Intensive Care Med (2019) 45:1632–1634

https://doi.org/10.1007/s00134-019-05777-w

LESS IS MORE IN INTENSIVE CARE

Endotracheal tube management

during mechanical ventilation: less is more!
Robert M. Kacmarek1,2* and Gianluigi Li Bassi3,4,5

© 2019 Springer-Verlag GmbH Germany, part of Springer Nature

Care of the endotracheal tube (ETT) is frequently not the Given that internal tracheal diameter ranges between
primary focus of ventilatory management of the critically 20–25 and 15–21 mm in men and women, respectively,
ill, but it does have a major impact on the trajectory of the most appropriate cuff diameter, as reported on the
recovery and complications that can extend long after ETT containing package, should be used. The application
the patient is extubated. Much of the approach to man- of positive end-expiratory pressure (PEEP), ≥ 5 cm ­H2O,
age the airway is based on long-standing assumptions, minimizes fluid movement across the cuff by counterbal-
not founded on evidence. As with all aspects of caring for ancing the hydrostatic pressure above the cuff [8].
the patient on mechanical ventilation (MV), evidenced- The use of ETTs with subglottic suction decreases VAP
based medicine should be the rule. All aspects of airway and are cost effective [9]. However, what is still unclear
care should be based on what is most appropriate for the is how best to remove secretions, through continuous or
patient. intermittent suction [10]. Preliminary data indicate tra-
The ETT is a conduit for the aspiration of contami- cheal injury with continuous suction [11]. Based on our
nated oral secretions [1]. Commercially available ETTs clinical experience we prefer intermittent suction.
cuffs are larger in size than human trachea internal diam- Airway suctioning is a very controversial topic. What
eter [2]. As a result, upon inflation, folds form on the cuff suction pressure? How frequent? How deep? What type
surface, because of cuff design or the anatomic structure of catheter? Airway suctioning is another example of
of the trachea, which transmit higher pressure against where less is more. Artificial airways should never be
the tracheal wall and establish channels through which suctioned at regular intervals, because of the risks of tra-
secretions can move via capillary action [3]. This move- cheal injury when secretions are not retained within the
ment can be minimized by good oral hygiene, removing airways [12]. Airway suction should only occur if aus-
secretions [4] and maintaining an appropriate cuff infla- cultation reveals secretions in the larger airway, the peak
tion pressure [5]. Cuff pressure needs to be maintained airway pressures increases, or the airway pressure wave-
at a level that does not cause inhibition of tracheal blood form indicates fluid in the system, i.e., sawtooth pattern.
flow, but minimizes the movement of fluid. With the Suction pressure should be regulated, in adults 120–
current ETT cuffs, because of their high-volume low- 140 mmHg [13]. Because of the trauma caused by suc-
pressure design, it is impossible to prevent this “silent tioning; desaturation, cardiovascular compromise [14]
aspiration”. Most recent clinical trials have failed to show and mucociliary clearance impairment [15], the suc-
any benefit, even with the use of the most promising cuffs tion catheter should only reach at maximum, the carina
[6]. Most guidelines suggest a cuff inflation pressure of and care should be exercised to avoid the lateral eye of
20–30 cm ­H2O [7] specifically applying the minimum the catheter from adhering to the tracheal wall, through
pressure that prevents leak at peak airway pressure. ETTs swift intermittent suction and continuous rotation of
cuffs should closely fit the tracheal internal diameter [2]. the catheter. If deep tracheal suctioning is required, this
should be performed under direct observation during
bronchoscopy.
*Correspondence: rkacmarek@partners.org Two airway suctioning approaches exist today—open
2
Respiratory Care, Massachusetts General Hospital, Boston, MA, USA
Full author information is available at the end of the article (OSS) and closed airway suctioning (CSS). OSS require
the patient be disconnected from MV before suctioning,
 1633

