Multimodal therapies for postoperative nausea and vomiting, and pain.

Postoperative nausea and vomiting (PONV) and pain are two of the major concerns for patients presenting for surgery. The causes of PONV are multifactorial and can largely be categorized as patient risk factors, anaesthetic technique, and surgical procedure. Antiemetics work on several different receptor sites to prevent or treat PONV. This is probably why numerous studies have now demonstrated that using more than one antiemetic is usually more effective and results in fewer side-effects than simply increasing the dose of a single antiemetic. A multimodal approach to PONV should not be limited to drug therapy alone but should involve a holistic approach starting before operation and continuing intraoperatively with risk reduction strategies to which are added prophylactic antiemetics according to the assessed patient risk for PONV. With the increasing understanding of the pathophysiology of acute pain, especially the occurrence of peripheral and central hypersensitization, it is unlikely that a single drug or intervention is sufficiently broad in its action to be adequately effective, especially with moderate or greater pain. Although morphine and its congeners are usually the foundation of pain management regimens, as their dose increases so does the incidence of side-effects. Thus, the approach for the management of acute postoperative pain is to use multiple drugs or modalities (e.g. regional anaesthesia) to maximize pain relief and reduce side-effects.