[Knowledge of perioperative risk associated with use of medicinal plants]

To assess physicians' knowledge of perioperative risk for patients who consume medicinal plants. To review interactions between drugs and the main medicinal plants with a view to justifying a plan for preoperative intervention.

Surgeons and anesthesiologists were sent an e-mail survey with questions on knowledge of and attitudes toward surgical patients' consumption of medicinal plants. At the same time, we performed a literature search on the species of plants that can interact with anesthetic and surgical processes. The species included were Allium sativum, Ephedra sinica, Echinacea purpurea, Ginkgo biloba, Panax ginseng, Hypericum perforatum, Piper methysticum, Glycyrrhiza glabra and Valeriana officinalis. The focus of the search was on indications for the use of these plants and their interactions with drugs.

The questionnaire was sent to 131 physicians. The response rate was 80.5%. Twenty-two physicians had trained in Spanish hospitals and 3 in hospitals abroad. Medicinal plants were believed to be effective by 55%, but 78% did not ask patients about their use. Only 3% knew the interactions of some of the plants mentioned in the survey and only 7% knew that the use of some should be suspended before surgery.

Medicinal plants are currently being used in our culture. In spite of appropriate warnings from such scientific bodies as the American Society of Anesthesiologists on timing the withdrawal of medicinal plants before surgery, our results indicate that the advice is not followed. We also found that physicians lacked knowledge of the indications for using these plants and their interactions, a situation which is alarming.