Specimen Requirements

Minimum Specimen Requirements

Stability

Days Performed

Thu

Turnaround Time

5 - 9 days

Methodology

Reference Range

Special Info

Do not draw from an arm with a heparin lock or heparinized catheter. Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio. The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples, except when using a winged blood collection device (ie, "butterfly"), in which case a discard tube should be used. When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells. Deliver to a plastic transport tube, cap, and recentrifuge for 10 minutes. Use a second plastic pipette to remove the plasma, staying clear of the platelets at the bottom of the tube and deliver to a plastic transport tube with screw cap. Freeze immediately and maintain frozen until tested. Specimens that are hemolyzed, clotted, diluted with IV fluids or have thawed before arriving in the performing laboratory will be rejected.

Clinical Info

Increased fibrinolytic activity is suggested by fibrin clot lysis that occurs in less than 3 hours. A shortened ELT result implies excessive fibrinolytic activity that may be secondary to pregnancy, obstetric complications (hydatidiform mole, amniotic fluid embolus), hypofibrinogenemia, malignancy, severe liver disease or thrombolytic therapy. Excessive fibrinolysis may also occur with dysfibrinogenemia, factor XIII deficiency, decreased PAI-1 levels or decreased alpha -2- antiplasmin activity. Clinical bleeding is a possible result of excessive fibrinolysis.