44: Unusual Cause of Persistent Refractory Hypoxemia Requiring Extracorporeal Membrane Oxygenation Support

Introduction: Pulmonary arteriovenous malformations (PAVMs) are rare vascular anomalies involving abnormal connections between pulmonary arteries and veins, which allow deoxygenated blood to bypass the capillary network and enter systemic circulation. Though uncommon in children, PAVMs are frequently linked with hereditary hemorrhagic telangiectasia (HHT). Early diagnosis is challenging, and severe cases may require extracorporeal membrane oxygenation (ECMO) support for refractory hypoxemia. Case Presentation: We report a 12-year-old girl presenting with acute respiratory failure and hypoxia, unresponsive to mechanical ventilation. Despite high oxygen settings, her oxygen saturation remained in the 60s%. She was started on venovenous ECMO, which improved her oxygenation to 85-90%. Imaging and bubble tests revealed multiple large PAVMs, and she underwent successful embolization. The patient was decannulated from ECMO after stabilization and discharged in good condition. This case underscores the challenges of managing refractory hypoxemia in a pediatric patient with undiagnosed PAVMs. ECMO provided crucial support for oxygenation while definitive diagnosis and intervention were pursued. The bubble test and pulmonary angiography were key diagnostic tools, and embolization effectively treated the PAVMs. The suspected association with HHT prompted further genetic investigation. Embolization significantly reduces mortality compared to untreated PAVMs. Conclusions: Refractory hypoxemia in children can result from rare causes like PAVMs. ECMO can serve as a lifesaving bridge to diagnosis and treatment, emphasizing the need for early recognition and intervention to prevent serious complications.