HEMODYNAMIC MONITORING

“It refers to measurement of pressure, flow and oxygenation of blood within the cardiovascular
system.”

Or

“Using invasive technology to provide quantitative information about vascular capacity, blood
volume, pump effectiveness and tissue perfusion.”

PURPOSES
 Early detection, identification and treatment of life threatening conditions such as heart
failure and cardiac tamponade.
 Evaluate the patient’s immediate response to treatment such as drugs and mechanical
support.
 Evaluate the effectiveness of cardiovascular function such as cardiac output and index.

INDICATIONS:-

 Any deficits or loss of cardiac function: such as myocardial infarction, congestive heart
failure, cardiomyopathy.
 All types of shock; cardiogenic shock, neurogenic shock or anaphylactic shock.
 Decreased urine output from dehydration, hemorrhage. G.I bleed, burns or surgery.
 Labile blood pressure
 haemodynamic instability
 Frequent blood sampling
 Morbid obesity (unable to fit an
 appropriately sized NIBP cuff)
 Frequent titration of vasoactive drips
 Unstable blood pressure
 Frequent ABGs or labs
 If unable to obtain Noninvasive BP

CONTRAINDICATIONS:-

 Absent pulse
 Thromboangiitis obliterans (Buerger disease)
 Full-thickness burns over the cannulation site
 Inadequate circulation to the extremity
  Raynaud syndrome
 Anticoagulation
 Atherosclerosis
 Coagulopathy
 Inadequate collateral flow
 Infection at the cannulation site
 Partial-thickness burn at the cannulation site
 Previous surgery in the area
 Synthetic vascular graft

EQUIPMENTS:-

 A CVP, pulmonary artery ,arterial catheter

 A flush system composed of intravenous solution,tubing stop cocks and a flush device
which provides for continous and manual flushing of system.
 A pressure bag placed around the flush solution that is maintained at 300 mmhg
pressure; the pressurized flush system delivers 3-5ml of solution per hour through the
catheter to prevent clotting and backflow of blood into the pressure monitoring system.
 A tranducer to convert the pressure coming from artery or heart chamber into an
electrical signal
 An amplifier or moniter which increases the size of electrical signal for display on an
occilloscope.

METHODS OF HEMODYNAMIC MONITORING

1. Arterial blood pressure
2. Central venous pressure
3. Pulmonary artery catheter pressure monitoring

1. ARTERIAL BP MONITORING SYSTEM

“Intra-arterial BP monitoring is used to obtain direct and continuous BP measurements in

critically ill patients who have severe hypertension or hypotension”
 SITE SELECTION
For adults, the preferred site selection is the following, in order of preference:

1. Radial

2. Femoral

3. Brachial

Any other sites must have the Attending physician approval.

PROCEDURE:-
 Ensure that all pre-procedure steps are taken and a time out is performed prior to the
procedure.
 Assure that pressure tubing with transducer is connected to bedside monitor.
 Wash hands and don gloves.
 Locate pulsating artery
 Cleanse area selected for arterial line placement.
 Prepare patient for puncture.
 Once an arterial site is selected (radial, brachial, femoral, or dorsalis pedis), collateral
circulation to the area must be confirmed before the catheter is placed.
 This is a safety precaution to prevent compromised arterial perfusion to the area distal
to the arterial catheter insertion site. If no collateral circulation exists and the
cannulated artery became occluded, ischemia and infarction of the area distal to that
artery could occur.
 Collateral circulation to the hand can be checked by the Allen test
 With the Allen test, the nurse compresses the radial and ulnar arteries simultaneously
and asks the patient to make a fist, causing the hand to blanch.
 After the patient opens the fist, the nurse releases the pressure on the ulnar artery while
maintaining pressure on the radial artery. The patient’s hand will turn pink if the ulnar
artery is patent.
 Stabilize artery by pulling skin taut.
 Puncture skin at 45-60 degree angle for radial artery; 90 degrees for femoral artery.
 Advance catheter when flash of blood is observed in catheter.
 Cleanse area of any blood and allow site to dry.
 Secure arterial line with tape or steri-strips and cover with a Tegaderm dressing.
 Secure I.V. tubing to prevent it from being caught and pulling on arterial catheter. If a
femoral arterial line is placed, it should be secured with a suture.
 Properly dispose of the I.V. sharps and other used materials.
 TRANSDUCER SET UP:-
 The arterial catheter is connected to the fluid filled tubing of the monitoring system.
 The transducer creates the link between the fluid filled tubing system and the electronic
system converting a mechanical signal into a waveform on the monitor.
 The transducer system must be set up correctly to ensure accuracy of the monitoring
system.
 Insert giving set attached to the transducer or transducer set, into 0.9% sodium chloride
bag, keeping end sterile, ready to pass to the staff performing the procedure.
 Ensure all roller clamps are open
 Place the sodium chloride into the pressure bag and inflate to 300 mmHg.
 Prime line by squeezing fast flush device.
 Ensure that all air bubbles are removed from the system and that all parts are primed
with fluid. Air can cause damping of the system and inaccuracy of monitoring.
 When the line is inserted and the proceduralist is ready connect to the cannula.
 Connect transducer to the Philip cable and watch for the arterial blood pressure trace
on the monitor.
 Zero + calibrate system.

