[Urokinase in a premature infant: its use in a case of right atrial thrombosis secondary to catheterization of the umbilical vein].

Newborns with vascular catheters must be investigated by echocardiogram for intracardiac thrombosis. We report the use of urokinase to treat an asymptomatic right atrial thrombus in a 31 weeks' gestation newborn; the thrombosis occurred after placement of a catheter in the umbilical vein. We obtained a safe and successful thrombolysis using urokinase 4000 U/kg/h in continuous infusion.