Background and Aim of study: Postoperative nausea and vomiting is a frequent complication of laparoscopic surgery. Several randomised trials have demonstrated that a single i.v. dose of 5-8 mg of dexamethasone is as effective as 4mg of ondansetron. The efficacy of lower doses of dexamethasone has not yet been explored. We present the preliminary results of a clinical trial in women undergoing ambulatory laparoscopic gynaecological surgery.
Materials and Methods: We designed a prospective, double blind and randomised study were 99 women ASA I-III undergoing ambulatory laparoscopic gynaecological surgery under general anaesthesia received during the induction: Group D (n = 54): 4mg dexamethasone, Group O (n = 42): 4mg ondansetron. Patients suffering of diabetes or morbid obesity were considered non eligible. Both groups were comparable for age, weight, smokers, surgery's duration, other risk factors for post-operative nausea and VAS of postoperative pain. T-test was used to compare quantitative variables, Fisher's Exact test for qualitative variables, variables found significant at a level of p < 0.2 were considered in the multivariate model (logistic regression). Variables with a p-value <0.05 were considered significant.
Results: We did not found significative differences in the global incidence of nausea, vomiting and the need of anti-emetic rescue in between the two groups: nausea D = 27%, O = 36%, p = 0.38; vomiting D = 11%, O = 14%, p = 0.75 and need of rescue D = 16%, O = 21%, p = 0.61. No differences were found when the incidence of nausea, vomiting and need of rescue was analysed within the following time intervals: <1 hour from surgery, between 1 and 6 hours and between 6 hours after surgery and discharge (data not shown).
Conclusion: In this randomised study, we have not found differences between 4mg of ondansetron and 4mg of dexamethasone in the incidence of nausea, vomiting or the needs of anti-emetic rescue. Therefore dexamethasone should be recommended as the most cost-effective alternative.