Fibrinolytic Therapy
For a patient experiencing an acute ST-elevation myocardial infarction (STEMI), the use of fibrinolytic therapy is an important clinical intervention. The administration of a fibrinolyic agent such as streptokinase (SK) or tissue plasminogen activator (tPA) results in the lysis of the acute thrombus so that the obstructed coronary artery can be opened and blood flow to the affected tissue can be restored. Adjunctive measures, such as the initiation of heparin infusions are then taken to prevent further clot formation and obstruction reoccurrence. Lysis is achieved by converting inactive plasminogen to plasmin, an enzyme that is responsible for the degradation of fibrin.
Patients with recent onset of chest pain with persistent ST elevation and those with underlying bundle branch blocks are ideal candidates for therapy. To ensure maximum effectiveness the a goal of 30 minutes from the onset of the patient’s pain to the administration of the agent, should be set.
Following the lysis of the thrombus, there are several phenomena that may be observed.
Pain
- As blood is restored to the ischemic myocardium, chest pain will stop abruptly
Reperfusion Dysrhythmias
- While many different dysrhythmias may occur, accelerated idioventricular rhythms have been shown to be the most frequent with reperfusion
- These dysrhythmias are usually limited do not require antidysrhythmic therapy unless they are sustained
ST segment
- Rapid return of ST segments to the isoelectric line indicated restoration of blood flow to the previously ischemic myocardial tissue
Cardiac Biomarkers
- Continued measurement of the biomarkers serves as evidence of successful reperfusion following administration of a fibrinolytic
Residual Coronary Stenosis
- Even after successful fibrinolysis, residual coronary artery stenosis from the underlying atherosclerotic process remains
- Prevention methods are crucial to preserving myocardial function and preventing the risk of late complications
Nursing responsibilities in fibrinolytic therapies include:
- Establishing IV access and ensuring continued patency
- Obtaining baseline laboratory values and vital signs
- Assess and monitor for signs of reperfusion
- Assess and monitor for signs of complications related to therapy
- Assess and monitor for clinical manifestations of bleeding
- Minimize potential for bleeding
- Health teaching for patient and family