In Reply:- Although I fully agree with the slogan that prevention is better than intervention (and that message is well embraced by the FAO2parameter in the desaturation model in my article), the slogan for my conclusion “if VEis thought to be 0, or near 0,” then “a rescue option should be instituted aggressively and early,” is that it is better to be safe than sorry. One must remember that my analysis probably underestimated the danger of severe hypoxemia by assuming complete alveolar denitrogenation (rarely achieved) and by ignoring the fact that concomitantly administered anesthetics may delay functional recovery (frequently true), result in loss of airway patency (often true), and adversely change physiologic variables (e.g., decrease functional residual capacity and cardiac output). In addition, and very importantly, I presented mean data, which means that for half of the population the danger will be greater and for half of the population the danger will be less. In the final analysis every practitioner has to ask themselves, given the boundary conditions in my article +/- 1 min, if they would be willing to simply wait for succinylcholine to wear off if there is no ventilation and no obvious likelihood there will be ventilation. A negative answer seems obvious. I would not want to try and justify injury to the patient on the basis of the myriad of arguments for increasing the margin of safety of 1 mg/kg succinylcholine brought forward by Dr. Bourke; the arguments are either not substantial (e.g., minor discrepancies in succinylcholine dosing used in the literature), agreed on (decreasing the succinylcholine dosage shortens the duration of apnea), unrealistic (use 0.20 - 0.25 mg/kg of succinylcholine), or potentially dangerous (some patients might survive breathing spontaneously [diaphragmatic movement does not necessarily equate with respiration] with a single twitch height that is only 50% of control).
Jonathan L. Benumof, M.D.
Professor of Anesthesia; University of Calfornia, San Diego; San Diego, California
