Treatment for nausea and vomiting after surgery and anesthesia typically calls for the use of anti-nausea (antiemetic) medications. However, the cost and side effects of these medications have raised interest in finding more simple and noninvasive ways to prevent the symptoms. The aim of the systematic review was to determine whether stimulation of the wrist acupuncture point is an effective option.

The Pericardium (P6) point is in the wrist and its stimulation prevents nausea and vomiting, the researchers found.

The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.

Author Anna Lee of the Department of Anesthesia and Intensive Care at The Chinese University of Hong Kong led the current review. It is an update of a previous 2004 Cochrane review, which Lee also led.

Stimulating the P6 point can occur by several methods such as acupuncture or acupressure. Acupuncture involves penetrating the skin with thin, metallic needles at defined points. It is one of the main medical treatments in traditional Chinese medicine and began there more than 2,000 years ago. One type of acupressure involves wearing a wristband that presses down on the P6 point.

Lixing Lao, a licensed acupuncturist and director at the Center for Integrative Medicine at the University of Maryland School of Medicine, described how the treatment works to prevent nausea.

"After a stimulation on the acupuncture point, the nerve system is then activated and signals the brain to release certain chemicals known as neurotransmitters, such as serotonin, dopamine or endorphins," Lao said. "These then block the other chemicals that cause the sickness, nausea and vomiting, in this case, in the central nerve system. Therefore, the patient won’t feel that sick or nauseated."

Lee and her colleague evaluated 40 studies comprising 4,858 patients. Most of the studies involved healthy adults undergoing elective surgery with general anesthesia. The studies all compared the stimulation of the P6 acupoint with sham (placebo) treatment or drug therapy with antiemetics for preventing nausea and vomiting after surgery.

The studies used 10 different methods of P6 stimulation, such as needle acupuncture, laser stimulation, transcutaneous (through the skin) nerve stimulation and acupressure wristbands. They used five different antiemetic drugs.

"Of the 40 trials included, the most common method of stimulation was wristband alone, in 17 studies," Lee said. "The wristbands used to prevent both postoperative nausea and vomiting are the same sold for seasickness, travel sickness, morning sickness and chemotherapy-related nausea and vomiting."

The Cochrane reviewers found that compared to sham treatment, stimulation of the P6 acupoint can significantly reduce the risk of nausea and vomiting after surgery, with few side effects. Lee said that "for 100 people, of whom 80 would vomit or feel sick after surgery if given sham treatment, about 25 people would benefit from P6 stimulation and 75 would not."

When compared to the use of antiemetic medications, however, the reviewers found no reliable evidence that showed any difference in whether acupoint stimulation is more effective in preventing postoperative nausea and vomiting. They concluded that it can be used as a "suitable alternative or addition to" the medications.

Lee concluded that reducing nausea and vomiting for surgery patients through P6 point stimulation could reduce costs, such as the cost of antiemetic medication and length of hospital stays, and improve the quality of patient care.

Lee said that in her homeland of Hong Kong, P6 stimulation methods are "not used widely, if at all."

"Generally, physicians and patients are not aware of this type of treatment for preventing postoperative nausea and vomiting," she said. "Translating the evidence from this updated Cochrane review into clinical practice will take time."