1. * Associate Professor of Clinical Anesthesiology, College of Physicians and Surgeons of Columbia University.† Assistant Professor of Anesthesiology, College of Physicians and Surgeons of Columbia University.‡ Professor of Anesthesiology, College of Physicians and Surgeons of Columbia University.§ Professor of Anesthesiology and Obstetrics and Gynecology, College of Physicians and Surgeons of Colu