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. In addition to 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 antidepressive effects as well as 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 a minimum of 200 hours of training in an accredited program. There are approximately 38,000 licensed acupuncture practitioners and more than 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. What this means is 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 (as low as 1 in 10,000 to 1 in 100,000 needle insertions). 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 have been reported in the literature; however, over more than 30 years, they are quite rare.

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 the fact that sham treatments can have 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

Prior reviews comparing acupuncture with sham control have found that it has been helpful in the management of acute postoperative pain, including reducing pain intensity, opioid consumption, and opioid-associated side effects. Multiple randomized controlled trials have found that acupuncture significantly improved postoperative function and reduced pain following a wide variety of surgical procedures. A 2016 systematic review and meta-analysis examining postoperative pain patients found that those treated with acupuncture had less pain and used fewer opioids. These findings were corroborated in a 2017 meta-analysis and review of postoperative management of knee replacement; and a 2019 review reports similar findings in abdominal surgery.

B. Nausea and Vomiting

Based on several dozen randomized controlled trials 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% confidence interval [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 2015 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 as well. A 2012 multicenter study of 480 adults showed benefit of acupuncture for prophylaxis of migraine, but acupuncture was only slightly better than sham acupuncture. A 2015 review concluded that acupuncture is at least as effective as conventional medication therapy as well as being safe and cost-effective. One 2016 Cochrane review concluded that acupuncture is at least as effective as treatment with migraine prophylactic medications and may have small benefit over sham acupuncture in the treatment of acute migraine attacks. A second 2016 Cochrane review concluded that acupuncture is effective for treating frequent episodic or chronic tension-type headaches. A 2017 randomized controlled trial in patients with migraine headaches without aura found that 4 weeks of nearly daily acupuncture resulted long-term reduction (24 weeks) in migraine recurrence compared with sham acupuncture or waitlist control. Finally, a 2020 systematic review of nine randomized trials totaling 1484 patients found that acupuncture is mildly more effective and much safer than pharmacologic prophylaxis.

D. Osteoarthritis

A 2006 systematic review and meta-analysis of 18 randomized controlled trials concluded that “sham-controlled trials suggest specific efficacy of acupuncture for pain control in patients with osteoarthritis of peripheral joints. The favorable safety profile makes acupuncture a worthy option of consideration, particularly for knee osteoarthritis.” A 2007 meta-analysis of nine clinical trials revealed clinically relevant short-term (but not long-term) improvements in pain and function compared with those in wait-list control groups. A 2007 cost-effectiveness trial involving almost 500 German patients who were randomized to routine care or routine care plus acupuncture concluded that acupuncture was a cost-effective treatment for osteoarthritis. In 2010, there was a Cochrane review of 16 trials of acupuncture for peripheral joint arthritis including 3498 patients; it concluded that there is a statistically significant benefit of acupuncture, although it also raised the concern that expectation and placebo effect might be contributing to the overall benefit. Nonetheless, the 2010 OARSI (Osteoarthritis Research Society International) recommendations reaffirmed the use of acupuncture for reducing pain from osteoarthritis and for improving function. A 2011 randomized controlled trial of geriatric inpatients found that acupuncture significantly improved gait performance during rehabilitation. A 2012 trial of 120 patients with osteoarthritis of the knee demonstrated a statistically significant benefit of acupuncture plus etoricoxib (a COX-2 inhibitor that is not used in the United States) over etoricoxib alone or etoricoxib plus sham acupuncture.

A 2017 systematic review and meta-analysis of acupuncture for knee osteoarthritis suggested that acupuncture offers pain relief in chronic knee pain; however, they were unable to draw any strong conclusion, and nothing could be said about function. Another 2017 meta-analysis also concluded that acupuncture is effective for knee osteoarthritis, although the studies reached differing conclusions regarding the duration of effect after acupuncture treatments are completed.

A 2018 Cochrane review of six clinical trials founds no benefit of acupuncture in the treatment of hip osteoarthritis.

