Thrombolysis

Thrombolysis ( from Greek thrombus " blood clot " lysis "Resolution" ) - in medical jargon briefly called lysis - is a medical therapy in new-onset occlusion of blood vessels. The method can be used to treat heart attack (myocardial infarction), pulmonary embolism, ischemic stroke, and even if it is found, this potentially causing thrombosis are used.

The substances used thereby activate plasmin, an enzyme in the body's fibrinolysis ( Fibrinspaltung ).

Pathophysiology

Myocardial infarction, pulmonary embolism, and ischemic stroke can be caused by blood clots (thrombi or emboli ), close the blood vessels of the affected organs (heart, brain). Result of this closure is that the supplied from the vessel area can no longer flow through blood and is therefore at risk of a heart attack. A relevant pulmonary embolism also leads due to lack of back flow of blood to the heart to acute heart failure.

Application

Drugs used for lysis consist of enzymes that can break down thrombus or embolus or from these substances that activate the body's own enzyme degradation ( plasminogen) and keep the bloodstream free again. It can be administered intravenously as a systemic lysis and in specific cases through a catheter intraarterially as local lysis. Is lysed sooner, the greater the chances of success. In hemodynamically unstable patients with pulmonary embolism can begin with thrombolysis, the emergency physician. This is also at heart attacks in the case where a cardiac catheterization center in a timely manner ( within 90-120 minutes) is not reachable. New studies reduce the time even further, fibrinolysis is a good alternative to perkutanten transluminal coronary intervention (PCI ) when the symptoms of myocardial infarction (STEMI ) have started more than three hours before transport would take more than an hour longer in a hospital.

If a specific time is exceeded, the risks outweigh the benefits, as the fabric may already be necrotic. As reference values ​​were usually obtained as safe and effective and the heart attack six hours, after which thrombolysis no use in stroke earlier three, according to new studies up to four and a half hours after the onset of stroke symptoms.

Side effects

Since the administration (application) blood clotting is maximally inhibited, is for the patient the risk of serious bleeding complications. As one of the most serious side effects can occur with a frequency of about 1% a cerebral hemorrhage.

At the heart attack may occur arrhythmias after successfully carrying out thrombolytic therapy. For these reasons, a patient must be closely monitored even after thrombolysis.

Used drugs - fibrinolytics

Be applicable either as so-called non-specific thrombolytics the (older) enzymes streptokinase or urokinase or genetically engineered so-called "modern fibrin-specific thrombolytic agents " such as alteplase (rt -PA), reteplase (r- PA) or tenecteplase ( TNK- tPA).

Contraindications

The contraindications to thrombolytic therapy must be considered as part of a benefit -risk assessment and in terms of alternative therapeutic methods ( interventional procedures ).

In general, acute bleeding or coagulopathy with thrombocytopenia or receiving oral anticoagulation, a major injury or surgery in the last three months, tumors, dissecting aortic aneurysm and previous or suspected acute cerebral hemorrhage and stroke, as well as the puncture of a major artery or lumbar puncture are considered absolute contraindications.