A recent meta-analysis showed that omitting N2O significantly reduced
postoperative vomiting (POV) compared with a N2O regime. Our study was designed to evaluate the effect of the combination of
desflurane with N2O versus
desflurane alone on
postoperative nausea and vomiting (
PONV) in a subgroup of female patients and
PONV was considered as the primary endpoint. After approval of the local Ethics Committee and informed consent 60 female in-patients (ASA I & II), aged 18-65 y, scheduled for breast surgery with a duration of 1-3 h were included. Obese patients or patients with a history of
PONV and
motion sickness were excluded. No prophylactic
anti-emetic therapy was allowed during the study. Patients received a standardized
anesthetic technique consisting of
propofol for induction,
vecuronium and
fentanyl for intubation, followed by
desflurane with or without N2O (randomisation list) and
fentanyl supplements if required for maintenance of
anesthesia. At the end of
anesthesia PONV was recorded during 24 h in different periods. There were no significant differences between the groups with respect to demographic data and duration of
anesthesia. In addition, there were no significant differences in the amount of intraoperative
fentanyl or postoperative
narcotics. The incidence of
PONV was significantly higher in the group of patients receiving
desflurane in N2O-O2 mixture compared with the group receiving
desflurane in AIR-O2 mixture. The combination of
desflurane with N2O in female patients undergoing breast surgery is associated with a significantly higher incidence of
PONV and a higher need of
antiemetic drugs, when compared to a N2O free regime.