The Difficult Airway
July 8, 2010 Leave a comment
One of the most tense moments in the emergency department is a rapid sequence intubation. The hallways of the emergency department are filled with beeping monitors, squeaking stretchers, and loud voices – and there is never a moment of silence until the paralytics and sedative medications are injected through the patient’s IV. A variety of people hover near the patient – nurses, physicians, students, techs. All attention is centered at the head of the bed. And then there is long moment of stillness. Everyone waits.
I hope that I will never lose my reverence for this moment. People can lose their lives if an airway is not successfully obtained. And the more times you miss an intubation, the more difficult it becomes to secure the airway – the blades begin to irritate the larynx and pharnyx, which results in swelling and bleeding; this ultimately leads to poor visualization of the cords.
Some of the new intubation tools used in the OR and the ED are changing the way we intubate patients – fiber optics, the GlideScope, the AirTraq. As they become more popular, the basic technique of direct laryngoscopy seems more and more like a thing of the past. An article published by EP Monthly in December of 2008 discusses some of the new trends in airway management, Tech Trends from the Exhibit Floor: Fiber-Optic Airway Management.
Many argue that it is still important to train new physicians in the technique of direct laryngoscopy so that they understand airway anatomy. However, a study published in 2009 in Anesthesiology, Laryngoscopy via Macintosh blade versus GlideScope, indicates that the GlideScope technique yields higher success rates, 90% as compared to 51% within 120 seconds, even for people untrained in intubation.
This and other new studies (Mixed Results for Video vs Direct Laryngoscopy for Tracheal Intubations) beg the question: is there still value, for patients and physicians, of direct laryngoscopy, now that we have expanded our capabilities of video laryngoscopy? Most studies indicate that video laryngoscopy is associated better success rates on first pass and has less complications (with the exception of power failure) than direct laryngoscopy. Moreover, the studies that analyze hospital length of stay, in-hospital mortality, and discharge Glasgow Coma Scale (GCS) demonstrate no significant difference in patient outcome between the two techniques.
Anesthesiologists still argue that it is important to be adept at several different intubation methods, in order to “troubleshoot” the airway and provide one’s own back-up. The airway is one of the most frightening parts of medical resuscitation, and it is essential that we carry enough tricks up our sleeve to avoid dangerous situations.
To complicate matters, the obesity epidemic in America has had a significant impact on intubation success rates, insofar as neck circumference plays a role. Patients with a larger neck circumferences are more difficult to intubate (see Morbid Obesity and Tracheal Intubation). Obese patients are also more difficult to bag-mask ventilate because of their excessive soft tissue that surrounds the airway – this makes a “difficult intubation” situation even more tenuous.
No matter what technique we use, it is important that we are adept with several different intubation “tools,” and it is also important that we maintain our calm during one of the most anxiety-ridden moments in medicine – standing at the head of the bed, watching the monitor as a paralyzed patient rapidly desaturates, all the while knowing that this moment is critical, and that securing the airway in the shortest window of time possible is the only intervention that will save this patient’s life.