DURHAM, N.C. – In the first such clinical trial of its kind, researchers at Duke University Medical Center have found that acupuncture is more effective at reducing nausea and vomiting after major breast surgery than the leading medication.
The researchers also found that patients who underwent the 5,000-year-old Chinese practice reported decreased postoperative pain and increased satisfaction with their postoperative recovery. In conducting the trial, the researchers also demonstrated that the pressure point they stimulated possesses previously unknown pain-killing properties.
Results of the Duke study were published Sept. 22, 2004, in the journal Anesthesia and Analgesia.
Treating postoperative nausea and vomiting (PONV) is an important medical issue. About 70 percent of women who undergo major breast surgery requiring general anesthesia suffer from this complication, according to Duke anesthesiologist Tong Joo (T.J.) Gan, M.D., who led the trial. These adverse side effects are important factors in determining how soon patients can return home after surgery.
"The patients in our randomized trial who received acupuncture enjoyed a more comfortable recovery from their surgery than those who received an antisickness medication," Gan said. "In the areas of PONV control, pain relief, and general overall satisfaction, acupuncture appears to be more effective than the most commonly used medication, with few to no side effects."
In the trial, Gan employed an electro-acupuncture device in which an electrode – like that used in standard EKG tests – is attached at the appropriate point. In this case, the point is known as P6 and is located below the wrist. Instead of actually breaking the skin with the traditional long slender needles, the electro-acupuncture device delivers a small electrical pulse through the skin.
"Electro-acupuncture enhances or heightens the effects of traditional acupuncture," Gan explained. "Also, in the busy and complicated setting of the operating room, the electro-acupuncture device is much more convenient to use."
The researchers enrolled 75 women who were to undergo major breast surgery (breast augmentation, breast reduction or mastectomy) requiring the use of general anesthesia. They were then randomized into three groups: one which received acupuncture, one which received the medication ondansetron (trade name Zofran), and a group that received neither.
The surgeries lasted anywhere from two to four hours, and the incidence of PONV and pain were tracked at 30-minute intervals for the first two hours after surgery, and then again 24 hours later.
Two hours after surgery, 77 percent of the patients receiving acupuncture experienced no PONV, nor did they require an antiemetic drug to reduce nausea and vomiting, compared to 64 percent for those who received ondansetron and 42 percent who received nothing. At 24 hours, the rates were 73 percent, 52 percent and 38 percent, respectively.
"When used for the prevention of PONV, electro-acupuncture stimulation or ondansetron was more effective than placebo with a greater degree of patient satisfaction, but the electro-acupuncture appears to be more effective in controlling nausea, compared to ondansetron," Gan said.
The electro-acupuncture was applied at the 6th point (P6) along the pericardial meridian, which is located two inches below the bottom of the palm of the hand and between the two tendons connecting the lower arm with wrist. According to Chinese healing practices, there are about 360 specific points along 14 different lines, or meridians, that course throughout the body just under the skin.
"The Chinese believe that our vital energy, known as chi, courses throughout the body along these meridians," Gan explained. "While healthiness is a state where the chi is in balance, unhealthiness arises from either too much or too little chi, or a blockage in the flow of the chi. By applying acupuncture to certain well-known points, the Chinese believe they can bring the chi back into balance."
While pressure on other acupuncture points – LI4 on the hand, SP6 on the leg and "back-shu" along the spine – are known to have pain-killing effects, this is the first to show that P6 also has analgesic effects to go along with its known antiemetic properties, Gan said.
While it is not completely known why or how acupuncture – whether electro-acupuncture or traditional – works, recent research seems to point its ability to stimulate the release of hormones or the body's own painkillers, known as endorphins, Gan said.
Interestingly, Gan said, low-frequency modulation of the electro-acupuncture device appears to release one type of endorphin that produces analgesia of slower onset but longer duration. When higher frequencies are used, the body appears to produce another type of endorphin that provides rapid analgesia, but of shorter duration.
The scientists will conduct further studies comparing the various combinations of these frequencies, as well as comparing the combination of acupuncture with other antiemetic medications.
Gan said that women in general are three times more likely to suffer from PONV after major surgery than men, though the reasons why are not known.
The research was supported by Duke's Department of Anesthesiology. Members of Gan's team were, all from Duke: Kui Ran Jiao, M.D., Michael Zenn, M.D., and Gregory Georgiade, M.D.
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