1. From the Departments of Anesthesiology/Critical Care Medicine (T.-Y. C., T.G., T.J.K.T., J.R.K., P.D.H., R.C.K., A.B.) and Neurology (A.B.), Johns Hopkins University School of Medicine, Baltimore, Md; Department of Anesthesiology and Peri-operative Medicine (J.R.K., P.D.H.), Oregon Health and Science University, Portland, Ore.