PROTHROMBIN TIME (Protime) on therapy

Message

Tube MUST be full for proper whole blood to anticoagulant ratio. See Additional Information below for details.
If a butterfly needle is used for collection, a NON-ADDITIVE discard tube must be drawn first.

Test Code

PTC

Alias/See Also

PT therapy; coumadin; warfarin; protime

CPT Codes
85610

Includes

Protime and INR result will be provided

Preferred Specimen

1 Blue tube (Sodium Citrate)

Minimum Volume

0.5 mL plasma

Other Acceptable Specimens

None

Instructions

PT and PTT can be performed on a single blue top tube. If ordered together, centrifuge and aliquot (transfer) platelet-poor plasma into a transfer tube then freeze. See Additional Information below for details.

Transport Temperature

Room temperature or frozen plasma

Specimen Stability

-20C plasma is stable
15-30C up to 24 hours
2-8C plasma will be tested for viability by technical staff (this temperature is not recommended)

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Hemolyzed samples; clotted; citrate tube underfilled or overfilled; sample received more than 24 hours after collection (has not been centrifuged and plasma frozen); whole blood or plasma that has been refrigerated.

Methodology
Photo-Optical Clot Detection

Setup Schedule

M, T, W, Th, F, Sa, Sun

Report Available

Within 24 hours of receipt at the performing laboratory. Stat testing is available.

Reference Range

For therapeutic ranges, please refer to the ACCP guidelines located at www.chestnet.org

Clinical Significance

Used to monitor oral anticoagulant therapy. Used to screen for defects of the extrinsic and common coagulation pathways. If blood is drawn from an indwelling catheter, the line should be flushed with saline and the first 5ml of blood discarded.

Performed By
Alverno Laboratories

Performing Laboratory
Alverno Central Lab
NHMC (Hematology, IL Coag)

Additional Information
BD Vacutainer Plus Blue Top Volume Guide
Obtaining A Platelet-Poor Sample

Last Updated: June 13, 2023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.