February 25, 2002

ontrolled, deep breathing relieves nausea in many patients recovering from surgery, according to a study conducted at the Health Center.

"Deep breathing alone appears to give relief from nausea," said Lynn Anderson, a registered nurse, who conducted the study with anesthesiologist Jeffrey Gross. She presented the results of her study at the annual meeting of the American Society of Anesthesiolo gists late last year.

"Deeply breathing the vapors of alcohol, peppermint, and a saline solution all worked equally well to relieve nausea in patients recovering from surgery," says Anderson, assistant nurse manager of the Post Anesthetic Care Unit at the Health Center.

Nausea scores were cut in half at five minutes after the breathing therapy, whether the patients breathed in alcohol, peppermint, or the placebo saline solution, she says. The use of anti-vomiting drugs was cut in half among patients in the study, and satisfaction scores were high.

"We were pretty surprised that it worked as well as it did and that patients were so pleased with the treatment," says Anderson. "Overall satisfaction was 87 percent - extremely high when you consider that the patients were pretty uncomfortable to begin with. They had to be complaining of nausea to be included in the study.

"We started our study to determine whether the aroma of alcohol or peppermint worked better to relieve nausea," Anderson says. "Our curiosity began after Dr. Gross asked the nurses to let post-operative patients inhale alcohol vapors when they were feeling nausea. We didn't think much of the idea at first, so we were amazed to find that it really seemed to work. Then we heard that the aroma of peppermint also worked to relieve nausea. So we wanted to find out which worked better."

Anderson and Gross studied 33 ambulatory surgery patients who reported nausea in the Post Anesthetic Care Unit. They were divided into three groups. One group received aromatherapy using isopropyl alcohol. Another group received the therapy using oil of peppermint, and the third group inhaled a placebo saline solution. With scented gauze pads held directly beneath their nostrils, patients were instructed to inhale slowly through the nose and exhale slowly through the mouth three times.

The patients were assessed for nausea at two and five minutes. The aromatherapy exercises halved nausea scores at five minutes after treatment, regardless of aroma, including the placebo. Nearly half the study patients (45 percent) still required medication for nausea during their stay in the unit, but typically 100 percent of the patients complaining of nausea would have received the drugs. "We think that's a big improvement," Anderson says.

"Physiologically, we think the deep breathing worked to reduce nausea because of the closeness of the vomiting center to the respiratory center in the brain," she adds. "Perhaps when the respiratory center in the brain is focused on taking controlled deep breaths, the vomiting center might be less able to process thoughts about nausea."

The breathing therapy has become part of routine practice in the Post Anesthetic Care Unit. And it has spread to other parts of the hospital, including obstetrics and inpatient surgery units. "It's cheap, immediately effective, and there are no known side effects," says Anderson. "It's even better than we thought."