e4-05: Acupuncture

Chinese medicine theory describes a vital energy called chi (pronounced "chee") that circulates in the body through 12 pathways called meridians. Disease occurs when the flow of chi in the body is disturbed or unbalanced. Acupuncture uses needles to stimulate anatomic points along the meridians to promote the proper flow of chi and thus treat illness and promote health. Many styles of acupuncture exist and are practiced as part of the thousands-of-years-old medical traditions of China, Japan, Korea, and other countries. Besides describing the structure and function of the organ itself, the naming of each meridian also reflects a broader energetic function in Chinese medicine. It is critical to note that the practice of Chinese medicine includes much more than acupuncture (eg, herbs, cupping, dietary advice, a form of massage called "tui na," etc). However, most published studies investigate acupuncture only.

The mechanism of action of acupuncture is not well understood, but physiologic effects can be measured when acupuncture points are stimulated, such as the release of endorphins and enkephalins. Functional MRI studies reveal that different areas of the brain are activated and deactivated during needling. In addition, there are increasing number of studies that are examining the role that acupuncture plays in modulating the biological planes that persist across fascia and connective tissue. There have been molecular and cellular targets identified for acupuncture analgesia and anti-depressive effects and inflammatory modulation and characterization of specific body locations for needle stimulation for specific conditions. In addition, studies are looking at how the connective tissue system and nervous system may be differentially involved in acupuncture efficacy.

Typical acupuncture training for nonphysicians in the United States involves completion of a 4-year (2500-hour) master's degree training program accredited by the Accreditation Commission for Acupuncture and Oriental Medicine (ACAOM). To become a licensed acupuncturist (Lac), a national and, frequently, state board examination must be passed. Although many states do not require physicians to obtain additional training, many encourage at least 200 hours of training in an accredited program. There are approximately 38,000 licensed acupuncture practitioners and over 10,000 physician acupuncturists in the United States, with only three states without acupuncture practice laws. In most states that license, register, or certify acupuncturists, these practitioners are permitted to work independently.

In the United States and Europe, acupuncturists typically conduct a comprehensive multisystem history, observation, and physical examination during the initial consultation. Examination primarily consists of inspection of the tongue to assess color, shape, and coating; and palpation of the pulse to assess its quality, rhythm, and strength. In classic acupuncture, each patient is viewed as having a unique constellation of symptoms and signs. This means that 10 patients presenting with migraine headaches might receive 10 unique Chinese medical diagnoses and 10 different treatments. Because acupuncture is one part of a comprehensive system of therapeutics, patients are also often prescribed Chinese botanical medicines; undergo treatment with moxibustion (burning of Artemisia at key acupuncture points) or electroacupuncture (small electrical current administered through acupuncture needles); and receive nutritional, exercise, and other lifestyle advice. Western-style practitioners also often will conduct a conventional examination. In clinical research, treatment protocols might use a fixed combination of acupuncture points for a given medical diagnosis (eg, a cohort of migraine sufferers will be treated in a similar way).

Treatment typically involves inserting 4 to 15 needles at selected acupuncture points for 10–30 minutes, although certain schools leave the needles in place for only a few seconds to minutes. Virtually all acupuncture is performed with thin, solid, stainless steel, sterile, disposable needles that are stimulated manually or occasionally with electricity or heat. A course of treatment usually consists of weekly or biweekly visits for 4–10 weeks, followed by less frequent visits as the condition improves. Length of treatment can range from several months to several years, depending on the condition and patient response.

The current practice of acupuncture in the United States and Europe is associated with a very low incidence of adverse events. A 2021 meta-analysis and systematic review found that an adverse event can be expected in every 10th patient that undergoes a series of acupuncture treatments and every 13th treatment. Minor adverse events were common but usually mild and transient. These may even be a part of the acupuncture treatment or therapeutically intended reactions (bleeding, needle site pain, and flare around the needle site). Reactions such as presyncope, syncope, and drowsiness can be easily prevented by having patients lie flat on the table, monitoring them during their initial visit, and permitting them to remain in the office until a normal state of awareness is achieved. Serious complications occur in every 10,000 patients during an acupuncture series and in every 125,000 treatments. Those most commonly reported were pneumothorax, cardiovascular or vasovagal reactions, and fall or trauma—with one to three cases in one million treatments.

