ACTIVATED PARTIAL THROMBOPLASTIN TIME (therapy)

Message

Tube MUST be full for proper whole blood to anticoagulant ratio. See Additional Information below.
Preferred sample is platelet-poor plasma; see Additional Information below for instruction.
If a butterfly needle is used for collection, a NON-ADDITIVE discard tube must be drawn first.
Whole blood specimen stability may be adversely affected by heparin therapy, labile clotting factors, and hepatic function.
It is preferred that samples are centrifuged, aliquoted, and frozen.

♦♦♦ Whole blood specimen stability may be adversely affected by heparin therapy, labile clotting factors, and hepatic function. It is preferred that samples are centrifuged, aliquoted, and frozen.♦♦♦

Test Code

APTTH

CPT Codes
85730

Preferred Specimen

1 Blue tube (Sodium Citrate)

Minimum Volume

0.5 mL platelet-poor plasma

Other Acceptable Specimens

None

Instructions

Centrifuge and remove platelet-poor plasma if testing will be delayed >1 hour from collection. If not tested within 4 hours of collection, freeze plasma. See Obtaining A Platelet-Poor Sample below.

PT and PTT can be performed on a single blue top tube. Centrifuge and aliquot platelet-poor plasma into a transfer tube then freeze.

If blood is drawn from an indwelling catheter, the line should be flushed with saline and the first 5ml of blood discarded.

Transport Temperature

Frozen

Specimen Stability

Frozen plasma is stable up to 14 days.

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

The following conditions will result in a rejected specimen.

Hemolyzed sample
Clotted sample
Sample tube underfilled or overfilled
Sample not received within 4 hours of collection if plasma has not been aliquoted and frozen

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.

Reference Range

Therapeutic range: 65-90 seconds

Clinical Significance

Used to monitor patient response to heparin therapy.

Performed By
Alverno Laboratories

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

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

Last Updated: August 2, 2024

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.