[1] Harvard Med Sch, Boston, MA 02115 USA
[2] Brigham & Womens Hosp, Dept Anesthesiol Perioperat & Pain Med, 75 Francis St, Boston, MA 02115 USA
[3] Brigham & Womens Hosp, Ctr Surg & Publ Hlth, 75 Francis St, Boston, MA 02115 USA
[4] Brigham & Womens Hosp, Ariadne Labs, 75 Francis St, Boston, MA 02115 USA
[5] Brigham & Womens Hosp, Dept Emergency Med, 75 Francis St, Boston, MA 02115 USA
[6] Ctr Med Simulat, Boston, MA USA