[Postoperative nausea and vomiting. Controversies, evidence and new drugs]

In spite of the availability of drugs to control postoperative nausea and vomiting, emesis remains an unresolved problem for the anesthesiologist. The etiology of postoperative nausea and vomiting is multifactorial: some causes are well-defined whereas others continue to be the object of debate. Statistical methods applying logistical regression have proven valuable for assessing the risk of emesis in individual patients. Taking a preanesthetic case history to investigate the presence of factors that might lead to emesis allows the anesthesiologist to establish with a certain degree of credibility that a patient, a priori, is likely to experience nausea or vomiting. Various strategies for preventing or treating emesis can then be established in function of risk. Meta-analysis has been applied to the large body of literature that evaluates and/or compares a variety of drugs and anesthetic techniques, thus facilitating evidence-based decision-making. The therapeutic options available for postoperative nausea and vomiting are moderately effective and are distinguishable by their side effects and prices. Clinical trials with a new group of drugs (neurokinin receptor antagonists) are currently underway. With their wider spectrum of action and absence of side effects, these drugs may represent a qualitative advance in the treatment of postoperative nausea and vomiting.