RESUMO
OBJECTIVE: To evaluate the efficacy of antiemetic prophylaxis with ondansetron administered before major ambulatory surgery. PATIENTS AND METHOD: We retrospectively analyzed 1,881 patients (566 women, 31%) who underwent ambulatory surgery for various conditions between January and December 1993; 84% were ASA I, 15% ASA II and 1% ASA III: Mean age was 35.82 +/- 21.66 years; mean weight was 61.26 +/- 21.77 kg, and mean height was 155.13 +/- 19.27 cm. The techniques employed were total intravenous anesthesia in 64.8%, epidural in 22%, regional intravenous in 5.8%, local in 3.8%, peripheral blockade in 2.6% and intradural in 1%. One thousand thirty-three patients were premedicated with 4 mg ondansetron 30 minutes before the start of surgery; the remaining 848 received no antiemetic drug. We determined the incidences of nausea and vomiting during the 24 hours after surgery and the data were subjected to analysis of variance, covariance adjustment for quantitative variables, chi 2 test with continuity correction for nausea and vomiting. RESULTS: The incidences of nausea and vomiting were significantly lower in the patients premedicated with ondansetron. Only 36 (3.48%) of the premedicated patients experienced nausea, in comparison with 63 (7.4%) patients with no antiemetic premedication. Vomiting was experienced by 68 (6.58%) patients who received ondansetron, as compared to 112 (13.2%) patients who did not receive the drug. CONCLUSION: In our experience, administering 4 mg of ondansetron before major ambulatory surgery significantly reduces the incidence of nausea and vomiting in the immediate postoperative period.
