Master PT/PTT Lab Values with Picmonic for Nursing RN

The approximate range for PT is 11-15 seconds. Elevated PT values indicate a longer clotting time, increases the risk for bleeding and bruising and may suggest liver damage, vitamin K deficiency, use of blood thinning medications, bleeding disorders, or other disorders like disseminated intravascular coagulation (DIC). Lower than normal PT value indicates blood is clotting too fast, increasing risk for dangerous clots and may suggest high vitamin K or blood-clotting disorder.

Activated Partial Thromboplastin Time (PTT or aPTT) evaluates the intrinsic and common pathways of the coagulation cascade. aPTT is used to measure the therapeutic effects of Heparin, which prevents clotting by blocking certain factors in the intrinsic pathway.

Although the value of PTT/aPTT depends on the reagents and instruments used, the normal range is often 25-40 seconds. The PTT/aPTT is monitored closely for patients on Heparin drips in the hospital. Elevated PTT/aPTT values indicate increased risk for bleeding and bruising and may suggest liver damage, vitamin K deficiency, use of blood thinning medications, or other bleeding disorders. If a patient's PTT/aPTT value is lower than normal, their blood is clotting too fast, increases risk for dangerous clots and may indicate blood-clotting disorder or other concerns.