Acupuncture as an Antiemetic: Is There a Point?
Acupuncture as an Antiemetic: Is There a Point?
By Christine M. Stoltz, MD
The new millennium has bred continued interest in the therapeutic effects of acupuncture. What was initially regarded as a mystical Asian cultural practice has found a secure position in popular American culture. Americans made more than 5 million visits to acupuncturists in 1997,1 and this number is expected to be much larger in 2002.
Therapeutic use of acupuncture by patients has outpaced acupuncture research. Although acupuncture has been used in the treatment of a variety of medical conditions, clinical research suggests that it may be useful for postoperative dental pain, as an antiemetic during pregnancy and cancer chemotherapy, and in patients with neuropathy, headache, and low back pain syndromes. The National Institutes of Health Consensus Development Conference found that "there is clear evidence that needle acupuncture is efficacious for adult postoperative and chemotherapy nausea and vomiting and probably for the nausea of pregnancy."2 The following provides an overview of acupuncture and its potential efficacy as an antiemetic.
Acupuncture is a family of therapies in which medical conditions are treated by stimulation of anatomic points on the skin. Its practice dates back to at least the first century BC in China.
The basis of acupuncture is the notion that vital energy or Qi (pronounced "chee") flows in specific pathways (called meridians) throughout the body. Although they are not discrete structures, meridians are conceptually similar to blood vessels: They supply certain structures and organs in the body with energy and should align in a predetermined manner. It is believed that meridians are interconnected, permitting flow between them. There are 12 major and eight minor meridians. Meridians are important because traditional Chinese medicine teaches that symptoms of disease result from an imbalance of Qi in one or more meridians. Along each meridian is a series of acupuncture points. The intention of the acupuncturist is to detect abnormalities in Qi, and then redirect it and re-establish proper flow using acupuncture points.
There are several different styles of acupuncture. The most basic technique is needling, in which fine needles (approximately 32-gauge) are inserted about 0.5-1.0 cm below the skin’s surface. Modifications of this technique include electroacupuncture, in which small amounts of electric current pass through the needle, and moxibustion, in which a Chinese herb called moxa is heated and held near or placed on the acupuncture point. Some therapists also may use laser stimulation of specific acupuncture points to yield the same result. Acupressure is a related technique in which manual pressure (instead of needles) is placed at specific acupuncture points, using fingers or specially designed bands. Using a combination of reported symptoms and physical findings, the acupuncturist determines one of more locations where Qi is disrupted and uses acupuncture or acupressure to redirect flow to its native pattern.
Potential Mechanisms of Acupuncture’s Antiemetic Action
Human research concerning the mechanisms of the antiemetic effects of acupuncture is lacking. Many of the human studies have been limited by a lack of appropriate controls and by small study populations.
Small-scale animal studies, mostly from the Chinese literature, have suggested several effects on gastrointestinal function, including increased gastric motility (as measured by strain gauges), decreased acid secretion, and release of B-endorphin and somatostatin. Such studies have used dogs or rabbits and employed variable acupuncture sites. Although there may be a demonstrable effect in other mammals, such studies need to be interpreted with caution, as no information about efficacy can be derived, and it is assumed that acupuncture sites are the same in animals. As in humans, blinding is difficult in these studies.
Clinical Studies of Acupuncture as an Antiemetic
Several studies concerning the antiemetic effects of acupuncture have focused on an acupuncture point called Pericardium 6 (P6). This point is located on the ventral forearm, approximately 2 inches proximal to the wrist crease, between the tendons of the flexor carpi radialis and palmaris longus muscles. (See Figure, below.) The P6 acupuncture point lies along the pericardium meridian, which starts lateral to the nipple and descends down the medial aspect of the arm, ending at the tip of the middle finger. This meridian contains nine acupuncture points that regulate circulatory, psychiatric, and gastrointestinal function.
Mayer recently reviewed the literature regarding acupuncture as an antiemetic.3 Previous reviews were published by Vickers4 and Parfitt.5 This article summarizes select studies that examined the antiemetic effects of acupuncture or acupressure to the P6 point in cancer chemotherapy, morning sickness during pregnancy, and postoperative nausea and vomiting.
