379 - Effects of Surfactant Administration and Ventilation on Cerebral and Pulmonary Oxygenation in Preterm Infants using Near-Infrared Spectroscopy (NIRS)

Publication Number: 379.4700

Ivonne E. Sierra-Strum, Children's Hospital Los Angeles, Los Angeles, CA, United States; Manoj Biniwale, Cedars Sinai Medical Center, Los Angeles, CA, United States; Piyawat Arichai, Children's Hospital Los Angeles, Pasadena, CA, United States; Rangasamy Ramanathan, Cedars Sinai Guerin Children's, Cedars Sinai Medical Center, Los angeles, CA, United States

Background: Premature infants are at high risk of hypoxemia due to surfactant deficiency and complex cardiopulmonary interactions during the transitional period. The role of Near-Infrared Spectroscopy (NIRS) in assessing oxygenation changes during different ventilation modes and following surfactant administration remains largely unexplored

Objective: We evaluated differences in pulmonary regional oxygen saturation (rpSO2) and cerebral regional oxygen saturation (rcSO2) in preterm infants using NIRS during invasive and noninvasive ventilation. The secondary goal was to assess changes in rpSO2 before and after surfactant administration and investigate correlations between rpSO2 and the SpO2/FiO2 (S/F) ratio

Design/Methods: We enrolled 30 preterm infants with respiratory distress syndrome (RDS) requiring noninvasive or invasive respiratory support. NIRS continuously monitored rpSO2 and rcSO2 over a 12 hr period. Changes in rpSO2 were analyzed before and after surfactant administration using the Wilcoxon signed-rank test. Correlations between rpSO2 values and S/F were evaluated with linear regression analysis

Results: Of the 30 preterm infants, 60% were male (n = 18). The mean gestational age was 28.7 ± 2.1, with a mean birthweight of 1,263 ± 402 grams. 83% (n = 25) received non-invasive ventilation. Mean rcSO2 values (77.97 ± 4.06) were consistently significantly higher (p < 0.01) than rpSO2 (72.45 ± 5.64) (Table 1). rcSO2 exhibited less variability than rpSO2, with a coefficient of variation of 5.21% compared to 7.79% for rpSO2. For the ten infants who received surfactant, rpSO2 increased significantly after surfactant administration (p < 0.01) (Figure 1). A subgroup analysis of infants with a higher baseline S/F (n=17) demonstrated a more significant rise in rpSO2 post-surfactant (p < 0.01). Linear regression analysis of rpSO2 and the S/F showed a strong correlation, with a slope of 8.724 (95% CI: 6.572 to 11.11), R-squared = 0.69, and p< 0.01 (Figure 2)

Conclusion(s): rcso2 values were higher and less variable than rpso2 values, aligning with existing research and reflecting different physiological oxygenation needs between the brain and lungs. The significant rise in rpso2 following surfactant underscores its effectiveness in improving pulmonary oxygenation in RDS. Baseline oxygenation status, as indicated by the S/F ratio, may influence the response to surfactant. The strong correlation between rpSO2 and the S/F ratio highlights NIRS potential as a non-invasive tool for guiding oxygenation strategies in the NICU. Further studies are needed to validate these findings and explore implications in larger populations

Mean ± (SD) of rpSO2, rcSO2, FOEL, and SpO2/FiO2 During Time Points (T0-T12)
rpSO2 (Regional Pulmonary Oxygen Saturation), rcSO₂ (Regional Cerebral Oxygen Saturation), FOEL (Fractional Oxygen Extraction in the Lungs)

rpSO2 Pre and Post Surfactant
rpSO2(Regional Pulmonary Oxygen Saturation)

Linear Regression Total rpSO2 ans S/F
rpSO2(Regional Pulmonary Oxygen Saturation, S/F(SpO2/FiO2)