25720:COAGULATION STUDY, PROLONGED PROTHROMBIN TIME (PT) EVALUATION
Prolonged Prothrombin Time (PT) Evaluation
Mechanical Clot Detection
Activated Partial Thromboplastin Time (APTT); Heparin Neutralized Prothrombin Time (PT) or Thrombin Time (TT); Hexagonal Phospholipid Neutralization Test; Mixing Study, Prothrombin Time (PT); Russell Viper Venom Time. Not all these tests are performed on each sample. Testing will vary, depending on the nature and magnitude of the defect. Each panel includes a pathologist’s interpretation.
Varies by test
7 days maximum
Specimen Collection Details
Four 4.5 mL light blue top tubes (sodium citrate). Collect by careful venipuncture to avoid tissue fluid contamination or hemolysis. Do not use needles smaller than 23 gauge. Fill tubes to maximum draw (at least 90% full). Mix by gentle inversion. Call the Special Coagulation Department (541.687.2134 x4612) when urgent testing is needed in order to assure STAT testing.
Due to short stability, specimen must either be sent STAT to arrive in laboratory within 4 hours, or sent frozen. For STAT, refrigerate and keep capped in original tubes. Call for STAT pick-up. For standard delivery, centrifuge to produce platelet-poor plasma and using a plastic pipette, transfer the plasma into 3-4 plastic vials. Label with patient name, I.D. number, test, and “citrate.” Freeze immediately. Send to laboratory within 7 days. If multiple tests are ordered, freeze a separate aliquot for this test.
4 hours ambient or refrigerated, or 7 days frozen.
Four 4. 5 mL light blue top tubes or 4 mL plasma (Min: two 2.7 mL light blue top tubes or 2 mL plasma).
Two 2.7 mL light blue top tubes or 2 mL plasma
Original tubes refrigerated if STAT, or plasma frozen on dry ice.
Indicate if STAT. Include information regarding the patient’s anticoagulant history and abnormal coagulation diagnoses. This panel is offered for the evaluation of patients with unexplained prolonged PTs. Patients on coumadin or heparin therapy will have prolonged PTs, and should not be submitted for prolonged PT evaluation until their anticoagulant has been discontinued.
Visible fibrin; moderate to marked hemolysis; refrigerated specimen received in laboratory more than 4 hours after collection.