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

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.

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.

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.

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.