Acupuncture has been practiced for more than 2000 years. Its origin continues to be debated, but is generally considered an important component of traditional Chinese medicine (TCM). The word acupuncture has Latin roots meaning “needle penetration” and involves the act of inserting metallic, solid thin needles through the skin to stimulate specific points on the body. The needle can be manipulated either manually or via electrical stimulation to improve pain. It is typically used for pain relief but has also been employed in treating a wide array of conditions.¹ It is believed to cause stimulation of small nerve endings and other structures around the acupoints, which results in both local and distant changes within the body.

Traditional acupuncture is based on ancient Chinese beliefs that “qi” (life force or energy) circulates throughout the body via energy carrying pathways called meridians. Twelve major meridians are thought to remain in continuous flow and in balance with two polarities yin and yang, reflecting good health and well-being. Illness occurs as a result of an imbalance between yin and yang due to a disruption of qi. Acupuncture is thought to reestablish the flow and balance by stimulating anatomical target points along the meridians in the body. The needles are typically stainless steel but may be made of gold and silver. Most needles are 1.3-12.7 cm long with a diameter of 26-36 gauge. The needles are inserted 3-15 mm under the skin.² A sensation, de-qi, is said to be felt when the acupuncture needle is inserted. This sensation can be described as numbness, pressure tingling, heaviness, soreness, or aching in nature. The sensation is also sensed by the proceduralist as a grasping of the needle with a sense of fullness, tightness, or even tension.³ Most acupuncturist believe that this sensation is needed to provide the full effect of acupuncture.

Acupuncture can be administered via manual acupuncture (MA) or electrical acupuncture (EA). MA is the insertion of needles into acupoints and then manually twisting the needle up and down, whereas in EA, a stimulating current via small clips is administered to the acupoints. Stimulation may be high (100-200 Hz), medium (15-30 Hz), or low (2-4 Hz).

The frequency and intensity can be modified depending on the aim of the treatment. Needles can be stimulated in pairs for <30 minutes. EA may also be administered without the use of needles in the form of transcutaneous electrical nerve stimulation (TENS), whereby electrodes are applied to the skin to stimulate identified points. EA is also advantageous in that the
needles do not have to be inserted into precise points as the stimulation of the needle affects a larger area.

There are various techniques and methodologies to the practice of acupuncture owing to different traditions from countries including China, Japan, Korea, and Vietnam. The overall thought is that the ears, hands, and feet are “micromodels” of the body and denote acupuncture points, meridians, organs, and body parts. The unifying principal of this practice remains in the application of acupuncture to specific anatomical target points to obtain a reduction in pain and induce other beneficial effects.²

First described in France by Paul Nogier, auricular acupuncture (AA) is similar to reflexology as it also uses a microacupuncture technique. It is believed that organs are represented on the human auricle and stimulation of identified points will have effects on the respective distant organs. Research has shown that it can be used to treat pain and anxiety, but more exploration is needed to confirm its use in the treatment of tobacco and substance abuse. Various materials such as stainless steel, sterile acupuncture needles, press-tack needles, Semen Vaccariae (SV, radish seeds), small metal pellets, or magnetized pellets have been used. Perhaps one of the best-studied auricular acupuncture protocols for acute pain is the battlefield acupuncture (BFA) protocol originally designed by Dr. Richard Niemtzow, which will be discussed in more depth later in the chapter.⁴,⁵ Medical practitioners can now be trained specifically in battlefield acupuncture as an adjunct outside of traditional Chinese medicine training or full acupuncture accreditation.⁶ A concern among modern researchers is the ability to standardize identified points in the ear and the lack of correlation with these identified areas and knowledge of anatomy and physiology. Wirx-Ridolfi discusses the likelihood of an increase in credibility of this practice if better comparable charts were available, which could be advantageous to spreading the acceptance of the practice in the scientific world as well as achieving improved patient results improved results for patients.⁷,⁸,⁹

Chinese scalp acupuncture is a technique that integrates traditional Chinese methods with Western medical knowledge of representative areas of the cerebral cortex. This technique has been shown to be an effective treatment of acute and chronic central nervous system disorders.
It produces excellent and almost immediate results with just a few needles. The areas identified on the scalp are based on Western medicine reflex somatotopic system, where needles are inserted subcutaneously into specific zones rather than into acupuncture points. These zones are areas within the cerebrum and cerebellum that perform motor and sensory functions, assist in vision, hearing, speech, and balance. Scalp acupuncture has been used for a variety of neurologic conditions, including Parkinson disease, stroke, and multiple sclerosis. An experienced practitioners is needed to perform this technique.¹⁰

This form of acupuncture was developed in Korea in 1971 by Dr. Tae-woo Yoo. Korean hand acupuncture therapy (KHT) is grounded in the same principals of Chinese acupuncture including yin and yang, meridians systems, and energy flow. In Korean hand acupuncture, the hand is viewed as a microcosm of the body, with all body parts and organs assigned a specific point on the hand. KHT uses short, narrow diameter needles, which are inserted 1-3 mm into points on the hand. KHT can also be performed by applying pressure to precise points on the hand or using metal pellets of opposite polarities. KHT is advantageous in that less invasive techniques can be used.¹¹,¹²

