(Leisure) Assistant Professor of Anesthesiology, Department of Anesthesiology, University of Virginia Medical Center, Charlottesville, Virginia.
(O'Flaherty) Chief Resident, Department of Anesthesiology, University of Virginia Medical Center, Charlottesville, Virginia.
(Green) Food and Drug Administration, Center for Drug Evaluation and Research, Office of Epidemiology and Biostatistics, Rockville, Maryland.
(Jones) Attending Physician, Vinton, Virginia.
Received from the Department of Anesthesiology, University of Virginia Medical Center, Charlottesville, Virginia. Submitted for publication March 23, 1995. Accepted for publication August 17, 1995.
Address correspondence to Dr. Leisure: Department of Anesthesiology, Box 238, University of Virginia Medical Center, Charlottesville, Virginia 22908.