When a patient is scheduled for an elective surgery, he/she usually has nothing to eat after midnight prior to the operation. A fasting period before surgery is done to avoid possible side effects during the placement of a breathing tube. Having an empty stomach is thought to decrease the chances of vomiting or aspiration while a breathing tube is placed. (Aspiration occurs when a substance, such as food provided by a tube feed, enters the airway.) However, some patients already have a breathing tube in place. The investigators do not know which is better for patients who already have a breathing tube in place: continuing feedings up until surgery or stopping them the night before.