Acupuncture was introduced in the United States in the 1970s, after President Nixon’s visit to China. During that visit, a member of the press corp, James Reston, a New York Times reporter, required an appendectomy. Reston’s postoperative pain was treated with acupuncture and his experience was highly publicized.¹³,¹⁴ Interest in this treatment modality grew in the 1970s with California being the first state to establish the need for a license to practice, with several states following suite. Research into this therapy further amplified interest, with studies delving into its mechanism of action, such as endorphin hypothesis, and the use of imaging modalities, including fMRI and positron emission tomography. The National Institutes of Health (NIH) continues to support experimental and clinical acupuncture studies and released a consensus statement in 1997, showing promise with the use of acupuncture in adult postoperative pain, chemotherapy-induced nausea and vomiting, as well as for postoperative dental pain. It also discussed the likelihood of acupuncture being used as part of a multimodal treatment regimen in patients with headaches, myofascial pain,
fibromyalgia to name a few. The NIH developed an Office of Alternative Medicine now known as the National Center for Complementary and Integrative Health (NCCIH) that continues to fund clinical trials to evaluate the efficacy of acupuncture. The World Health Organization also describes a variety of medical conditions that may benefit from acupuncture, including the prevention and treatment of nausea and vomiting; treatment of addiction to tobacco, alcohol, and other drugs; and treatment of pulmonary conditions. It can be used to assist with rehabilitation after neurological damage such as those caused by a stroke. Concerns regarding study designs, sample size, the ability to properly control studies (placebo vs sham acupuncture, insertion of needle into nonacupuncture points) were highlighted.¹⁵ For many years, acupuncture needles were classified as class III medical devices, which are considered devices with a high risk to the patient or user. In the 1990s, a group of lawyers and acupuncturist petitioned the U.S. Food and Drug Administration (FDA) to designate the needles as class II medical devices.

As previously stated, acupuncture can be delivered via MA or EA. James Kennedy describes MA as the insertion of needles into acupoints and then manually twisting the needle up and down. MA results in the stimulation of A-β, A-δ, and C fibers. EA involves the application of a stimulating current to the acupoints and is thought to excite A-β and a portion of A-δ fibers. EA has been widely studied in fMRI, compared to the gate control theory, as well as studied for its role with NMDA receptors and central sensitization.¹⁶ Despite ongoing research, the exact mechanism of acupunctures effects continues to be debated with the endorphin theory appearing to be the most accepted. Chernyak et al. described a mechanism of action proposed by Pomeranz and Stux that involves three components contributing to the analgesic properties, with effects at the spinal cord level, the midbrain, and in the pituitary-hypothalamic complex. At the level of the spinal cord, it is thought to cause the release of enkephalin and dynorphin, inhibiting pain signals from ascending into the spinothalamic tract. In the midbrain, it stimulates the cells in the periaqueductal gray matter and the raphe nucleus, resulting in descending signals that cause the release of serotonin and norepinephrine, which lessens pain by reducing signal transmission through the spinothalamic tract. Finally, in the pituitary-hypothalamic complex, it causes release of endorphins
and adrenocorticotropic hormone.²,¹⁷ Kawakita and Okada, described a pharmacological study conducted by a group at Peking University that described endogenous opioid peptides as having a major role in electroacupuncture analgesia (EAA). This theory is further strengthened because EAA is said to be antagonized by naloxone, an opioid receptor antagonist. Han’s group showed that low-frequency (2 Hz) EAA caused the release of enkephalin, β-endorphin, and endomorphin, which in turn activated µ- and δ-opioid receptors; while high-frequency (100 Hz) EAA resulted in the release of dynorphins, which affected κ-opioid receptors in the spinal cord.¹⁸,¹⁹ Lin and Chen touched on the response of animals with hyperalgesia to acupuncture, noting that these animals may respond differently to EA. This study also highlighted the role of the inflammatory reflex and the autonomic nervous system as it pertains to antihyperalgesic properties seen with acupuncture treatment. This reflex also modulates the immune system and may explain the role of acupuncture in inflammatory states.²⁰ More research is needed to determine the exact mechanism for acupuncture exerting its analgesic effect, though current evidence supports the endogenous opioid response, modulation of long-term potentiation and neural plasticity through activation at the level of the brain as well as peripheral nerves, and the release of various anti-inflammatory and neuro-hormones.

