Activated clotting time (ACT)

Definition

Activated clotting time (ACT) is a test that measures the time it takes for blood to clot in the presence of an activator. It is commonly used to monitor high-dose heparin therapy during procedures such as cardiac surgery.

5 Must Know Facts For Your Next Test

1. ACT is used to monitor anticoagulation effects during surgeries and invasive procedures.
2. High-dose heparin therapy requires frequent monitoring using ACT to ensure therapeutic levels are maintained.
3. An abnormal ACT result can indicate either excessive anticoagulation or insufficient anticoagulation, requiring dosage adjustments.
4. The normal range for ACT varies depending on the procedure and the patient's baseline levels.
5. Point-of-care devices are often used for rapid ACT testing in clinical settings.

Review Questions

• What is the primary purpose of measuring Activated Clotting Time (ACT)?
• Why is ACT particularly important during cardiac surgery?
• How does an abnormal ACT result influence patient care during high-dose heparin therapy?

Related terms

Heparin: An anticoagulant medication used to prevent and treat blood clots.

Prothrombin Time (PT): A test that measures how long it takes for blood plasma to clot, commonly used to monitor warfarin therapy.

Partial Thromboplastin Time (PTT): A test that measures the time it takes for blood to clot, often used to evaluate intrinsic pathway coagulation factors and monitor heparin therapy.