title: Reply.
authors.affiliation: Department of Emergency Medicine, University Hospitals Ahuja Medical Center, Case Western Reserve University, Cleveland, Ohio.
authors.forename: Jessica
authors.initials: J
authors.lastname: Resnick
authors.affiliation: Department of Emergency Medicine, MetroHealth Medical Center, Case Western Reserve University, Cleveland, Ohio.
authors.forename: Rita
authors.initials: R
authors.lastname: Cydulka
authors.affiliation: Department of Emergency Medicine, Brigham and Women's Hospital, Harvard University, Boston, Massachusetts.
authors.forename: Elke
authors.initials: E
authors.lastname: Platz
authors.affiliation: Department of Emergency Medicine, MetroHealth Medical Center, Case Western Reserve University, Cleveland, Ohio.
authors.forename: Robert
authors.initials: R
authors.lastname: Jones
mesh_terms: D001782:Blood Donors; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D012771:Shock, Hemorrhagic / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging*