To the Editor:-It was with great interest that I read Dr. Larson's description of "the best treatment" for laryngospasm.  I am not only familiar with the said maneuver, but have had the opportunity to use it on multiple occasions. In my experience it only works in the semiconscious patient with supraglottic obstruction that is unrelieved by simple airway support measures. I believe that it works because the intense stimulus induces an increase in the tone of many muscle groups, including those that support the airway. This serves to enhance the effectiveness of the jaw thrust maneuver. It is highly unlikely that the stimulus directly relaxes the vocal cords because this maneuver is ineffective in the absence of proper jaw thrust. Applying significant pressure posterior to the angle of the mandible achieves the twin purpose of jaw thrust (provided the jaw is unlocked) and a pain-induced change in the level of anesthesia.
The diagnosis of airway obstruction during the perioperative period is very difficult. It is sometimes impossible to differentiate clinically between true laryngospasm and unrelieved supraglottic obstruction. Inspiratory stridor and intercostal and subcostal retractions associated with rapidly deteriorating oxygenation can be consistent with both supraglottic obstruction or laryngospasm. The diagnosis can be confirmed only by directly visualizing the vocal cords while the patient makes inspiratory efforts.
I practiced anesthesiology for 5 yr in New Delhi, India, with halothane and ether (slow wake-up times). At the time of extubation we suctioned the pharynx under direct laryngoscopic vision and then, when ready, extubation was accomplished under direct vision, noting the condition and function of the vocal cords. The blade was removed and an airway was placed. This practice taught me two important lessons:(1) unrelieved supraglottic obstruction is far more common than laryngospasm, and (2) nothing works better than a laryngoscope blade for supraglottic obstruction.
Govind R. C. Rajan, M.D.
Department of Anesthesiology; Washington University School of Medicine; St. Louis, Missouri 63110;email@example.com
(Accepted for publication March 18, 1999.)