A meta-analysis of 30 randomly controlled trials confirms that acupuncture at acupoint PC6 is successful in reducing postoperative nausea and vomiting. 
Acupuncture Point Neiguan, PC6Other measures showing significant clinical results include combining PC6 with other acupuncture points, electroacupuncture at PC6 and acupressure applied directly to PC6. The researchers conclude that PC6 is effective for the prevention of postoperative nausea and vomiting and that further research is warranted given the results of this investigation.
The researchers primarily investigated the effects of PC6 on postoperative nausea and vomiting (PONV) based on prior clinical evidence. However, the researchers uncovered significant evidence to suggest that other acupuncture points are clinically effective for the treatment of PONV including: K9, BL10, GB34, BL11, BL18-26, SP4, SP6, ST34, ST36, ST44. One study of interest demonstrated that children experienced significantly less vomiting after strabismus corrective procedures if prophylactically treated with acu-plasters bilaterally at BL10, BL11 andGB34. The investigation revealed that preventative treatments create significant positive clinical outcomes. Treatment in the recovery room after the onset of hyperemesis was also confirmed as an effective measure of patient care.
A total of 186 studies were initially investigated. Sorting was performed to include quality trials and exclusion criteria. A total of 30 studies met the final inclusion criteria for meta-analysis. One of the studies was a pediatric investigation and the other studies were limited to adults. Two studies were of patients receiving PC6 stimulation under i/v anesthesia, 15 under general anesthesia, 3 under infusion-inhalation anesthesia, 2 under spinal anesthesia, 4 under epidural anesthesia, 2 under local anesthesia and another 2 did not report the type of anesthesia employed. A total of 16 studies were preventative applications of PC6 only, 6 studies combined PC6 with other acupuncture points and 8 studies examined other acupuncture points (excluding PC6).
The researchers noted that “acupuncture is safe” and “few reports of local erythema,” swelling and tenderness were reported. All side effects “were local and no major events followed.” Notably, the studies reviewed involved highly trained licensed acupuncturists. This is limited to highly trained,licensed acupuncturists using filiform acupuncture needles at the correct acupuncture point locations.
Meta-analysis Factoids
A significant reduction for “time to home readiness” was achieved for patients discharged on the day of surgery when acupuncture was applied perioperatively over preoperative only.
Acupuncture administered preoperatively showed significant effects for the reduction of nausea but not vomiting in a comparison with antiemetic prophylaxis.
Acupuncture was found more effective than placebo controls for the prevention of nausea and vomiting.
Antiemetic results were found effective for conscious patients over patients receiving acupuncture while unconscious under anesthesia.
Patients undergoing laparoscopy under general anesthesia had less PONV when receiving 2Hz/100Hz electro-acupuncture.
Electro-acupuncture decreased opiod adverse effects after lower abdominal surgery.
A general observation of the effective studies was that deqi was obtained and to a degree to which minimal discomfort was perceived.
A pediatric study of tonsillectomy and adenoidectomy demonstrated less vomiting in the acupuncture group over the control group.
Acupuncture point combination PC6 combined with ST36 demonstrated the ability to reduce PONV over controls.
General anesthesia did not block the antiemetic action of needling PC6 in a randomized, controlled study.
Acupuncture Clinical Highlight
Let’s take a look at the Traditional Chinese Medicine (TCM) classical view of acupuncture point PC6, also known as P6, P-6 and Neiguan (Inner Pass, Inner Gate). The information presented is part of the Healthcare Medicine Institute’s (HealthCMi) dedication to acupuncture continuing education and is drawn from classical TCM resources. Explore the HealthCMi website to learn more about acupuncture continuing education for acupuncture CEU and acupuncture PDA credit for the USA, Canada and more.
The PC6 acupuncture point is located 2 cun above the transverse crease of the wrist on the medial aspect of the forearm between the tendons of the palmaris longus and flexor carpi radialis. It is a luo point and confluent point of the Yin Wei (Linking) channel. PC6 functions to calm the heart and Shen, regulate Qi, harmonize the stomach, invigorate blood, calm the fetus, induce lactation, open the chest and diaphram, clear heat and suppress pain. Traditional indications for the use of PC6 include cardiac and chest pain, palpitations, stomachache, nausea, vomiting, hiccup, mental disorders and seizures including epilepsy.
PC6 is a paired confluent point with SP4, confluent point of the Chong (Thoroughfare) channel. In this combination, it is indicated for the treatment of heart, chest and stomach disorders. Several confluent points are also luo points, connecting points that are located where the interiorly-exteriorly related channels cross. Both SP4 and PC6 are both confluent points and luo points. The other confluent points that are luo points are LU7 and TB5. The luo point power of PC6 gives it the ability to regulate the San Jiao channel in an exterior-interior channel relationship. It combines with TB4, which is the Yuan (source) point of the San Jiao channel, in a host and guest (source-luo) application. A traditional use of the source-luo combination is the selection of the source point from the primary channel affected by a disorder and the luo point from the secondary channel affected by a disorder. This combination creates a synergistic effect.
PC6 is indicated for the treatment of cardiac pain when combined with PC4. It is also indicated for suffocated chest syndrome when combined with CV17. PC6 is a distal point, sometimes combined with ST36, for the treatment of upper abdominal pain. It is a distal point often combined with ST40 for the treatment of chest pain.
The great Prof. Wae Shui indicated Neiguan (PC6) for the treatment of painful ribs and chest, gastralgia, palpitations, hiccoughing, nausea, vomiting, asthma, swollen and painful throat, hysteria and epilepsy. Prof. Shui included Neiguan in his prescription for the treatment of “incessant vomiting, diarrhea, gastralgia and bellyache due to unwholesome food and drinks.” The following acupuncture point prescription is applied with mild stimulation of the needles: ST36 (Zusanli), CV12 (Zhongwan), CV13 (Shangwan), Qizhou (four points located on each side of the navel at 0.5 cun distance) and PC6 (Neiguan).
Needling technique is dependent upon clinical requirements. PC6 is perpendicularly needled 0.5 to 1.0 cun or it is connected to SJ5 (Waiguan). A 1.0 to 1.5 cun oblique, proximal insertion technique is applied for disorders of the chest whereas a distal insertion angle is applied for disorders of the fingers. Notably, the median nerve is located directly beneath this point. Deqi is achieved and an electric sensation is often experienced, however, continued manipulation of PC6 is not applied after deqi is achieve to avoid damage to the median nerve. Application of PC6 is therefore only to be applied by licensed acupuncturists.
Many classical TCM acupuncture point prescriptions for the treatment of cardiac pain include PC6. The Shen, spirit, aspect of the point goes to the inclusion of PC6 in acupuncture point prescriptions for mental restlessness, insomnia, emotional disturbances and hypertension. A great deal of TCM literature is devoted to the application of PC6 for the treatment of rebellious stomach Qi including nausea, vomiting and hiccups. Other digestive disorders indicated include abdominal pain and distention, blood in the stools, borborygmus, diarrhea, prolapsed anus and food stagnation. PC6 is also indicated for febrile diseases including fever with the absence of sweating, icteric sclera, jaundice and malaria. PC6 is indicated for the treatment of local pain but also for pain of the upper arm, head and neck.
Reference:
Cheong, Kah Bik, Ji-ping Zhang, Yong Huang, and Zhang-jin Zhang. "The Effectiveness of Acupuncture in Prevention and Treatment of Postoperative Nausea and Vomiting-A Systematic Review and Meta-Analysis." PLOS ONE 8, no. 12 (2013): e82474.
