The laboratory at United Health Services, at the Wilson site, is now performing a new screening test for primary hemostasis done on a PFA-100 analyzer, which will replace the Bleeding Time test. This represents a step forward from the Bleeding Time test which is known to be fraught with reasons for variability. Required are two blue topped tubes. Testing must be done within 4 hours of the draw. The specimens cannot be spun or refrigerated. Time of draw must be documented on the tube and specimens must be rejected if they are over 4 hours old. When timeliness of transportation is not possible, it will be necessary for patients to come to Wilsonís Out-Patient Laboratory for drawing.
Providers are encouraged to order Platelet Function Analysis (PFA-100) in place of the Bleeding Time, which will no longer be available after June 1, 2007. Platelet Function Analysis by PFA-100 is an excellent screen to rule out platelet dysfunction and von Willebrandís Factor defects. Please keep in mind that neither the Bleeding Time nor the PFA-100 were designed to predict bleeding during surgical procedures. The best pre-operative screening test available remains a detailed clinical history that includes family, surgical and drug histories.
Platelet Function Analysis on the PFA-100 involves measurement of platelet plug formation in seconds. Two closure times are reported, Collagen/Epinephrine and Collagen/ADP. Interpretive comments will be included on the report.
For any questions you may have, you can call Sandy Wilson, Hematology Supervisor at 763-6198 or Dr. Jagmohan Sidhu at 763-6164.