The hemodynamic effects of local anesthetic injection into the carotid body during carotid endarterectomy.

Hemodynamic changes consisting of hypertension, hypotension, or bradycardia are commonly seen in patients undergoing carotid endarterectomy. It is a potentially serious clinical problem that may increase mortality rates or incidence of neurologic deficits. The frequency of hemodynamic alterations has been believed to be related to the proximity of the carotid sinus baroreceptor to the endarterectomized region. Consequently, intraoperative or postoperative injection of local anesthetics into the carotid body have been recommended to help offset this compensatory mechanism. However, its effectiveness has not been thoroughly studied. We examined this situation with a prospective, randomized, double-blind clinical study consisting of 99 patients. Xylocaine (short-acting anesthetic), bupivacaine (long-acting anesthetic), or saline (control) was injected into the carotid body intraoperatively. Intraoperative and postoperative hemodynamic changes were then closely monitored and evaluated. We were unable to detect a significant difference in hypotension, hypertension, or bradycardia either during or after surgery. Therefore, on the basis of this study, routine use of local anesthetic injection into the carotid body cannot be recommended.