1 Division of Pulmonary, Allergy, and Critical Care, Duke University Medical Center, Durham, NC; Department of Internal Medicine, Duke University Medical Center, Durham, NC. Electronic address: Evan.schwartz@duke.edu.
2 Department of Internal Medicine, Duke University Medical Center, Durham, NC; Division of Adult Cardiothoracic Anesthesiology, Duke University Medical Center, Durham, NC; Department of Anesthesiology, Duke University Medical Center, Durham, NC.
3 Department of Internal Medicine, Duke University Medical Center, Durham, NC; Department of Anesthesiology, Duke University Medical Center, Durham, NC; Duke University School of Medicine, Durham, NC; Durham VA Health Care System, Durham, NC.
4 Department of Internal Medicine, Duke University Medical Center, Durham, NC; Department of Anesthesiology, Duke University Medical Center, Durham, NC; Division of Adult Critical Care Anesthesia, Duke University Medical Center, Durham, NC.