Fibrin degradation products

Alternative names:

FDPs; fibrin breakdown products; fibrin split products; FSPs

What the risks are:

• excessive bleeding
• fainting or feeling lightheaded
• hematoma (blood accumulating under the skin)
• infection (a slight risk any time the skin is broken)
• multiple punctures to locate veins

Special considerations:

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 plasma acts to dissolve 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, as occurs in disseminated intravascular coagulation (DIC) and primary fibrinolytic disorders.

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.