1. Department of Cardiovascular and Thoracic Surgery, University of Louisville, Louisville, KY, USA
2. Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA.
3. Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO, USA
4. Department of Anesthesiology & Perioperative Medicine, University of Louisville, Louisville, KY, USA