Platelet Function Screen

Clinical assay interference and limitations: Patients on aspirin, non-steroidal anti-inflammatory agents and other platelet inhibiting medications may show increased closure times. Patients with platelet counts below 150,000/uL or hematocrits below 30% may show increased closure times. Samples containing platelet clumps or hemolysis due to difficult blood draws may show increased closure times. The platelet function screen may not detect some rare platelet aggregation defects.

Contact UW-MT Coagulation Lab at 206-598-6242 for consultation.

Clotted Sample will be automatically cancelled after determination by MLS in Coagulation.

Clinical assay interference and limitations: Patients on aspirin, non-steroidal anti-inflammatory agents and other platelet inhibiting medications may show increased closure times. Patients with platelet counts below 150,000/uL or hematocrits below 30% may show increased closure times. Samples containing platelet clumps or hemolysis due to difficult blood draws may show increased closure times. The platelet function screen may not detect some rare platelet aggregation defects.

Peripheral stick only: Collect blood in three 2.7 mL draw plastic BLUE TOP (CITRATE) tubes [or total of 10 mL blood in BLUE (CITRATE) tubes]. If using 1.8mL draw tube (Light Blue) collect five (5) Blue tops. Mix each tube by gentle inversion 5-8x after extraction.

Deliver or Take sample to UW-MT Coag Lab Immediately. DO NOT SEND through Pneumatic Tube System. If ordered for AM draw and before 7am, reschedule time of draw. This is a time sensitive test and needs to be sent to UWMC Coagulation in a timely manner.

Notify UWMC Coag lab when sending sample for testing at 206 598-6242.

Sample handling is critical for the assay. The blood should be drawn peripherally, kept at room temperature. Mix sample gently as soon as blood is drawn to the tube by inverting gently 5-8x. Do not allow tube to sit at bedside or collection tray unmixed.

Carry specimen to the laboratory at room temperature within 2 hours. DO NOT SEND SAMPLES IN PNEUMATIC TUBE SYSTEM

Take sample to UW-MT Coag Lab Immediately. If ordered for draw prior to 7am, reschedule time of draw. This is a time sensitive test and needs to be sent to UWMC Coagulation in a timely manner.

Notify UWMC Coag lab when sending sample for testing at 206 598-6242.

HMC SPS: Send whole blood to UW-MT Coag Lab Immediately by Cab. DO NOT wait for next courier run.

Outside Laboratory: Send whole blood at room temperature. Sample must be received in Coagulation lab within 2 hours of being drawn. Notify UWMC Coag lab when sending sample for test at 206 598-6242.

UW-NW outpatient: Refer to UW-MT Laboratory for collection.

Testing is performed only from 0700-2130 same day of draw.

Sample is stable for 4hrs. after collection. Check for clots and marked tubes as 1-3 (depeding on how many is received). Give the three tubes to Hematology for Platelet count and smear review for Platelet morphology and clumping.

Hematology MLS1, please give result to Coagulation MLS performing PLFS for testing.