What are the efficacy and safety of P6 acupoint stimulation in preventing postoperative nausea and vomiting (PONV)?
TYPE OF REVIEW
This is a Cochrane systematic review of interventions with meta-analyses.
RELEVANCE FOR NURSING
PONV is among the most common complication of general, regional, or local anesthesia, with incidences of up to 80%. Its possible complications include wound disruption, fatigue, dehydration, electrolyte imbalance, and increased risk of pulmonary aspiration. And because of the immobility, delayed recovery, and increased length of stay associated with PONV, it can also be costly.
Drug therapy is only partially effective in preventing PONV and may cause adverse effects, such as sedation, hypotension, dizziness, and headache. An alternative method to decrease PONV involves stimulating the pericardium (P6) acupuncture point on the wrist. Located between the tendons of the palm and flexor muscles of the radius, 1.5 in. (4 cm) proximal to the wrist crease, it's easily accessible.
CHARACTERISTICS OF THE EVIDENCE
Forty randomized controlled trials involving 4,858 participants were included in this review (15%  were children, ranging in age from one to 18 years). All studied the prevention of PONV by stimulation of the P6 acupoint compared with either sham treatment or antiemetic drugs. Techniques to stimulate the P6 acupoint included acupuncture, electro acupuncture, laser acupuncture, transcutaneous electrical nerve stimulation (TENS), acupressure, and capsicum plaster. Sham treatment was defined as a device applied at a non-P6 location, or any attempt to imitate P6 acupoint stimulation, such as wristbands with or without studs. Antiemetic drugs included metoclopramide (Reglan and others), cyclizine (Marezine), prochlorperazine (Compazine), droperidol (Inapsine), and ondansetron (Zofran).
Separate meta-analyses were performed for each of the following primary outcomes: risk of postoperative nausea and risk of postoperative vomiting (defined as either retching or vomiting, or both), and secondary outcomes: risk of patients requiring a rescue antiemetic drug and risk of adverse effects. Postoperative nausea and vomiting weren't combined because it wasn't known whether patients who vomited were also nauseated.
Results showed that when compared with sham treatment, P6 acupoint stimulation significantly reduced nausea, vomiting, and the need for a rescue antiemetic. But there was no difference between P6 acupoint stimulation and antiemetic drugs or between P6 acupoint stimulation and invasive or noninvasive acupoint stimulation, as would occur with the use of TENS, on these outcomes. P6 acupoint stimulation was also found to be equally effective in adults or children.
The adverse effects associated with P6 acupoint stimulation were minor and self-limiting, including redness, swelling, and irritation at the site.
BEST PRACTICE RECOMMENDATIONS
P6 acupoint stimulation is safe and effective in reducing the incidence of PONV and may be a suitable alternative or addition to antiemetic drugs in preventing PONV in adults and children.
Further research can evaluate the duration of P6 stimulation necessary for adequate reduction of PONV or whether combinations of interventions (such as P6 stimulation and antiemetic drugs) work better than each intervention alone and whether they interact. Future trials can also focus on the lower costs associated with this method.
Lee A, Fan LTY. Stimulation of the wrist acupuncture point P6 for preventing postoperative nausea and vomiting. Cochrane Database Sys Rev 2009(2):CD003281.