* Fellow, Human Pharmacology Laboratory, Department of Anesthesiology, Duke University Medical Center. Current position: Attending Anesthesiologist, Department of Anesthesiology, Mackay Memorial Hospital, Taiwan. † Fellow, Human Pharmacology Laboratory, Visiting Associate, Department of Anesthesiology, Duke University Medical Center. Current position: Attending Anesthesiologist, Department of Anesthesiology, Catholic University School of Medicine, Santiago, Chile. ‡ Associate Clinical Professor, ∥ Assistant Clinical Professor, Department of Anesthesiology, # Assistant Professor, Director, Human Pharmacology Laboratory, Department of Anesthesiology, Duke University Medical Center. § Professor of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, Dallas, Texas. Chief of Anesthesiology, VA North Texas Health Care System, Dallas, Texas.