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Laboratory Test Directory

Von Willebrand Workup without Platelet Function Analysis

Components

Name Method Department Units
Von Willebrand Workup without PFA Clot detection
Core Lab, Coagulation

Battery Members

PT; APTT; Ristocetin Cofactor; Quant. Factor VIII:C; von Willebrand Antigen; Fibrinogen; Thrombin Time

Specimen Requirements

Platelet poor plasma

Container Type Container Size Specimen Volume
Preferred

Blue plastic tube (Citrate)

2.7 mL 12 mL
Stability

Frozen - 2 week(s)

Specimen Preparation

  • Fill tubes to appropriate mark.
  • Mix by gentle inversion immediately after collection
  • Centrifuge, remove plasma/serum and freeze
  • Plasma must be platelet free

Reasons for Rejection

  • Clotted specimen
  • Over or under filled tube
  • Not received within specified time frame
  • Gross hemolysis
  • Wrong collection tube

Comments

**This package does not include a Platelet Function Analysis. Refer to test code VWW for information regarding the von Willebrand Workup that includes a Platelet Function Analysis. Sample testing is batched (several tests are not performed daily). ** Reflexive testing is the Factor VIII Multimer Analysis (test code: XVWFM) ordered by the pathologist. A pathologist's interpretation (billed through Pediatric Pathology associates (PPAC)) may be ordered and charged. A Pathologist's consult/interpretation may extend the expected turnaround time. Four 2.7 mL collection tubes should be drawn from the patient to perform all tests in the workup. For frozen plasma: Centrifuge citrate tubes according to Lab policy, remove platelet-poor plasma and freeze. Each aliquot tube should contain approximately 1 mL of plasma. Whole blood samples must be received by NCH Laboratory Services within 4 hours of collection.

CPT Code

  • 85245
  • 85240
  • 85384
  • 85730
  • 85610
  • 85670
  • 85246