Analyze Early versus Analyze Late Results

September 30, 2011

The Resuscitation Outcomes Consortium study about Early versus Later rhythm analysis for cardiac arrest was published in the New England Journal of Medicine this month (click here to link to article).  In this study, paramedics compared two strategies of providing a rescue shock (defibrillation) to patients with cardiac arrest.  In the first strategy, patients had CPR until an ECG could be obtained and a rescue shock could be administered as soon as possible (an average of 71 seconds).  In the second strategy, patients had CPR for 3 minutes (171 seconds) prior to the ECG and rescue shock.  This 3-minute bout of CPR was designed to provide blood flow to the heart and prepare it for defibrillation.   Not every patient requires a rescue shock, but all cardiac arrest patients need CPR.

Investigators found that there was no difference in survival to hospital discharge between the two treatment groups: 8.1% and 8.0% respectively.   A total of 5290 patients received the first strategy (early ECG and rescue shock), and 4643 patients received the second strategy (three minutes of CPR before rescue shock).  Paramedics in the Pittsburgh region enrolled 630 subjects in this study.  These subjects reflected the demographics of cardiac arrest in our region: slightly more males than females have cardiac arrest, and the average age of patients with cardiac arres is about 65 years.  

This study has provided extensive data about the treatment of cardiac arrest.  Investigators plan further analyses of the information collected in order to design further improvements in emergency care.