Lung Ultrasound for the Differential Diagnosis of Respiratory Distress in Neonates

Background: Respiratory distress (RD) is the most common neonatal illness. Lung ultrasound (LUS) is a technique previously tested in neonatal studies on RD, but literature regarding its routine clinical applicability is still lacking. Objective: To assess the concordance between LUS performed by neonatologists with different training levels and chest X-ray (CXR) for the diagnosis of RD in newborns during the first 24 h of life. Methods: We enrolled newborns with RD during the first 24 h of life. Patients underwent LUS and CXR. LUS and CXR diagnosis were compared to evaluate concordance. Twenty percent of patients received two LUS (one from an experienced and one from a novice sonographer) to calculate the interobserver agreement. The difference in time needed to reach a diagnosis with LUS and CXR, and from novice and expert operators, was measured. Results: We studied 124 patients; 134 diagnoses were reported. The concordance between LUS and CXR diagnosis was 91% (95% CI 86–96%) with a κ statistic of 0.88 (95% CI 0.81–0.94). The median time to diagnosis was shorter for LUS (9.5 min, IQR 5–15) than for CXR (50 min, IQR 33–64) (p < 0.0001). In 25/124 patients, LUS was performed by both novice and experienced sonographers with complete concordance. The median time to diagnosis was shorter for expert (9 min, IQR 5–15) than novice operators (15 min, IQR 10–20) (p < 0.0002). Conclusion: LUS and CXR have a high concordance in the differential diagnosis of neonatal RD in the first 24 h of life. LUS has a shorter operation time than CXR.