Supplemental oxygen reduces the incidence of postoperative nausea and vomiting.

Postoperative nausea and vomiting (PONV) are unpleasent for patients and increase the risk of aspiration pneumonia. PONV is the leading cause of unexpected admission following planned day surgery. Despite new anaesthetic drugs and antiemetics, the incidence of PONV remains high. The incidence of PONV depends numerous factors including age, gender, obesity, anxiety, gastroparesis, history of motion sickness, previous PONV, and the duration and type of surgery. Anaesthesia related factors include premedication, ventilation techniques, and postoperative pain management. Recently, the intraoperative inspired oxygen concentration was identified as a factor that influences PONV. Among the three studies that evaluated intraoperative supplemental O2 for prevention of PONV, two found that it halves PONV while the third failed to identify any benefit. Since supplemental O2 is inexpensive and essentially risk-free, it appears preferable to pharmacologic anti-emetics for prevention of PONV in abdominal surgery.