The Role of Recombinant Human Tissue-Type Plasminogen Activator in the Treatment of Acute Pulmonary Thromboembolism

The effect of intravenous recombinant human tissue-type plasminogen activator (tPA) on arterial blood gases was compared with the effect of heparin treatment in acute pulmonary thromboembolism. Fifteen patients received heparin alone (group A), 5 cases were treated with 7.7 × 10⁶I.U. of tPA (group B) and 10 cases with 15 × 10⁶I.U. of tPA (group C) combined with heparin treatment. Arterial oxygen tension before treatment was not significantly different among the three groups. PaO₂ was dramatically improved on the 1st day in group C. By the 7th day, PaO₂ of group B had improved to the level of group C. However, the PaO₂ of group A on the 7th day was not significantly different compared to the pre-treatment value. In group C, post-treatment perfusion lung scintigrams were improved compared to the pre-treatment images, but this was not the case in group B. Treatment with tPA is more effective for acute pulmonary thromboembolism than heparin alone and a high dose of tPA (15 × 10⁶I.U.) leads to rapid improvement in arterial blood gases and lung perfusion images.