Background and purpose: Postoperative nausea and vomiting (PONV) is a side effect of anesthesia. Without prophylactic intervention, it occurs in about one-third of patients (10 to 60%) under general anesthesia. PONV could be more uncomfortable than postoperative pain. The aim of this study was to compare the efficacy of ondansetron and dexamethasone in reducing nausea and vomiting after laparoscopic cholecystectomy.

Materials and methods: A randomized double blind clinical trial was performed and 90 patients (in Imam Khomeini Hospital in 2011) undergoing laparoscopic cholecystectomy were randomly allocated into three groups (n=30 per group) and received continuous intravenous anesthesia. Before induction of anesthesia the patients in first group (D) had 8mg dexamethasone injection, the second group (O) had 4 mg intravenous ondansetron and the control group (P) received 2 cc injection of normal saline. Anesthesia complications and PONV were recorded in recovery room at 6 and 24 hours following the surgery. Data was analyzed in SPSS applying Chi-square test and analysis of variance (ANOVA).  

Results: The incidence of nausea in groups P, D, and O was 66.7%, 33.3% and 33.3%, respectively. A significant difference was seen between the control group and intervention groups (P=0.01) but the difference was not significant between groups D and O. The incidence of vomiting in control group was 56.7%, and in groups D and O were 23.3% and 26.7%, respectively indicating a significant difference between the controls and intervention groups. But, no significant difference was observed between the intervention groups (group O: P=0.01 and group D: P=1).

Conclusion: In preventing nausea and vomiting after laparoscopic cholecystectomy, dexamethasone and ondansetron were found to be similarly effective.

(Clinical Trials Registry Number: IRCT201111094093N2)