Nurse Anesthetist Study Reveals Possible Risks toSurgical Patients Who Use...

Health/Medical Editors

PARK RIDGE, Ill.--(BW HealthWire)--March 14, 2000

AANA Advises Full Disclosure of Herb, Vitamin

and Supplement Use Before an Operation

The American Association of Nurse Anesthetists (AANA) recently published a study reporting that patients

The study, titled "Use of complementary and alternative medicines by surgical patients," appears in the February issue of the AANA Journal and evaluates the interaction of vitamins, herbs, dietary supplements and homeopathic medicines with anesthetics. Based on a survey of 500 elective surgical outpatients from the University of Colorado Health Sciences Center (UCHSC) in Denver, the study categorizes complementary and alternative medicines (CAM) according to their potential to cause "adverse effects" with drugs used during surgery. The study, which underscores the relationship between conventional and unconventional medicines, profiles patient use of CAM.

Of the 500 patients surveyed, more than half consumed one or more types of alternative medicines during a two-week period before surgery. Garlic and cranberry represented the most common herbal substances consumed followed by echinacea, gingko and ginseng respectively. The vitamins most frequently taken included vitamin C, multivitamins and vitamin E. The survey also indicates that 220 patients took 31 types of dietary supplements including calcium, fish oil, magnesium or zinc.

More popular with women than men, the study found that some alternative medicines can increase bleeding and prolong coagulation during surgery. Twenty-seven percent of patients surveyed consumed vitamins, herbs and supplements that could increase the time it takes for blood to clot. Alternative medicines that may prolong coagulation include alfalfa, chamomile, some Chinese herbs, garlic, ginko, kava, licorice, vitamin E and fish oil.

Fifty-eight patients or 12 percent of survey respondents took herbs that could adversely impact blood pressure levels during surgery. Black cohosh, used to treat menopause, menstrual cramps and osteoporosis, can lower a patient's blood pressure. St. John's wort, used to control depression, can raise blood pressure as well as cause confusion, agitation and drowsiness in surgical patients.

The study also links some herbs to heart irregularities and others to electrolyte imbalance. Ephedra, an herb used to treat coughing, asthma and weight loss, can trigger arrhythmia and high blood pressure while licorice, used to control coughing and soothe sore throats, can raise the risk of hypokalemia, a potassium deficiency that can cause arrhythmia. Herbal diuretics, which increase urine output, can also deplete potassium levels and cause electrolyte imbalance. Sedative herbs, like kava, can cause severe drowsiness when combined with the hypnotic drugs used during surgery.

Carol Norred, a Certified Registered Nurse Anesthetist (CRNA), researcher and Ph.D. student at the UCHSC Department of Anesthesiology and School of Nursing, believes that more scientific research is needed to safely integrate CAM into the management of surgical patients. Norred, who spearheaded "Use of complementary and alternative medicines by surgical patients," believes an open dialogue between patients and providers can prevent complications related to the use of unconventional medicines.

"Most patients who take alternative medicines never tell their providers about it. This can compromise a patient's safety if these medicines aggravate a health condition or interact poorly with the drugs used during surgery. As advocates of patient safety, we at the AANA advise patients to disclose information about CAM use prior to surgery," she says.

About the American Association of Nurse Anesthetists

Founded in 1931 and located in Park Ridge, Ill., the American Association of Nurse Anesthetists (AANA) is the professional organization for more than 27,000 Certified Registered Nurse Anesthetists (CRNAs). Advanced practice nurses, CRNAs administer approximately 65 percent of the 26 million anesthetics delivered in the United States each year. CRNAs practice in every setting where anesthesia is available and are the sole anesthesia providers in more than two-thirds of all rural hospitals.