Randall Hough, BSN, Stanford Life Flight, Stanford University Medical Center, California.

Sylvan Charles Cox, MD, Division of Critical Care, Department of Internal Medicine, Stanford University Medical Center, California.

Erica Chimelski, MD, Department of Emergency Medicine, Stanford University Medical Center, California.

Fred G. Mihm, MD, Department of Anesthesiology, Stanford University Medical Center, California.

Joshua M. Tobin, MD, MSc, Department of Anesthesiology, Stanford University Medical Center, California.

The authors have disclosed that they have no significant relationship with, or financial interest in, any commercial companies pertaining to this article.

Ethics approval for this investigation was granted by the Stanford University Medical Center Institutional Review Board (no. 55991).

Address correspondence and reprint requests to: Joshua M. Tobin, MD, MSc, Department of Anesthesiology, Stanford University Medical Center, 300 Pasteur Dr, Rm H3580, MC 5640, Stanford, CA 94305 ([email protected]).