apparat, der der Krankheit zu Leibe geht, wenn sie in ein reiches
Haus eingebrochen ist, war in Tätigkeit.
Der Wagen des berühmten Spezialisten hielt morgens, mittags und
abends vor der Tür. Der vornehme Hausarzt wich kaum von dem
Krankenlager, und ein jüngerer Kollege war zur Hand, wenn er seiner
anderen Praxis nachgehen mußte.
Im Krankenzimmer selbst waltete eine barmherzige Schwester mit
trüben Augen und fest zusammengezogenem Munde ihres Amtes.
Was die Medizin an Hilfsmitteln geben konnte, war in Anwendung,
aber das Fieber, das an dem zarten Körper fraß und schüttelte,
übertrumpfte alle Sorgfalt, alle Bäder und alle Medikamente.
Atemnöte und Beklemmungen füllten die langen, bangen Stunden ...
und wenn die Temperatur nur ein weniges zurückging, wollte das
Herz seinen Dienst nicht mehr tun.
Nach mühseligem Kampf gegen die zunehmende Schwäche kam
der Augenblick, in dem die Ärzte andeuteten, daß man, wenn nicht
ein Wunder geschähe, in kurzem auf das Schlimmste gefaßt sein
müßte ...
Herr Doktor Lohrer, der seinen vollen Anteil an der Pflege
aufopfernd Tag und Nacht getragen hatte, nahm die Botschaft
stumm und mit gebotener Fassung entgegen und achtete nach wie
vor auf die peinlich genaue Ausführung der ärztlichen Anordnungen.
Inzwischen lief er ruhelos zwischen dem Krankenzimmer und
seinem Schreibtisch hin und her.
Auf einer dieser Wanderungen, nachdem er minutenlang das arme
zuckende und gedunsene Gesicht der Sterbenden kummervoll
betrachtet hatte, ging er zu dem Marmorporträt in seinem Zimmer
hinüber, das vor zwei Jahren in Brüssel Lambert von ihr geschaffen
hatte.
Aus dem, wie es die Mode betont, teilweise roh gebliebenen
Marmor, hob sich das feine Köpfchen Erikas mit dem überzarten
Halsansatz. Ein träumerisch scheues Lächeln, eine kleine
melancholische Ironie belebten die regelmäßigen Formen.
Ja, d a s war die Gattin von Lovis Lohrer, das war das Bild der
Frau, die seinem schönen Hause den Stempel zartester Ästhetik
aufgedrückt hatte, das war das Bild, vor dem er erleichtert
aufatmete. Von dem der armen Leidenden, die schmerzentstellt,
Vernichtung in den verzerrten Zügen, da drüben kämpfte, wendete
sich etwas ihm ab ...

Draußen kroch der Tag langsam und grau heran.

Da hörte auf dem Sterbelager das stoßweise Atmen und Röcheln
plötzlich auf.
Die Schwester schreckte zusammen und beugte sich über ihre
Kranke.
Die lag, plötzlich weiß und schmal geworden, mit großen,
schimmernden Augen da.
Die Schwester trocknete ihre feuchte Stirn und nahm ihre Hand.
»Muß ich sterben?« flüsterte Frau Erika heiser, an der Pflegerin
vorüberblickend.
Die sah sich mit scheuem Auge um, und als auch im Nebenzimmer
alles still blieb, sagte sie feierlich und laut:
»Ja! ... Wir wollen beten!« ...
Frau Erika antwortete nicht.
Sie richtete sich mühsam auf und flüsterte Unverständliches vor
sich hin.
»Das ist ja alles nicht wahr,« sagte sie dann plötzlich ganz klar.
»Wenn ich leben bleibe, dann will ich wirklich ... wirklich ... nicht
bloß zum Schein ... nicht hindämmern« ...
»Nach der Dämmerung bricht der leuchtende Tag des Herrn an,«
sagte die Schwester, »der leuchtende Tag, der Tag der Erlösung. Der
Friede ...«
 »Finster ... Finster ...« ächzte Frau Erika und griff mit zuckenden
Händen um sich.
Dann taumelte sie in den Abgrund, in dem Schein und Sein
versinken.

In dem kleinen Wintergarten, der sich an das grüne Wohnzimmer

schloß, unter weißen Rosen und weißem Treibhausflieder ruhte nun
die Herrin dieser Räume noch eine kleine Stunde, ehe sie unter die
verschneite Erde gebettet wurde.
