Association between early arterial oxygenation and neurological outcome after pediatric out-of-hospital cardiac arrest: a multicenter retrospective study

Background

Optimal arterial oxygen targets after return of spontaneous circulation (ROSC) in pediatric out-of-hospital cardiac arrest (OHCA) remain uncertain. We examined whether arterial oxygen tension on the first arterial blood gas after ROSC is associated with neurological or survival outcomes.

Methods

Using the Japanese Association for Acute Medicine OHCA Registry, we retrospectively studied pediatric patients (<18 years) with OHCA in whom ROSC was confirmed at or after hospital arrival. Patients were categorized by PaO₂ on the first arterial blood gas after ROSC as normoxemia (60–200 mmHg) or hyperoxemia (>200 mmHg). Missing covariate data were handled using multiple imputation, and associations were estimated using inverse probability-weighted logistic regression. Outcomes were favorable neurological status at 30 days, defined as a Pediatric Cerebral Performance Category score of 1–3, and 30-day survival. Multiple sensitivity analyses were performed, including analyses using an alternative PaO₂ threshold, restricting the timing of PaO₂ measurement, and excluding extracorporeal cardiopulmonary resuscitation cases.

Results

A total of 189 patients were included (95 normoxemia, 94 hyperoxemia). A favorable neurological outcome occurred in 21 of 95 (22.1%) normoxemia and 13 of 94 (13.8%) hyperoxemia patients, and 30-day survival in 40 of 95 (42.1%) and 42 of 94 (44.7%), respectively. After weighting, covariate balance was achieved with standardized mean differences below 0.1. Hyperoxemia was not significantly associated with favorable neurological outcome (adjusted odds ratio [aOR] 0.94, 95% confidence interval [CI] 0.49–1.77) or 30-day survival (aOR 1.49, 95% CI 0.88–2.54). Sensitivity analyses yielded consistent results.

Conclusions

Early hyperoxemia after ROSC was not significantly associated with neurological or survival outcomes in pediatric out-of-hospital cardiac arrest. These findings suggest that a single early PaO₂ measurement may be insufficient to characterize the clinical impact of oxygen exposure after resuscitation. Future research should focus on phase-specific and individualized oxygen management incorporating serial physiological assessment.

CLINICAL PERSPECTIVE

What Is New?

• This multicenter registry study evaluated the association between the first post-ROSC PaO₂ measurement and outcomes exclusively in children with out-of-hospital cardiac arrest.

• After multiple imputation and inverse probability weighting, hyperoxemia (>200 mmHg) was not significantly associated with favorable neurological outcome or 30-day survival.

• The findings were consistent across analyses using an alternative PaO₂ threshold, restricting measurement timing, and excluding extracorporeal cardiopulmonary resuscitation cases.

What Are the Clinical Implications?

• A single early PaO₂ value should not be interpreted as a complete measure of post-resuscitation oxygen exposure or used alone for prognostication.

• These findings do not support permissive hyperoxemia; oxygen should continue to be titrated while avoiding hypoxemia and unnecessary hyperoxemia.

• Prospective studies with serial, standardized physiological measurements are needed to define phase-specific and individualized oxygen targets.