Prothrombin Time is used to measure how long it takes for the blood to clot. It can also be called as INR which stands for International Normalized Ratio. The INR is used to standardize the result of PT no matter what the testing method is. If PT is more than 2.5 times the controlled value or when the INR is more than 4.0, the person tested is in high risk for bleeding.
This is the Fifth of my series explaining the Coagulation Fishbone Diagram with the Focus on Coumadin and Heparin with PT prothrombin Partial Thrombin Time PTT and INR International Normalized RationElect rolytes Hyponatremia VS Hypernatremia Hyperkalemia and Hypokalemia will be next along with BUN and Creatinine and glucose, Study sheets for nurses! The Nurses Notes Nursing School
The prothrombin time (PT) and its derived measures of prothrombin ratio (PR) and international normalized ratio (INR) are measures of the extrinsic pathway of coagulation. This test is also called "ProTime INR" and "INR PT". They are used to determine the clotting tendency of blood, in the measure of warfarin dosage, liver damage, and vitamin K status. PT measures FI (fibrinogen), II (thrombin), V, VII, and X. It is used in conjunction with aPTT which measures the intrinsic pathway.