1 Departments of Anesthesiology, Critical Care, and Surgery (Cardiothoracic), Duke University School of Medicine, 2301 Erwin Rd, 5691H HAFS, Box 3094, Durham, NC 27710. Electronic address: jerrold.levy@duke.edu.
2 Divisions of Hematology and Critical Care, Department of Pediatrics, University of Minnesota School of Medicine, Minneapolis, Minnesota.