[Premedication with intraoperative clonidine and low-dose ketamine in outpatient laparoscopic cholecystectomy]

Abstract

Objective: To determine the efficacy of premedication with intraoperative clonidine in association with low-dose ketamine to reduce the need for postoperative opiate analgesia in outpatient laparoscopic cholecystectomy.

Patients and methods: We performed a prospective study of patients undergoing outpatient laparoscopic cholecystectomy between November 2005 and November 2006. The patients were distributed randomly in 2 groups: patients in the clonidine-ketamine group received clonidine (0.15 mg orally 60 minutes before surgery) and ketamine (20-mg intravenous bolus followed by intraoperative perfusion of 20 mg h(-1)); patients in the control group did not receive this medication. Pain assessed on a verbal numerical scale, number of times rescue analgesia was required to achieve a value below 3, and adverse effects of the medication were recorded in the postoperative period.

Results: Thirty-one patients (16 in the clonidine-ketamine group and 15 in the control group) were enrolled. Rescue analgesia was required on 2 occasions by 25% of patients in the clonidine-ketamine group and on 2 or 3 occasions by 533% of patients in the control group. Adverse effects were reported by 87.5% of patients in the clonidine-ketamine group (mainly visual disturbances, sedation, and nausea) and by 46.7% in the control group. This difference was significant during the patients' stay in the postanesthesia recovery unit.

Conclusions: Patients receiving clonidine and ketamine required less additional opiate analgesia to achieve mild pain values (<3 on the numerical verbal scale) but suffered more adverse effects during their stay in the postanesthesia recovery unit. Discharge was not delayed, however.