Intrapulmonary artery infusion of urokinase for treatment of massive pulmonary embolism: A review of 26 patients with and without contraindications to systemic thrombolytic therapy

Background: Pulmonary emboli (PE) are a common event seen in over 600,000 patients a year. Occurring suddenly, PE often result in a high rate of mortality. To combat the high rate of mortality, more aggressive therapies including the use of thrombolytics are often indicated. The use of intrapulmonary artery infusion of urokinase has been shown to promote rapid resolution of emboli and restoration of normal pulmonary hemodynamics. Hypothesis: The study was undertaken to review the effectiveness and safety of pulmonary artery infusion of urokinase in 26 patients with and without contraindications to the use of systemic thrombolytic therapy. Methods: We reviewed the outcomes of 26 patients who received infusion of urokinase, using a usual loading dose of 4,000 U/kg body weight given as a bolus, followed by 4,000 U/kg/h for 12 to 24 h, using either/or unilateral or bilateral infusions. Pulmonary angiograms were obtained prior to and following the urokinase infusions. Results: Intrapulmonary artery infusion of urokinase was given to 26 patients, 9 of whom had contraindications to the use of systemic thrombolytic therapy. Six patients were recent post operative, one was receiving oral anticoagulants, one was receiving chemotherapy with bleeding complications, and one had received cardiopulmonary resuscitation. Twenty of the patients returned to their baseline state (normal heart rate, blood pressure, and pO(2)), one was minimally improved, and five deaths occurred. Of the five deaths, three occurred within 1 h of starting urokinase infusion, the remaining two died more than 36 h after treatment with urokinase as a result of their basic underlying disease. Minor bleeding occurred from puncture sites, two hematomas occurred at the puncture site, and there were two gastrointestinal bleeds, one of which occurred a week post urokinase therapy while the patient was receiving heparin and coumadin. No central nervous system bleeds occurred and no transfusions were required as a result of urokinase intrapulmonary artery infusions. The overall mortality rate in this series was 11.5%. Conclusions: Intrapulmonary artery infusion of urokinase in extensive pulmonary embolism is a safe and efficient treatment in patients with and without contraindication to the use of systemic thrombolytic therapy. With a usual loading dose of 4,000 U/kg body weight, followed by an infusion of 4,000 U/kg/h for 12 to 24 h, it produces significant and rapid resolution of pulmonary emboli with a low morbidity and mortality rate. In our series, the mortality rate was 11.5%, and none of the deaths was the direct result of urokinase therapy.