In einer Stunde nämlich versammelte sich der Bekanntenkreis,
und dann kam auch der Geistliche, die Verstorbene für die letzte
Fahrt einzusegnen, die sie nach der thüringischen Heimatstadt
antreten sollte, um neben ihrem Kinde zu schlafen, wie sie es wohl
gewünscht haben würde, wenn ihr in ihrem geräuschvollen Leben
der Gedanke an ewige Ruhe je gekommen wäre.
Herr Doktor Lohrer ging durch alle Räume, um mit dem Blick des
Herrn festzustellen, ob alles der Sachlage und seinen Anordnungen
gemäß auf der Höhe wäre.
Zuletzt kam er in den Wintergarten und warf einen prüfenden
Blick auf die Tote, deren leise Stimme noch in diesem Raum zu
klingen schien.
Er hatte sich mit dem Ungeheuerlichen, das über ihn hergefallen
war, als Mann von Selbstbeherrschung äußerlich abzufinden gesucht.
Aber seine Gestalt sah sehr zusammengefallen und das Fuchsgesicht
spitz und gelb aus.
Er schloß einen Augenblick die Augen, deren Lider rot und
geschwollen waren. Als er sie wieder öffnete, fiel ihm die rötliche
Orchidee in den starren Händen der Ruhenden auf, und er überlegte,
ob dieser einzige Farbfleck die Harmonie des weißgrünen Bildes
herabsetzte oder erhöhte. Er bemerkte auch, daß irgend etwas um
das holde, friedvolle Gesicht nicht stimmte, es leer scheinen ließ ...
Natürlich! Wie hatte er es übersehen können! Die weiße Locke, die
viel bewunderte, fiel ja nicht in die Stirn wie im Leben. Der Friseur
hatte sie ungeschickterweise versteckt. Er fuhr mit spitzen Fingern in
das Haar und zog sie vor.
Aber sie hatte das Flockige verloren und lag rauh und ohne Glanz
da.
Welch ein Glück, daß er im letzten Augenblick das noch ändern
konnte!
Er rief nach der treuen Lina, die in angemessener Trauerhaltung
nach kurzem Schaudern mit der Brennschere die gewohnte Ordnung
herstellte.
Den scheuen Blick, mit dem sie aus zitternden Lidern ihren Herrn
streifte, bemerkte er nicht.
Er winkte ihr, hinauszugehen, und dann nahm er doch die blaßrote
Orchidee fort, die »wie ein Tropfen Lebensblut das Bild des Todes in
seiner Absolutheit störte.« So dachte er.
Er legte sie auf den Kübel der Latanie, die sonst über die
Chaiselongue im Nebenzimmer ihre großen Blätter hängen ließ ...
Die Blume fiel auf einen Scherben, ein rotes Ohr mit einem
blanken Ring darin. Vor einigen Tagen hatte man ihn der
fieberglühenden, jetzt erstarrten Hand entrissen und ihn auf den
Platz geworfen, auf dem er achtlos liegen geblieben war.
... Und nun konnte die Trauerfeier vor sich gehen. Die
Wachskerzen, die Doktor Lohrer selbst anzündete, legten ihren
klaren, gelblichen Schein auf ein Bild von unbeschreiblicher,
ruhevoller Schönheit und Poesie.
Er stand davor voller Bewunderung und Rührung. Mit einem
Gefühl von Dankbarkeit streichelte er die eisigen Hände und
rechnete in Wehmut und Güte mit der Toten ab.
 »Sie hat ihren Zweck erfüllt ... sie war der Schmuck meines
Lebens ... Vielleicht durfte sie nicht hinwelken ... um mir ein
unvergeßliches Bild zu hinterlassen ... Aber auch ich hatte sie weich
gebettet nach ihrem traurigen Jugendschicksal ... in Glück und Glanz
... Nicht jeder ... aber gleichviel ... es ist hart ... bitter hart ...«
Nach einem letzten trüben Blick auf die Ruhende richtete Doktor
Lohrer sich straff auf und dachte an seine Pflicht.
Aus den Nebenräumen drang Stimmengemurmel. Er schob den
Vorhang zur Seite – – und mit noch feuchten Augen, war das erste,
was er leise befriedigt wahrnahm –, der weiße Spitzbart des
Unterrichtsministers ...
