This practical question was sent to the ASCLS Consumer Web Forum over the weekend:
Where would you draw blood from a hemodialysis patient to obtain an ACT? I was always taught to draw from venous port to ascertain the ACT in the system to prevent clotting and blood loss.
Thank you for your question. As a general rule, line draws are discouraged because vascular access devices tend to cause hemolysis, rendering the specimen useless. Nevertheless, we use line draw often for convenience and patient comfort and can prevent hemolysis by withdrawing slowly. The venous port is the correct port to collect from. First flush with 5 mL saline, then withdraw and discard a volume of blood that is 2X the volume of the device, typically 5 mL. Then collect the specimen for the ACT. There is a terrific book by Dennis Ernst, Blood Specimen Collection FAQs, published by theCenter for Phlebotomy Education that answers any venipuncture and infusion questions you may have. Dennis references the guidelines published by the Clinical Laboratory and Standards Institute and the Infusion Nurses Society “Procedures and Policies for Infusion Nursing.”