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Introduction: Bronchopulmonary dysplasia (BPD) remains one of the most common complications of preterm birth. Acquired lobar overinflation (ALO) is a rare, but serious complication of advanced BPD. Characterized by hyperinflation of the affected lobe, it can cause mediastinal shift with collapse of the contralateral, healthy lung resulting in decreased pulmonary reserve. Pathogenesis remains a mystery, but current hypotheses include a combination of intraluminal obstruction and bronchomalacia in the setting of barotrauma from prolonged intubation and lung immaturity1. We describe one case of acquired lobar overinflation in a patient with severe BPD and pulmonary hypertension (PH).
Case Description: The patient is a 4-month-old infant with history of prematurity (born at 26 weeks gestational age), BPD and hypoxemia requiring 0.5 L/min of supplemental oxygen who was admitted to the intensive care unit for respiratory distress secondary to adenovirus. He required Venovenous Extracorporeal Membrane Oxygenation (VV ECMO), and subsequently developed severe pulmonary hypertension requiring Sildenafil, Bosentan, and IV Treprostinil along with eventual tracheostomy. Serial imaging demonstrated hyperaeration of the left lingula with subsequent mediastinal shift and compression atelectasis of the right lung. Bronchoscopy showed significant malacia and obstruction at the orifice of the left lingula on exhalation. Perfusion scan showed patchy perfusion consistent with pulmonary vascular disease. Due to lack of clinical improvement with aggressive PH management and mechanical ventilation, the right mainstem was selectively intubated. Imaging demonstrated increased aeration of the right lung with improvement of oxyhemoglobin saturations and pCO2. A left lingular lobectomy was performed, and post-operatively over time, the residual left lung re-expanded and pulmonary pressures, oxygenation and ventilation status started improving. After 18 months, he was discharged home on oral Sidenafil, Bosentan and subcutaneous Treprostinil and is currently undergoing evaluation for decannulation.
Achieving optimal oxygenation and ventilation in patients with severe lobar overinflation and pulmonary hypertension can be challenging. Selective intubation may help to further delineate between healthy versus diseased lung. In this case, right mainstem intubation was both therapeutic and diagnostic; it improved ventilation and facilitated expansion of the previously compressed right lung. More importantly it demonstrated adequate function of the right lung, which is crucial information when considering surgical resection and determining overall prognosis.
Melzer, Lilah; Birnbaum, Brian; and Singh, Alvin, "Role Of Selective Intubation To Inform Decision Making For Surgical Treatment Of Acquired Lobar Overinflation (ALO) In The Setting Of Pulmonary Hypertension (PH): A Case Report" (2021). Research at Children's Mercy Month 2021. 3.