Table 1 Do’s and Don’ts of ETT management during mechanical ventilation

Do’s Don’ts Comments

Use ETTs comprising cuffs that closely fit human trachea Use ETTs comprising very large cuffs Guidelines recommend
Inflate ETT cuff to 20–30 cm ­H2O Overinflate or underinflate ETT cuff Guidelines recommend
Intermittent gentle suction of subglottic secretions and prompt Continuous aspiration of subglottic secretions Controversial
interruption if resistance upon aspiration is encountered
Set wall suction at 120–140 mmHg pressure Use higher suction pressures Guidelines recommend
Suction only to the level of the carina Perform deep suction without bronchoscopy guidance Guidelines recommend
Tracheal suction only when retained secretions are evident Recurring tracheal suctioning Controversial
Use single closed suction system Use single-use open suction systems Controversial
Optimize humidification of gases Use minimal humidification Guidelines recommend
Leave the patient connected to the ventilator throughout the Disconnect the patient from the ventilator and perform Controversial
suctioning procedure manual bag ventilation
Use saline instillation with obstruction only Use saline instillation prior to all suctioning Controversial
ETT endotracheal tube

while CSS are part of the ventilator circuit. Despite man- requiring ventilatory support [19]. When pressures
ufacturer’s recommendations to change these in-line CSS have been measured during manual ventilation pres-
catheters frequently, there is no evidence of patient harm sure commonly exceeds 60 cm ­H2O, establishing a pla-
if they are used until malfunctioning, normally allowing teau pressure ≥ 50 cm ­H2O increasing the likelihood of
for use of a single catheter for over 2 weeks [16]. This also ventilator-induced lung injury [20]. Most importantly,
makes intuitive sense, since we do not routinely change there is no data to support the use of manual ventila-
the ETT. This of course is a benefit to the patient, since tion preceding airway suctioning (Table 1 summary of
OSS causes substantial pulmonary volume loss, mostly recommendations).
secondary to the ventilator disconnection. In addition, Airway care is frequently a bedside technique that
CSS are cost effective. A single-use catheter through a is taken for granted, utilizing techniques that are not
swivel connector also avoids ventilator discontinuance. based on evidence with the perception that more is bet-
Routine instillation of normal saline is highly contro- ter. More, however, can cause airway injury, ventilator-
versial [17, 18]. One RCT [18] showed that the instillation induced lung injury, desaturation and cardiovascular
of isotonic saline, before tracheal suctioning decreases compromise. This is an area where additional research
the incidence of microbiological proven VAP. However, is needed. Appropriate application of a technique is
our clinical experiences differ from these results. Saline always more beneficial than the concept of MORE!
solution hardly emulsifies thick and tenacious secretions
and alternative strategies are available for airway obstruc-
Author details
tion. Furthermore, thick tenacious secretions normally 1
Department of Anesthesiology, Harvard Medical School, Boston, MA, USA.
imply inadequate humidification of ventilatory gases 2
Respiratory Care, Massachusetts General Hospital, Boston, MA, USA. 3 Division
and/or a negative fluid balance. Routine instillation of of Animal Experimentation, Critical Care Research Group, The Prince Charles
Hospital, Chermside, Australia. 4 University of Queensland, Brisbane, Australia.
saline has been associated with increased airway pres- 5
BITRECS Fellow, Institut d’Investigacions Biomèdiques August Pi i Sunyer
sure, desaturation, asynchrony and cardiovascular com- (IDIBAPS), Barcelona, Spain.
promise. In addition, the volume of fluid instilled is never
Compliance with ethical standards
recovered during the subsequent suctioning attempt,
ultimately resulting in an increase in retained secretions. Conflicts of interest
Manual ventilation before suctioning results in a loss Dr. Kacmarek is a consultant for Orange Medical and Medtronic and has
received research grants from Orange Medical and Medtronic. Dr. Bassi has no
of PEEP, pulmonary collapse and desaturation, espe- conflicts of interest.
cially with high PEEP. This is recovered by manual
ventilation with PEEP. But at what cost? It is highly Publisher’s Note
unlikely that a pressure manometer is maintained in- Springer Nature remains neutral with regard to jurisdictional claims in pub-
line while ventilating? The clinician has no idea of lished maps and institutional affiliations.
the level of pressure being applied to the lung. Lung- Received: 3 July 2019 Accepted: 3 September 2019
protective ventilation should be applied to all patients Published online: 17 September 2019
1634

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