**5.5 Postoperative nausea and vomiting**

One of the most prevalent adverse events following surgery is postoperative nausea and vomiting (PONV). It is unpleasant for patients, raises the possibility of additional adverse consequences, including readmission, and increases the costs, the health care facility revenue [63]. Nausea indicates a feeling of upcoming vomiting, while vomiting defines the reflux of gastrointestinal contents [64]. A number of factors, including the patient's demographics and the surgery type, influence the risk of PONV. Some surgeries, such as gynecologic, breast, and open-heart surgery, have been associated with an increased risk of PONV [65], whereas patient risk factors include female gender, nonsmoking, a history of PONV, and motion nausea [66]. Weibel et al. evaluated the quality of evidence for the effectiveness and safety of single-antiemetic drugs and combinations of antiemetic drugs used to prevent postoperative nausea and vomiting in adults following general anesthesia [67] and discovered high-certainty evidence of clinical efficacy compared to placebo for aprepitant, ramosetron, granisetron, dexamethasone, and ondansetron; moderate certainty evidence of. However, more studies are needed to investigate the drugs' possible side effects as well as patient populations with comorbidities (e.g., individuals with diabetes and heart disease) [67]. Hypnosis, relaxation imagery, music therapy, aromatherapy, acupressure, acupuncture, and electroacupuncture have all been included in recent studies and publications as complementary and alternative medicine interventions for PONV [68]. Numerous studies were placebo-controlled clinical trials, which effectively eliminated the placebo effect. Acupuncture appears to be more successful at controlling nausea than vomiting [69–71]. The PC6 acupoint is one of the most commonly utilized and studied acupoints for the prevention and treatment of PONV. Cheong et al. showed that using a single point of PC6 alone or in combination with other acupoints and alternative acupoints could help in the prevention and treatment of PONV [72]. The mechanism underlying acupuncture's effectiveness to reduce PONV is still under investigation. Serotonin transmission and beta-endorphin release may be affected [73–75].
