Prothrombin Time and International Normalized Ratio (PT/INR) CPT: 85610
Expected Turnaround Time
Within 1 day
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Light-blue top (3.2% sodium citrate)
1. Centrifuge, remove plasma, and centrifuge plasma again.
2. Aliquot plasma into plastic vial leaving 0.25 mL in the bottom of centrifuged vial.
Additional Information: Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
Maintain specimen at room temperature.
|Room Temperature||3 Days|
|Freeze/thaw/ cycles||X 3|
A prothrombin time (PT) is a test used to help detect and diagnose a bleeding disorder or excessive clotting disorder; the international normalized ratio (INR) is calculated from a PT result and is used to monitor how well the blood-thinning medication (anticoagulant) warfarin (Coumadin®) is working to prevent blood clots.
When you are taking warfarin or when you have unexplained or prolonged bleeding or inappropriate blood clotting.
A blood sample drawn from a vein; sometimes blood from a fingerstick.
None needed, although if you are receiving anticoagulant therapy, the blood sample should be collected before taking your daily dose.