1 Department of Anesthesiology, University of Minnesota School of Medicine, Minneapolis, Minnesota Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, Iowa Department of Anesthesiology, University of Minnesota School of Medicine, Minneapolis, Minnesota Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, Iowa, mmtodd@umn.edu, michael-todd@uiowa.edu.