A patient presents in cardiac arrest, morbidly obese, her face covered in blood and vomit. As the paramedics bag her, froth sprays out to the sides. You place an oral airway and 2 nasal trumpets, while the resident pulls a jaw thrust and the ventilations get better. On a tough intubation you want the resident to have the best shot at first pass success. What can be done at the bedside?
This is a difficult airway, no doubt, but it is interesting that when difficult airway is defined as Cormack grade III (unable to visualize the vocal cords) the studies often show that a simple bedside maneuver will resolve the problem.(eg Takenaka Can J Anesth 1999) In that sense, the difficult airway can be thought of in relative terms, dependent on modifiable anatomical factors.
Richard Levitan recommends horizontally aligning the ear canal to the sternal notch as the ultimate standard. This has not been universally accepted but it does seem to offer a reasonably uniform standard.
After the initial positioning, if we encounter a problem we can reassess the anatomy:
Head: Additional elevation may sometimes improve the view (Schmitt J Clin Anesth 2002)
Neck: Extremes of extension and flexion impair the view
Cheek: Can block vision, pull it away when needed (left molar instead of right molar approach accomplishes this with the blade). (Yamamoto Anesthesiology 2000)
Jaw: Jaw thrust maneuver can open up pharynx for visualization (Corda J Anesth 2012)
Larynx: External laryngeal manipulation (Benumof J Clin Anesth 1996)
“Back up” position – partially sitting up may improve the view (Khandelwal Anesth Anal 2016)
The bottom line is that during a case, any of the variables might need to be manipulated, and the emergency physician should be prepared to try any of these. New ideas continue to emerge, including the idea of rotating the head (Ueda 2018).
The resident fails on the first attempt, but realizing the folds of soft tissue are part of the problem, the attending physician asks that the pannus and soft tissue be retracted. This retracts the tissues around the neck, and the second attempt is a success.
Take home points:
The difficult airway is by definition an anatomical problem
The anatomy of the cheek, jaw, head, neck, larynx, and thorax can often be manipulated