Intravenous nicardipine for treatment of intraoperative hypertension during abdominal surgery

Abstract

Twenty patients, American Society of Anesthesiologists class I or II, who developed intraoperative hypertension (mean arterial pressure greater than 110 mm Hg) during abdominal surgery under balanced general anesthesia were randomly assigned to two groups. The nicardipine group (n = 10) received 5 mg of nicardipine hydrochloride, and the placebo group (n = 10) received 5 mL of nicardipine solvent injected intravenously over a 5-minute period in a blind manner. Arterial pressure was recorded for 15 minutes after the injection was started. If the mean arterial pressure did not decrease at least 10% at 15 minutes, the trial was opened and patients received 5 mg of nicardipine. None of the patients in the nicardipine group received nicardipine in an open manner, in contrast with 7 of the 10 patients in the placebo group (P less than 0.03, Fisher exact test). During both the blind period and the open trial, nicardipine induced a 34% decrease in systolic, diastolic, and mean arterial pressure. Minimal values of pressure were noted at 6 minutes; however, arterial pressure remained below the pre-nicardipine injection values and near preoperative values for 45 minutes. No severe hypotension was observed, but the nicardipine injection was stopped at 3 mg in two cases during the blind period because of the rate of pressure reduction. Heart rate remained unchanged during the decrease in arterial pressure in both groups. This study indicates that nicardipine is an effective, long lasting, and safe therapy for intraoperative hypertension during abdominal surgery.