[The effect of oral ondansetron in the prevention of postoperative nausea and vomiting]. / Ondansetrona oral na prevenção de náuseas e vômitos pós-operatórios.

ABSTRACT

OBJECTIVES: Not so many years ago, the incidence of postoperative nausea and vomiting used to reach 40% to 50%. More recent publications indicate that this complication still reaches considerable frequency 20 to 30%. The present study had the objective of evaluating the impact of oral administration of ondansetron on the incidence of postoperative nausea and vomiting among patients submitted to general anesthesia. METHODS: This was a prospective, randomized, controlled, double-blind study. It included 178 patients divided into two groups Ondansetron (n = 89) and Placebo (n = 89). Fast-dissolving oral tablets specially prepared for this study were utilized. The medication was administered between 60 and 30 minutes before anesthesia was induced. Factors with possible influence on the event were noted down, such as gender, age, history of dyskinesia or postoperative nausea and vomiting, smoking, type of surgery, body mass index, reversal of neuromuscular blockade using neostigmine, and the severity of postoperative pain. RESULTS: There was no significant difference between the characteristics of the groups regarding the factors annotated, except in relation to smoking and body mass index, which were greater in the Placebo group. These factors did not interfere in the analysis of the results. Postoperative nausea and vomiting were observed in 23 patients (26%) of the Ondansetron group and 38 patients (43%) of the Placebo group (p < 0.05). CONCLUSION: Ondansetron, 16 mg orally, administered before the operation significantly reduced the incidence of postoperative nausea and vomiting. The simplicity of administration and low cost of this presentation justify the choice of this administration route.