The Universal Emergency Airway Algorithm (1) from the 2012 4th edition of the Manual of Emergency Airway Therapy is used after the decision to intubate has been made. See Deciding to Intubate article (2) available on this blog.
This algorithm is the overall method once we have decided that intubation is necessary.
Is this patient unconscious and unreactive, near death?
The first question in the algorithm is: Is this patient near death meaning unresponsive and unreactive or in a cardiac or respiratory arrest. These patients are, Dr. Walls points out, are nearly dead or newly dead.
Unconscious and unreactive is different from simply unconscious. “Many unconscious patients are still reactive. They have normal vital signs and they could [still] bite down on the laryngoscope. We’re talking here about a patient who would be unreactive to direct laryngoscopy. If I put a direct laryngoscope into this patient’s mouth or a video laryngoscope or started to do any other airway procedure on this patient, would they react in any way?
If the answer to this question is no, then we use the crash airway algorithm.
But if the patient is not unreactive and unresponsive, then we ask:
Is this patient going to have a difficult airway?
To decide if it is going to be a difficult airway we use our memory aids (LEMONS, MOANS, RODS, and SMART) to help decide. The four pneumonics are discussed in in the book and help alert us to difficulty with direct laryngoscopy, difficulty with bag mask ventilation, difficult for placement of an extra glottic device, or a difficult cricothyroidemy.
If using these mneumonics we answer yes to the question “Is this patient going to have a difficult airway?”, then we go to the difficult airway algorithm.
If the answer to the question is no, then we are going to perform rapid sequence intubation and so we go to the rapid sequence algorithm. We perform rapid sequence intubation in this case because it is the safest and fastest way to gain control of the airway (and remember, we’ve already decided that the patient needs endotracheal intubation).
There are two ways to end up at the failed airway algorithm. And first we have to be able recognize that we are now at the failed airway algorithm.
The first way is to be unable to maintain the patient’s oxygenation. The second way to fail is for an experienced operator to be unable to intubate with three attemps.
“If the original technique fails [whether crash airway algorithm, difficult airway algorithm, or rapid sequence intubation algorithm], we have a failed airway and we use the failed airway algorithm.”
(1) The algorithm is from the book, but the quotes are from Dr. Wall’s lecture “Airway Algorithms 2012” at www.theairwaysite.com.
(2) Deciding to Intubate available at http://www.tomwademd.net/2012/04/03/deciding-to-intubate/