To identify predictors of good neurologic outcome after pulseless electrical activity

Our county EMS system has a specific protocol for PEA arrest which includes use of mechanical CPR following first cycle, non-rebreather mask with BLS adjunct, hypothermia with cold  (4⁰C) saline infusion of 30mL/kg up to a maximum of 2L, followed by IV/IO epinephrine and, placement of orogastric tube and systematic consideration of the possible causes of PEA. 

Prospective observational study conducted as part of our county EMS system’s quality and research program. Our IRB approved prehospital research registry participates in the Cardiac Arrest Registry to Enhance Survival (CARES) database. 

Sustained ROSC was defined as maintenance of a pulse through the end of EMS resuscitation and arriving to the hospital alive. A good neurologic outcome was defined as a Cerebral Performance Categories (CPC) score of 1. A CPC of 1 corresponds to the patient being able to work and lead a normal life. Patients may have mild dysphasia, non-incapacitating hemiparesis, or minor cranial nerve abnormalities. 

235 patients suffered OHCA due to PEA. 26% achieved sustained ROSC. This is 10x the national average. 7% made it out of the hospital alive. 3% had a good neurologic outcome. Median time to CPR was 5 min (IQR 2-11).

Factors associated with sustained ROSC included female sex (OR 2.5, 95% CI 1.3-4.6, P=0.0043), and receiving hypothermia care (OR 1.9, 95% CI 1.0-3.7, P=0.0454). 

For good neurologic outcome, time to first CPR was extremely significant (OR 65, 95% CI 7-641, P=0.0001). The goodness of fit for this model was robust with a R² of 36%. The area under the curve for the receiver operating characteristic was also robust at 89%. 

A defined prehospital protocol specific to peri-arrest rhythm appears to confer a significantly better chance for good neurologic outcome.