Test Background Platelet aggregation at sites of vascular damage is a vital mechanism in the formation of a haemostatic plug. Inability to form a haemostatic plug successfully is linked to several inherited and acquired bleeding disorders. Platelet dysfunction may be inherited, acquired or induced by platelet-inhibiting agents, such as acetyl salicylic acid (aspirin). Studies indicate the platelet function assay (PFA) and template bleeding time (BT) give equivalent results in about 75 % of cases. Most of the discrepancies are patients with a normal BT and abnormal PFA test. Aspirin and von Willebrand disease (vWD) are the most common causes for this discrepancy, since the bleeding time is very insensitive to aspirin and may miss as many as one third of cases of vWD.
Clinical Indications Preoperative evaluation of platelet function Evaluation of women with menorrhagia Determining the presence of drug-induced platelet dysfunction Determining patient compliance with aspirin and other anti-platelet drugs Determining platelet functionality in high-risk pregnancy Evaluation of patients with suspected inherited or acquired platelet disorders, such as vWD Evaluation of the bleeding patient Monitoring DDAVP treatment in patients with type I vWD
Reference Range COLL/ADP 60-120 s COLL/EPI 75-165 s
Sample Required 4.5 mL sodium citrate (pale blue top)Additional samples will be needed where extended platelet function studies are required. Please contact the laboratory before taking samples.
Turnaround Time 24 hours
Notes Additional platelet function tests are available on request.