Delayed Right Hemidiaphragmatic Dysfunction Associated with Obstetric Brachial Plexus Injury Presenting as Recurrent Respiratory Infections: A Case Report

Introduction Obstetric brachial plexus injury, particularly Erb’s palsy, may rarely be accompanied by phrenic nerve injury and ipsilateral diaphragmatic dysfunction. While most reported cases are recognized during the neonatal period, delayed presentation may mimic recurrent pulmonary infection and delay diagnosis. Case Presentation A 4-month-old male infant with right-sided Erb’s palsy following shoulder dystocia presented with recurrent respiratory distress and persistent right lower lung abnormalities. He had been born vaginally at 36+6 weeks following premature rupture of membranes, shoulder dystocia, and obstructed labor. At birth, he was flaccid and required approximately 2 minutes of bag-mask ventilation, and examination demonstrated right upper-limb adduction, wrist flexion, and an abnormal Moro reflex. At 4 months, he presented with cough, increased respiratory effort, wheezing, subcostal retractions, and markedly decreased air entry over the right lower lung. Chest radiography demonstrated persistent right lower lung opacity with elevation of the right hemidiaphragm and volume loss. Thin-section multidetector computed tomography demonstrated marked right hemidiaphragm elevation, compression and passive atelectasis of the right lower lobe, and mild leftward mediastinal shift without diaphragmatic discontinuity, pleural effusion, intrathoracic mass, or focal consolidation. Persistent respiratory morbidity and recurrent right lower lobe collapse led to surgical diaphragmatic plication, followed by clinical and radiographic improvement. Conclusion Diaphragmatic dysfunction should be considered when recurrent respiratory symptoms or persistent unilateral pulmonary abnormalities occur in infants with a history of obstetric brachial plexus injury.