Prolonged aPTT Bleeding Evaluation [19644X]

18181

Partial Thromboplastin Time, Activated (aPTT)
Impression

If the baseline aPTT is minimally prolonged, then test Minimally Prolonged aPTT Profile (includes Factors VIII, IX, XI, VWF Antigen, Ristocetin Cofactor Activity) will be performed at an additional charge (CPT code(s): 85384, 85610, 85670, 85246, 85245).

If the baseline aPTT is prolonged, then aPTT 1:1 mixing study progressive will be performed at an additional charge (CPT code(s): 85732).

If a correction pattern is observed with the aPTT mixing study, then Factor VIII, IX and XI Activities will be performed at additional charge (CPT code(s): 85240, 85240, 85270).

If an inhibitor pattern is observed with the aPTT mixing study, then the Hexagonal Phase Confirm (CPT code(s): 85598) and Thrombin Time (CPT code(s): 85670) are performed at an additional charge.

Additional assays, as necessary will be performed at an additional charge to determine the cause of the abnormality.

1 mL (x4) platelet-poor plasma collected in 3.2% sodium citrate (light blue-top) tubes

0.5 mL (x4)

4 mL citrated platelet poor plasma, frozen.
Submit 4 plasma aliquots, each with 1 mL plasma for possible additional testing.

Refer to Quest Diagnostics Nichols Institute Directory of Services under Specimen Collection section, Coagulation Testing for further information on specimen processing.

Frozen

Room temperature: 24 hours
Refrigerated: 24 hours
Frozen: 14 days

Specimens received room temperature • Received refrigerated • Hemolysis

Set up: Mon-Sat; Report available: Next day

See Laboratory Report

This evaluation is for the patient with a prolonged Activated Prolonged Thromboplastin Time with a history of bleeding/bruising. The investigation follows a testing algorithm with an endpoint of arriving at a final diagnosis, most commonly a factor deficiency or von Willebrands disease.