PROTHROMBIN TIME (Protime) no therapy

Message

Tube MUST be full for proper whole blood to anticoagulant ratio.

If a butterfly needle is used for collection, a NON-ADDITIVE discard tube must be drawn first

Test Code

CPT Codes
85610

Includes

Protime and INR result will be provided

Preferred Specimen

1 Blue tube (Sodium Citrate)

Minimum Volume

0.5 mL plasma (see Specimen Collection)

Other Acceptable Specimens

None

Instructions

PT and PTT can be performed on a single blue top tube. If ordered together, the preferred sample handling is to centrifuge and aliquot platelet-poor plasma into a transfer tube then freeze. Whole blood or plasma maintained at room temperature will be accepted for non-therapeutic patients only.

Transport Temperature

Room temperature whole blood or plasma
or frozen plasma

Specimen Stability

Whole blood or plasma is stable at room temperataure up to 24 hours; frozen plasma is stable up to two weeks. Refrigerated samples will be tested for viability by technical staff.

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

The following criteria will result in a rejection:

Hemolyzed samples
Clotted sample
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

10.1 - 13.1 seconds

Clinical Significance

Used to screen for defects of the extrinsic & 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)

Last Updated: June 4, 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.