Association of Pediatric Post-Cardiac Arrest Ventilation and Oxygenation with Survival Outcomes.

RATIONALE: Adult and pediatric studies provide conflicting data whether post-cardiac arrest hypoxemia, hyperoxemia, hypercapnia and/or hypocapnia are associated with worse outcomes.

OBJECTIVES: Determine if post-arrest hypoxemia or post-arrest hyperoxemia are associated with lower rates of survival to hospital discharge compared to post-arrest normoxemia, and if post-arrest hypocapnia or hypercapnia are associated with lower rates of survival compared to post-arrest normocapnia.

METHODS: Embedded prospective observational study during a multi-center interventional cardiopulmonary resuscitation trial from 2016-2021. Patients ≤18 years and ≥37 weeks corrected gestational age who received chest compressions for cardiac arrest in one of 18 ICUs were included. Exposures during the first 24 hours post-arrest were hypoxemia, hyperoxemia, or normoxemia defined as lowest PaO2 <60mmHg, highest PaO2 ≥200mmHg, or every PaO2 60-199mmHg, respectively, and hypocapnia, hypercapnia, or normocapnia defined as lowest PaCO2 <30mmHg, highest PaCO2 ≥50mmHg, or every PaCO2 30-49mmHg, respectively. Associations of oxygenation and carbon dioxide group with survival to hospital discharge were assessed using Poisson regression with robust error estimates.

MEASUREMENTS AND MAIN RESULTS: The hypoxemia group was less likely to survive to hospital discharge compared with the normoxemia group (aRR 0.71, 0.58-0.87), whereas the hyperoxemia group survival did not differ from the normoxemia group (aRR 1.0, 0.87-1.15). The hypercapnia group was less likely to survive to hospital discharge compared with the normocapnia group (aRR 0.74, 0.64-0.84), whereas the hypocapnia group survival did not differ from the normocapnia group (aRR 0.91, 0.74-1.12).

CONCLUSIONS: Post-arrest hypoxemia and hypercapnia were each associated with lower rates of survival to hospital discharge.