Association of cumulative oxygen and carbon dioxide levels with neurologic outcome after pediatric cardiac arrest resuscitation: A multicenter cohort study

Objective: We aimed to (1) determine the association between cumulative PaO₂ and PaCO₂ exposure 24 h post-return of circulation and survival with favorable neurologic outcome. And (2) to assess adherence to American Heart Association post-cardiac arrest care treatment goals (PaO₂ 75-100 mmHg and PaCO₂ 35-45 mmHg).

Design and setting: Prospectively collected data were analysed from five Pediatric Resuscitation Quality collaborative sites supplemented with retrospective PaO₂ and PaCO₂ data.

Patients: Children aged 1 day-17 years with return of circulation after cardiac arrest, admitted 2019-2022, with ≥ 4 arterial blood gasses spanning at least 12 h within 24 h post-return of ciculation, were eligible. Congenital cyanotic heart disease events were excluded.

Measurements: Area under the curve calculation provided hourly cumulative PaO₂ and PaCO₂ exposures per child and similarly guideline recommended cumulative ranges. The primary outcome was survival to hospital discharge with favorable neurologic outcome defined as a Pediatric Cerebral Performance Category 1-3, or no pre-arrest baseline difference.

Main results: Among 292 included children (median age 2.6 years (IQR 0.4-10.9)), 57 % survived to discharge and 48 % had favorable neurologic outcome (88 % of survivors). Cumulative PaO₂ and PaCO₂ exposure 0-24 h post-return of circulation were not significantly associated with favorable neurologic outcome in multivariable analysis (OR 1.0, 95 %CI 0.98-1.02 and OR 0.97, 95 %CI 0.87-1.09 respectively). Cumulative PaO₂ and PaCO₂ remained within guideline recommended ranges for 24 % and 58 % of children respectively with median areas under the curve over 0 - 24 h of 2664 mmHg (2151 - 3249 mmHg) for PaO₂ and 948 mmHg (853 - 1051 mmHg) for PaCO₂. AHA post-cardiac arrest care guideline recommendations for PaO₂ (1800-2400 mmHg) and PaCO₂ (840-1080 mmHg) were recalculated as area under the curve ranges. Achieving both normoxia and normocapnia was observed in 12 % of children.

Conclusions: Cumulative PaO₂ and PaCO₂ exposure in the first 24 h post-return of circulation was not associated with survival with favorable neurologic outcome. Pediatric AHA post-cardiac arrest care guideline normoxia and normocapnia goals were often not met. Larger cohort studies are necessary to improve the accuracy of cumulative exposure calculations, assess the long-term effects of PaO₂ and PaCO₂ exposure, and explore the influence of other post-cardiac arrest care therapeutic strategies.