Supplemental oxygen does not reduce postoperative nausea and vomiting after thyroidectomy

Background. Supplemental intra-operative oxygen 80% halves the incidence of nausea and vomiting after open and laparoscopic abdominal surgery, perhaps by ameliorating intestinal ischaemia associated with abdominal surgery. It is unlikely that thyroid surgery compromises intestinal perfusion. We therefore tested the hypothesis that supplemental perioperative oxygen does not reduce the risk of postoperative nausea and vomiting (PONV) after thyroidectomy. Methods. One hundred and fifty patients undergoing thyroidectomy were given sevoflurane anaesthesia. After induction, patients were randomly assigned to the following treatments: (i) 30% oxygen, (ii) 80% oxygen, or (iii) 30% oxygen with droperidol 0.625 mg. Results. The overall incidence of nausea during the first 24 h after surgery was 48% in the patients given oxygen 30%, 46% in those given oxygen 80%, and 22% in those given droperidol (P=0.004). There were no significant differences between the oxygen 30% and 80% groups in incidence or severity of PONV, the need for rescue antiemetics, or patient satisfaction. Droperidol significantly shortened the time to first meal. Conclusions. Supplemental oxygen was ineffective in preventing nausea and vomiting after thyroidectomy, but droperidol reduced the incidence.