Well over 1000 English-language reviews of the clinical use of acupuncture in humans have been published since the 1970s, many pointing out the challenge of designing high-quality trials with effective placebo controls. Several types of placebos have been tried: needling at nonacupuncture points, using a retractable sham needle that does not penetrate the skin, and needling at true acupuncture points that are inappropriate for the condition being treated. Data analysis is complicated by sham treatments having physiologic effects. Acupuncture has been shown to be most effective in treating pain and nausea and vomiting, with sustained benefits at 12 months in many studies. Many other diverse conditions have been studied. Below are some common conditions for which patients seek acupuncture care.

A. Postoperative Pain

Reviews comparing acupuncture with sham control have found it helpful in the management of acute postoperative pain, reducing pain intensity, opioid consumption, and opioid-associated side effects. Multiple RCTs have found that acupuncture significantly improved postoperative function and reduced pain following a wide variety of surgical procedures. Reviews and meta-analyses examining postoperative pain patients found that those treated with acupuncture had less pain and used fewer opioids. A prospective RCT of 180 women scheduled for elective cesarean delivery found that acupuncture was safe and effective in reducing pain and accelerating mobilization of patients on the first day after cesarean delivery (sitting up, standing up, removing Foley catheter, and ambulation).

B. Nausea and Vomiting

Based on multiple RCTs involving more than 10,000 patients, there is strong evidence that acupuncture is effective in the treatment of pregnancy-induced, chemotherapy-induced, and postoperative nausea and vomiting. A systematic review identified 43 trials using a specific acupuncture point (P6) for treatment of nausea and vomiting. P6 is located on the anterior surface of the forearm, approximately 2 cm proximal to the wrist crease between the tendons of palmaris longus and flexor carpi radialis. Results across trials were the most consistent for postoperative nausea and vomiting. Compared with sham procedures, P6 stimulation was more effective than comparison in preventing nausea (relative risk [RR] 0.72, 95% CI 0.59–0.89) and vomiting (RR 0.71, 95% CI 0.56–0.91). In the nine trials that compared P6 stimulation with antiemetic medication, P6 stimulation was superior in preventing nausea and equivalent in preventing vomiting. Electroacupuncture was reported to be effective for first-day vomiting after chemotherapy. A Cochrane review of P6 stimulation included 59 trials and over 7600 patients and concluded that there is moderate-quality evidence showing that P6 stimulation and antiemetic medications were equally effective in preventing postoperative nausea and vomiting. A pilot study found that intraoperative laser acupuncture stimulation of P6 acupoints combined with antiemetic medication prophylaxis decreased postoperative nausea and rescue antiemetic medication need in patients who underwent a laparoscopic cholecystectomy.

C. Headache

Systematic reviews have concluded that acupuncture is a safe and effective option for preventing and treating migraine headaches and possibly for preventing tension headaches. A 2012 multicenter study of 480 adults showed benefit of acupuncture for prophylaxis of migraine, although it was only slightly better than sham acupuncture. A review concluded that acupuncture is at least as effective as conventional medication therapy and is safe and cost-effective. A Cochrane review concluded that acupuncture is as effective as migraine prophylactic medications and may have small benefit over sham acupuncture in the treatment of acute migraine attacks. Another Cochrane review concluded that acupuncture is effective for treating frequent episodic or chronic tension-type headaches. Finally, a 2020 systematic review of nine RCTs including a total of 1484 patients found that acupuncture is slightly more effective and much safer than pharmacologic prophylaxis of migraine headaches.

D. Osteoarthritis

The efficacy of acupuncture in the treatment of OA remains uncertain. Systematic reviews and meta-analyses of RCTs suggested that acupuncture may be efficacious for pain control and function (eg, gait performance) in patients with OA of peripheral joints, particularly for knee OA. Its favorable safety profile as well as significant expectation and placebo effect may contribute to its overall benefit. It may also be a cost-effective treatment for OA. Notwithstanding the uncertainties surrounding its efficacy, the 2010 OARSI (Osteoarthritis Research Society International) recommendations reaffirmed the use of acupuncture for reducing pain from OA and for improving function. Questions remain about the duration of effect and the style of acupuncture used. In a 2020 multicenter RCT, 480 patients with knee OA were randomly assigned to receive intensive electroacupuncture, intensive manual acupuncture, or sham acupuncture, 3 times weekly for 8 weeks. This study found that intensive electroacupuncture treatment resulted in less pain and better function than sham acupuncture, with benefits persisting through 6 months. Intensive manual acupuncture treatment had no benefit for knee OA at week 8; however, by week 16 a benefit was apparent that was maintained at 6 months.

