[1] Johns Hopkins Med Inst, Dept Anesthesiol & Crit Care Med, Baltimore, MD 21205 USA
[2] Johns Hopkins Med Inst, Dept Pharm, Crit Care Surg Div, Baltimore, MD 21205 USA
[3] Johns Hopkins Med Inst, Dept Pathol, Baltimore, MD 21205 USA
[4] Johns Hopkins Med Inst, Dept Anesthesiol & Crit Care Med, Armstrong Inst Patient Safety & Qual, Johns Hopkins Hlth Syst Blood Management Program, Baltimore, MD 21205 USA