Best pre-ductal PaO₂ prior to extracorporeal membrane oxygenation as predictor of mortality in patients with congenital diaphragmatic hernia: a retrospective analysis of a Japanese database

Purpose: Predicting lethal pulmonary hypoplasia in infants with congenital diaphragmatic hernia (CDH) before extracorporeal membrane oxygenation (ECMO) initiation is difficult. This study aimed to predict lethal pulmonary hypoplasia in patients with CDH prior to ECMO. Methods: This was a multicenter cohort study involving neonates prenatally diagnosed with isolated unilateral CDH (born 2006–2020). Patients who required ECMO due to respiratory insufficiency were included in this study. Patients who underwent ECMO due to transient disorders were excluded from analysis. Blood gas analysis data within 24 h of birth were compared between survivors and non-survivors. Predictive abilities were assessed for factors with significant differences. Results: Overall, 34 patients were included (18 survivors and 16 non-survivors). The best pre-ductal PaO₂ was significantly lower in non-survivors than in survivors (50.4 [IQR 30.3–64.5] vs. 67.5 [IQR 52.4–103.2] mmHg, respectively; p = 0.047). A cutoff PaO₂ of 42.9 mmHg had a sensitivity, specificity, and positive predictive value of 50.0%, 94.4%, and 88.9%, respectively, to predict mortality. Conclusion: The best PaO₂ within 24 h after birth predicted mortality following ECMO initiation. This should be shared to families and caregivers to optimize the best interests of the infants with CDH.