1. From the Department of Anesthesiology and Pain Management (E.E.H.) and Department of Clinical Sciences (A.M.), University of Texas Southwestern Medical Center, Dallas, Texas; and Department of Anesthesiology, The University of Texas Medical Branch, Galveston, Texas (M.S., S.R.V., C.F.Z., S.M.S., A.E.A.). Department to which work attributed: University of Texas Medical Branch, Galveston, Texas.