 Unter gleichem Winde

Gerade als die buntfarbigen Laternen in der nebeligen

Dämmerung des Novemberabends die ganze Tauentzienstraße
hinunter unnatürlich groß aufflammten, sprang eine Dame an der
Haltestelle der Kaiser-Wilhelm-Gedächtniskirche von einem Wagen
der A-Bahn, ehe er noch vollständig stillstand. Ein großgewachsener,
hagerer Herr, der anscheinend mitfahren wollte, kam in ihren Weg
und streckte höflich den Arm aus, um sie zu stützen. In der
Heftigkeit des Sprunges aber taumelte sie gegen ihn, und eine aus
dem Mantel herausfliegende Lorgnonkette hängte sich so fest an den
Knopf seines Überziehers, daß er sie nicht schnell genug losmachen
konnte und den Wagen, den er hatte benutzen wollen,
vorüberfahren lassen mußte.
»Pardon – wie ärgerlich!« sagte die Dame und zog an der Kette.
»Wollen gnädige Frau vielleicht bis zum Schaufenster dort treten,
damit wir in dem helleren Licht die Schnur, oder was es ist, lösen
können, ohne sie zu zerreißen?«
Die Dame fuhr zusammen und sah ihm ins Gesicht. Sie hatte eine
kleine und zierliche Gestalt, rasche, lebendige Bewegungen, und ihre
Farben schienen hinter dem Punktschleier jung und rosig, aber die
Art ihrer eleganten Straßenkleidung zeigte doch auf den ersten Blick,
daß sie mehr auf Würde als auf Jugendlichkeit Anspruch zu machen
hatte.
 Sie standen nun in der strahlend weißen Beleuchtung der
Tapetenhandlung und sahen einander an, ohne an die Kette zu
denken, prüfend und voll ängstlichen Staunens.
»Ist das möglich,« sagte die Dame leise und riß mit einem Ruck
ihre Kette los, »Doktor Ender?«
Er hob den Hut und fuhr sich über die kahle Stirn. »Ja, gewiß. Und
Sie? Wie ich Sie zu nennen habe, weiß ich nicht einmal. Man hat mir
vor Jahren erzählt, daß Sie sich nach dem Tod von Major Splettner
wieder verheiratet haben.«
Sie nickte. »Frau von Betzwold ... Irmgard Betzwold ...«
Ein nervöser Zug, der wie ein verzerrtes Lächeln aussah, zuckte
um seinen Mund.
»Jawohl ... Irmgard! ... Leben Sie denn hier?«
»Ja, seit langem. Mein Mann ist Beamter. Geheimrat – im
Verkehrsressort ... Und Sie?«
»Ich halte mich seit mehreren Jahren hier auf.«
Sie waren ein paar Schritte weitergegangen und blieben nun
wieder stehen. Fragende, verstehende, überquellende Blicke senkten
sich ineinander.
Die Frau schüttelte zuerst den Bann des Schweigens ab, der sich
auf sie gelegt hatte.
»Da vermeidet man sich ein halbes Leben lang, und dann kommt
solch ein närrischer Zufall und kettet einen sozusagen wieder
aneinander ... Wollen wir eine Viertelstunde zusammenbleiben?«
»Gewiß,« sagte er. »Es wäre unnatürlich, wenn wir uns jetzt mit
höflichem Gruß trennen wollten. Wo befehlen Sie?«
»Möchten Sie ein Stück mit mir gehen? Ich wohne in der
Leibnizstraße und wollte ohnedies zu Fuß nach Hause.«
 Er schwieg erst und deutete dann auf die Menge der Menschen,
die beide Seiten des Kurfürstendamms hinauf und hinunter strömte,
schwatzend, eilend oder schlendernd und gegeneinander drängend.