The use of acupuncture continues to grow, as such it is important to keep track of its safety profile. In 2016, Chan et al. evaluated all systematic reviews (SRs) for adverse events associated with acupuncture and related therapies. Seventeen systematic reviews were identified and adverse effects were categorized based on organ or tissue injuries, infections, local adverse events or reactions, and other complications such as dizziness or syncope. The most common organ or tissue injury was pneumothorax. Infections included hepatitis, tetanus, auricular infection, septic arthritis, and staphylococcal infection. Local adverse events or reactions, such as contact dermatitis, local bleeding, and pain, as well as burns and bruising were also reported, as were more systemic effects such as nausea and vomiting, dizziness or syncope, and vasovagal reactions. Chan et al. concluded that serious and minor adverse effects do occur albeit rare. However, uncommon, it is important to be able to promptly identify them as some can lead to increased mortality. The importance of referring patients to credible acupuncturist was also stressed.²¹ Similarly, Park et al. investigated adverse events associated with acupuncture. Of the 2226 patients enrolled in the study, 99 reported adverse events including hemorrhage (32%), hematoma (28%), and needle pain site (13%). Sixty-four patients ended treatment with 62 of those patients with adverse events reporting diminished or a disappearance of the symptoms. Of the 35 remaining cases of adverse events in which treatment was continued, 28 patients reported a reduction or disappearance of the symptoms. Park et al. also acknowledged that acupuncture is associated with adverse events, but patients in this study did not experience serious adverse events. Again, the authors stressed the importance of referral to practitioners with experience who can perform this technique in accordance with set guidelines.²²

Uncontrolled postoperative pain remains a challenging problem and has been shown to lead to chronic pain. The standard of care for treating postoperative pain is slowly shifting away from using opioids as the sole agent to a multimodal treatment approach. Wang et al. performed a follow-up study reviewing the use of complementary and alternative medicines (CAM) by surgery patients and discovered that most surgical patients were willing to use CAM, with 7% of these patients agreeable to the use of acupuncture for postoperative pain reduction. The authors determined
that acupuncture is an effective part of regular care, is safe, and rarely causes significant adverse effects.²³ Wu et al. performed a systematic review and meta-analysis to determine the effectiveness of acupuncture and acupuncture-related techniques in treating postoperative pain. As compared to the control group, patients who received traditional acupuncture and transcutaneous electric acupoint stimulation (TEAS) reported less pain on day 1 after surgery. The TEAS group were reported to use significantly less opioids. Based on these finding, the authors support the use of acupuncture for the treatment of postsurgical pain.²⁴ Similarly, Sun et al. performed a systematic review to quantitatively evaluate the available evidence for the efficacy of acupuncture and related techniques in postoperative pain management. The results showed a reduction in postoperative opioid use, most evident at the 72-hour mark, as well as a reduction in postoperative pain scores at the 8- and 72-hour mark. Both the reduction in pain intensity and the reduction in absolute opioid consumption was thought to only be modest. Overall, the authors determined that acupuncture may be a good addition to postoperative analgesia.²⁵ Hendawy and Abuelnaga sought to determine the efficacy of ear acupuncture in patients undergoing abdominal hysterectomy with patients sorted based on who received spinal analgesia alone (control group) and spinal analgesia and electric ear acupuncture (EAA). Their findings revealed an increased threshold in somatic pain when acupuncture and TENS are employed. The study also revealed a reduction in PCA use in the first 24 hours after surgery in the treatment group and a delay in the time to request first supplemental analgesia. Again, the authors concluded that acupuncture is a useful part of a multimodal treatment regimen and improves patient satisfaction with minimal risk associated with its use.²⁶

The safety of acupuncture in pregnancy is relatively well accepted. Studies have shown that acupuncture may be beneficial during pregnancy and delivery. Favorable effects during pregnancy include ameliorating nausea and vomiting, improving sleep, back pain, and depression. During childbirth and delivery, it has been reported to prevent postterm dates, promote cervical ripening, shorten time of labor, and reduce postpartum bleeding. In a recent meta-analysis of acupressure including 13 randomized controlled trials and 1586 patients, Chen et al. concluded that there is moderate quality data to support the effects of acupressure for relieving labor pain.²⁷ Its use to promote induction may not be supported.²⁸ Allais et al. highlighted acupuncture as a potential therapy for nausea, vomiting, and migraine attacks during the first trimester of pregnancy and should be considered a treatment.²⁹ Park et al. performed a systemic review evaluating the safety of acupuncture in pregnancy, as some of acupuncture’s peripartum effects are thought to be related to oxytocin release from stimulation at specific acupoints, including those around the ankle and sacrum. The review concluded that acupuncture is associated with mild and transient adverse events, such as unspecified pain, pain at needling site, and bleeding. Of the serious adverse events identified, they were deemed to likely be unrelated to the acupuncture therapy.²² Carr revisited the debate surrounding the possibly harm of performing acupuncture at forbidden points including in the sacral region and lower abdomen. This concern runs high among traditional acupuncturist and less so in Western medicine acupuncture since it is not based on evidence. These points have been considered to be contraindicated before 37 weeks of pregnancy, given concerns surrounding cervical ripening, uterine contraction, and risk of uterine penetration. Carr summarized that acupuncture at these identified locations is not associated and did not increase the risk of adverse events in controlled and observational trials nor did it induce miscarriage or labor. He was reassured that additional factors may contribute to adverse pregnancy outcomes.³⁰ Furthermore, Asher et al. performed a study where they determined that acupuncture when compared to normal medical care or sham acupuncture was not effective in inducing labor nor did it affect the rate of cesarean delivery.³¹ Mansu et al. concluded that acupuncture seems to be safe and well tolerated by women in all trimesters. The authors urge practitioners to use judgment when selecting appropriate patients, selecting acupuncture points, combination, and order as well as the strength of the stimulation.³²