[1] George Washington Sch Med & Hlth Sci, Dept Anesthesiol & Crit Care Med, Washington, DC USA
[2] Univ Mississippi, Med Ctr, Dept Anesthesiol, Jackson, MS 39216 USA
[3] Univ Mississippi, Med Ctr, Dept Pediat, Jackson, MS 39216 USA
[4] NHLBI, Sickle Cell Branch, NIH, Bldg 10, Bethesda, MD 20892 USA
[5] NIH, Dept Perioperat Med, Clin Ctr, Bldg 10, Bethesda, MD 20892 USA