Alternative names 
Fibrin degradation products; FSPs; Fibrin split products; Fibrin breakdown products

This is a test that measures fibrin degradation products (which are caused when clots dissolve) in blood.

How the test is performed
Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a tourniquet (an elastic band) or blood pressure cuff is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the tourniquet to distend (fill with blood). A needle is inserted into the vein, and the blood is collected in an airtight vial or a syringe. During the procedure, the tourniquet is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

Infant or young child:
The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

How to prepare for the test
The health care provider should be notified if you are using any drugs that can affect the test result. Drugs that may increase FDPs include barbiturates, heparin, streptokinase, and urokinase.

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child’s age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child’s age:

  • Infant test or procedure preparation (birth to 1 year)  
  • Toddler test or procedure preparation (1 to 3 years)  
  • Preschooler test or procedure preparation (3 to 6 years)  
  • Schoolage test or procedure preparation (6 to 12 years)  
  • Adolescent test or procedure preparation (12 to 18 years)

How the test will feel
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.

Why the test is performed

As a result of the coagulation process, fibrinogen is split into fibrin monomer and fibrin. Fibrin monomer polymerizes to form fibrin polymer (the clot).

Coagulation factor inhibitors and plasmin (which eventually lyses the fibrin clot) are simultaneously activated by damaged tissue, but they function more slowly and over a longer period of time than the coagulation factors. The most important of the coagulation inhibitors is antithrombin III, a protein that requires endogenous (produced by the body) heparin for its activity.

The measurement of FDPs provides a direct indication of the activity of the fibrinolytic (clot-dissolving) system. When plasmin dissolves fibrin blood clots, FDPs are formed. These degradation products, which have an anticoagulant effect and inhibit clotting, can be measured. When they are present in large amounts, they indicate increased fibrinolysis, or clot breakdown, as occurs in disseminated intravascular coagulation (DIC) and primary fibrinolytic disorders.

Normal Values

The result is normally less than 10 mcg/mL.

Note: mcg/mL = micrograms per milliliter

What abnormal results mean
Increased FDPs may indicate primary or secondary fibrinolysis (clot dissolving activity) from such conditions as:

  • Abruptio placentae  
  • Burns  
  • Congenital heart disease  
  • Disseminated intravascular coagulation (DIC)  
  • Following cardiopulmonary (heart and lungs) pump surgery  
  • Following massive blood transfusion  
  • Hypoxia  
  • Infections  
  • Intrauterine fetal death  
  • Leukemia  
  • Liver disease (see cirrhosis)  
  • Portacaval shunt  
  • Preeclampsia  
  • Renal disease (see kidney failure)  
  • Septicemia  
  • Thromboembolic states  
  • Transplant rejection  
  • Transfusion reaction

What the risks are

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

Special considerations

Veins and arteries vary in size from one patient to another, and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Johns Hopkins patient information

Last revised: December 6, 2012
by Simon D. Mitin, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.