1 Department of Anesthesia & Perioperative Care, University of California, San Francisco, 500 Parnassus Avenue, Campus Box 0648, San Francisco, CA 94143, USA. Electronic address: elizabeth.whitlock@ucsf.edu.
2 Department of Anesthesiology, Columbia University Irving Medical Center, 622 West 168th Street PH5-546, New York, NY 10032, USA. Electronic address: raw9@cumc.columbia.edu.