THE EFFECTS OF CAROTID-SINUS NERVE BLOCKADE ON HEMODYNAMIC STABILITY AFTER CAROTID ENDARTERECTOMY

Objective: To determine whether intraoperative administration of bupiv acaine reduces the incidence of hypotension after carotid endarterecto my (CEA). Design: Prospective, double-blinded, randomized controlled t rial. Setting: A single-institute, tertiary-care medical center. Parti cipants: Patients (n = 135) who were referred for CEA without prior ip silateral CEA, diabetes mellitus, or allergies to local anesthetics. I nterventions: 2 mL of 0.25% bupivacaine or 2 mL NaCl (control) injecte d by the surgeon at the carotid sinus immediately after CEA. Measureme nts and Main Results: Blood pressure and heart rate were measured befo re induction, before carotid reperfusion, 2 minutes after reperfusion, before carotid sinus injection, and every 15 minutes thereafter for 2 hours. Anesthesia was induced and maintained with fentanyl, pancuroni um, and 0.5% to 1% enflurane. Hypertension was defined as a systolic b lood pressure 30% above baseline or greater than 180 mmHg. Hypotension was defined as a systolic blood pressure 30% below baseline or less t han 100 mmHg. Postoperative incidences of hypertension, hypotension, a nd the associated use of corrective medications were compared in both groups using the chi-squared test to determine statistical significanc e. Patients in the bupivacaine group (n = 61) had a similar incidence of postoperative hypotension as controls (n = 74) but a higher inciden ce of hypertension (40% v 24%; p = 0.043). The bupivacaine group requi red vasodilators more often (33% v 18%; p = 0.04). Baseline hypertensi on and preoperative use of beta-blockers also were predictive of posto perative hypertension. Conclusions: Carotid sinus area infiltration wi th bupivacaine after CEA does not reduce the incidence of postoperativ e hypotension but significantly increases the incidence of postoperati ve hypertension. Thus, its routine use cannot be recommended in caroti d endarterectomy. Copyright (C) 1997 by W.B. Saunders Company.