[Thrombolytic therapy of pulmonary embolism--a therapeutic alternative?].

The spontaneous prognosis of pulmonary embolism is mainly dependent on the degree of pulmonary artery obstruction. As for the cause of spontaneous lysis, submassive pulmonary embolism generally will be survived with complete restitution of the pulmonary artery trunk. On the other hand, the hallmark of massive pulmonary embolism is a tremendously high early mortality. In the decision for thrombolysis in patients with pulmonary embolism, major attention must therefore be paid to the severity of pulmonary obstruction. Up to now, neither a reduction in mortality nor in secondary morbidity by thrombolysis has convincingly been shown in patients with submassive pulmonary emboli. In the rare cases with submassive pulmonary emboli, when one still tends to decide in favor of thrombolysis, beyond the thrombus obstructing the pulmonary artery, the thrombus identified as the source of the emboli should also be attacked. In these patients, careful attention has to be paid to the contraindications of thrombolysis, and low-dose continuous infusion regimens like the ones used in deep venous thrombosis should be selected. In patients with massive and life-threatening pulmonary embolism, however, thrombolysis has the potential to save lives and, therefore, must be judged in a different way. In spite of their high frequency, for the critical prognosis of these patients only minor attention must be paid to the contraindications of thrombolysis. In these critically ill patients, high-dose intravenous, brief duration infusions of the thrombolytics therefore can be considered as the best option. The far lower cost (about one-tenth) and the comparable success rates with embolectomy makes thrombolysis the regimen of choice, especially when embolectomy is not readily available.