What Is Prothrombin Time?

Prothrombin time (PT) refers to the time required to add excess tissue thromboplastin and calcium ions to platelet-deficient plasma, which converts prothrombin to thrombin, causing plasma to clot. Prothrombin time is an indicator of the activity of coagulation factors , , , , and X in plasma. Prothrombin time measurement is a screening test to check the function of the exogenous coagulation system of the machine, and it is also an important monitoring indicator for clinical anticoagulation therapy.

Basic Information

Chinese name

Prothrombin time

Clinical significance of prothrombin time

The prothrombin time test is not only applicable to the diagnosis of congenital coagulation diseases and acquired bleeding diseases of the exogenous coagulation pathway, but also has important significance for the diagnosis of severe hepatitis and early liver cirrhosis. Preferred test indicators.

1. Prolongation: congenital factor , , , and X deficiency; fibrinogen (Fg) deficiency (<0.5g / L); afibrinogen (Fg) anemia; abnormal fibrinogen (Fg) Disseminated intravascular coagulation; primary fibrinolysis; severe acute and chronic liver disease; obstructive jaundice; Vit-K deficiency; increased circulating anticoagulant substances, etc.

2. Shorten: congenital factor increase, thrombotic diseases, disseminated intravascular coagulation (DIC) hypercoagulable period; oral contraceptives, etc.

Reference range of normal prothrombin time

Time: 11.0 to 13.0 seconds; Activity: 75.0% to 115.0%; INR: 0.90 to 1.15.

Prothrombin time considerations

1. Take fasting upper limb venous blood.

2. The blood collection process strictly follows the aseptic operation, all use the same type of test tube, and all use sodium citrate for anticoagulation.

3. The prothrombin time detection was performed under different conditions, using the same experimental detection reagents.

4. During the testing process, strictly follow the operating procedures to avoid other factors affecting the test results.