The fibrinolytic system is the most important anticoagulation system in the body. During lysis, thrombin hydrolyzes fibrin, releasing soluble fibrin monomers, which, under the action of factor xIIIa, form stable cross-linked fibrin. In late stages of disseminated intravascular coagulation, the fibrinolytic system is activated due to intravascular coagulation, resulting in secondary fibrinolysis and more pronounced bleeding symptoms. How is secondary enhanced fibrinolysis diagnosed? Prolonged prothrombin time is prolonged when there is a significant decrease in fibrinogen or an increase in fibrin(pro)degradation products (FDP), but the results of the measurement can be influenced by heparin therapy. The use of continuous prothrombin time is a more sensitive indicator for the diagnosis of FDP. Plasma snake venom coagulation time was measured using an enzyme derived from snake venom (Reptilase) instead of thrombin. When FDP is increased, the coagulation time is prolonged. The advantage of this method is that it is not affected by heparin. Fibrin degradation products are examined in normal human serum only in trace amounts of FDP. if there is a significant increase in FDP, it means that there is hyperfibrinolysis, which indirectly reflects DIC. there are many methods of measurement, including the immunoassay Fi test (i.e. latex particle agglutination test, normal titer <1:8), FDP flocculation test, radioimmunodiffusion method, staphylococcal hedgehog test (normal FDP value is 0.57±0.1 μg/dl, and up to 60 μg/dl in DIC), ellagic acid than red blood cell indirect hemagglutination inhibition test (normal serum FDP value <10 μg/dl, more than 20 μg/dl in DIC), and enzyme membrane immunosorbent technique. If FDP is increased, it indicates the possibility of acute DIC. Plasma fisetin paraclotting test (referred to as 3P test) and ethanol gel test This is a test that reflects the soluble fibrin complex within the plasma. When intravascular coagulation occurs, FDP binds to the monomer of fibrin to form a soluble complex that cannot be coagulated by thrombin. Fisetin separates the complex and re-processes the fibrin monomer. As a result, self-polymerization of fibrin monomer and FDP occurs, forming a flocculent precipitate visible to the naked eye, called the paraclotting test. The ethanol gel test is based on the same principle as the 3P test. Domestic data reported that the positive rate of the 3P test was 72.6 to 88.2%, and the positive rate of ethanol gel was low. Both methods can have false-positive or false-negative results. In contrast, the ethanol gum test is less sensitive but more reliable; while 3P has poor specificity and more false positives, such as when the molecular weight of FDP lobes is small, the 3P test can also be negative. It is best to compare the two with each other for reference, the significance is even greater.