»Können wir nicht eine Viertelstunde irgendwo ungestört sitzen?«
fragte er. »Ich weiß hier in einer Nebenstraße ein kleines Restaurant,
in dem man um diese Zeit sicher niemand trifft.«
»Nein,« sagte sie, ein wenig lächelnd. »Es dürfte doch
befremdend wirken, wenn zufällig jemand von meinen Bekannten
mich in so einem Lokal sähe. Dagegen können wir hier in die
Konditorei eintreten. Da kennt man mich – wir sitzen in dem Erker
da – sehen Sie – vor aller Augen und doch ganz allein.«
Er musterte sie einen Augenblick verwundert, als ob er fragen
wollte: Was fürchtest du denn noch? Sie verstand und antwortete
auf die stumme Frage: Nein, nein. Sie mache durchaus Gebrauch
von dem Recht ihrer weißen Haare – aber in dem Beamtenstaat, in
dem sie lebe, wäre alles gewissermaßen numeriert, die Leute, mit
denen man umginge, die Orte, die man besuche. Übrigens hätte sie
auch aus den Erfahrungen ihrer früheren Jahre gelernt, etwas wie
Schutz in einer umzäunten Lebensenge zu finden ... Sie könne gut
mit einem Jugendbekannten in einer vornehmen, großen Konditorei
zusammensitzen – in einer obskuren, kleinen Restauration, die sie
sonst nicht beträte, würde es aussehen, als ob sie mit ihm über wer
weiß was zu reden hätte ...
Sie sagte das lächelnd, im Eintreten; und sich geschickt durch die
enggestellten Tische windend, dirigierte sie ihn zugleich in den
vorhin bezeichneten Erker, der durch zwei Goldsäulen von dem
großen Raum geschieden war.
Und nun saßen sie einander gegenüber. Ein Paar Tassen zwischen
sich, von dem faden Geruch der süßen Backware, des Kaffees, des
Grogs eingehüllt, von dem leisen Rauschen der Zeitungsblätter in
den Händen der ringsumher Lesenden, von dem Kommen und
Gehen der Gäste, von durcheinanderhallenden Gesprächsbrocken
umgeben.
 Doktor Ender hatte sich aufgestützt und ließ den kahlen Kopf
hängen. Frau von Betzwold nestelte an dem Schleier, musterte
zerstreut und unruhig das Publikum und wandte sich dann, in den
Schatten der Säule rückend, ganz dem Schweigenden zu.
»Wir müssen aber die kurze Zeit, die wir uns schenken, ausnützen
... Erzählen Sie zuerst von sich, lieber Freund! Was haben Sie in all
den langen Jahren angefangen?«
Der verbitterte und traurige Zug um seinen Mund vertiefte sich,
und das nervöse Zucken zitterte sekundenlang über eine Hälfte
seines Gesichts.
»Ich habe nicht viel Tatsächliches zu erzählen ... Mein Onkel
Farrstein – wenn Sie sich noch erinnern,« Frau von Betzwold nickte –
»starb ein paar Jahre nach – nach unserer Trennung und hinterließ
ein viel größeres Vermögen, als ich erwartet hatte. – Übrigens
machte ich damals den letzten Versuch, mich Ihnen zu nähern – ich
bekam aber meinen Brief, den ich nach Sagan schickte, wohin Ihr
Gatte doch gegangen war, als unbestellbar zurück.«
»Das wird wohl in der Zeit gewesen sein, in der ich in Sanatorien
herumwanderte – die Jungen im Korps waren – mein Mann auf
irgendeiner der Probestellungen, die er nach seiner Pensionierung in
allen möglichen Branchen suchte ... Schließlich landeten wir ja dann
doch wieder in Sagan, wo er auch starb ... Aber zu Ihnen, lieber
Freund – was fingen Sie nun an?«
»Meine Erbschaft ermöglichte es mir, die Last des traurigen Berufs
abzuwerfen.«
»Sie waren doch Lehrer aus Passion! ...«
»Nicht mehr nach unserem Erlebnis! ...«
»Und womit beschäftigten Sie sich denn? ... Sie hatten doch einen
so ungeheuren Tätigkeitsdrang....«
 »Nicht mehr nach unserem Erlebnis,« wiederholte Doktor Ender.
»Ich bin in der Welt herumgewesen, habe gesehen und erlebt, was
man als Reisender ohne Anhang und ohne Ziel erlebt ... Und zuletzt,
als mich das zu ermüden anfing – ich auch die eine Note begriffen
hatte, auf die mein ganzes Wesen – seit damals – gestimmt war –
habe ich mich in eine Tätigkeit gestürzt, die nun eine Art
Lebenszweck geworden ist ... Ich versuche nämlich, unschuldig
Verurteilten zu helfen – nach meiner Meinung ist ihr Prozentsatz ein
erschreckend hoher. – Alle großen Mordprozesse, bei denen die
Täterschaft zweifelhaft ist, durcharbeite ich mit und suche sie mit
Aufwand all meiner Kräfte und Mittel aufzuhellen. Hier und da habe
ich auch schon einen kleinen Erfolg gehabt, – die öffentliche
Meinung beeinflußt im Sinn der Gerechtigkeit. – Ich betrachte meine
Arbeit als eine Art Sühne ... Sie werden das begreifen, nicht? ...«
Die Geheimrätin sah sehr bestürzt vor sich nieder und erwiderte
nichts.
