Acute pulmonary embolism treated with thrombolytic agents: current status of tPA and future implications for emergency medicine.

Pulmonary embolism is diagnosed 120,000 times yearly in the United States and contributes to 30,000 deaths. This probably represents an underestimate of incidence because massive acute pulmonary embolism may often result in rapid and therefore unexplained death in the absence of autopsy confirmation. The innovative and judicious use of thrombolytic agents by emergency department and paramedical ambulance personnel may lead to a decreased mortality for this disease. Clinical studies are necessary to determine if the cardiopulmonary compromise associated with massive pulmonary embolism can be rapidly reversed through thrombolysis and whether that reversal will lead to increased survival. The use of thrombolytic agents will gain favor only if their risk:benefit and cost:benefit ratios are acceptable. We discuss the results of using first- and second-generation thrombolytic agents in the treatment of pulmonary embolism and review the encouraging data that have emerged from our studies with recombinant tissue-type plasminogen activator (tPA). This agent has relative fibrin specificity and may provide therapeutic advantages over the conventional thrombolytic agents, urokinase and streptokinase, particularly when the latter are administered in the currently recommended dose schedules for treatment of pulmonary embolism.