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Test Code LAB2910 PT-INR

Important Note

As of 9/27/2023, there are no longer separate screen (PROS) and therapy (PROT) orders. Instead, there is one order, PT-INR.

PT specimens should be kept at room temperature and tested within 10 hours. Do not refrigerate PT specimens. If testing cannot be completed within 10 hours, separate the plasma into an aliquot container and freeze the specimen at -20°C. Specimens frozen offsite should be double spun / plasma separated prior to freezing. Frozen specimens should be thawed at room temperature, remixed thoroughly, and tested immediately.

Additional Codes

CPT Code: 85610

Performing Laboratory

TidalHealth Peninsula Regional - Core Laboratory: Hematology

Specimen Requirements

Draw blood in a light blue-top (3.2% sodium citrate) tube, and send 4.5 mL of sodium citrate whole blood at room temperature. Light blue-top tube must be at least 90% full for accurate results. (Clotted or hemolyzed specimen is not acceptable.) Forward promptly to laboratory. Specimens should be kept at room temperature (18-24°C).

Reference Values

Reference Range:

PT: 9.4 - 12.5 seconds

INR: 0.9 - 1.2

 

Critical value (automatic call-back):

PT (<6 months): >30 seconds

INR (all ages): >5.0

Additional Information

Available STAT

Direct Oral Anticoagulants can prolong results for hemostatis assays.