»Und Sie?« fragte er, als sie schwieg.
»Ach, mit mir hat's das Leben schließlich noch gut gemeint. Wohl
als Revanche für die schrecklichen Erfahrungen ... Daß ich damals –
nachdem ich Sie verließ, an der See schwerkrank war, und von da
gleich nach Jena in eine Nervenheilanstalt geschickt wurde, haben
Sie wohl noch erfahren ... Dann haben Sie ja aufgehört, nach mir zu
fragen, wofür ich Ihnen übrigens von Herzen dankbar gewesen bin –
denn ich hätte ein Zusammenkommen nicht mehr ertragen, wie ich
auch lieber gestorben wäre, als nach Kreuzstadt zurückzugehen ...
Nachdem dann die gräßliche Geschichte dort ihre – Erledigung
gefunden hatte und ich wieder fähig war, unter gesunden Menschen
zu existieren, bin ich nach Sagan gekommen. Daß der Tod meines
Mannes, der bald darauf erfolgte, mich nicht besonders tief traf,
werden Sie begreifen ... Zwei Jahre danach lernte ich in Thüringen
meinen jetzigen Gatten kennen, und da ist dann alles Böse und
Traurige versunken, und ich bin eine recht glückliche Frau
geworden ...«
 »Und die Buben – die Zwillinge?!« fragte Doktor Ender.
»Beide vor dem Oberleutnant – prachtvoll geworden. Und meine
beiden Mädel aus d i e s e r Ehe auch liebe, schöne Geschöpfe ... Ich
bin eine sehr stolze Mutter – und, wie gesagt, ich habe allen Grund,
zufrieden zurück und wohl auch in die Zukunft zu sehen.«
»Irmgard Splettner,« sagte Doktor Ender nach kurzem Schweigen,
»ich bewundere Sie. Ich bewundere Ihre Selbstbeherrschung und
Ihre Lebenskraft ... Fast noch jugendlich und blühend an der
Schwelle des Alters ... Ich habe mich nicht so bemeistern können.
Mir hat unser Erlebnis – unsere Schuld das Leben zerbrochen, jedes
Streben vernichtet ... Dabei habe ich mir noch Vorwürfe gemacht,
daß ich dich, das Weib, die schwächere, nicht stützen und trösten
konnte – und nun bist du ...«
Bei diesem »Du« zuckte Frau Irmgard zusammen und machte eine
kleine, abwehrende Bewegung.
Doktor Ender bemerkte es nicht. Er saß zusammengesunken da
und sah mit den ausgeblaßten, trüben Augen starr vor sich hin.
»Lieber Freund – wir haben, seitdem das – das Peinliche sich
ereignete, so viel erlebt und erfahren, Schlimmes und Gutes,
jedenfalls Ausfüllendes – Sie doch auch – daß jenes Erlebnis restlos,
man kann wohl sagen – verschlungen ist ... Warum jetzt noch
einmal darauf zurückkommen? ...«
»Haben Sie denn wirklich und wahrhaftig vergessen – und ohne
Gewissensqualen weiter leben können? ...«
Frau Irmgard seufzte ein wenig beklommen.
»Mein Gott, natürlich habe ich seinerzeit viel ausgestanden,
tödliche Angst vor allem – aber es ist doch auch viel geopfert
worden – alle Wünsche – und – das, ja – Sie wissen es ja am besten
– wir haben uns doch nie wiedergesehn seitdem.«
 »Ich weiß, daß wir auseinandergegangen und aneinander
vorübergeschlichen sind wie zwei Feiglinge, wie zwei Verbrecher, die
wir schließlich auch waren ...«
Frau Irmgard wurde weiß bis in die Lippen.
