Aim: Early identification of late preterm and term infants with respiratory distress who will require invasive respiratory support (IRS) remains challenging. This study evaluated whether early oxygen saturation index (OSI) values, particularly the maximum value within the first 24 hours, were associated with the subsequent need for IRS in infants born at ≥34 weeks’ gestation.
Study Design: This retrospective cohort study included 192 neonates admitted between January 2021 and December 2022. Admission OSI and maximum OSI within the first 24 hours were analyzed. The primary outcome was the need for the IRS.
Results: IRS was required in 22 of 192 infants (11.5%) at a median of 22 hours (interquartile range [IQR]: 10–39.5) after admission. Infants requiring IRS had higher admission and maximum OSI values than those managed non-invasively (p=0.007 and p<0.001, respectively). Receiver operating characteristic (ROC) analysis identified a cut-off value of 1.8 for admission OSI (area under the curve [AUC]: 0.673, 95% confidence interval [CI]: 0.544–0.821) and 2.84 for maximum OSI (AUC: 0.988, 95% CI: 0.975–1.000), with maximum OSI demonstrating greater discriminative performance.
Conclusions: Higher early OSI values, particularly the maximum value within the first 24 hours, were associated with the subsequent need for invasive respiratory support in late preterm and term infants with respiratory distress. However, given its temporal relationship to clinical deterioration, maximum OSI may reflect evolving respiratory compromise and should therefore be interpreted as a non-invasive marker of respiratory failure rather than an independent predictor of intubation. Prospective validation is warranted.