Increased survival after EMS witnessed cardiac arrest. Observations from the Resuscitation Outcome Consortium (ROC) Epistry--Cardiac arrest.
David Hostler, Elizabeth G. Thomas, Scott S. Emerson, James Christenson, Ian G. Stiell, Jon C. Rittenberger, Kyle R. Gorman, Blair L. Bigham, Clifton W. Callaway, Gary M. Vilke, Tammy Beaudoin, Sheldon Cheskes, Alan Craig, Daniel P. Davis, Andrew Reed, Ahamed Idris, Graham Nichol and The Resuscitation Outcomes Consortium Investigators. Resuscitation, In Press, Available online 18 April 2010
Data were analyzed from a prospective, population-based cohort study in 10 U.S. and Canadian ROC sites. Individuals with non-traumatic OHCA treated 04/01/06–03/31/07 by EMS providers with defibrillation or chest compressions were included. Cases were grouped into EMS-witnessed, bystander witnessed, and unwitnessed and further stratified for bystander CPR. Multiple logistic regressions evaluated the odds ratio (OR) for survival to discharge relative to the EMS-witnessed group after adjusting for age, sex, public/private location of collapse, ROC site, and initial ECG rhythm. Of 9991 OHCA, 1022 (10.2%) of EMS-witnessed, 3369 (33.7%) bystander witnessed, and 5600 (56.1%) unwitnessed.
The most common initial rhythm in the EMS-witnessed group was PEA which was higher than in the bystander- and unwitnessed groups (p < 0.001). The adjusted OR (95% CI) of survival compared to the EMS-witnessed group was 0.41, (0.36, 0.46) in bystander witnessed with bystander CPR, 0.37 (0.33, 0.43) in bystander witnessed without bystander CPR, 0.17 (0.14, 0.20) in unwitnessed with bystander CPR and 0.21 (0.18, 0.24) in unwitnessed cases without bystander CPR.
Immediate application of prehospital care for OHCA may improve survival. Efforts should be made to educate patients to access 9-1-1 for prodromal symptoms.