Despite new anesthetic drugs and antiemetics, the incidence of postoperative nausea and vomiting remains between 20% and 70%. The authors tested the hypothesis that seasonal diet and temperature change and preoperative gastric emptying time affects the incidence of postoperative nausea and vomiting.

We conducted a retrospective cohort study of 626 women had undergone laparoscopic hysterectomy. Patients were anesthetized with nitrous oxides and inhalation anesthetics or propofol and injected butorphanol or nalbuphine or patient-controlled analgesia for postoperative pain control. Data were collected from records of recovery room and ward nurse's record and analysed with student t-test or chi-square test and logistic regression. Results are presented as mean ± SD; P < 0.05 was considered significant.

The incidence of PONV was 19.2%. Younger age, intraoperative dehydration, non-anemic preoperative state, usage of nalbuphine increase the incidence of PONV. But the incidence of PONV was not increased by type of anesthetic agent (inhalation or propofol), BMI, duration of operation, preoperative gastric emptyng time.

There are controversy in cause of PONV. Further well-controlled, double-blind prospective study may be needed.