The previous studies on the influence of perioperative supplemental oxygen or generous fluid on postoperative nausea and vomiting (PONV) were inconsistent. We hypothesized in this trial that together with supplemental intraoperative oxygen and liberal fluid therapy would decrease PONV and pain.

Two hundred ASA 1 or 2 patients undergoing laparotomy and laparoscopic abdominal or gynecological surgery were randomly assigned to one of 4 groups: intraoperative FiO₂ 0.3 and crystalloid 6 ml/kg/h; FiO₂ 0.3 and 18 ml/kg/h; FiO₂ 0.8 and 6 ml/kg/h; FiO₂ 0.8 and 18 ml/kg/h. The incidence of PONV, nausea and pain scores, and amount of rescue antiemetic and analgesic drugs were studied.

Overall incidence of PONV was 38%, 50%, 48%, 44% for group 1, 2, 3, and 4, respectively. There were no statistically significant differences among the 4 groups in the incidence of PONV, degree of nausea and pain, and the amount of antiemetics and analgesics in 2, 6, and 24 h postoperatively. The number of laparotomy and laparoscopy, and gender ratio were similar among the groups.

We could not demonstrate an advantage of combination of intraoperative supplementary oxygen and liberal fluid in reducing PONV, pain, and amount of antiemetics and analgesics after intra-abdominal surgery.