Health Lab

Test Name:

PARTIAL THROMBOPLASTIN TIME(aPTT), ACTIVATED

Test Code:

2180059

Alias:

aPTT
LAB325
PTT

CPT Code(s):

85730

Test Includes:

*This CPT code is subject to a Medicare Limited Coverage Policy and may require a signed ABN when ordering.

National Coverage Determination (NCD) for PTT: https://www.cms.gov/medicare-coverage-database/details/ncd-details.aspx?NCDId=74&ncdver=1&bc=AgEAAAAAAAAA

Container:

1 - full (see line on tube) Sodium Citrate (lt blue) tube

Minimum Volume:

1 - full (see line on tube) Sodium Citrate (lt blue) tube or 1.0 mL frozen platelet-poor plasma

Collection Instructions:

Invert tube 5 to 10 times immediately after filling and transport at room temperature (stable for 24 hrs). NOTE: For patients on heparin, specimen must be centrifuged within 1 hour of collection and tested within 4 hours if kept at room temperature. To increase stability send frozen platelet-poor plasma.

For frozen platelet-poor specimens: Centrifuge the specimen for 15 minutes within 1 hour of collection. Using a plastic pipette, remove the plasma taking care to avoid the WBC/platelet buffy layer and transfer the plasma into a properly labeled transfer tube. Centrifuge the transferred plasma a second time and transfer platelet-poor plasma into a new properly labeled transfer tube. Label tube as "platelet-poor". Freeze immediately and transport to the lab frozen.

Transport Temperature:

Room temperature

Stability:

Room temperature: 24 hours (patients on heparin: 4 hours room temperature)
Frozen: 14 days (platelet-poor plasma)

Rejection Criteria:

Hemolysis
Clotted
Underfilled tube

Additional Information:

Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion (see fill line on tube) to ensure a proper blood-to-anticoagulant ratio. Submit difficult draws in pediatric tube (0.5 mL frozen platelet-poor plasma). The sample should be mixed immediately by gentle inversion to ensure adequate mixing of the anticoagulant with the blood.

Schedule:

Set up: Daily; Results in 24 hours

Method:

Optical clot detection

Clinical Significance:

This test may be used as a screening test for deficiencies or inhibitors of plasma coagulation factors other than factors VII and XIII.

To monitor patients on intravenous direct thrombin inhibitors such as Agratroban and Angiomax (Bivalirudin), the aPTT anticoagulation protocol test code 2181740 should be used.

Reference Ranges:

Reference Ranges Updated 1/30/24

Reference Range Table

Result	Units	Gender	Age	Range
APTT	seconds	Both	0 Year - 999 Year	24.8 - 38.4

The CPT codes included in this publication are in accordance with Current Procedural Terminology, a publication of the American Medical Association. CPT codes are provided here for the convenience of our clients; however, correct coding often varies from one carrier to another, and HealthLab may bill specific carriers using codes other than those shown. Clients who bill for services should verify the code(s) with the applicable payor to confirm that their use is appropriate in each case.