/clinical/,/clinical/tools-resources/,/clinical/tools-resources/lab-test-directory/,/clinical/tools-resources/lab-test-directory/coagulation/,

/clinical/tools-resources/lab-test-directory/coagulation/name-67823-en.labtest

Jan 4, 2018

page

100

UWHC,UWMF,

Clinical Hub,Tools & Resources,UWHC Lab Test Directory,Coagulation

Platelet Function Screen

Platelet Function Screen (HCPFS) Coagulation Lab Test

Name: Platelet Function Screen

Test Name: Platelet Function Screen

Health Link Test Code: HCPFS

LIS Test Code: PFS

CPT Code(s): 85576x2

Test Component:

Testing is performed using two cartridges: one with collagen/epinephrine (PFAEPI) and a second with collagen/ADP (PFAADP).

Methodology: Shear Flow Closure Time

Clinical Information:

Screen for platelet function. Especially recommended as part of a workup for von Willebrand disease.

Days Performed: Mon-Fri, 0800-1600. Testing requested outside of these hours please call 608-263-5005 before collection.

In-Lab Turnaround Time: 4 hours.

Stat In-Lab Turnaround Time: 2 hours.

Patient Preparation:

Fasting specimen preferred. Patient ingestion of aspirin or aspirin-containing medications for 7 days and/or antihistamines, non-narcotic analgesics, or NSAIDs for 48 hours prior to specimen collection may cause abnormal results.

Specimen: Blood

Collection Container: Light blue top (3.2% NaCitrate)

Collection Instructions:

Indicate if von Willebrand disease is suspected. Do NOT draw through a line containing heparin. The venipuncture MUST be atraumatic to avoid hemolysis, contamination with tissue factors, or platelet activation. Tube must be allowed to fill completely.

Hand deliver specimen to University Hospital lab immediately. Do not send through the pneumatic tube system.

Please indicate patient history and if patient is receiving anticoagulant (Coumadin/Heparin/Vitamin K antagonist), direct thrombin inhibitor or fibrinolytic agent therapy and duration.

Collection Volume: Two full 3.5 mL tubes

Pediatric Collection Volume: 2 full pediatric tubes filled to mark

Stability Ambient:

4 hours unspun

Stability Refridgerated:

Not acceptable

Stability Frozen:

Not acceptable

Sample Analyzed: Whole Blood

Testing Volume: 7 mL

Pediatric Testing Volume: 3.6 mL

Specimen Processing:

Do NOT freeze, refrigerate, or centrifuge. Do NOT open tube.

Specimen Transport:

Hand deliver specimen to University Hospital lab immediately. Do not send through the pneumatic tube system.

Unacceptable Criteria:

Hemolyzed or clotted specimens are not acceptable. A partially filled tube is NOT acceptable.

Interpretation:

 Age 1 years and up:  
 Collagen/Epinephrine  85-175 seconds
 Collagen/ADP  65-120 seconds

 

A reference interval has not been established for children less than 1 year of age.

Interpretation Type: Reference Interval

Test Limitations:

Abnormal results on samples with hematocrit less than 25 mL/dL and/or platelet count less than 100 K/µL may be difficult to interpret.

Additional Information:

The PFA-100® system is an instrument in which the process of platelet adhesion and aggregation following a vascular injury is simulated in vitro. Use of cartridges coated with collagen and either epinephrine or ADP allows the differentiation of aspirin-induced platelet defect from congenital and acquired platelet dysfunction. Collagen/ADP is generally normal after ingesting aspirin. A normal Collagen/Epinephrine test with an abnormal Collagen/ADP test may be seen in mild von Willebrand disease. Results above the reference range should be interpreted in the context of the clinical history and other findings. Abnormal results on samples with hematocrits less than 25 mL/dL and/or platelet counts less than 100 K/µL may be difficult to interpret.