Herbal medicines--a cautionary tale

We report an extensive intra-operative bleed which may have occurred as a result of the patient taking a herbal medicine. The patient underwent orthognathic surgery as a part of his orthodontic treatment, and lost approximately 3.5 litres of blood during the procedure. Preoperative blood tests were normal; the patient took no prescription medications and an appendectomy had been performed without incident. To aid healing, however, the patient had taken arnica the day before his operation. A concise literature review is presented which outlines the causes of surgical bleeding and discusses some of the bleeding concerns that herbal medicine use may raise for clinicians. Herbal medicines may contribute to unexplained surgical bleeding in the absence of other causative factors; it would therefore be useful to include an enquiry about the taking of herbal remedies at the history-taking stage for dental and maxillofacial surgical procedures.