Previous reviews on PONV focused only on P6 meridian acupoint and reported results combining adults and children, as well as acupuncture and acupressure studies together, of which 14 studies were related to acupressure effects. We have located 24 trials for acupressure effects on PONV. The most investigated meridian point is P6 acupoint (23 trials), and K K-9 acupoint was used in one study. General abdominal surgeries were included in 8 studies; women undergoing gynecological surgeries in 9 studies; cesarean (C-) section in 4 studies; cardiac patients in 2 studies; and urology surgery in 1 study. These papers were coded and reviewed by two raters for the quality and the calculation of pooled relative risk (RR) rate.
RR was reduced to 0.46 for nausea symptom and 0.53 for vomiting (n = 3136, P < 0.0001) comparing acupressure to placebo effects. Acupressure had no effects for urology patients in one study. Acupressure was less effective for women and cardiac patients. RR on vomiting was 0.59 for gynecology patients, 0.52 for C-section (spinal anesthesia), and 0.55 for cardiac patients, compared to 0.49 for general surgery patients with combined gender. Most studies examined PONV for 24 hours. Acupressure treatment is safe and effective for PONV. More quality research is needed to standardize the dose, frequency, and duration of different acupoints for acupressure effects in different populations.