CPT® Code 85366

The CPT® Code 85366 refers to a laboratory test that measures fibrin(ogen) degradation (split) products (FDP) (FSP) utilizing a method known as paracoagulation. This test is significant in the evaluation of the body's coagulation status, particularly in conditions where the breakdown of blood clots is a concern. Fibrin degradation products are fragments that result from the dissolution of fibrin, a protein essential for blood clot formation, which occurs when the enzyme plasmin acts on a clot. The presence of these fragments can indicate various pathological conditions, including hypercoagulation, where there is an increased tendency for blood to clot. The test specifically assesses soluble intermediates that arise during the conversion of fibrinogen to fibrin, which is a critical process in hemostasis. By employing erythrocytes that are coated with fibrin monomers, the test can detect the soluble fibrin monomer complex (SFMC), which serves as a sensitive marker for hypercoagulation. This makes the test particularly useful in diagnosing and monitoring disseminated intravascular coagulation (DIC), a serious condition characterized by widespread clotting and bleeding. To perform this test, a blood sample is collected, typically through a venipuncture, which is a separately reportable procedure. The analysis is conducted on platelet-poor plasma using qualitative hemagglutination techniques to ensure accurate measurement of the fibrin degradation products.