Abstract 384: The Association of End-Tidal Carbon Dioxide During Pediatric Cardiopulmonary Resuscitation With Survival Outcomes

Abstract

Background: Pediatric resuscitation guidelines recommend monitoring end-tidal carbon dioxide (ETCO 2 ) as an indicator of CPR quality but note that “specific values to guide therapy have not been established in children.” Aims & Hypotheses: We aimed to determine the association of ETCO 2 during CPR with pediatric IHCA outcomes. We hypothesized that event-level average ETCO 2 ≥20 mmHg would be associated with higher rates of survival to hospital discharge. Methods: NHLBI-funded ancillary prospective observational cohort study of pediatric IHCAs in 18 U.S. ICUs from the ICU-RESUS trial (NCT02837497). Children with invasive mechanical ventilation at the start of CPR were included. The primary exposure was event-level average ETCO 2 (≥20 mmHg vs. <20 mmHg). The primary outcome was survival to hospital discharge. Secondary outcomes were ROSC and intra-arrest CPR quality and physiology measurements. Average ETCO 2 <10 mmHg was a secondary exposure. The associations between ETCO2 and outcomes were evaluated with multivariable Poisson regression. Exploratory analyses used receiver operating characteristic (ROC) and spline curves to identify alternative ETCO 2 targets. Results: Among 234 patients, 133 (57%) had average ETCO 2 ≥20 mmHg. After controlling for a priori covariates, average ETCO 2 ≥20 mmHg was associated with higher rates of survival to hospital discharge (aRR 1.33, CI 95 1.04 - 1.69, p=0.023) and ROSC (aRR 1.22, CI 95 1.00 - 1.49, p=0.046) compared to lower values. Average ETCO 2 ≥20 mmHg was associated with higher blood pressures during CPR (diastolic: 46.5 [37.9, 57.9] mmHg vs. 33.3 [26.8, 42.9] mmHg, p<0.01); systolic: 90.6 [75.1, 118.7] mmHg vs. 70.9 [55.5, 86.4] mmHg, p<0.01), higher chest compression fraction (0.98 [0.94, 1.00] vs. 0.97 [0.92, 0.99], p=0.034), and lower ventilation rates (26.2 [19.7, 30.9] min -1 vs 29.5 [22.8, 41.4] min -1 , p<0.01). Average ETCO 2 <10 mmHg was not associated with outcomes. Exploratory analyses did not detect an alternative ETCO 2 target (ROC cutpoint: 19.6 mmHg). Conclusions: In this multicenter study, ETCO 2 ≥20 mmHg was associated with higher quality CPR and superior outcomes. ETCO 2 <10 mmHg was not associated with worse outcomes, suggesting resuscitation should not be terminated based on low ETCO 2 alone.