»Ich bitte Sie – leise! Was wollen Sie mit diesen pathetischen
Worten – mit diesem gewaltsamen Aufwecken längst verschollener
Dinge? Das war ein anderes Leben, so weit ab von dem jetzigen ...«
»Natürlich, natürlich.« Er nickte und lachte mit einem gequälten,
höhnenden Ton. »So weit ab, wie etwa das Lokal hier – von der
Wirtschaft – dem Heidekrug ...«
»Schweigen Sie!« befahl Frau von Betzwold. »Sonst gehe ich auf
der Stelle ... Ich will das nicht – ich bin fertig damit ... Wie können
Sie nur,« lenkte sie ein, als sie in sein graues, vergrämtes Gesicht
mit den trostlosen Augen sah. »Warum quälen Sie s i c h und
schließlich auch m i c h so? ...«
»Sie haben recht, es ist ganz überflüssig. Aber ich bitte Sie –
bleiben Sie. Sie mögen mich für einen sehr schwachen Menschen
halten. Aber bedenken Sie – das lebenslange Schweigen, das
Herumirren in der Welt unter Fremden, immer in der Maske des
Ehrenmanns, der man vor sich doch nicht ist – und nun plötzlich die
einzige, die einen kennt, mit der man sprechen kann über all diese
verquälte Zeit, weil sie die gleiche Last durch das Leben geschleppt
hat ...«
»Nein, nein, ich sagte schon wiederholt, ich habe das längst
abgetan ... Mein Gott – unsere gemeinsame Schuld – gewiß, es war
eine, – in meiner Welt von jetzt genau wie in der von damals – ich
war sicherlich eine untreue Frau – aber wenn man die mürrische,
grausame Strenge meines Mannes bedenkt – – und w i r zwei hatten
uns lieb – waren so jung und so froh! ... Was haben wir zusammen
gelacht und geschwärmt ... Schöne Zeiten waren es trotz
alledem!« ...
 Ja, jene Zeiten!
Durch den bläulichen Dunst, das leise Stimmengeschwirr, durch
die hastende Unruhe im Kommen und Gehen schlichen sie in den
Erker und schütteten die Erinnerungen an harmlose Freuden und
Leiden, an verschwiegenes Wünschen und erfülltes Sehnen über die
beiden Menschen, die traumverloren da saßen ...
Frau Irmgard sah ein paar längst versunkene Lebensbilder zum
Greifen deutlich vor sich aufzucken.
Das kleine Haus der Bezirkskommandantur in der stillen Straße
hinter dem Ordenstor, ihr damaliges Heim ... Major Splettner, ihr
damaliger Gatte, grämlich und verbittert wegen der zu früh
abgeschlossenen Karriere ... Seine ewig scheltende Stimme mischt
sich mit dem zwitschernden Jubel der Zwillingspuppen, mit denen
sie selbst kindlich froh herumtobt, wenn der Hausherr nicht da ist ...
Wie ein Schatten huscht der lange Adjutant über die Straße, der
vierte in dem lustigen Bund, und in der Kaprifoliumlaube des
verwilderten Hausgartens kräht er zum Ergötzen seines dankbaren
Publikums wie ein Hahn, gackert wie ein Huhn, wenn es ein Ei gelegt
hat, und läßt mit dem Mund Champagnerpfropfen knallen ...
Aber das Tollen muß aufhören, die Jungen, noch nicht sechsjährig,
sollen zu lernen anfangen, bestimmt der Major. Und da bringt eines
Tages der Adjutant seinen Freund Doktor Ender ins Haus. Er ist
Reserveoffizier bei dem Infanterieregiment, von dem zwei Bataillone
im Städtchen liegen; das legitimiert den jungen Gymnasiallehrer bei
dem Major, der ihn sonst nicht ernsthaft genug und bedenklich jung
findet ... Mutter und Lehrer bemißtrauen sich im Anfang
anscheinend, sind eifersüchtig aufeinander und beklagen sich
gegenseitig bei dem gemeinsamen Freunde. Aber auf dem ersten
Spaziergang mit ihm und den Kindern, an einem Märztag, längs den
abfallenden Ufern der raschfließenden Aller – beim Kätzchenpflücken
– stehen sie plötzlich voreinander – tief erschrocken, einander
stumm anblickend: das bist du ... das hab' ich ja nicht gewußt ...
 »Es ist sonderbar, daß man in einem Augenblick ganze Monate in
der Erinnerung durchleben kann,« sagte Frau Irmgard von Betzwold
aufatmend ...
