End tidal CO2 and cerebral oximetry for the prediction of return of spontaneous circulation during cardiopulmonary resuscitation

Abstract Background End Tidal CO 2 (ETCO 2 ) is a reasonable predictor of Return of Spontaneous Circulation (ROSC) in cardiac arrest (CA), though with many limitations. Cerebral Oximetry (CerOx) non-invasively measures brain O 2 saturation and correlates with flow. Objectives This study compares ETCO 2 and CerOx for ROSC prediction during both out of hospital (OHCA) and emergency department cardiac arrests (EDCA). Methods We conducted a prospective study on CA patients resuscitated in the ED. ETCO 2 and CerOx simultaneously measured during ED CPR. Data was analyzed with logistic regression modeling and area under the curve (AUC). Results 176 patients were analyzed, 66.7% were witnessed, 52.8% had bystander CPR. EMS alert to ED arrival was 27.0 ± 10.6 min. Initial rhythm was 31.8% asystole, 27.8% PEA, 25.6% VF/VT with 26.1% achieving ROSC. AUC predictors of ROSC were: last 5 min trend [CerOx = 0.82 ; ETCO 2  = 0.74], delta first to last [CerOx = 0.86 ; ETCO 2  = 0.73], the penultimate minute [CerOx = 0.81 ; ETCO 2  = 0.76], and final minute [CerOx = 0.89 ; ETCO 2  = 0.77]. AUC comparison of simultaneous measurements (n = 125) revealed: last 5 min trend [CerOx = 0.80 ; ETCO 2  = 0.79], delta first to last [CerOx = 0.83 ; ETCO 2  = 0.75], penultimate minute [CerOx = 0.83 ETCO 2  = 0.74], and final minute [CerOx = 0.89 ; ETCO 2 = 0.75]. Conclusions Our data shows, both ETCO2 and rSO2 are good predictors of ROSC. We found CerOx superior to ETCO 2 in predicting ROSC.