Patent Ductus Arteriosus and Left Mainstem Bronchus Compression in a Term Infant: Broad Differential, Novel Diagnostics, and Surgical Resolution.

The differential diagnosis of respiratory distress in term neonates is broad and includes infectious, cardiac, parenchymal, airway, metabolic, and genetic etiologies. We present the case of a full-term, 10-day-old infant with tachypnea, feeding difficulties, and progressive right-sided lung opacification, initially presumed to be infectious in origin. A systematic diagnostic evaluation ultimately revealed a large patent ductus arteriosus (PDA) associated with airway compression due to the large PDA. Multimodal assessment using chest radiography, echocardiography, computed tomography, bronchoscopy, and electrical impedance tomography was critical in establishing the diagnosis and guiding the initiate and definitive management. The infant underwent successful surgical ligation and division of the PDA, with complete clinical recovery and discharge on room air. This case highlights the importance of a structured diagnostic approach in term neonates with persistent respiratory distress and emphasizes the need to consider vascular-mediated airway compression in the differential diagnosis.