»Ja, ich habe eben auch vieles deutlich gesehn und empfunden,
was über dem grausigen Abschluß längst vergessen war ... Vieles
Schöne und Liebe.«
»Und schließlich war es auch nicht einmal eine Schuld,« sagte
Frau Irmgard unbewußt. »Es hätte so aussehen können, wenn es je
einer geahnt hätte ... Was nahm ich ihm denn? ... Gar nichts! Ich
versteckte unser kurzes Glück vor ihm, wie ich vor seiner
Gehässigkeit jede kleinste Lebensfreude verbergen mußte ...«
»Freilich war diese Schuld eine geringfügige gegen das andere,«
sagte er. »Sonderbar übrigens, daß das, was uns zum erstenmal
einander in die Arme jagte, auch ein Mord war ... Denkst du
daran? ...«
Ob sie daran dachte ... An den unvergeßlich grauenhaften und
doch schönen Tag ...
Die Nachbarkatze hatte das einzige, was der Major auf der Welt
liebte – seinen Kanarienvogel, gefressen – und er, mit dem Burschen
gemeinsam, sie gefangen und mit einem alten Degen lebendig an
die Wand gespießt.
Sie schauderte noch heute, wenn sie daran zu denken wagte. Halb
bewußtlos vor Grauen, war sie zitternd aus der Wohnung gelaufen.
In der Abenddämmerung durch den Garten über den Wiesenweg zu
dem kleinen Haus neben dem Tannenkrug, in dem Doktor Ender
allein wohnte ...
Fassungslos war sie ihm um den Hals gefallen und hatte nicht
mehr fortgehen wollen – und war dann doch selig – als sein Weib –
unempfindlich gegen das, was sie zu Hause erwarten konnte,
heimgeschlichen ...
 »Hätten wir damals – nach jenem Maiabend, den Mut gehabt, uns
zueinander zu bekennen« – sagte Doktor Ender nachdenklich.
»Um Gottes willen,« rief die Geheimrätin. »Ohne Existenzmittel –
die Kinder in seinen Händen ... Sie selbst haben das doch damals für
unmöglich gehalten ... Ich hätte es ja auch gar nicht überlebt –
Splettner hätte mich wie jene Katze, glaube ich – doch warum diese
überflüssigen Erwägungen? ... Vier Jahre später war er tot ...«
»Und wieder ein paar Jahre später war ich ein wohlhabender
Mann – aber was half uns beiden das? Uns hatte die Nacht vom
8. September auseinandergefegt. Und doch hätte sie uns
zusammenkitten müssen, wenn man's recht bedenkt ...«
»Nein, nein, es war schon richtig so, daß wir uns nicht mehr
sahen ...«
»Angst war es vor der Welt – bei mir mißverstandenes Ehrgefühl
dazu. Darüber haben wir einen unschuldigen Menschen ins
Verderben und in einen frühzeitigen Tod gejagt. Haben Sie daran nie
gedacht? ...«
»Dieser Kellner Hake war ohnedies ein verlorener Mensch. Er hatte
allerlei Schandtaten auf dem Gewissen. Ich habe mich später
erkundigt ...«
»Aber die, wegen der er lebenslänglich verurteilt, wurde und dann
auch im Zuchthaus starb, hatte er nicht begangen. Und wir wußten
es.«
»Wir konnten es nicht genau wissen – es war immerhin
möglich ...«
»Beschönige es nicht. Sieh noch einmal das Ganze, wie es war ...«
Frau von Betzwold stützte sich auf und sah mit überquellenden
Augen in ihre Schokoladentasse, aber sie schwieg. Sie ließ die Worte
des Mannes über sich hinstreichen wie einen Wind, dem man
schutzlos preisgegeben ist.
Welcome to our website – the ideal destination for book lovers and
knowledge seekers. With a mission to inspire endlessly, we offer a
vast collection of books, ranging from classic literary works to
specialized publications, self-development books, and children's
literature. Each book is a new journey of discovery, expanding
knowledge and enriching the soul of the reade

Our website is not just a platform for buying books, but a bridge
connecting readers to the timeless values of culture and wisdom. With
an elegant, user-friendly interface and an intelligent search system,
we are committed to providing a quick and convenient shopping
experience. Additionally, our special promotions and home delivery
services ensure that you save time and fully enjoy the joy of reading.

Let us accompany you on the journey of exploring knowledge and

personal growth!

ebooknice.com