The timing of Ondansetron Administration in Prevention of Postoperative Nausea and Vomiting A comparative Study for Female Patients Undergoing Laparoscopic Cholecystectomy


BACKGROUND : Postoperative nausea and vomiting (PONV) is a common distressing experience in patients followinglaparoscopic cholecystectomy. OBJECTIVE:This study was aimed at comparing the better timing of Ondansetron administration in prevention of PONV in female patients underwent elective laparoscopic cholecystectomy done under generalanesthesia.PATIENTS AND METHODS: Fifty ASA physical status I and II female patients, aged 19 to 45 years, were enrolled in this prospectivestudy to receive 4mg IV Ondansetron preoperatively (Group A), or 4 mg IV Ondansetronpostoperatively (Group B), 25 patients each. A standardized general anesthetic technique wasemployed. Any episode of PONV was assessed at 8 hours postoperative period, every 2 hours, startingat time zone 0 (at post-anesthesia recovery unit), and ending at time zone 3 ( hour 8 postoperatively).Complete response is defined as no PONV during 8 hours postoperative period. Incomplete response isdefined as developing of postoperative nausea only during 8 hours postoperative period. Failure ofprevention is defined as developing of PONV during 8 hours postoperative period.RESULTS: Complete response occurred in 60 and 64% in Groups A and B respectively. Incomplete responseoccurred in 12 and 4% in Groups A and B respectively. Failure of prevention occurred in 28 and 32%in Groups A and B respectively. CONCLUSION: There is no significant clinical difference between preoperative or postoperative Ondansetronadministration of the same dosage in both groups in prevention of postoperative nausea and vomiting.