ALTEPLASE USE FOR PULMONARY ARTERY THROMBUS IN A CHILD ON EXTRACORPOREAL MEMBRANE OXYGENATION.

Abstract

Thrombus formation has become an increasingly recognized problem in critically ill children. Recently, guidelines for antithrombotic therapy in children have been revised. We report the use of alteplase (tPA) for thrombolysis of a large pulmonary artery (PA) clot in a male infant on extracorporeal membrane oxygenation (ECMO). The patient was a 10 month old, with a history of unbalanced atrioventricular canal, transposition of the great arteries/double-outlet right ventricle, total anomalous pulmonary venous connections (TAPVC), and dextrocardia status post-TAPVC repair and PA banding. He was admitted to our cardiothoracic ICU following a superior cavopulmonary anastomosis. His postoperative course was complicated by progressive opacification of the right hemithorax, initially diagnosed as ventilator-associated pneumonia. Bronchoscopy noted normal-appearing airways with copious secretions that isolated Enterobacter species. Due to worsening hypoxemia and elevated PA pressures (PAP 22), he was placed on ECMO. A contrast injection into the right SVC demonstrated complete obstruction of the right PA. Thrombolysis was initiated with a tPA infusion at 0.5 mg/kg/h for 12 hours, as directed by the Children9s Thrombophilia Network thrombolytic guidelines without serious complications such as intracranial or gastrointestinal hemorrhage. Despite continued aggressive supportive measures, multiorgan system failure ensued and the family decided to withdraw support. A limited autopsy confirmed thrombolysis of the right PA was achieved; however, a new organized clot had developed in the left PA. Results from a genetics workup suggested the presence of a hypercoagulable state. To our knowledge this is only the second report of tPA use during ECMO support in a child. We believe that tPA can be used concomitantly with ECMO for thrombolysis.