A positive test result reflects the presence of fibrin monomers, indicative of thrombin activity and consistent with a diagnosis of intravascular coagulation. A negative result does not mean that intravascular coagulation is not present. A positive result may also be seen in some cases of severe liver disease and in inflammatory disorders caused by accumulation of products of coagulation in the circulation.
The detection of fibrin monomers and early-stage FSPs in plasma is useful in the diagnosis of DIC. Heparin therapy does not interfere with this test.
Obtain a 5-mL venous blood sample anticoagulated with sodium citrate (blue-topped tube). The two-tube technique is used.
Label the specimen with the patient’s name, date and time of collection, and test(s) ordered.
Place the specimen on ice and transport to the laboratory. The test must be performed within 1 hour after collection.
A positive test is indicative of DIC.
Patients with DVT occasionally have positive results.
The test may be positive in severe liver disease or metastatic cancer.
Pretest Patient Care
Explain test purpose and procedure. If possible, obtain sample before heparin therapy is started.
Avoid prolonged use of tourniquet.
Follow guidelines in Chapter 1 for safe, effective, informed pretest care.
Posttest Patient Care
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 DIC and thrombosis.
Follow guidelines in Chapter 1 for safe, effective, informed posttest care.
Have the patient resume normal activities.
False-positive results may occur in the following situations:
Traumatic venipuncture
During or immediately before menstruation
During streptokinase therapy (thrombolytic therapy)