[Postoperative nausea and emesis: mechanisms and treatment]

The incidence of postoperative emetic symptoms in patients varies between 3 and 91%. Nausea and emesis remain the most common as well as unpleasant side-effects experienced by patients following general anaesthesia, both in the ambulatory and non-ambulatory care setting. Furthermore, emesis carries the risk of severe postoperative complications and is associated with additional costs. Multiple factors are associated with an increased risk of developing postoperative nausea and emesis including age, gender, weight, preexisting disease, as well as anaesthetic and surgical procedures. Routine antiemetic prophylaxis is not currently advisable in patients with a low Emesis Risk, due to undesirable side-effects of antiemetics and additional costs. However, anti-emetic prophylaxis is recommended for patients with an increased risk. Besides administration of antiemetics, other factors that may provoke postoperative emesis need to be considered such as gastric distension, early mobilisation, insufficient analgesia, choice of anaesthetic drugs. High-risk patients may be anaesthetized with propofol, if possible. If symptoms do develop in the recovery room, tight fitting oxygen masks should be avoided and adequate hydration and analgesia ensured. To avoid side effects, antiemetics should be administered in minimally effective dosages. If emesis persists, combination of antiemetic drugs with different profiles of receptor action may be particularly useful.