Module 12
The American Society of Anesthesiologists'
Management
of the Difficult Airway Algorithm
and Explanation-Analysis of the Algorithm
Summary of the ASA Algorithm
Difficulty in managing the airway is the
single most important cause of major anesthesia-related
morbidity and mortality. Successful management of a
difficult airway begins with recognizing the potential problem.
All patients should be examined for their ability to open their
mouth widely and for the structures visible upon mouth opening,
the size of the mandibular space, and ability to assume the
“sniffing” position. If there is a good possibility that
intubation and/or ventilation by mask will be difficult, then
the airway should be secured while the patient is still awake
rather than after induction of general anesthesia. In
order for an awake intubation to be successful, it is absolutely
essential that the patient be properly prepared; otherwise, the
anesthesiologist will simply fulfill a self-defeating prophecy.
Once the patient is properly prepared, it is likely that any one
of a number of intubation techniques will be successful.
If the patient is already anesthetized and/or paralyzed and
intubation is found to be difficult, many repeated forceful
attempts at intubation should be avoided because progressive
development of laryngeal edema and hemorrhage will develop and
the ability to ventilate the lungs via mask consequently may be
lost. After several attempts at intubation, it may be best
to awaken the patient, perform regional anesthesia (if
appropriate: see Chapter 42)
proceed with the case using mask or LMA ventilation or do a
semielective tracheostomy. In the event that the ability
to ventilate via mask is lost and the patient's lungs still
cannot be ventilated, LMA ventilation should be instituted
immediately. If LMA ventilation does not provide adequate
gas exchange, either TTJV or a surgical airway should be
instituted immediately. Tracheal extubation of a patient
with a difficult airway over a jet stylet permits a controlled,
gradual, and reversible (in that ventilation and reintubation is
possible at any time) withdrawal from the airway.
Four concepts emerge from the
preceding discussion, four very important, take-home messages on
the ASA difficult airway algorithm as presented in Box 4.
BOX 4 ASA difficult airway
algorithm take home messages
1. If suspicious of trouble → Secure
the airway awake
2. If you get into trouble → Awaken
the patient
3. Have a plan B, C, immediately
available/in place = think ahead
4. Intubation choices → Do what you do
best
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