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Specimen Collection Manual and Test Catalog

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PLATELET FUNCTION ASSAY PANEL

Geisinger Epic Procedure Code:  LAB3490    Geisinger Epic ID:  119767

SPECIMEN COLLECTION
Specimen type: 

Whole blood


Preferred collection container: 
Alternate collection container: 
Lavender-top (K2 EDTA) microcollection tube
Other size blue-top (3.2% sodium citrate) tubes (e.g., 1.8 mL, 4.5 mL)
Specimen required: 

3.0 mL blue-top (3.2% sodium citrate) tube AND 3mL lavender-top (K2 EDTA) tube.


Special notes: 

This test is available at a limited number of laboratories and may only be collected and performed at testing sites (see below).


Patient preparation: 

Patient's hematocrit must be >30% or <55% and platelet count must be >50,000/uL. Patient should not be on any medication known to affect platelet function.
Perform venipuncture using a 21 gauge or larger diameter needle for specimen collection to minimize trauma. 
Indwelling catheter requires catheters to be flushed with 5mL of saline and the first 5 mL of blood discarded to avoid contaminating sample with tissue thromboplastin or heparin.
Butterfly needle setup collection requires a discard blue-top tube be drawn first to remove air from tubing.



SPECIMEN PROCESSING
Processing instructions: 

Do not centrifuge, refrigerate or freeze blue-top specimens. Do not transport specimen via the pneumatic tube system or courier.


Transport temperature: 

Room temperature


Specimen stability: 

4 hours


Rejection criteria: 
  • Clotted specimen. 
  • Hematocrit <30% or >55%. 
  • Platelet count <50,000/µL. 
  • Overfilled or underfilled tubes. 
  • Stability limits exceeded.


TEST DETAILS
Reference interval: 

89-193 seconds Collagen/EPI 
64-120 seconds Collagen/ADP


Interpretation guide: 
Collagen/EPICollagen ADPInterpretation
Within normal rangeNot performedNo platelet or von Willebrand disorder (vWD) detected
ProlongedWithin normal rangeAspirin or aspirin like drug(s) may be present. Stop medication and repeat testing in 7-14 days.
ProlongedProlongedPossible vWD, intrinsic platelet dysfunction, and some non-aspirin drugs
ShortenedShortenedIncreased platelet function or elevated platelet count

 

Notes:   The PFA-100® is insensitive to thienopyridine drugs (clopidogrel).
               Low hematocrit (<35%) and/or low platelet count (50,000–150,000/uL) may affect results.


CPT code(s):  85576, 85014, 85049 if needed 85576
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.
The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.

Test includes: 

PFA100(EPI/COLL), HCT, PLT, PFA100 (ADP/COLL), if indicated


Methodology: 
Platelet adhesion and aggregation
Synonyms: 

PFA 100, PLATELET FUNCTION SCREEN, PFASCR


Clinical significance: 

The platelet function assay panel is used to screen patients suspected of having a bleeding disorder that may be caused by intrinsic platelet defects, von Willebrand disease, or exposure to platelet inhibiting agents. Additional platelet function testing may be indicated if results are abnormal.


Doctoral Director(s): 
Michelle Grant DO
Review Date:  03/04/2025

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