1. From the Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois (F.M.P., N.H., P.T., M.J.J.); Department of Anesthesia, University of Iowa Carver College of Medicine, Iowa City, Iowa (C.A.W.); Department of Anesthesiology, Rush University Medical Center, Chicago, Illinois (R.J.M.).