Overdiagnosis and overtreatment of pulmonary embolism: the emperor may have no clothes

Pulmonary embolism is being overdiagnosed and overtreated, especially in previously normal women using oral contraceptives, with undesirable consequences in heparin treatment. This is in part a consequences of high estimates of its occurrence based on postmortem data and in part of technologic developments in diagnostic methods. Blood gas data are not diagnostically very helpful. Perfusion scans should be used, largely to exclude the diagnosis. Ventilation scans are only occasionally helpful and are expensive. Pulmonary angiography is the most accurate diagnostic means currently available. Further studies are needed to elucidate the prevalence and natural life history of pulmonary embolism in the previously healthy person.

Urokinase in the management of vitreous hemorrhage

Urokinase is a plasminogen activator of human origin which breaks up the fibrin base of blood clots. When given as an intravitreal injection it produces hypopyon and glaucoma, both of which transient. In a series of 27 patients (34 eyes) with unresolved vitreous haemorrhage, this simple and relatively atraumatic treatment has produced marked objective improvement in 10, and greatly improved the life styles of a further 9. This series brings the total of reported cases to 93. When compared with recent American reports of surgical vitrectomy for vitreous haemorrhage, intravitreal urokinase appears to have a higher success rate, with a lower complication rate both in the short and long term. This study suggests that, despite the high cost of the purified enzyme, urokinase should be come the first line of attack in vitreous haemorrhage, vitrectomy being reserved for those patients who fail to respond.

Intracranial bleeding associated with urokinase therapy for acute ischemic hemispheral stroke

Four patients undergoing urokinase infusion therapy for acute occlusive cerebrovascular disease had intracerebral hemorrhage in the ischemic hemisphere. Three patients died during the acute phase of their illness and an autopsy was performed on two. The pathogenesis of cerebral bleeding in these case reports is discussed.

A pilot study of urokinase therapy in cerebral infarction

Thirty-one patients with acute cerebral infarction were treated with the thrombolytic agent urokinase for either a single or a double infusion period, each of ten hours. The effects of urokinase therapy administered at dosage rates of 1,200, 1,500 or 1,700 CTA urokinase units per pound of body weight per hour were followed by serial blood coagulation and other biochemical studies. In the dosage used, urokinase produced a prompt sustained increase, 20-fold to 40-fold, of plasma thrombolytic activity with relatively minor disturbance of the blood coagulation system. Nevertheless, hemorrhagic complications occurred in several patients and distinctly favorable therapeutic effects were not observed.

Streptokinase and urokinase in the treatment of pulmonary thromboemboli; from a national cooperative study

In Phase I of this study of 160 patients with pulmonary embolism, it was demonstrated that of 12 hours of urokinase accelerated the resolution of pulmonary thromboemboli compared to heparin alone. Phase II compared 12 hours of urokinase, 24 hours of urokinase and 24 hours of streptokinase in 167 patients. All patients had a clinical history and angiographic diagnosis of pulmonary embolism. Patients were randomly allocated to treatment. All physicians making patient observations were unaware of drug assignment. Resolution of the thromboembolism 24-30 hours after therapy had been instituted was determined by pulmonary angiography, lung perfusion scans and cardiopulmonary hemodynamics. Twenty-four hours of urokinase did not demonstrate greater clot resolution than 12 hours of urokinase. Twenty-four hours of urokinase resulted in greater improvement than streptokinase in lung perfusion scans, but not in angiograms. In patients with massive embolism, this difference was statistically significant. Hemodynamic differences varied. Bleeding complications and morbidity due to allergic reactions with streptokinase and urokinase were minimal. There was no statistically significant difference in mortality in the three threatment groups. From the Phase I and Phase II data it is reasonable to conclude that all three regimens of thrombolytic therapy are more effective than heparin alone in accelerating resolution of pulmonary emboli. Thrombolytic therapy offers the clinician an alternative to pulmonary embolectomy.

The prophylactic use of thio-tepa and urokinase in transitional cell carcinoma of the bladder: a preliminary report

The prevention of recurrences of bladder cancer was attemped in 48 patients by means of the combined intravesical instillation of thio-tepa and urokinase and in 28 patients through the instillation of thio-tepa alone. The recurrence rates of both therapies for the postoperative 18 months were 7.9 and 32.6 per cent, respectively, indicating a significant drop in the recurrence rate in the group subjected to the combined therapy. No significant difference was found between the 2 instillation groups in terms of the blood transmission of 32-P thio-tepa. Serious leukopenia was found in 2 of the 48 patients receiving the combined instillation therapy but we concluded that this was not attributable to the use of urokinase.

[Thrombolytic treatment with urokinase (author's transl)]

Compared with streptokinase, thrombolytic treatment with urokinase has the advantages of being better tolerated and of practically unlimited applicability. Its disadvantage is the high cost. A good lytic action can be obtained with a dosage of 150,000 Ploug Units/12 hours for a duration of lysis of 8-14 days combined with heparin, the therapy being monitored by determination of the products of fibrinolysis. This dosage is not possible if the time factor plays a decisive role in the success of the treatment, e.g. in myocardial infarction. Urokinase is indicated when streptokinase cannot be used, or if continuation of the streptokinase therapy is necessary because of extensive thromboses.