6688 The utility of sonographic assessment in lung and diaphragmatic dimensions as a novel predictive tool for surfactant therapy in preterm neonates

Objectives To evaluate the utility of sonographic assessment in lung and diaphragmatic dimensions as an adjunct to clinical parameters for determining surfactant replacement in neonates <34weeks. Primary outcome was evaluation of the diaphragmatic dimensions to indicate the severity of respiratory distress in aiding for early surfactant therapy. Diaphragmatic ultrasound has been studied widely in adult patients and is a rather novel entity in predicting need for surfactant therapy in the neonatal population.¹ Methods In a prospective observational study among preterm neonates less than 34 weeks of gestational age admitted to the NICU with clinical diagnosis of respiratory distress syndrome. Babies were initially stabilized in the delivery room as per recent Newborn resuscitation guidelines – 8th edition. Babies were subsequently stabilized in the Neonatal Intensive Care Unit as per Golden hour management protocol and unit policy. Initial clinical parameters were recorded (Silverman Anderson scoring, maximum FiO2 requirement, ventilator settings, SpO2/FiO2 ratio). Semiquantitative lung ultrasound score ² was obtained using a linear transducer in the CX 50 machine. Lung fields considered include anterior, lateral, and posterior in supine position.³ To account for observer bias, three scans were performed in each lung field, and average considered for analysis. Diaphragmatic dimensions, thickening fraction and excursion were obtained by the subcostal approach, using M- mode ultrasonography.⁴ The procedure was performed under aseptic conditions by a trained neonatologist, and resident under guidance. Intraprocedural hemodynamics were monitored cautiously. Study endpoints were determination of surfactant delivery by INSURE technique based on lung ultrasonography and diaphragmatic dimensions.⁵ Results During the study period, 58 neonates were enrolled, of which 18 babies required surfactant administration and 18 required invasive ventilation. The median (IQR) lung ultrasound score was 7.44,¹ with mean in the surfactant requiring group as 12.58 (p <0.001). After adjustment for gestational age and birth weight, Karl Pearson correlation of lung ultrasound score with the need surfactant therapy showed strong significance (r – 0.858, p <0.005). Diaphragmatic thickness fraction was significantly higher in the group requiring surfactant therapy (p<0.001) with Pearson rank correlation factor significant with Silverman Anderson scores and need for surfactant (r value 0.82, confidence interval – 0.95, p value <0.001). Conclusion In preterm neonates diagnosed with respiratory distress syndrome, the utility of lung ultrasound parameters and diaphragm dimensions have relevant clinical implications in taking therapeutic decisions. Further studies are required to standardize diaphragm ultrasound in utility as a benchmark for delivering surfactant therapy. References Gupta, et al. Pediatric Pulmonology 3rd April 2023. Brat, et al. Jama Pediatrics 3rd August 2015. Syzmanzski, et al. BMC Pediatrics 6th January 2021. Bahgat, et al. European Journal of Pediatrics 28th September 2020. Alonso- Ojembarrena, et al. Chest journal February 2023. Perri, et al. Diagnostics 7th August 2022.