1 Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE, USA. Electronic address: teschult@unmc.edu.
2 Department of Anesthesia, Brigham and Women's Hospital, Boston, MA, USA.
3 Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
4 Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA.
5 Department of Anesthesiology, University of Colorado Anschutz School of Medicine, Aurora, CO, USA; Department of Anesthesiology, Orthopedics and Rehabilitation; and Surgery, University of Vermont Larner College of Medicine, Burlington, VT, USA.