ARTERIAL TRANSDUCER LEVELING AND ZEROING (CALIBRATING THE SYSTEM)

RATIONALE:
To ensure consistency and accuracy of the arterial blood pressure monitoring the
transducer must be positioned and calibrated regularly to an anatomically consistent
site. This site is called the phlebostatic axis.

LEVELING:
 The phlebostatic axis is the anatomical reference point on the chest that is used as
baseline for consistent transducer site placement. This point represents the position of
the atria and therefore reflects central blood pressure.
 The site of the phlebostatic axis is at the intersection of the fourth intercostal space and
mid axillary line.
 SCHEMA OF THE PHLEBOSTATIC LEVEL

Zeroing:-

 Zeroing is the method of calibrating the monitoring system so that the effects of
atmospheric and hydrostatic pressure are eliminated.
 Zeroing must be carried out once per shift or as required such as after
disconnection from the monitor and/or transducer cable, after re dressing the
arterial site, after accessing the arterial line for blood sample, after
troubleshooting the line, etc.

PROCEDURE FOR ZEROING

 Position patient on their back
 Patient may be positioned with the head of the bed elevated between 0-60°
 Flush the system
 Level transducer to phlebostatic axis (see figure).
 Turn stop-cock on transducer so that it is off to the patient.
 Remove cap
 Press zero on the module
 Ensure that zero appears on screen replace cap and turn stop-cock so that it is open to
monitoring and patient.

COMPLICATIONS:-
 Haemorrhage may occur if there are leaks in the system.
 Connections must be tightly secured and the giving set and line closely observed..
 Emboli Air or thromboemboli may occur. Care should be taken to aspirate air bubbles
 Accidental drug injection may cause severe, irreversible damage to the hand.
 No drugs should be injected via an arterial line
 The line should be labelled (in red) to reduce the likelihood of this occurring
  Arterial vasospasm
 Sepsis or bacteraemia

ARTERIAL PRESSURE WAVEFORM:-

2. CENTRAL LINE INSERTION

“The CVP, the pressure in the vena cava or right atrium, is used to assess right ventricular
function and venous blood return to the right side of the heart. The CVP can be continuously
measured by connecting either a catheter positioned in the vena cava or the proximal port of a
pulmonary artery catheter to a pressure monitoring system”

INDICATIONS:-

 Measure central venous pressure

 Access for resuscitation
 Selected drug administration
 Placement of pulmonary artery catheter

COMPLICATIONS

 Hematoma/vessel injury/blood loss

 Pneumothorax/hemothorax
 Cardiac arrhythmias
 Infection
Common CVP Insertion sites:-

1. Right Internal Jugular

2. Left Internal Jugular
3. Right Subclavian
4. Left Subclavian
5. Femoral

PROCEDURE:-
 Obtain verbal consent
 Position patient supine or semi recumbent to 30-45 degree elevation
 Prime pressure tubing with Sodium chloride 0.9%, close connection
 Check flushing mechanism
 Apply the pressure bag and inflate to 300mmHg
 Connect to monitor transducer cable
 Calibrate zero and level the transducer to the phlebostatic axis
 Attach extension tubing to central venous catheter, open fluid path, and adjust rate
 Close the stopcock to the patient and open to air and read the display monitor at end of
expiration
 Reopen stopcock to patient; recommence intravenous transfusion at prescribed rate
 Record the result
 Report abnormal readings or change in trends
 Monitor insertion site for infection, bleeding and disconnection.

Typical CVP waveform:-

 Three peaks

a- atrial contraction
c- Closure of tricuspid valve

v – Ventricular diastole

Two descents
x – Atrial relaxation

y- Tricuspid valve reopening

PULMONARY ARTERY PRESSURE MONITORING

“Pulmonary artery pressure monitoring is an important tool used in critical care for
assessing left ventricular function, diagnosing the etiology of shock, and evaluating the patient’s
response to medical interventions (eg, fluid administration, vasoactive medications).

Pulmonary artery pressure monitoring is achieved by using a pulmonary artery catheter

and pressure monitoring system.”

Development of the balloon-tipped flow directed catheter has enabled continuous

direct monitoring of PA pressure Pulmonary artery catheter otherwise known as “swan- ganz
catheter”.
Indications for Pulmonary Artery Catheterization:-

 Identification of the type of shock

 Cardiogenic (acute MI)
 Hypovolemic (hemorrhagic)
 Obstructive (PE, cardiac tamponade)
 Distributive (septic)
 Monitoring the effectiveness of therapy

Complications of Pulmonary Artery Catheterization:-

General central line complications

 Pneumothorax
 Arterial injury
 Infection
 Embolization
 Inability to place PAC into PA
 Arrhythmias (heart block)
 Pulmonary artery rupture

Pulmonary Capillary Wedge Pressure:-s

 Zero the transducer to the patient’s phlebostatic axis.

 Measure the PCWP at end expiration
 PCWP should not be higher than PA diastolic
 PCWP is an indirect measurement of left ventricular end diastolic pressure.
 NORMAL HEMODYNAMIC VALUES

PARAMETERS NORMAL VALUE

Stroke volume 50-100 mL
Cardiac output 4-8 L/min
Cardiac index 2.5-4.0 L/min/M 2
MAP 60-100 mm Hg
CVP 2-6 mm Hg
PAP systolic 20-30 mm Hg
PAP diastolic 5-15 mm Hg
PAWP (wedge) 8-12 mm Hg