Lung ultrasound (LUS) in pre-term neonates with respiratory distress: A prospective observational study

To find out the diagnostic use of lung ultrasound (LUS) in respiratory distress in neonates by taking clinico-radiological (clinical plus X-ray) diagnosis as the gold standard. Secondary objectives were to find out if modified LUS score can predict the need for surfactant therapy.

A prospective observational study was done in a tertiary care neonatal intensive care unit over a period of 1 year (January-December 2018). All pre-term infants with respiratory distress were screened with LUS and CXR within 2 h of admission and modified LUS score was calculated to find out the lung water content and its correlation with the severity of respiratory distress syndrome (RDS).

In total, 92 neonates were screened during the study period, and 61 were finally diagnosed as RDS. The Kappa statistic between the clinico-radiological diagnosis and LUS diagnosis was 0.639. LUS diagnosis and CXR diagnosis had a Kappa correlation value of 0.786 (95% CI: 0.678-0.983). The most common LUS feature in RDS was pleural line thickening (100%), followed by whiteout lungs (75.4%). The modified LUS score was higher in babies who needed surfactant therapy (median (IQR): 49 (44, 53.5) vs. 29.5 (21, 46)) (P < 0.0001).

Our study shows that LUS in neonatal RDS can predict the severity of the disease, need for surfactant therapy and has good agreement with clinical and Xray diagnosis.