Abstract 15065: A Novel Predictor of Unsustained Return of Spontaneous Circulation in Patients in Cardiac Arrest Through a Combination of Capnography and Pulse Oximetry

Abstract

Introduction: Unsustained return of spontaneous circulation (ROSC) is a critical barrier to survival in cardiac arrest patients. However, no parameter so far can be used to predict the sustainability of ROSC. Research Questions: End-tidal carbon dioxide (ETCO 2 ) is regarded as an indicator of ROSC in cardiac arrest patients. Pulse oximetry photoplethysmogram (POP) parameters have been shown to be associated with peripheral perfusion in critically ill patients. We hypothesized that the combination of ETCO 2 and POP parameters might be discriminative for early recognition of patients at risk of unsustained ROSC before rearrest. Aims: This study examined whether ETCO 2 and POP parameters can be used to identify unsustained ROSC. Methods: We conducted a multicenter observational prospective cohort study of consecutive patients with cardiac arrest managed from 2013 to 2014. Patients’ general information, ETCO 2 , and POP parameters, including area under the curve (AUCp) and amplitude (Amp) of POP waveform, were collected and statistically analyzed. Results: The included 105 ROSC episodes (from 80 cardiac arrest patients) comprised 51 sustained ROSC episodes and 54 unsustained ROSC episodes. Patients with unsustained ROSC had lower 24-hour survival rate than sustained ROSC patients (11.5% vs. 25.0%, respectively; P<0.05). The logistic regression analysis showed that, ΔETCO 2 (difference in ETCO 2 between after to before ROSC) and ΔAUCp (difference in AUCp between after to before ROSC) were independently associated with sustained ROSC (OR = 0.931, P = 0.011 and OR = 0.998, P < 0.001). The area under the receiver operating characteristic curve of ΔETCO 2 , ΔAUCp, and the combination of both to predict unsustained ROSC were 0.752 (95% CI 0.660-0.844), 0.883 (95% CI 0.818-0.948), and 0.902 (95% CI 0.842-0.962). Conclusion: Patients with unsustained ROSC have a poor prognosis. Combined ΔETCO 2 and ΔAUCp showed significant predictive value for unsustained ROSC.