BACKGROUND: The aim of the study was to evaluate the prophylactic effect of ondansetron on the postoperative nausea and vomiting (PONV) after a laparoscopic cholecystectomy (LC).

METHODS: In this prospective, randomized, double-blind, placebo-controlled study, 77 healthy female patients, who underwent a LC under general anesthesia using sevoflurane were investigated. Patients were randomly divided into two groups; the ondansetron group (n = 39) was administered 4 mg ondansetron, and the placebo group (n = 38) 2 ml of normal saline before the end of surgery. The incidence and severity of PONV, and the need for rescue antiemetics during the first 6 h and 24 h after surgery were evaluated.

RESULTS: The incidence of nausea in the ondansetron was significantly lower than in the placebo group during the 0-6 h (early nausea, P<0.05), but not in the 6-24 h (late nausea) postoperative period. However, the total incidence of nausea over the whole 24 h postoperative period was significantly lower in the ondansetron (36%) than in the placebo group (61%)(P<0.05), due to the low incidence of early nausea in the former. The incidence of vomiting was significantly lower in the ondansetron than in the placebo group during the 0-6 h and 6-24 h postoperative period. Therefore the total incidence of vomiting was significantly lower in the ondansetron (5%) than in the placebo group (46%)(P<0.001) over the whole 24 h postoperative period. The severity of nausea was also significantly lower in the ondansetron than in the placebo group.

CONCLUSIONS: Ondansetron significantly reduces the PONV in female patients undergoing a LC during the first 24 h after surgery, and has a greater anti-vomiting than anti-nausea effect.