Awake Intubation: A Very Brief Guide
July 7th, 2013
by reuben in airway
Awake intubation is placing an endotracheal tube in the trachea while
the patient continues to breathe. The principle advantage over RSI is
that you do not take away the patient’s respirations or airway reflexes,
which makes the process safer in many circumstances. The disadvantages
are that the patient’s personality and movements, as well as the
patient’s airway reflexes, must be managed, which takes time, and even
when done well, the view you get won’t be as good as in
a paralyzed patient. Instrumenting the back of the throat may cause
gagging and possibly vomiting, though this is quite unlikely to lead to
clinically significant aspiration (because the patient is awake). The more difficult airway features, and the less urgent the intubation, the more likely you should intubate awake. Patients who are at high risk to vomit are not good candidates for an awake technique.
The two arms of awake intubation are local anesthesia and systemic
sedation. The more cooperative your patient, the more you can rely on
local; perfectly cooperative patients can be intubated awake without any sedation at all.
More commonly in the ED, patients will require sedation. Ketamine is
the agent of choice in most circumstances, as it sedates without
depressing respiration or airway reflexes. In somewhat cooperative
patients, 20 mg boluses, titrated to effect, work very well. In very
uncooperative/agitated patients, a full dissociative dose (1.5 mg/kg) is
an effective strategy though a brief period of apnea is usual if
dissociative doses are delivered as a bolus, and laryngospasm is a
possible complication. For those patients where raising heart rate or
blood pressure is undesirable, benzodiazepine sedation will have a less
effective but still salutary effect. Dexmedetomidine is probably a
better agent in these scenarios, but is a little tricky to use and not
available in most EDs.
Even if using full dissociative dose ketamine, do your best to
anesthetize the airway, using the steps listed in the box
above, excerpted from the ED intubation checklist.
Local is much facilitated by a dry mucosa, so the first step, if
possible, is to dry the mucosa with glycopyrolate or atropine, followed
by suction and dabbing with gauze. Once this is done, anesthesia is
delivered by nebulization, atomization (ideally using a purpose-built
atomizer like a MAD device), and drip techniques.
Once the patient is adequately anesthetized/sedated, you gently
proceed with your intubation method of choice. When you see the cords,
you can pass the tube without paralysis, place the bougie and then
paralyze, or paralyze before placing the bougie/tube. I recommend the
second option, and I also recommend that you prepare to do a full RSI,
with whatever equipment and drugs you would use in an RSI case.
When done well, awake intubation is quite anticlimactic, as the
patient simply continues to breathe, and saturation is maintained, for
as long as needed. While RSI is terrific and will work very well in most
cases, if you perform RSI on a patient who was a good candidate for an
awake technique, and it doesn’t go well, you have made a consequential
mistake. Awake technique requires little additional skill; it is
under-utilized in emergency medicine because it requires what emergency
providers often lack: patience. In this case, however, patience is well
rewarded.
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