Use in Patients Undergoing Cancer Chemotherapy
Much of the research in this area has been published in the European literature. In one study, Dundee and colleagues recruited 105 patients undergoing chemotherapy in either an inpatient or outpatient setting for breast cancer, testicular cancer, or lymphoma.6 Before receiving chemotherapy, electroacupuncture was administered to the P6 point and compared with a control ("sham") point, located near the elbow, outside any acupuncture meridian. Treatments lasted five minutes. In a crossover design, the P6 point was shown to be an effective antiemetic for a period of about eight hours. Although statistical significance was not calculated by the authors, the effects appear to favor acupuncture.
A subsequent, smaller study of 20 patients showed that the duration of antiemesis could be extended to 24 hours by applying acupressure to the P6 point every two hours after acupuncture.7
Use in Morning Sickness During Pregnancy
Nausea and vomiting associated with morning sickness is troublesome to some pregnant women. Because of concerns about teratogenicity, women may be reluctant to use medications for their symptoms and have turned to acupressure and acupuncture for relief.
The use of complementary therapies in pregnancy recently has been well-reviewed elsewhere.8 There are many studies of acupuncture and acupressure for morning sickness. Because some practitioners prefer not to perform acupuncture during the first trimester of pregnancy, acupressure frequently is used.
De Aloysio and Penacchioni conducted a study in which 60 pregnant women were randomized to either acupressure using an elastic wristband with a stud positioned over the P6 point or placebo (a band without a stud that exerted a negligible amount of pressure over the point).9 Subgroups included patients who received unilateral vs. bilateral treatment or placebo. Patients were prospectively followed and evaluated with respect to their symptoms of nausea and vomiting. Although a placebo effect (of approximately 30%) was observed in patients receiving placebo acupressure, about 66% of patients who received true acupressure reported improvements in their symptoms. Therefore, acupressure at the P6 point resulted in an antiemetic effect that was approximately twice that of placebo-treated patients.
Another group studied 90 pregnant women receiving either acupressure at P6 or sham acupressure at an inert point for 10 minutes four times daily for seven days. The results showed that while nausea scores improved with acupressure, the incidence of vomiting was unaffected.10
Use for Perioperative Nausea and Vomiting
Acupuncture has been employed in the treatment of perioperative nausea and vomiting. Several studies have been conducted and reviewed by Parfitt.5 The studies were heterogeneous in design, although the larger and more rigorously designed trials suggest a favorable effect of acupuncture as an antiemetic during the postoperative period. Even the better-designed studies vary with respect to the patients enrolled, type of surgery, timing of acupuncture, and duration of follow-up. Most studies administered acupuncture within two hours of surgery and followed patients for 6-48 hours after surgery. Some of the studies in which no effect was observed administered acupuncture while the patient was sedated with general anesthesia, leading several investigators to question the validity of the results.
Limitations of Research in this Area
The challenge of performing research studies of acupuncture is in blinding. Many studies have used "sham" or inert areas as controls, but there is debate as to whether this is appropriate. To address this critical issue of blinding, instruments such as a "blinded acupuncture needle" are in development, in which the acupuncturist feels as if the needle is penetrating the skin and the patient feels a sensation whether the needle is inserted or not. Use of such devices will enable more rigorous studies that also will allow for blinding of the acupuncturist, which to date, has remained a difficult task.
When considering the literature about antiemesis, it is important to remember that the stimuli that provoke nausea and vomiting are complex and that there may be a placebo effect. For example, data for use of acupuncture/acupressure for chemotherapy-induced nausea need to be considered in light of the fact that such patients may have "anticipatory" symptoms that are thought to result from classical behavioral conditioning and that placebo effects may exist. Nonetheless, it seems that acupuncture may be helpful given the effectiveness of the P6 point over a sham point.
In general, acupuncture is safe when performed by a trained professional. As with any needle inserted below the skin, there are risks (see Table, below). Most adverse effects are benign.11 Pneumothoraces and cardiac tamponade have been reported in the literature, but these are rare events. The risk of infection (e.g., viral hepatitis) has been reduced by the use of sterile, disposable needles and avoidance of needling in areas of overlying skin disease.
