Fibrin degradation products (FDPs) are the substances left behind when clots dissolve in the blood. This article discusses the blood test to measure these products.

FDPs; FSPs; Fibrin split products; Fibrin breakdown products

A blood sample is needed. For information on how this is done, see: Venipuncture

The blood is sent to a laboratory. The laboratory specialist will run tests on the blood sample to measure the products that are left behind when blood clots dissolve.

Your health care provider may tell you to stop taking certain drugs before the test. Drugs that may increase FDPs include barbiturates, heparin, streptokinase, and urokinase.

Do not stop taking any medicine without first talking to your doctor.

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

This test is done to see if your clot-dissolving (fibrinolytic) system is working properly. Your doctor may order this test if you have signs of disseminated intravascular coagulation (DIC) or another clot-dissolving disorder.

The result is normally less than 10 micrograms per milliliter (mcg/mL).

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

The example above shows the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.

Increased FDPs may be a sign of primary or secondary fibrinolysis (clot-dissolving activity) due to a variety of causes, including:

• Abruptio placentae
• Burns
• Congenital heart disease
• Disseminated intravascular coagulation (DIC)
• Hypoxia
• Infections
• Intrauterine fetal death
• Leukemia
• Liver disease (See: cirrhosis)
• Portacaval shunt
• Preeclampsia
• Recent blood transfusion
• Recent surgery that involved a heart and lung bypass pump
• Renal disease (See: kidney failure)
• Septicemia
• Thromboembolic states
• Transplant rejection
• Transfusion reaction

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Liebman HA, Weitz IC. Disseminated intravascular coagulation. In: Hoffman R, Benz EJ Jr., Shattil SJ, et al, eds. Hoffman Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingstone Elsevier; 2008:chap 132.

Lijnen HR, Collen D. Molecular and cellular basis of fibrinolysis. In: Hoffman R, Benz EJ Jr., Shattil SJ, et al, eds. Hoffman Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingstone Elsevier; 2008:chap 119.

Schafer AI. Hemorrhagic disorders: Disseminated intravascular coagulation, liver failure, and vitamin K deficiency. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 181.