Prediction of surfactant requirement in Indian preterm infants by lung ultrasound scores: a diagnostic accuracy study from a developing country

The purpose of this study is to validate lung ultrasound score (LUS) for prediction of surfactant replacement therapy (SRT) in Indian infants of 27-33^6/7 weeks gestational age (GA). This prospective diagnostic accuracy study was conducted in a level 3 neonatal care unit in India. Consecutively born preterm infants with respiratory distress syndrome (RDS) were enrolled. Surfactant was administered if oxygen requirement exceeded > 30%. Baseline characteristics, respiratory parameters, and lung ultrasound images were recorded soon after admission and compared between surfactant and non-surfactant groups. Adjusted odds ratio (OR) and diagnostic accuracy of LUS were calculated for SRT. Among 78 infants with RDS included in the final analysis, 62 received surfactant (79.48%). Median time of performing lung ultrasound was 50 min of life in both groups. Median LUS in the anterior and posterior chest areas of either side as well as total LUS was significantly higher in the surfactant group. After adjusting for other confounders, LUS was found to be a significant predictor of SRT (adjusted OR (95%CI): 1.55 (1.15-2.087)). Diagnostic accuracy of LUS was determined by receiver operating characteristic (ROC) curve analysis (AUC (95% CI): 0.751 (0.64-0.842), p < 0.001). A cutoff score of ≥ 9 for LUS was considered optimal for SRT (sensitivity (95%CI): 70.97% (57.87-81.45), specificity (95%CI): 68.75% (41.48-87.87)).

Lung ultrasound is a valid diagnostic tool for SRT in Indian setting with a cutoff score ≥ 9.

CTRI/2021/11/038269.

• Surfactant requirement in preterm infants with RDS has been traditionally based on FiO2 criteria. • Lung ultrasound score can predict the need for surfactant although majority of the studies originated in developed countries.

• Lung ultrasound is a valid tool for surfactant replacement therapy even in developing countries like India.