Fibrinolytic therapy, also known as thrombolytic therapy, is a time-sensitive medical treatment that uses 'clot-busting' drugs to dissolve dangerous blood clots in blood vessels. It is most often used in emergencies to treat ischemic strokes, ST-elevation myocardial infarctions (STEMI), and high-risk pulmonary embolisms. While life-saving, these medications carry a significant risk of bleeding, making it crucial to screen patients for contraindications.
Clinicians categorize these contraindications into two types: absolute and relative. An absolute contraindication means the treatment poses a life-threatening risk and must not be administered under any circumstances. A relative contraindication means caution is required, and the treatment should only be given if the potential benefits clearly outweigh the substantial risks.
Absolute Contraindications: When Fibrinolysis is Off-Limits
Absolute contraindications are conditions that present an unacceptably high risk of catastrophic bleeding, particularly intracranial hemorrhage (ICH). The decision to withhold therapy in these cases is straightforward to protect the patient from severe harm. Key absolute contraindications include a history of intracranial hemorrhage or known structural cerebral vascular lesions like AVMs or aneurysms. Known malignant intracranial neoplasms also increase bleeding risk. A recent ischemic stroke (within the last 3 months) is a contraindication for using fibrinolytics for other conditions. Suspected aortic dissection is an absolute contraindication due to the risk of fatal rupture. Active bleeding or a known bleeding diathesis, including low platelet count, elevated INR, or recent DOAC use, are also contraindications. Significant head or facial trauma or intracranial/intraspinal surgery within the last 3 months are further absolute contraindications.
Relative Contraindications: A Risk vs. Benefit Analysis
Relative contraindications require careful clinical judgment, weighing the benefits against increased risks, and decisions are individualized.
| Contraindication Category | Specific Examples | Rationale |
|---|---|---|
| Blood Pressure | Severe, uncontrolled hypertension on presentation (e.g., Systolic >180 mmHg or Diastolic >110 mmHg). | High blood pressure increases the shear stress on blood vessels, raising the risk of hemorrhagic stroke. |
| Medical History | History of chronic, severe, poorly controlled hypertension; dementia; or history of ischemic stroke >3 months prior. | These conditions may indicate underlying cerebrovascular fragility or make neurologic assessment more difficult. |
| Recent Procedures/Trauma | Major surgery within the last 3 weeks; traumatic or prolonged CPR (>10 min); recent internal bleeding (within 2-4 weeks); or non-compressible vascular punctures. | These sites are vulnerable to severe and difficult-to-control bleeding once the body's clotting ability is impaired. |
| Specific Conditions | Active peptic ulcer disease; pregnancy; or current use of anticoagulants (with elevated INR or aPTT). | These conditions inherently increase bleeding risk. In pregnancy, there is also risk to the fetus. |
| Patient Characteristics | Advanced age (e.g., >75 years). | Older patients may have more comorbidities and a higher baseline risk of bleeding complications, although age alone is not always an exclusion criterion. |
Special Populations and Considerations
Certain groups require specific consideration. Pregnancy is a relative contraindication due to maternal and fetal hemorrhage risk, used only in life-threatening situations. Recent major surgery (within 14 days to 3 weeks) presents a significant bleeding risk at the surgical site. Patients on anticoagulants with elevated INR (>1.7) or recent DOAC use are generally not candidates due to severe bleeding risk.
Conclusion
Determining when you can not give fibrinolytic therapy requires careful evaluation of patient history and current status. Absolute contraindications prevent devastating hemorrhagic complications, while relative contraindications necessitate a risk-benefit analysis. Understanding these exclusions is vital for safe and effective use of these potent medications. For more detailed guidelines, consult authoritative sources such as the American Heart Association/American Stroke Association guidelines.
