Test Code LAB318 Platelet Function Analysis
Useful For
Use: The PFA is a screening test of platelet function. It is abnormal in > 95% of von Willebrand’s Disease. It is a screening test for acquired and primary platelet function disorders.
If possible, aspirin and other non-steroidal anti-inflammatory medications (NSAIDS) should be avoided for 10 days prior to collection of the PFA specimen. Note: Exception to NSAIDS are the ibuprofen medications *such as Advil, Nuprin, Motrin, etc.). These need to be avoided for 48 hours. A long list of specific medications with platelet inhibitory effects is available by request from the laboratory.
Performing Laboratory
Asante Rogue Regional Medical Center (ARRMC)/ Asante Three Rivers Medical Center (ATRMC)
Performing Department
Coagulation
Specimen Required
Venipuncture should be performed using a 21G or larger needle (20G or 19G).
RRMC: Glass One full 4.5 mL blue top tube (sodium citrate)
Blue top tube_4.5 mL_Sodium Citrate
Draw the blue tube before any other tubes to avoid cross-contamination of the sample with clot activators. No vigorous shaking, tube system transport, mechanical rockers. Glass tube is preferred over plastic to minimize platelet clumping, especially if testing will not be performed immediately. Fill tube to maximum draw (at least 90% full). Mix by gentle inversion (3-4 times). Do not overmix to avoid platelet activation and clumping. Avoid prior aspirin ingestion (see comment section below).
Standard Volume: 4.5 mL tube whole blood
Minimum Volume: 2.7 mL tube whole blood
TRMC: Plastic Two full blue top tubes 2.7 mL 3.2 % Na Citrate tube
Blue top tube_2.7 mL Sodium Citrate
Room Temp transport. No vigorous shaking, tube system transport, mechanical rockers. Sample is stable 4 hours at room temp.
Specimen Stability Information
RRMC
Original tube ambient and uncentrifuged.
Keep tube at ambient temperature. Do not refrigerate or centrifuge. Deliver entire specimen to the Laboratory within 3 hours (specimen must be tested within 4 hours of collection).
TRMC
Room Temp transport. No vigorous shaking, tube system transport, mechanical rockers. Sample is stable 4 hours at room temp.
Reject Due To
RRMC: Hemolysed sample
TRMC: Hemolysed sample, <2.7ml, clotted sample, glass tubes
Day(s) Performed
Monday through Sunday
Method Name
Whole Blood Platelet Aggregation
TRMC: PFA-100 analyzer determines platelet aggregation by using high shear flow conditions and exposure to antagonist (COL/EPI or COL/ADP) to measure the endpoint closure time.
CPT Code Information
85576 (if normal) – Platelet, aggregation (in vitro), each agent
85576.59 x2 (if abnormal)
Billing Code
2011914 (EPI), 2011922 (ADP)
Reference Values
TRMC: Reference Ranges are : COL/EPI = 81-190sec and COL/ADP = 62-144 sec