[1] Univ Calif San Diego, Dept Anesthesiol, San Diego, CA 92103 USA
[2] John H Stroger Jr Hosp Cook Cty, Dept Anesthesiol & Pain Management, Chicago, IL USA
[3] Louisiana State Univ, Hlth Sci Ctr, Dept Anesthesiol, New Orleans, LA USA
[4] US Anesthesia Partners, Ft Lauderdale, FL USA
[5] Harvard Med Sch, Brigham & Womens Hosp, Dept Anesthesiol Perioperat & Pain Med, 75 Francis St, Boston, MA 02115 USA