Page 409 - ACCCN's Critical Care Nursing

386 P R I N C I P L E S A N D P R A C T I C E O F C R I T I C A L C A R E

There are four methods described for assessing cuff Confirmation of Tube Position
inflation:
The correct position of the ETT distal end is 3–5 cm above
1. minimal occluding volume (MOV) the carina. A lip level of 20 cm for women and 22 cm for
2. minimal leak test (MLT) men should prevent endobronchial intubation, with the
3. cuff pressure measurement (CPM) proximal end fixed at either the centre or the side of the
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4. palpation. mouth. Confirmation of the ETT position is required
immediately following intubation and at regular intervals
In Australia and New Zealand, CPM is the most common thereafter as movement of the tube can occur.
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form of cuff pressure assessment, in contrast to the UK
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and North America where CPM is used infrequently. Chest auscultation is the traditional method to confirm
Cuff pressure varies with head and body position, tube ETT position. Observation of chest expansion is, however,
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position and airway pressures. The optimum frequency unreliable, as the chest may appear to rise with oesopha-
of cuff pressure monitoring is unclear; at a minimum it geal intubation. Conversely the chest may not rise with a
should be done post-intubation, on arrival in ICU and correctly positioned tube if the patient is obese or has a
once per nursing shift. A persistent cuff leak or pressures rigid chest wall. Patients with left main bronchus intuba-
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of ≥30 cmH 2 O (22 mmHg) to generate a seal should be tion may exhibit bilateral breath sounds. End-tidal CO 2
reviewed and referred to medical staff. monitoring is the ‘gold standard’ method for confirming
ETT placement. Disposable devices that change colour in
If performing MOV and MLT, aspiration should be pre- the presence of CO 2 are inexpensive and easy to use, but
vented by semi-recumbent positioning, suctioning at the may be inaccurate during cardiopulmonary resuscitation,
back of the mouth (as far back as tolerated), aspiration or if contaminated. Capnography is the most reliable
of the nasogastric tube and discontinuation of feeds technique to identify ETT placement in both arrest and
before cuff deflation. non-arrest situations. Continuous end-tidal CO 2 moni-
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toring during intubation is recommended as a minimum
standard by the College of Intensive Care Medicine of
Practice tip Australia and New Zealand. 42
If the pilot tube for the ETT is accidentally cut, cannulate the
tubing with a 23- or 24-gauge needle to reinflate the cuff and Practice tip
clamp the tubing. If using a clamp with serrations, place gauze
between the tube and the clamps to avoid further damage to Always ensure there is someone who is skilled at intubation
the pilot tube. immediately available when extubating a patient.

Endotracheal Tube Fixation TRACHEOSTOMY
The purpose of ETT fixation is to maintain the tube in Tracheostomy may be required for upper airway obstruc-
the correct position, prevent unintended extubation and tion, although it is most commonly performed for ICU
facilitate mechanical ventilation while maintaining skin patients who require prolonged mechanical ventilation.
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integrity and oral hygiene. ETT fixation methods include: The advantages of tracheostomy over endotracheal intu-
● tying cotton tape around the tube, then around the bation include decreased risk of laryngeal damage and
patient’s neck subglottic stenosis, reduced airway resistance and dead-
● taping the tube to the patient’s face using medical space which decreases the work of breathing and there-
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adhesive tape fore supports weaning, and improved patient tolerance
● commercial tubeholders of varying designs. enabling reduction of sedation. The optimum time to
perform tracheostomy remains contentious, and is often
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There is no evidence supporting a preferred method influenced by a patient’s diagnosis. 44
with each having specific strengths and weaknesses. Two
nurses are required to prevent ETT dislodgement during PROCEDURE
fixation. Although there is also no evidence to recom-
mend a preferred frequency, ETT fixation is generally Tracheostomy can be performed using a surgical tech-
changed at least daily, to allow assessment of the underly- nique (ST) or percutaneous dilatational technique (PDT).
ing skin with particular attention to the tops of the ears PDT is contraindicated in patients with anatomical
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and corners of the mouth and to facilitate oral hygiene. anomalies of the neck and serious bleeding disorders,
The ETT position in the mouth is alternated at this time. and should be undertaken with caution in patients who
are obese, have a cervical spine injury, coagulopathy, dif-
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ficult airway or require high levels of ventilatory support.
PDT is more commonly performed than ST in Australian
Practice tip and New Zealand ICUs. 45
Adhesive devices may become dislodged as facial hair grows A variety of tracheostomy tubes are available that
under them. facilitate secretion clearance, communication and differ-
ing patient anatomy. Inner cannulas (re-usable or