Transesophageal atrial pacing reduces phenylephrine needed for blood pressure support during carotid endarterectomy

Objective: To determine whether transesophageal atrial pacing reduces pheny lephrine requirement for blood pressure support during general anesthesia f or carotid endarterectomy. Design: Prospective randomized clinical study. Setting: University hospital. Participants: Thirty-six patients undergoing elective carotid endarterectom y under general anesthesia. Interventions: Adults of either sex (n = 36) received general anesthesia us ing a standardized anesthetic regimen for elective carotid endarterectomy. Phenylephrine requirements were measured in patients having carotid endarte rectomy and randomized to phenylephrine infusion (group 1, 19 patients) or phenylephrine infusion plus transesophageal atrial pacing (group 2, 17 pati ents) to maintain systolic blood pressure within +/-20% of baseline systoli c blood pressure. Measurements and Main Results: Measurements included (1) the amount of phen ylephrine required in each group, (2) the variance of systolic blood pressu re outside the desired range, and (3) the occurrence of postoperative elect rocardiogram or myocardial enzyme changes suggesting myocardial ischemia. T he average requirement for phenylephrine was less for group 2 (0.28 +/- 0.1 6 mu g/kg/min) than for group 1 patients (0.46 +/- 0.23 mu g/kg/min) (p = 0 .02 by t-test). Conclusions: Under controlled conditions of general anesthesia for carotid endarterectomy, transesophageal atrial pacing reduced by 40% the amount of phenylephrine needed for blood pressure support and helped in the treatment of disadvantageous sinus bradycardia. Copyright (C) 2000 by W.B. Saunders Company.