[1] Univ Texas Southwestern Med Ctr Dallas, Dept Anesthesiol & Pain Management, 5323 Harry Hines Blvd, Dallas, TX 75390 USA
[2] Northwestern Univ, Dept Anesthesiol, Feinberg Sch Med, Chicago, IL 60611 USA
[3] SUNY Stony Brook, Dept Anesthesiol, Stony Brook, NY 11794 USA
[4] Univ Texas Austin, Dept Surg & Perioperat Care, Dell Med Sch, Austin, TX 78712 USA