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Test Code PRO PROTHROMBIN TIME (PT WITH INR)

Important Note

Test subject to Medicare National Coverage Determination (NCD).

See Medical Necessity documentation requirements by clicking on  

Medicare National Coverage Determinations under General Information

to left of this screen.

Additional Codes

LAB320

Day(s) Performed

Daily; Available STAT

Methodology

Photo-optical clot detection

Test Classification and CPT Coding

85610

Container

Review Collecting a Coagulation Test for complete instructions before drawing specimen.

 

Specimen Type: Whole blood
Container/Tube: Light-blue top (citrate)

Specimen Volume: 1 full tubes

Specimen Minimum Volume: 2.7 mL

Collection Instructions: 

1. Tubes must be full.

2. Send specimen in original tubes at room temperature.

2. Sample stable 24 hours at room temp.

Normal Reference Values

SEC: 9.0-12.3; INR: 0.8-1.2 Moderate Intensity Coumadin INR = 2.0-3.0.


Adjustments in anticoagulant therapy dose should be based upon the INR and not the PT in seconds. The INR is used only on patients on stable oral anticoagulant therapy. It makes no significant contribution to the diagnosis or treatment of patients whose PT is prolonged for other reasons.

Critical Values

INR >4.0

Performing Location

Porter Hospital Laboratory