[1]Department of Emergency Medicine and Center for Resuscitation Science University of Pennsylvania Philadelphia PA 19104 USA;
[1]Department of Emergency Medicine and Center for Resuscitation Science University of Pennsylvania Philadelphia PA 19104 USA;
[1]Department of Emergency Medicine and Center for Resuscitation Science University of Pennsylvania Philadelphia PA 19104 USA;
[1]Department of Emergency Medicine and Center for Resuscitation Science University of Pennsylvania Philadelphia PA 19104 USA;
[4]School of Nursing University of Pennsylvania Philadelphia PA 19104 USA;
[1]Department of Emergency Medicine and Center for Resuscitation Science University of Pennsylvania Philadelphia PA 19104 USA;
[2]Department of Medicine University of Pennsylvania Philadelphia PA 19104 USA;
[2]Department of Medicine University of Pennsylvania Philadelphia PA 19104 USA;
[3]Department of Biostatistics and Epidemiology University of Pennsylvania Philadelphia PA 19104 USA;
[1]Department of Emergency Medicine and Center for Resuscitation Science University of Pennsylvania Philadelphia PA 19104 USA;