Hyperoxia, hypocapnia and hypercapnia as outcome factors after cardiac arrest in children

PurposeArterial hyperoxia after resuscitation has been associated with increased mortality in adults. The aim of this study was to test the hypothesis that post-resuscitation hyperoxia and hypocapnia are associated with increased mortality after resuscitation in pediatric patients.MethodsWe performed a prospective observational multicenter hospital-based study including 223 children aged between 1 month and 18 years who achieved return of spontaneous circulation after in-hospital cardiac arrest and for whom arterial blood gas analysis data were available.ResultsAfter return of spontaneous circulation, 8.5% of patients had hyperoxia (defined as PaO2 > 300 mmHg) and 26.5% hypoxia (defined as PaO2 < 60 mmHg). No statistical differences in mortality were observed when patients with hyperoxia (52.6%), hypoxia (42.4%), or normoxia (40.7%) (p = 0.61). Hypocapnia (defined as PaCO2 < 30 mmHg) was observed in 13.5% of patients and hypercapnia (defined as PaCO2 > 50 mmHg) in 27.6%. Patients with hypercapnia or hypocapnia had significantly higher mortality (59.0% and 50.0%, respectively) than patients with normocapnia (33.1%) (p = 0.002). At 24 h after return of spontaneous circulation, neither PaO2 nor PaCO2 values were associated with mortality. Multiple logistic regression analysis showed that hypercapnia (OR, 3.27; 95% CI, 1.62-6.61; p = 0.001) and hypocapnia (OR, 2.71; 95% CI, 1.04-7.05; p = 0.04) after return of spontaneous circulation were significant mortality factors.ConclusionsIn children resuscitated from cardiac arrest, hyperoxemia after return of spontaneous circulation or 24 h later was not associated with mortality. On the other hand, hypercapnia and hypocapnia were associated with higher mortality than normocapnia.