Test Code PFA Platelet Function Analysis, Blood
Methodology
Siemens PFA Analyzer: Adhesion and aggregation response of platelets to Epinephrine and ADP
Testing begins wtih the Collagen/Epinephrine (EPI) test, which can detect platelet dysfunction induced by intrinsic platelet defects, von Willebrand disease or exposure to platelet inhibiting medications. If the EPI test is elevated, the Collagen/ADP test is reflex ordered. The ADP test is used to indicate if an abnormal result obtained with the EPI test may have been caused by the effect of acetyl salicylic acid (ASA) or medications containing (ASA).
Performing Laboratory
Bronson Methodist Hospital Laboratory-Coagulation Department
Specimen Requirements
Specimen must be tested within 4 hours of draw.
Specimen Type: Whole blood
Container/Tube: 2-mL Greiner Vacuette light blue citrate tubes
1.8 ml or 2.7 ml BD Vacutainer tubes are also acceptable
Specimen Volume: 2 full tubes
Collection Instructions:
- Tubes must be full to fill line.
- Gently invert 5 to 10 times to mix blood.
- Do not centrifuge.
- Do not refrigerate or freeze specimen.
- If collected through a blood collection set (butterfly), a discard tube must first be drawn to eliminate dead space from tubing.
- Causes for rejection include tube not filled to line, clotted specimen, refrigerated or frozen specimen.
See "Important Note" at top of this page for additional information on laboratory site specific collection options.
Specimen Transport Temperature
Ambient YES
Refrigerate NO
Frozen NO
Reference Values
Collagen/Epinephrine Reference Range: 70 - 170 seconds.
If the result is <171 seconds, no further testing is indicted and the following comment is reported
Platelet function appears normal. If patient history or physical examination gives strong indication of a bleeding disorder, suggest repeat testing for confirmation. If repeat results remain normal, consider other causes of bleeding.
If the result is >170 seconds, the Collagen/ADP test is run.
Collagen/ADP Reference Range: 54-121 seconds.
If the result is <122 seconds the following comment is reported:
Platelet function appears abnormal. This pattern is most commonly seen in patients with won Willebrand’s disease or congenital platelet defects. When evaluated in conjunction with clinical history and other test findings, this may indicate the need for further diagnostic testing.
If the result is <122, the following comment is reported:
Results suggest drug induced platelet dysfunction. This is most commonly seen after aspirin ingestion.
Day(s) Test Set Up
Monday through Sunday
Test Classification and CPT Coding
85576 X 1 if only EPI test is run
85576 x 2 if reflex to ADP test is also run