According to the Free Dictionary, the reverse Trendelenburg position is one in which a person is lying supine with the head elevated higher than the rest of the body and the feet supported with a foot board. It is the opposite of the Trendelenburg position, in which a person is placed in a supine position with the foot of the bed raised about 30 to 45 degrees.
Wikipedia explains that the Trendelenburg position was first described by German physician Friedrich Trendelenburg, a prominent surgeon. It is the preferred position for patients undergoing pelvic and lower abdominal surgery since it results in the abdominal organs shifting upward and away from the surgeon's view. The reverse Trendelenburg position is often preferred by surgeons who are operating on morbidly obese individuals.
According to an article in Anesthesia and Analgesia, the reverse Trendelenburg position improves the patient's breathing and maintains the arterial blood pressure in a more stable range. Even in non-obese individuals, the position has some surgical benefits, according to Oxford Journals. These include improved drainage of blood from the head and neck region, reduced intracranial pressure and a decreased likelihood of regurgitation of stomach contents. The most common complications associated with this position are lowered blood pressure and venous air embolism, or introduction of air into the venous blood.