Abstract 303: End-Tidal CO2 Reactivity Is Associated with Defibrillation Success

Abstract

Background: High quality cardiopulmonary resuscitation (CPR) appears to modulate ventricular fibrillation (VF) morphology and increase defibrillation success. However, VF waveform analysis has not proven to be clinically effective in guiding resuscitation. End-tidal CO2 (PetCO2) correlates well with cardiac perfusion during CPR. Objective: To evaluate PetCO2 as a predictor of defibrillation success. Methods: This was a prospective, observational study conducted at two urban academic hospitals with a combined total of 500 beds. Data regarding defibrillation attempts, CPR process, and PetCO2 were abstracted from monitor/defibrillators. All arrest victims with primary VF or ventricular tachycardia (VT) for whom CPR and PetCO2 data were available were included in this analysis. Patients with return of spontaneous circulation (ROSC) were compared to those without ROSC with regard to the change in PetCO2, mean and final compression rate and depth, and chest compression fraction (CCF). Results: A total of 32 patients were included in this analysis; 19 of these (59%) had ROSC. PetCO2 values prior to the final defibrillation attempt were 121% higher than initial PetCO2 values in patients with ROSC versus only 19% higher in patients without ROSC (p<0.01). Patients with and without ROSC were similar with regard to mean compression depth (2.5 vs. 2.7 inches, p=NS), final compression depth (2.7 vs. 2.8 inches, p=NS), mean compression rate (119/min for both, p=NS), final compression rate (121/min vs. 123/min, p=NS), mean CCF (83% vs. 85%, p=NS), and final CCF (83% vs. 91%). Conclusions: An increase in PetCO2 was associated with ROSC among inpatients with VF/VT arrest. No differences with regard to overall or final CPR process measures were observed. The “PetCO2 responsiveness” to CPR may reflect an underlying physiology that predicts defibrillation success.