Prediction of Post-Intubation Oxygenation Using Saturation Oxygen Pressure Index in Newborns

In neonatal intensive care, the management of mechanical ventilation frequently transitions from non-invasive to invasive techniques. Predicting post-intubation oxygenation status is essential before intubation. We aimed to validate the correlation between the saturation oxygen pressure index (SOPI) during non-invasive positive pressure ventilation (NPPV) and post-intubation oxygenation saturation index (OSI), and to determine the SOPI cut-off values corresponding to the OSI after initiation of invasive mechanical ventilation.

This is a multicentre retrospective observational study. A total of 203 neonates who required synchronised intermittent mandatory ventilation after NPPV management for continuous positive airway pressure (CPAP) or bilevel positive pressure ventilation (BPPV) between April 2012 and January 2026 were enrolled. Pre-intubation SOPI and post-intubation OSI were calculated. Their correlations were analysed using Spearman's rank correlation coefficient. Receiver operating characteristic (ROC) curve analysis was performed to determine the cut-off values of SOPI of all NPPV at OSI of 2.0, 3.0 and 4.0.

SOPI was positively correlated with OSI (all NPPV: ρ = 0.699, p < 0.001; CPAP: ρ = 0.703, p < 0.001; BPPV: ρ = 0.670, p < 0.001). ROC curve analysis identified the optimal SOPI cut-off values as 1.49 (sensitivity 71.0%, specificity 86.5%) for OSI = 2.0, 2.30 (94.3%, 63.6%) for OSI = 3.0 and 2.49 (89.8%, 87.5%) for OSI = 4.0.

SOPI is a useful predictive marker of post-intubation oxygenation status in newborns. It may serve as a non-invasive, continuous and objective tool for clinicians to assess the oxygenation status of newborns managed with NPPV.