Correlation of End-Tidal Carbon Dioxide to Neurological Outcome in Out-of-Hospital Cardiac Arrest

Background: Previous studies have established that end tidal carbon dioxide (ETCO2) can positively predict a return of spontaneous circulation (ROSC) and survivability in out-of-hospital cardiac arrest (OHCA). Objective: To assess if ETCO2 predicts neurological outcome as measured by cerebral performance category (CPC) score in an independent cohort of patients suffering OHCA. Methods: This was a retrospective chart review conducted at MedStar Mobile Healthcare of patients who suffered non-traumatic OHCA between January 2014 and July 2014. ETCO2 values were continuously recorded while standard advanced cardiac life support (ACLS) protocols were followed. Results: OHCA was confirmed in 689 patients. ACLS was initiated in 421 patients. Of those, 214 patients were transported to the hospital. There was a good neurologic outcome (CPC 1or 2) in 22 patients and a poor neurologic outcome (CPC of 3, 4, or 5) in 183 patients. Initial ETCO2 (p=0.027, OR 1.002, 95% CI 1.000-1.003) and ETCO2 after ROSC (p=0.007, OR 0.997, 95% CI 0.995-0.999) were correlated to neurological outcome when using binary logistic regression. Conclusion: Initial ETCO2 and ETCO2 after ROSC are predictors of neurological outcome in OHCA. After further research this data can be incorporated into criteria on whether to perform cardiopulmonary resuscitation on patients suffering OHCA.