In general, patients with implanted cardiac pacemakers should avoid electroacupuncture, as should patients with bleeding diatheses. Acupuncture points that have been shown to affect uterine contraction (such as Spleen 6 and Large Intestine 1-4) should be avoided during pregnancy.12
Incidence of adverse effects of acupuncture
Adapted from: Ernst E, White AR. Prospective studies on the safety of acupuncture: A systematic review. Am J Med 2001;110:481-485.
Accreditation and Questions for the Acupuncturist
Patients considering the use of acupuncture should be aware that there is an educational and licensing procedure that is required in most states. Licensure is contingent upon completing coursework and passing a certification examination. Individuals who are interested in receiving acupuncture should seek a licensed practitioner. Patients should inquire about the details of the treatment plan, the anticipated outcome, the duration of treatment (generally 6-8 sessions), and the cost (usually $40-$60/session).
For additional information about physician acupuncturists, patients may contact the American Academy of Medical Acupuncture (http://www.medicalacupuncture.org). For non-physician acupuncturists, patients can contact the American Association of Oriental Medicine (http://www.aaom.org).
The available evidence suggests that acupuncture or acupressure may be useful as an antiemetic in the morning sickness of pregnancy and in cancer chemotherapy. It also may have a role in the management of postoperative nausea and vomiting. Some, but probably not all, of its benefit is from placebo effect. To more specifically ascertain the effects of acupuncture and acupressure, additional research will need to employ techniques that allow for double blinding. In addition, although animal studies have suggested that acupuncture may increase gastric motility and reduce acid secretion, the mechanism by which acupuncture may work in humans is unclear and deserves further study.
Acupuncture may be an option for patients who have ongoing needs for antiemetic treatment, but either have not responded to conventional pharmacological therapy or should avoid or want to avoid pharmacological therapy. When performed by a trained professional, acupuncture generally is safe.
Dr. Stoltz is Instructor of Medicine, Division of General Internal Medicine, Presbyterian Medical Center, University of Pennsylvania Health System in Philadelphia.
1. Eisenberg DM, et al. Trends in alternative medicine use in the United States, 1990-1997: Results of a follow-up national survey. JAMA 1998;280:1569-1575.
2. National Institutes of Health Consensus Conference. Acupuncture. JAMA 1998;280:1518-1524.
3. Mayer DJ. Acupuncture: An evidence-based review of the clinical literature. Annual Rev Med 2000;51:49-63.
4. Vickers AJ. Can acupuncture have specific effects on health? A systematic review of acupuncture antiemesis trials. J R Soc Med 1996;89:303-311.
5. Parfitt A. Acupuncture as an antiemetic treatment. J Altern Complement Med 1996;2:167-174.
6. Dundee JW, et al. Acupuncture prophylaxis of cancer chemotherapy-induced sickness. J R Soc Med 1989; 82:268-271.
7. Dundee JW, Yang J. Prolongation of the antiemetic action of P6 acupuncture by acupressure in patients having cancer chemotherapy. J R Soc Med 1990; 83:360-362.
8. Petrie KA, Peck MR. Alternative medicine in maternity care. Prim Care 2000;27:117-136.
9. De Aloysio D, Penacchioni P. Morning sickness control in early pregnancy by Neiguan point acupressure. Obstet Gynecol 1992;80:852-854.
10. Belluomini J, et al. Acupressure for nausea and vomiting of pregnancy: A randomized, blinded study. Obstet Gynecol 1994;84:245-248.
11. Ernst E, White AR. Prospective studies on the safety of acupuncture: A systematic review. Am J Med 2001;110:481-485.
12. Dunn PA, et al. Transcutaneous electrical nerve stimulation at acupuncture points in the induction of uterine contractions. Obstet Gynecol 1989;73:286-290.Stoltz CM. Acupuncture as an Antiemetic: Is There a Point? Altern Med Alert 2002;5:1-4.
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