1. Prothrombin Time (PT)

It mainly reflects the condition of the exogenous coagulation system, in which INR is often used to monitor oral anticoagulants. PT is an important indicator for the diagnosis of prethrombotic state, DIC and liver disease. It is used as a screening test for the exogenous coagulation system and is also an important means of clinical oral anticoagulation therapy dose control

PTA<40% indicates large necrosis of liver cells and decreased synthesis of coagulation factors. For example, 30%<PTA<40% in the early stage of liver failure; 20%<PTA<30% in the middle stage; PTA<20% in the late stage.

The prolongation is seen in:

a. Extensive and serious liver damage is mainly due to the generation of prothrombin and related clotting factors.

b. Insufficient VitK, VitK is required to synthesize factors II, VII, IX, and X. When VitK is insufficient, the production decreases and prothrombin time is prolonged. It is also seen in obstructive jaundice.

C. DIC (diffuse intravascular coagulation), which consumes a large amount of coagulation factors due to extensive microvascular thrombosis.

d. Neonatal spontaneous hemorrhage, congenital prothrombin lack of anticoagulant therapy.

Shorten seen in:

When the blood is in a hypercoagulable state (such as early DIC, myocardial infarction), thrombotic diseases (such as cerebral thrombosis), etc.

 

2. Thrombin time (TT)

Mainly reflects the time when fibrinogen turns into fibrin.

The prolongation is seen in: increased heparin or heparinoid substances, increased AT-III activity, abnormal amount and quality of fibrinogen. DIC hyperfibrinolysis stage, low (no) fibrinogenemia, abnormal hemoglobinemia, blood fibrin (proto) degradation products (FDPs) increased.

The reduction has no clinical significance.

 

3. Activated partial thromboplastin time (APTT)

It mainly reflects the condition of the endogenous coagulation system and is often used to monitor the dosage of heparin. Reflecting the levels of coagulation factors VIII, IX, XI, XII in plasma, it is a screening test for the endogenous coagulation system. APTT is commonly used to monitor heparin anticoagulation therapy.

The prolongation is seen in:

a. Lack of coagulation factors VIII, IX, XI, XII:

b. Coagulation factor II, V, X and fibrinogen reduction few;

C. There are anticoagulant substances such as heparin;

d, fibrinogen degradation products increased; e, DIC.

Shorten seen in:

Hypercoagulable state: If the procoagulant substance enters the blood and the activity of coagulation factors increases, etc.:

 

4. Plasma fibrinogen (FIB)

Mainly reflects the content of fibrinogen. Plasma fibrinogen is the coagulation protein with the highest content of all coagulation factors, and it is an acute phase response factor.

Increased seen in: burns, diabetes, acute infection, acute tuberculosis, cancer, subacute bacterial endocarditis, pregnancy, pneumonia, cholecystitis, pericarditis, sepsis, nephrotic syndrome, uremia, acute myocardial infarction.

Reduction seen in: Congenital fibrinogen abnormality, DIC wasting hypocoagulation phase, primary fibrinolysis, severe hepatitis, liver cirrhosis.

 

5. D-Dimer (D-Dimer)

It mainly reflects the function of fibrinolysis and is an indicator to determine the presence or absence of thrombosis and secondary fibrinolysis in the body.

D-dimer is a specific degradation product of cross-linked fibrin, which increases in plasma only after thrombosis, so it is an important molecular marker for the diagnosis of thrombosis.

D-dimer increased significantly in secondary fibrinolysis hyperactivity, but not increased in primary fibrinolysis hyperactivity, which is an important indicator for distinguishing the two.

The increase is seen in diseases such as deep vein thrombosis, pulmonary embolism, and DIC secondary hyperfibrinolysis.