New horizons: looking east to remedy nausea.

Researchers at Duke University published the findings of a randomized controlled comparison of two very different techniques to reduce post-operative nausea and vomiting in women undergoing major breast surgery. The standard drug ondansetron, 4 mg of which were administered by IV to a third of the 75 women, was effective at reducing post-operative nausea--but not as effective as electro-acupoint stimulation (beginning 30 minutes before anesthesia). This needle-free, electrode-based acupuncture technique stimulated an area of the wrist thought in traditional Chinese medicine to be linked to one of the body's major energy lines, the pericardial meridian. A third group of women received no drugs and only sham acupoint, which consisted of electrode placement without an electrical pulse.

The anesthesia regimen was standardized across all three groups, and incidence of nausea, vomiting and anti-emetic (anti-vomiting) use, as well as patient pain and satisfaction levels, were assessed every 30 minutes for two hours, and then at 24 hours post-surgery. At two hours, 77% of acupoint patients had no nausea, vomiting or need for anti-emetic rescue, compared to 64% and 42% for the ondansetron and placebo groups, respectively.

The most dramatic differences in the treatment groups were in incidents of nausea: 19% of the acupoint group, 40% of the drug therapy group and 79% of the group receiving no treatment. The researchers also found the acupoint treatment to have analgesic effects not found with ondansetron use.

When used for the prevention of post-operative nausea and vomiting, electro-acupoint stimulation and ondansetron were each more effective than placebo and provided a greater degree of patient satisfaction, but electro-acupoint stimulation seems to be more effective in controlling nausea. The mechanism by which acupoint works is not well understood, but similar results have been reported before.

In 2002, a double-blind, randomized, placebo-controlled study in Austria found that with minor gynecological surgery, incidents of post-operative nausea and vomiting were reduced with Korean hand acupressure (a needle-free procedure that involves the application of pressure using acupressure "seeds"). The treatment groups did not differ with regard to demographics, surgical procedure, or anesthetic administered. In the acupressure group, the incidence of nausea and vomiting was significantly less (40% and 22.5%) than in the placebo group (70% and 50%).

And in January of 2004, the University Hospital of Vienna applied the same technique to geriatric pre-hospital trauma care patients, who during transportation to the hospital are frequently prone to motion sickness. The 100 minor-trauma patients who participated in the study were randomly divided into acupressure and sham acupressure groups. All patients had been nauseated at the emergency site, and nausea levels were similar between groups, but at the time of arrival in the hospital, nausea scores were significantly different between the acupressure and sham groups. Peripheral vasoconstriction was used to measure nausea, and the study found that only 4 of the 50 patients were constricted in the acupressure group, compared to 48 of the 50 in the placebo group. At the hospital, the acupressure group also had a significantly lower heart rate, of 65 +/- 6 bpm versus 98 +/- 8 bpm in the sham group. Neither group experienced a significant change in blood pressure.

Acupressure, acupuncture and electro-acupoint stimulation clearly need further testing, given that the precise reasons they appear effective remain mysterious, but these studies are promising. In particular, the electrode placement approach may be the most practical because it does not rely on special knowledge of non-traditional therapies; any anesthesiologist who learns the correct placement of the electrodes can administer the treatment.

(Anesth. Analg., 2004, Vol. 99, No. 4, pp. 1070-1075; Vol. 98, No. 1, pp. 220-223; 2002, Vol. 94, No. 4, pp. 872-875)