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Introduction ⬇

Primary fibrinolysis, without any sign of intravascular coagulation, is extremely rare. Secondary fibrinolysis is usually seen and follows or occurs simultaneously with intravascular coagulation. This secondary fibrinolysis is a protective mechanism against generalized clotting.

This test is done to evaluate fibrinolytic activity. Shortened time indicates excessive fibrinolytic activity. Lysis is marked and rapid with primary fibrinolysis but can be minimal in secondary fibrinolysis. The diluted whole blood is used to monitor urokinase and streptokinase therapy.

Normal Findings ⬆ ⬇

ELT—no lysis of plasma clot at 37 °C in 60–120 minutes. The clot is observed for 24 hours. Euglobulin clot lysis normally completes within 2–4 hours.

Diluted whole blood clot lysis: No lysis of clot in 120 minutes at 37 °C.

Clinical Alert

A lysis time of 1 hour signifies that abnormal fibrinolysis is occurring

Procedure ⬆ ⬇

  1. Collect a 5-mL venous blood sample in a tube containing sodium citrate using the two-tube method. Label the specimen with the patient’s name, date and time of collection, and test(s) ordered. Place the specimen in a biohazard bag.

  2. Put the sample on ice and transport to the laboratory immediately or start at bedside.

  3. The test must be started within 90 minutes after the blood is centrifuged.

Clinical Implications ⬆ ⬇

  1. Shortened ELT (signifying increased fibrinolysis) occurs in the following conditions:

    1. Primary fibrinolysis

    2. Within 48 hours after surgery

    3. Cancer of prostate or pancreas

    4. Circulatory collapse, shock

    5. During lung and cardiac surgery

    6. Obstetric complications (e.g., antepartum hemorrhage, amniotic embolism, septic abortion, death of fetus, hydatidiform mole)

    7. Long-term DIC (may be normal if plasminogen is depleted)

    8. Liver disease

    9. Administration of plasminogen activators (tPA, streptokinase, urokinase)

  2. Heparin does not interfere with the ELT.

Interventions ⬆ ⬇

Pretest Patient Care

  1. Advise the patient of test purpose and procedure; no exercise before test.

  2. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Posttest Patient Care

  1. Review test results; report and record findings. Modify the nursing care plan as needed. Counsel the patient regarding abnormal findings; explain the need for possible follow-up testing and treatment. Monitor for fibrinolytic crisis.

  2. Follow guidelines in Chapter 1 for safe, effective, informed posttest care.

Interfering Factors ⬆

  1. Increased fibrinolysis occurs with moderate exercise and increasing age.

  2. Decreased fibrinolysis occurs in arterial blood, compared with venous blood. This difference is greater in arteriosclerosis (especially in young persons).

  3. Decreased fibrinolysis occurs in postmenopausal women and in normal newborns.

  4. FDPs interfere with fibrinolysis.

  5. Normal results can occur if fibrinolysis is far advanced (plasminogen depleted).

  6. Fibrinolysis is increased by very low fibrinogen levels (less than 80 mg/dL or less than 0.8 g/L) and decreased by high fibrinogen levels.

  7. Increased fibrinolysis can be caused by traumatic venipuncture or a tourniquet that is too tight.

  8. see Appendix E for drugs that affect test outcomes.