Background: Postoperative nausea and vomiting (PONV) affects 20% and 30% of patients. As many as 60%-80% patients at high risk may be affected. Dexamethasone (D) and midazolam (M) are well studied as antiemetic. Use of D can be associated with certain undesirable side effects so minimum dose is preferred. M is a routinely used premedicant. Hence, this study was designed with both D and M in high risk patients for PONV to find minimum effective dose of D.
Aims: To determine the minimum dose of D that combined with M would provide effective prophylaxis of PONV after laparoscopic cholecystectomy (LC) in patients at high risk for PONV.
Setting and design: This is a prospective, randomized double-blind trial.
Materials and methods: One hundred and fifty-five patients scheduled for elective LC were randomized to 5 groups of 31 each. Group C was given normal saline, and the rest were administered D 1 mg (group MD1), 2 mg (group MD2), 4 mg (group MD4), or 8 mg (group MD8) in combination with 0.04 mg/kg M at induction. The incidence of nausea, vomiting, severity of nausea, and the use of rescue antiemetic and postoperative pain was analyzed.
Statistical analysis: Chi-square test was used to compare incidence of study variables. Independent Student's t-test was used for continuous variables. Demographic data were compared using ANOVA. P < 0.05 was considered statistically significant.
Results: The incidence of nausea was significantly lower in group MD4 (29%) and MD8 (6%) compared to placebo group (71%) (P < 0.001) and of vomiting was significantly lower in groups of MD2 (58%), MD4 (48%), and MD8 (6%) compared with placebo (90%) (P < 0.001) at 24 h. There was significant reduction in nausea, pain severity, and incidence of use of rescue antiemetic in MD4 and MD8 groups with no discernable side effects of the drugs.
Conclusion: We conclude that 4 mg D with M and 2 mg D with M is effective for prevention of nausea and vomiting, respectively, in patients at high risk for PONV undergoing LC.
Keywords: Dexamethasone; laparoscopic surgery; midazolam; postoperative nausea and vomiting.