The effect of preoperative ondansetron on the incidence of postoperative nausea and vomiting in patients undergoing outpatient dentoalveolar surgery and general anesthesia

Abstract

Purpose: The purpose of this investigation was to evaluate the efficacy of ondansetron in controlling postoperative nausea and vomiting (PONV) when used prophylactically in patients undergoing routine dentoalveolar surgery performed under general anesthesia.

Patient and methods: This was a prospective, double-blind, randomized, placebo-controlled evaluation. Fifty adult ASA I or II patients, requiring routine dentoalveolar surgery performed under general anesthesia, without a prior history of PONV, were randomly assigned to the experimental or control groups. Ondansetron (2.0 mL = 4.0 mg) or normal saline (2.0 mL) were administered intravenously before surgery. Age, gender, type of surgery, duration of surgery, anesthetic dosages, and PONV were evaluated. PONV was evaluated at time 0 (end of anesthesia) and at 30 and 60 minutes postoperatively. Nausea was evaluated using a visual analog scale (1, not nauseous; 5, about to vomit). Vomiting was assessed as a yes or no response. At 20 to 28 hours postoperatively, PONV was evaluated via a telephone call as a yes or no response, along with the number of episodes of nausea, vomiting, or both. Means and standard deviations were calculated for age, surgery, and anesthetics, and differences were assessed using an independent samples t-test. Differences for gender between the control and experimental groups were tested by a nonparametric chi-squared test. Differences between groups for nausea and vomiting were tested with a continuity correction chi-squared test. Differences were considered significant for a P < .05.

Results: No significant differences (P < .05) were found between the PONV groups for gender, duration of procedure, or anesthetic dosages. Statistically significant differences were noted in age and the type of surgical procedures performed. No statistically significant differences (P < .05) were noted between groups for nausea or vomiting.

Conclusion: Based on the results of this study, PONV occurred in approximately 20% of patients (20% for nausea, 8% for vomiting). With the types of anesthetic agents and techniques used in this investigation, there were no significant differences between ondansetron and placebo for prophylaxis against PONV.