E. Low Back Pain

The updated clinical practice guidelines from the American College of Physicians on noninvasive treatments for acute and chronic low back pain recommended acupuncture as an option for acute, subacute, and chronic low back pain. Similarly, the 2017 Canadian clinical practice guideline also endorsed use of acupuncture for chronic low back pain. Furthermore, a systematic review of therapies for low back pain concluded that acupuncture is a cost-effective option. In contrast, a 2020 Cochrane review found that acupuncture may not better than sham acupuncture in the relief of chronic low back pain, although it is more effective than no treatment in improving pain and function. In 2020, the Centers for Medicare & Medicaid Services approved coverage of acupuncture for Medicare patients with chronic low back pain. Many other insurance providers also offer coverage for acupuncture.

F. Other Pain Conditions

Acupuncture appears effective for temporomandibular joint (TMJ) pain, other orofacial pain, chronic neck pain, chronic shoulder pain, peripheral neuropathy, acute zoster pain, plantar heel pain, and arthralgias from aromatase inhibitors in women with breast cancer. A systematic review of acupuncture in the treatment of TMJ suggested it is beneficial compared with placebo and has equivalent efficacy to occlusal splints; however, studies were few, and larger sample sizes are needed. A 2019 meta-analysis found that the placebo response may play a large role in TMJ pain management.

A 2021 meta-analysis of aromatase inhibitor-induced arthralgia in patients with breast cancer examined seven trials involving 603 patients. This study found significant differences between the acupuncture and control groups. No adverse events were noted, suggesting that acupuncture is a safe treatment option for these patients. A 2020 systematic review and meta-analysis of 17 RCTs involving 1111 patients found that acupuncture and/or acupressure was significantly associated with reduced cancer pain and decreased use of analgesics. Due to significant heterogeneity among studies, the evidence was graded moderate. More rigorous trials are needed in this patient population.

G. Tobacco, Alcohol, and Substance Use Disorders

Reviews have yielded conflicting results on the benefit of acupuncture promoting smoking cessation in patients with nicotine addiction. The most recent Cochrane systematic review of 38 trials concluded that there is no consistent, bias-free evidence that acupuncture has a sustained benefit on smoking cessation for 6 months or more. Because of methodological problems, no firm conclusions can be drawn.

A systematic review and meta-analysis of nine studies, comprising more than 1000 patients, found that acupuncture could be effective in treatment of opioid use disorders. A 2021 retrospective study of 52,346 patients with chronic pain found a clinically significant reduction in all-cause and pain-related emergency department use in the 12-month follow-up period. More studies are needed to be done to better understand which modality of acupuncture is best, what symptoms are being treated, and length of treatment.

H. Other Conditions

Acupuncture has been studied in a variety of other conditions with interesting results. A 2019 systematic review and meta-analysis of 12 studies with 798 patients with COPD found that acupuncture improved health-related quality of life. Notably, the authors did not find improvements in lung function above and beyond standard of care (medication and pulmonary rehabilitation).

Acupuncture has also shown benefit in patients with mental health conditions. A 2021 network meta-analysis of 71 studies involving 5856 patients with major depression disorder found that combined interventions of electroacupuncture with SSRIs and manual acupuncture with SSRIs were more effective in improving depression symptoms compared with acupuncture alone, pharmacological interventions alone, or other inactive groups. This study indicates that acupuncture in combination with pharmacotherapy could be a safe and effective interventions for patients with major depressive disorder. Larger, well-designed studies are needed.

Increasing research with acupuncture in cancer patients has shown benefits in symptom management. A meta-analysis of 10 RCTs, representing over 1300 patients, found that acupuncture had a beneficial effect on cancer-related fatigue, compared with sham acupuncture and usual care.

Acupuncture has long been used to assist with labor and delivery. A 2015 study comparing two different acupuncture point treatments and a control group found that the use of electroacupuncture significantly decreased labor pain and shortened the duration of the active phase of labor. A 2017 Cochrane review examined 22 trials that included over 3000 women and found that there was no clear benefit of acupuncture or acupressure in reducing rates of cesarean delivery.

A 2021 meta-analysis of 17 studies of acupuncture for menopausal hot flashes included 1123 women with seven or more hot flashes per day. The efficacy of acupuncture was significantly related to treatment duration, reaching 50% of maximum effect at 2 weeks and 80% at 8 weeks. In addition, the higher the baseline level of hot flashes, the better the efficacy of acupuncture. The effects were comparable to pharmacotherapy such as SSRIs and SNRIs.

A 2021 systematic review of acupuncture for urinary incontinence found that it was clinically effective at reducing urine leakage in middle-aged and older women.