Because currently no single antiemetic available is especially effective on its own, experts recommend a multimodal approach. Anesthetic strategies to prevent<unk>  include using regional anesthesia whenever possible and avoiding medications that cause<unk> . Medications to treat and prevent<unk>  are limited by both cost and the adverse effects. People with risk factors likely warrant preventive medication, whereas a "wait and see" strategy is appropriate for those without risk factors. Preoperative fasting Fasting guidelines often restrict the intake of any oral fluid 2-6 hours preoperatively, but in a large retrospective analysis in Torbay Hospital, unrestricted clear oral fluids until transfer to theatre could significantly reduce the incidence of<unk>  without an increased risk in the adverse outcomes for which such conservative guidance exists. Medications A multimodal approach to treating a patient with<unk>  can be efficacious. Numerous patient factors and medication adverse effects must be taken into consideration when selecting a treatment regimen. * Serotonin (5-HT3) receptor antagonists can be administered as a single dose at the end of surgery. Adverse effects include prolongation of the QT interval on electrocardiogram (EKG). Medications include ondansetron, granisetron, and dolasetron. * Anticholinergics can be used as a long-acting patch placed behind the patient's ear. Adverse effects include dry mouth and blurry vision. Care must be taken when handling the patch, as transfer of medication to the eye can induce pupillary dilation. Avoid use in elderly patients. Medications include scopolamine. * Glucocorticoids have direct antiemetic effects and can reduce need for postoperative opioids. Adverse effects include a transient increase in serum glucose level, and poor wound healing (controversial). Medications include dexamethasone. * Butyrophenones are typically administered as a single injection at the end of surgery. Adverse effects include prolongation of the QT interval on EKG. Medications include droperidol and haloperidol. * Phenothiazines are particularly effective in treating opioid-induced<unk> . Adverse effects are dose-dependent and include sedation and extrapyramidal symptoms. Medications include promethazine and prochlorperazine. * Neurokinin 1 (NK1) receptor antagonists prevent an emetic signal from being transmitted. Medications include aprepitant and rolapitant. * Histamine receptor antagonists can be administered by multiple routes, including orally, intramuscularly, or rectally. Adverse effects include dry mouth, sedation, and urinary retention. Medications include dimenhydrinate and diphenhydramine. * Propofol, an anesthetic medication, confers its own antiemetic properties. The 2020 Cochrane Anaesthesia Review Group review of Drugs for preventing<unk>  in adults after general anaesthesia: a network meta-analysis (Review) demonstrated that combination therapy is more effective than single anti-emetic, and that dexamethasone and ondansetron (a commonly used combination) are two of the most effective anti-emetics for<unk> . The review adds robust evidence of efficacy for drugs in newer classes, such as aprepitant or fosapreitant, or newer agents in familiar classes, such as ramosetron. The review does not cover the cost effectiveness of the agents included and, despite increased efficacy for newer novel agents, this may preclude their immediate utilisation in anaesthetic practice. Alternative medicine In conjunction with antiemetic medications, at least one study has found that application to the pericardium meridian 6 acupressure point produced a positive effect in relieving<unk> . Another study found no statistically significant difference. The two general types of alternative pressure therapy are sham acupressure and the use of the P6 point. A 2015 study found no significant difference between the use of either therapy in the treatment or prevention of<unk> . In a review of 59 studies, both therapies significantly affected the<unk>  aspect, but had no significant effect on<unk> . Cannabinoids have also been used for treatment of<unk> , but its safety and efficacy are controversial.
Postoperative nausea and vomiting
Postoperative fever
Post-vagotomy diarrhea
Postoperative cognitive dysfunction
Abdominal compartment syndrome
Short bowel syndrome
Retroperitoneal bleeding
Acute abdomen