Lung Ultrasound Score Predicts Surfactant Need in Extremely Preterm Neonates

Background and objectives: There are several lung ultrasound scores (LUS) for evaluating lung aeration in critically ill adults with restrictive lung disorders. A modified LUS adapted for neonates correlates well with oxygenation and is able to be used to predict the need for surfactant in preterm neonates with respiratory distress syndrome (RDS). However, no data are available for extremely preterm neonates for whom timely surfactant administration is especially important. We hypothesized that LUS might be reliable in extremely preterm neonates with RDS who are treated with continuous positive airway pressure. We aimed to determine the diagnostic accuracy of LUS in predicting the need for surfactant treatment and re-treatment in this population.

Methods: We performed a prospective cohort diagnostic accuracy study between 2015 and 2016 in a tertiary-care academic center. Inborn neonates at ≤30 weeks' gestation with RDS treated with continuous positive airway pressure were eligible. Surfactant was given on the basis of oxygen requirement thresholds derived from European guidelines, and a LUS was not used to guide surfactant treatment. We calculated the LUS after admission and analyzed its diagnostic accuracy to predict surfactant treatment and re-treatment.

Results: We enrolled 133 infants; 68 (51%) received 1 dose of surfactant and 19 (14%) received 2 surfactant doses. A LUS is significantly correlated with oxygenation index (ρ = 0.6; P < .0001) even after adjustment for gestational age (P < .0001). A LUS can be used to accurately predict the need for the first surfactant dose (area under the curve = 0.94; 95% confidence interval: 0.90-0.98; P < .0001) and also the need for surfactant redosing (area under the curve = 0.803; 95% confidence interval: 0.72-0.89; P < .0001). The global accuracy for the prediction of surfactant treatment and re-treatment is 89% and 72%, respectively.

Conclusions: LUS may be used to predict the need for surfactant replacement in extremely preterm neonates with RDS.