Bivalirudin/heparin

Abstract

Lack of efficacy: case report A 7-month-old boy exhibited lack of efficacy during treatment with heparin and bivalirudin for thrombosis [not all routes stated]. The boy had double outlet right ventricle, centrally confluent hypoplastic poorly arborizing native pulmonary arteries with 6 aortopulmonary collaterals, tricuspid hypoplasia, transposition of the great arteries with near pulmonary atresia, secundum atrial septal defect and subpulmonic ventricular septal defect underwent bilateral unifocalisation, bidirectional Glenn and clipping down of the shunt. His clinical examination led a concern for thrombus and ultrasound confirmed nonocclusive thrombus in his upper extremity arteries and extensive venous thrombosis with sluggish arterial flow. Treatment with heparin infusion 20 units/kg/hr was initiated. However, a large thrombus in the right atrium prompting transition was noted. Hence, the boy’s treatment with heparin was switched to bivalirudin. A week later, he developed arteriovenous malformations and underwent clot extraction from the right pulmonary artery, left pulmonary artery, superior vena cava, right atrium and branch pulmonary arteries. Following surgery, he was hypotensive and hypoxic. Hence, he was cannulated to veno-arterial extracorporeal membrane oxygenation (ECMO). Despite receiving high dosing of bivalirudin (maximum dose 2 mg/kg/hr), he developed extensive circuit clot burden and required multiple circuit changes. Therefore, following consultation with haematology and several experienced clinicians, he was switched to enoxaparin-sodium after a circuit change. Subsequently, his circuit health was maintained and required only one circuit change after 6 days. Thereafter, a significant improvement was observed and he was decannulated after 8 days.