Why must I fast prior to surgery?

Anesthesia depresses the normal gag reflex that prevents solids and liquid matter from entering our lungs. The process of reflux of material from the stomach into the trachea and lungs is called aspiration. Fortunately, the incidence is quite low. According to recent studies, the rate is between 1-5 per hundred thousand anesthetics. Assuring that the stomach is as empty as possible prior to anesthesia is a mainstay in aspiration reduction. This has been routinely accomplished by nothing to eat or drink after midnight, the day of surgery (NPO after midnight). In emergency operations, patients obviously have not fasted. In these cases we can alter the anesthetic delivery and induction to insure maximum safety .