[1] Washington Univ, Sch Med, Div Emergency Med, Dept Anesthesiol,Div Crit Care, St Louis, MO 63110 USA
[2] Univ Iowa, Dept Anesthesia, Roy J & Lucille A Carver Coll Med, Dept Emergency Med,Div Crit Care, Iowa City, IA 52242 USA
[3] Barnes Jewish Hosp, Dept Pharm, St Louis, MO 63110 USA
[4] Washington Univ, Sch Med, Div Emergency Med, St Louis, MO 63110 USA