To the Editor.—Before accepting the conclusion of Dr Corson and colleagues1 that regional is preferable to general anesthesia for patients undergoing carotid endarterectomy, one should take a critical look at what general anesthesia encompasses, as opposed to what the authors choose to define as general anesthesia.
The authors' protocol for general anesthesia does not mention the use of preanesthetic medications; these medications, which are routinely used, can and do depress circulation and respiration—particularly so in the elderly, whose cardiovascular and respiratory systems may be compromised by emphysema and/or atherosclerosis. Next, the protocol states that endotracheal intubation was carried out in all patients and this usually entails the injection of two muscle relaxant drugs (first a nondepolarizing and then a depolarizing drug). It is also stated that all patients received nitrous oxide, which increases intrapulmonary shunting, and isoflurane, which mandates mechanical ventilatory support. At this point, muscular paralysis is