By Mary L. Hardy, MD
Postoperative nausea and vomiting (PONV) is a common side effect in 30% of all surgeries.1 Higher risk for PONV may depend on patient factors (female sex, a prior history of motion sickness or PONV) or medical issues (use of opiates for analgesia or abdominal surgery). High-risk patients may have up to a 70% incidence of PONV. Although PONV is not life-threatening, it causes patients distress, may extend the length of hospital stay, and increases utilization of medication or other services. Patients are more concerned about avoiding nausea postoperatively than pain, so there is great interest in developing effective strategies without side effects.
A 1998 NIH consensus panel identified nausea and vomiting as one of the conditions for which acupuncture would be effective.2 Most studies have used a specific point, pericardium 6 (P6), in therapeutic trials. The P6 point, also called the Nieguan point, is located on the flexor surface of the wrist, 4 cm proximal to the wrist crease between the palmaris longus and flexor carpii radialis tendons. Acupuncture points can be stimulated many ways—by needle, with electrical stimulation, and by direct pressure. Since this treatment appears to be successful with the stimulation of a single point, it is a very attractive method. However, use of needles or electrical stimulation may require some technical assistance not readily available at all times in the hospital. Therefore, a method of stimulating the points, which is more readily available and long-lasting, would be preferred.
Acupressure stimulation of the P6 point can be achieved either by direct pressure or by use of a special wrist band. A well-executed study that recently was reported has demonstrated the benefit of acupressure bands for relief of PONV following gynecological surgery.3 This study had two control groups—a sham treatment group and an untreated conventional therapy group—thus allowing for the measurement of the effect of the use of the band itself. It appeared that the band, even in an "incorrect" position, had a benefit—either due to inadvertent activation of the P6 point or through other non-specific mechanisms. However, in all cases, active therapy was more effective than sham treatment. The benefit was not statistically significant in the laparoscopic surgery group and was most effective for vaginal cases. It is worth noting that the bands were placed before the initiation of anesthesia (this is likely important) and were worn continuously for the first 24 hours. This is the largest reported study on this therapy for this indication and its results should encourage the consideration of acupressure bands for gynecological surgery patients. The cost is minimal ($10), it is not technically difficult, and it seems to be well-tolerated. Proper fit and placement of the bands is the only difficulty. If the bands are too loose, they are not effective and if they are too tight, they are difficult to wear. New bands have adjustable straps in order to provide a firm but comfortable fit for the patients.
An even more novel P6 stimulation method was tested by a research group in Korea.4 In addition to traditional Chinese style acupuncture, a variant involving stimulation of set points on the hand, called Korean hand acupuncture, is practiced routinely in Korea. The K-D2 point on the lateral distal phalanx of the index finger just below the nail has been identified as a useful point in the treatment of nausea, much like the P6 point. This trial evaluated the effect of stimulation of either the P6 point (n = 50), the K-D2 point (n = 50), or usual care (n = 60). However, a novel method was used to stimulate the points—a capsicum patch, containing the same active ingredients as the over the counter Zostrix patches. Presumably, substances in the capsicum plaster directly stimulated the point via local irritation or vasodilatation. The plaster or patch was standardized to contain a certain amount of capsicum powder and tincture. A small (5 mm square) piece was applied for 30 minutes prior to anesthesia induction and was maintained for 8 hours postoperatively at either the P6 or K-D2 points bilaterally. The incidence of vomiting and the use of rescue medication were significantly lower in both treatment groups at 24 hours after surgery. Both active treatments seemed to be equally effective. No adverse effects were reported and the cost of the plaster is much less than $1. These kinds of plasters are used extensively in oriental medicine to treat local pain and could be found in Chinese drugstores.
Both of these articles provide low-cost, low-tech, well-tolerated effective treatment strategies for the bothersome problem of PONV. Additional research should be done to evaluate these therapies more fully, but given the safety and low cost, they should be considered as a useful adjunct to the management of selected patients.
Dr. Hardy, Medical Director, Cedars-Sinai Integrative Medicine Medical Group, Los Angeles, CA, is on the Editorial Advisory Board of Alternative Therapies in Women’s Health.
1. Gan T. Postoperative nausea and vomiting—Can it be eliminated? JAMA 2002;2887:1233-1236.
2. NIH Consensus Development Panel on Acupuncture. NIH consensus conference: Acupuncture. JAMA 1998; 280:1518-1524.
3. Alkaissi A, et al. P6 acupressure may relieve nausea and vomiting after gynecological surgery: An effectiveness study in 410 women. Can J Anesth 2002;49: 1034-1039.
4. Kim KS, et al. Capsicum plaster at the Korean hand acupuncture point reduces postoperative nausea and vomiting after abdominal hysterectomy. Anesth Analg 2002;95:1103-1107.