Longer oxygen administration after surgery dose not reduce postoperative nausea and vomiting: An open label, clinical controlled study

Background

From previous studies, “intraoperative” supplemental oxygen did not seem to affect postoperative nausea and vomiting (PONV). However, less attention has been directed toward the relationship between “postoperative” oxygen administration and PONV. We have experienced some cases in which PONV was suppressed after oxygen was resupplied, and others in which PONV occurred immediately after stopping oxygen. Therefore, we hypothesized that administering oxygen postoperatively should have an antiemetic effect, and that longer postoperative oxygen administration should reduce PONV.

Methods

This study is a single-center, open label, and quasi-randomized controlled trial. Participants were patients undergoing laparoscopic gynecological surgery. They were randomly allocated to either a 1 h (1H) group or 5 h (5H) group according to their hospital ID number. The 1H group received oxygen for 1 h postoperatively; the 5H group received oxygen for 5 h. We investigated whether the duration of postoperative oxygen affects the likelihood of PONV under propofol-based general anesthesia. The primary outcome was the difference in overall incidence of nausea between the two groups.

Results

After excluding 168 patients before and after allocation, 628 patients for 1H patients and 588 patients for 5H were followed up and analyzed. The incidence of nausea was 44.1 % in the 1H group and 45.2 % in the 5H group (p = 0.73). No significant difference in early or late PONV was observed between the groups.

Conclusions

Longer-duration postoperative oxygen administration did not reduce the incidence of PONV in patients undergoing laparoscopic gynecological surgery.