Respiratory Severity Score Predicts Need for Surfactant Administration

Henry Alfredo Zapata, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Jack Koueik, University of Wisconsin, United States; Heather Becker, UnityPoint Health Meriter Hospital, United States; Prem Fort, Johns Hopkins School of Medicine, United States; Scott O. Guthrie, Vanderbilt University School of Medicine, Nashville, TN, United States; Dinushan C. Kaluarachchi, University of Wisconsin - Madison, Madison, WI, United States

Background: Respiratory distress syndrome (RDS) is a contributor to neonatal morbidity and mortality in the NICU. CPAP is an initial strategy to stabilize airways, but preterm infants may require subsequent surfactant administration. Although no consensus, the most common practice for surfactant administration is an FiO2 more than 0.3. However, using it as its sole criteria can be misleading as FiO2 is affected by the level of mean airway pressure (MAP). As less invasive surfactant administration techniques become more prevalent, it’s desirable to identify patients who would benefit from early rescue surfactant treatment. Therefore, we will evaluate the utility of the Respiratory Severity Score (RSS) as criteria for early rescue surfactant administration in preterm infants

Objectives: To determine the utility of using RSS (FiO2 x MAP) during the first 3 hours of life (HOL) as a predictor for surfactant administration in preterm infants during the first 72 HOL

Design/Methods: We conducted a post-hoc analysis of patients who received usual care from a multicenter AERO-02 clinical trial. Intubated patients and/or received surfactant during the first 3 HOL, or whose RSS was unable to calculate were excluded. Mean RSS and linear trend were expressed. Logistic regression was used to assess whether RSS summary measures were associated with odds of surfactant administration within 72 HOL

Results: Study cohort included 146 neonates. Median gestational age (GA) and birthweights were 32.9 weeks and 1.86 Kg respectively. RSS during HOL 1–3 were 1.05–5.50, mean of 1.8 ± 0.7. 45% received surfactant (median 6 hours, IQR 4-15) (Table 1). Administration of surfactant was associated with the mean RSS over the first 1-3 HOL (p < 0.01) and with the linear RSS trend (p < 0.01). A 0.5 unit increase in mean RSS was associated with a 45% increase in the odds of needing surfactant. Each 0.5 unit increase for linear trend in RSS per 1 HOL was associated with a 4.6-fold increase in the odds (Table 2). These associations remained statistically significant after adjusting for GA

Conclusion: We demonstrate a novel marker using RSS as a predictor for surfactant administration. Often clinicians delay surfactant therapy due to its invasive nature, but it’s desirable to identify patients who would benefit from early rescue surfactant therapy. RSS as a screening tool in the early course of the RDS predicts need for surfactant administration. We can use our novel data to design large prospective cohort studies to determine optimal RSS thresholds for surfactant administration