William P McKay1, Trevor Krysak2, Chung-Chun Tyan3. 1. Department of Anesthesia, University of Saskatchewan, Saskatoon, SK, Canada. bill.mckay@usask.ca. 2. Department of Anesthesia, University of Saskatchewan, Saskatoon, SK, Canada. 3. Division of Respirology, Sleep Medicine, and Critical Care, University of Saskatchewan, Saskatoon, SK, Canada.