partial thromboplastin time

The blood coagulation mechanism is divided into internal and external coagulation systems. The endogenous coagulation system includes factors XII, XI, IX, VIII, X, V, prothrombin and fibrinogen, which can be determined by activated partial thromboplastin time (APTT). For screening experiments. Basic Information Specialist classification: growth and development examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Warm reminder: specimens should not be placed more than 3h, and the incubation time should not be shorter than 3min. Normal value Male 31.5 ~ 43.5s, female 32 ~ 43s. Clinical significance (1) PTT prolongation (measurement of the subject is longer than the normal control value for more than 10 s) Factor VIII, IX, III, XII deficiency, and is seen in severe factors X, V, prothrombin, fibrinogen deficiency This test is also prolonged when there is anticoagulant in the blood circulation. (2) PTT shortening factor VIII, V activity increased, DIC high blood coagulation period, thrombotic disease, thrombocytosis and the like. High results may be diseases: neonatal hemorrhagic disease, hemophilia A, late-onset vitamin K deficiency in children, thrombotic thrombocytopenic purpura, vascular hemophilia in children, thrombotic thrombocytopenic purpura in pregnancy, acquired Vitamin K-dependent coagulation factor abnormalities, corpus luteum cysts, acquired circulatory anticoagulant substance syndrome, severe liver disease caused by acquired clotting factor abnormalities (1) The specimen should not be placed more than 3 hours, and the incubation time should not be shorter than 3 minutes. (2) When separating plasma, be sure to remove platelets. (3) This test is sensitive to clotting time and can detect mild hemophilia with factor VIII:C less than 25%. Inspection process (1) 0.109mol/L sodium citrate anticoagulant plasma 0.1ml, add 0.1ml of white clay partial thromboplastin suspension, shake well, incubate for 3min in 37°C water bath, gently shake it. (2) Add 0.1ml of 0.025mol/L calcium chloride solution, start the stopwatch at the same time, shake it in a 37°C water bath, take out the test tube at about 30s, observe the time of fibrin wire, and take the average twice. Not suitable for the crowd Those without examination indications should not be tested. Adverse reactions and risks 1, dizziness or fainting: in the blood draw, due to emotional overstress, fear, reflex caused by vagus nerve excitement, blood pressure decreased, etc. caused by insufficient blood supply to the brain caused by fainting or dizziness. 2. Risk of infection: If you use an unclean needle, you may be at risk of infection.