What it means
A clotting test, usually reported with the INR (international normalized ratio), which puts the result on a standard scale so labs can be compared. It checks some of the clotting factorKLOT-ing FAK-terAny of the proteins in blood plasma that work together in a chain to form a blood clot.Full entry s made in the liver that need vitamin K. It is used to monitor warfarin, to check liver function and to look for bleeding problems. A longer time means the blood clots more slowly.
For the nurse
Check the PT/INR before giving warfarin and report a value above the goal range. Watch for bleeding signs. Vitamin K reverses warfarin's effect.
At a glance
| Normal range | About 11–13.5 seconds; INR 0.8–1.1. Each lab sets its own reference range. On warfarin the INR goal is usually 2–3. |
|---|---|
| Abbreviations | PT; PT/INR |
| Spanish | tiempo de protrombina |
| Also written | pro time |
Related terms
anticoagulant
A drug that slows the blood's ability to form clots.
bleeding
Blood escaping from a blood vessel, either out of the body or inside it.
clotting factor
Any of the proteins in blood plasma that work together in a chain to form a blood clot.
liver disease
Any condition that damages the liver or keeps it from working normally.