Postoperative nausea and vomiting is a nuisance. The anaesthetist is usually blamed, despite evidence that postoperative nausea and vomiting results from several factors, some related to anaesthesia, others to surgery, and some to the patients themselves. The importance of postoperative nausea and vomiting is generally underestimated because it is self limiting, never becomes chronic, and almost never kills. However, its impact on the cost of health care is not negligible. Ten per cent of the population undergo general anaesthesia every year,1 and about 30% of them are affected by postoperative nausea and vomiting.2 This amounts to about two million people in the United Kingdom every year. About 1% of patients undergoing ambulatory surgery are admitted overnight because of uncontrolled postoperative nausea and vomiting.2

Surgical patients prefer to suffer pain rather than postoperative nausea and vomiting3 and would be willing to pay considerable amounts of money for an effective antiemetic.4 However, successful control of postoperative nausea and vomiting has proved elusive. A major obstacle to the development of an effective treatment has been the lack of a valid animal model for postoperative nausea and vomiting. New insights into pathways for emesis and efficacy of antiemetics have come from animal research with highly emetogenic chemotherapy. Extrapolation of these data to postoperative nausea and vomiting has been of …