T T Dong1, J Mellin-Olsen2, A W Gelb3. 1. Department of Anesthesia and Perioperative Care, University of California San Francisco, 513 Parnassus Avenue, Room S436, San Francisco, CA 94143, USA. 2. Department of Anaesthesiology and Intensive Care Medicine, Baerum Hospital, PO Box 83, Oslo N-1309 RUD, Norway. 3. Department of Anesthesia and Perioperative Care, University of California, San Francisco, 521 Parnassus Avenue, San Francisco, CA 94143, USA adrian.gelb@ucsf.edu.