Measurement of lung oxygenation by near-infrared spectroscopy in preterm infants with respiratory distress syndrome: A proof-of-concept study

Abstract

Introduction: Noninvasive markers more accurate than FiO₂ would be useful to assess the severity of RDS and guide its treatment. Our aim was to assess for the first time the possibility of continuously monitoring lung oxygenation (rSO₂ L) by near-infrared spectroscopy (NIRS) and to evaluate whether rSO₂ L correlates with other oxygenation indices and RDS severity.

Methods: We carried out this proof-of-concept study on 20 preterm infants with RDS requiring noninvasive respiratory support. Patients were continuously studied for 24 h by NIRS and rSO₂ L was correlated with SpO₂ /FiO₂ ratio, a/APO₂ , and O.I.

Results: The overall value of rSO₂ L was 80.1 ± 6.2%, without significant differences between the right and left hemithorax (80.2 ± 6.7 vs. 80.0 ± 5.7%; p = 0.869). Mean values of total, right, and left rSO₂ L did not significantly change during the 24-h study period. Linear regression analysis demonstrated a significant positive relationship between total rSO₂ L and SpO₂ /FiO₂ ratio (p < 0.001) and a/APO₂ (p = 0.040), and a negative relationship between total rSO₂ L and O.I. (r = -0.309; p = 0.022).

Conclusions: Continuous monitoring of rSO₂ L by NIRS in preterm infants with RDS is feasible and safe. The correlation of rSO₂ L with other indices of oxygenation and RDS severity supports the accuracy and reliability of this measurement.

Keywords: lung oxygenation; near-infrared spectroscopy; preterm infants; respiratory distress syndrome.