Up to 80 percent of patients who have surgery complain of nausea and vomiting afterwards, but stimulating an acupoint in their wrists can help reduce these symptoms, finds a new evidence review.
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."