Evidence Based Practice and Quality Assurance
Background and Goal of Study: Postoperative nausea and vomiting (PONV) is one of the problems feared by surgical patients. Supplemental intraoperative oxygen is found to be effective or ineffective for PONV in some studies. The mechanism by which supplemental oxygen reduces PONV remains unknown but may be related to hyperoxia ameliorating subtle intestinal ischemia secondary to bowel manipulation and/or compression. We therefore tested the hypothesis that supplemental perioperative oxygen does not reduce the risk of PONV.
Materials and Methods: Sixty seven patients (ASA I-II, age 27-60), undergoing laparoscopic cholocystectomy were enrolled in a double randomized study. Anesthesia was induced with midazolam 20 mcg kg−1, fentanyl 2 mcg kg−1, propofol 2.5 mg kg−1 and cis-atracurium 0.15 mg kg−1. Patients were given sevoflurane-remifentanyl anesthesia. The patients were randomly assigned in two groups, group 1 received 40% oxygen balance air (n = 33), group 2 received 80% oxygen balance air (n = 34). The incidence and the severity of nausea (none, moderate, severe) and the episodes of vomits were evaluated before living the PACU and then every 6th hour. Pain score was assessed with VAS score. A rescue antiemetic tropisetron 5 mg i.v. was available where nausea persisted for more than 30 min or 2 episodes of vomits. Factors known to influence nausea and vomiting were comparable in two groups. We separately evaluate nausea and vomiting scores for 0 through 6 h and 6 h through 24 h. The results were compared with Pearson chi square.
Results: There were difference in the incidence of nausea the first 6 hours (P = 0.024), in total nausea (P = 0.036). There were no statistical difference in the results for the 6th to 24th hour for nausea, for vomiting the first 6 hours and for the 6th to 24th and in total vomiting (P > 0.05).
Conclusion: Supplemental intraoperative oxygen was effective in preventing nausea but not in preventing vomiting after laparoscopic cholocystectomy.
1 Goll V, Akca O, Greif R, et al. Ondansetron is no more effective than supplemental intraoperative oxygen for prevention of postoperative nausea and vomiting. Anesth Analg 2001; 92:112-7.