Effect of prophylactic ondansetron on postoperative nausea and vomiting after elective craniotomy

This prospective, randomized, placebo-controlled, double-blind study was de signed to evaluate the efficacy of ondansetron, a 5-HF3, antagonist, in pre venting postoperative nausea and vomiting (PONV) after elective craniotomy in adult patients. The authors also tried to discover certain predictors fo r postcraniotomy nausea and vomiting. We studied 170 ASA physical status I and II patients, aged 15 to 70 years, undergoing elective craniotomy for re secting various intracranial tumors and vascular lesions. A standardized an esthesia technique and postoperative analgesia were used for all patients. Patients were divided into two groups and received either saline placebo (G roup 1) or ondansetron 4 mg (Group 2) intravenously at the time of dural cl osure. Patients were extubated at the end of surgery and episodes of nausea and vomiting were noted for 24 hours postoperatively in the neurosurgical intensive care unit. Demographic data, duration of surgery, and anesthesia and analgesic requirements were comparable in both groups. Overall, a 24-ho ur incidence of postoperative emesis was significantly reduced in patients who received ondansetron compared with those who received a saline placebo (39% in Group 1 and 11% in Group 2, P =.001). There was a significant reduc tion in the frequency of emetic episodes and rescue antiemetic requirement in patients treated with ondansetron; however, ondansetron did not signific antly reduce the incidence of nausea alone (14% in Group 2 vs 5% in Group 1 , P =.065). Prophylactic ondansetron had a favorable influence on PONV outc ome measures such as patient satisfaction and number needed to prevent emes is (3.5). Side effects were similar in both groups. We conclude that ondans etron 4 mg given at the time of dural closure is safe and effective in prev enting emetic episodes after elective craniotomy in adult patients.