Test Code PFA PLATELET FUNCTION ANALYSIS
Methodology
The PFA-100® instrument simulates in vitro the process of platelet adhesion and aggregation following vascular injury. When blood is drawn through a capillary, platelets are activated via the shear force generated. The specimen passes through an aperture in a membrane coated with collagen and epinephrine or ADP. Platelet adhesion to the membrane and subsequent aggregation eventually occludes the aperture and stops the flow. The result is reported as “closure time.”
Useful for detecting platelet dysfunction due to uremia, von Willebrand’s disease, Glanzmann’s thrombasthenia, and exposure to acetylsalicylic acid (ASA)-containing medications (such as aspirin).
Specimen Requirements
Specimen must arrive at the KRMC Lab within 2 hours of draw.
Container/Tube: Light
blue-top (3.2% buffered sodium citrate, with yellow-striped label)
tube
Specimen Volume: Full tube
Collection Instructions:
- Perform venipuncture using a 21-gauge or larger needle.
- DO NOT Centrifuge.
- Do NOT use 25-gauge needles.
- Do NOT use butterflies.
- It is imperative that tube is completely filled.
- The ratio of blood to anticoagulant is critical for valid coagulation results.
- Hand deliver to laboratory, Do Not use pneumatic tube system.
Specimen Rejection
- Hemolyzed specimen is not acceptable.
- Specimen collected or delivered to incorrectly.
- Centrifuged specimens.
Specimen Retention Time
4 hours
Day(s) Test Set Up
Monday through Sunday
Maximum Laboratory Time
Must be tested within 4 hours of draw
Specimen Stability
- Specimen must arrive at the KRMC Lab within 2 hours of draw.
- Hand deliver to laboratory, Do Not use pneumatic tube system.
Specimen Type | Temperature | Time |
Ambient | < 2 hours | |
Refrigerate | NO | |
Frozen | NO |
Reference Values
EPI: 82-150 seconds closure time
ADP: 62-100 seconds closure time (ADP reported only if EPI >150)
Note: Specimens with platelet counts <150,000 K/mm3 and/or hematocrits of <35% may exhibit prolonged results due to impaired primary hemostasis both in vivo as well as with this test method.
Performing Laboratory
Logan Health Medical Center Laboratory
Test Classification and CPT Coding
85576