E. Low Back Pain

More than 50 clinical trials of acupuncture for the treatment of low back pain were reviewed by the American Pain Society and American College of Physicians as part of clinical practice guidelines that were published in 2007. They concluded that there was a fair level of evidence supporting a moderate benefit of acupuncture in treating subacute (4–8 weeks) or chronic low back pain. In most studies, acupuncture has not been shown to be more effective compared to other active treatments but provides additional benefit when added to conventional therapies. A 2008 systematic review of 23 randomized controlled trials involving more than 6000 patients treated with acupuncture versus no treatment or acupuncture as an adjunct to conventional care concluded that it should be advocated in guidelines for the treatment of chronic low back pain. A 2012 multicenter randomized controlled trial of patients with acute low back pain showed that acupuncture reduced levels of disability compared to usual care but not significantly more than sham acupuncture. The updated 2017 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 2017 systematic review of cost-effectiveness of therapies for low back pain concluded that acupuncture is a cost-effective option. In 2020, Centers for Medicare & Medicaid Services (CMS) approved coverage of acupuncture for Medicare patients with chronic low back pain. Many other insurance providers also are covering 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 2017 systematic review of acupuncture in the treatment of TMJ suggested it is beneficial compared with placebo and its effectiveness is like treatment with occlusal splints; however, studies were few, and larger sample sizes are needed.

A 2015 study showed favorable results for acupuncture in the management of renal colic. The trial randomized 120 patients to receive acupuncture, intravenous acetaminophen, or intramuscular diclofenac for renal colic and used visual analog pain scale measurements at 10, 30, 60, and 120 minutes after treatment. Results showed a faster sustained reduction in pain at 10 minutes with acupuncture but a lower level of pain at 120 minutes with the medications. Another similarly designed 2018 study compared acupuncture to intravenous titrated morphine, randomizing 115 patients. This study also showed improvements in pain at 10 minutes, with a faster achievement of analgesia. Of note, significantly more individuals experienced side effects in the morphine arm of the study.

A 2018 study of 226 randomized patients with early-stage breast cancer looked at the experience of aromatase inhibitor–related joint pain. Compared to waitlist control and sham acupuncture, true acupuncture treatment resulted in a statistically significant decrease in pain at 6 weeks; however, its clinical significance was uncertain.

G. Tobacco, Alcohol, and Substance Use Disorders

A 2012 meta-analysis of randomized controlled trials of CIT for smoking cessation included six trials on acupuncture and concluded there was significant benefit with acupuncture for nicotine addiction and smoking cessation. However, a 2014 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 2006 Cochrane systematic review of seven studies in which 1433 patients were treated with auricular acupuncture for cocaine dependence concluded that there is currently no evidence to support its use in that role. However, a 2009 meta-analysis and a 2010 randomized controlled trial suggested that acupuncture may have benefit in the treatment of opioid dependence, although evidence in these studies is mixed.

In a 2014 randomized controlled trial assessing the clinical efficacy of acupuncture as an adjunct to methadone maintenance treatment, 60 people with heroin use disorder were randomly assigned to true acupuncture or sham acupuncture twice weekly for 4 weeks. From week 2 onward, the daily requirement for methadone was reduced by a significantly greater amount in the true acupuncture group compared to the sham acupuncture group. At follow-up, true acupuncture was also associated with a greater improvement in sleep latency. The authors concluded that acupuncture appears to be a useful adjunct to methadone maintenance therapy in heroin use disorder.

A 2018 systematic review and meta-analysis of nine studies, composed of more than 1000 patients, found that acupuncture could be effective in treatment of opioid use disorders. However, 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 various conditions with interesting results, challenging the idea that acupuncture is limited in scope of treatment capabilities. A 2012 randomized placebo-controlled study in 68 chronic obstructive pulmonary disease patients using a specially designed sham acupuncture needle found statistically significant improvements in both distance and Borg scale score with 6-minute walk tests at 12 weeks.

Acupuncture has also shown benefit in patients with mental health conditions. A 2013 study randomized 755 primary care patients with moderate to severe depression in a 2:2:1 ratio to acupuncture, counseling, and usual care alone. Investigators found an improvement in Patient Health Questionnaire-9 depression scores compared to placebo at 3 months and 12 months for both acupuncture and counseling, with no significant difference between the two.

Increasing research with acupuncture in cancer patients has shown benefits in symptom management. A 2018 meta-analysis of 10 randomized controlled trials, representing over 1300 patients, found that acupuncture had a beneficial effect on cancer-related fatigue, compared to 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 looked at 22 trials with over 3000 women and found that there was no clear benefit of acupuncture or acupressure in reducing rates of caesarean delivery.

A 2016 randomized controlled trial of acupuncture for menopausal hot flashes, studied 327 women who had at least seven hot flashes per day and found no benefit for acupuncture versus noninsertive sham. A 2018 randomized controlled study of 360 women found no benefit of electroacupuncture over sham acupuncture as well.

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