clot contraction time

Clot contraction time (CRT), or clot retraction test, is a test that reflects the function of platelet thrombus contractile proteins. There are commonly used whole blood methods and quantitative methods for the determination methods. Prolong idiopathic or secondary thrombocytopenic purpura, thrombocytopenia, idiopathic thrombocytosis, aplastic anemia, acute leukemia, neonatal hemorrhage, pernicious anemia, multiple myeloma. Basic Information Specialist classification: growth and development examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Reminder: The examination must be carried out at 37 ° C, and the temperature is too high or too low clot shrinkage is affected. Normal value Sieve method begins to shrink at 1h, reaching the peak at 24h Semi-quantitative serum 0 no (0 no) +0.05~0.10 (+5%~10%) ++0.10~0.20 (++10%~20%) +++0.20+0.35 (+++20%~35%) normal ++++>0.35(++++>35%) Solid blood clot Triangulation from three sides Quantitative (plasma recalcification) 56 ± 14 mg (blood weight) Clinical significance Prolong idiopathic or secondary thrombocytopenic purpura, thrombocytopenia, idiopathic thrombocytosis, aplastic anemia, acute leukemia, neonatal hemorrhage, pernicious anemia, multiple myeloma. Precautions (1) Whole blood method: 1 The syringe and test tube must be clean, otherwise the blood clot will stick to the tube wall. 2 must be carried out at 37 ° C, the temperature is too high or too low clot shrinkage is affected. 3 severe anemia, red blood cell reduction, can affect the results. 4 to distinguish between blood clot shrinkage and fibrinolysis, the latter clots appear irregular, there are broken pieces, and finally the blood clot completely dissolved and disappeared, blood cell sedimentation. (2) Quantitative method: A 1 gauge small tube requires a clear and accurate volumetric scale. 2 If a positive control is required, 5 mol/L N-ethylmaleimide can be added to normal platelet-containing plasma to inhibit the contraction of platelet thrombus contractile protein. 3 other with the whole blood method. Inspection process (1) Whole blood method: 1 Take 1 ml of venous blood on an empty stomach and gently inject into a dry test tube. 2 The stopper was placed in a 37 ° C water bath, and the contraction of the blood clot was observed at 1/2 h, 1 h and 24 h, respectively, and recorded. (2) Quantitative method: 1 Take 5 ml of venous blood and slowly inject it into a graduated centrifuge tube. 2 Insert the glass rod, insert the lower end of the scorpion into the blood, place the cork stopper on the centrifuge tube, and incubate in a 37 ° C water bath. 3 After the blood is completely coagulated, the blood clot is gently separated to separate it from the tube wall, and the blood clot is raised and discarded. 4 After the centrifuge tube was re-centrifuged, the amount of serum and formed components was observed. Not suitable for the crowd A patient with hemophilia and severe clotting factor deficiency. Adverse reactions and risks Subcutaneous hemorrhage: subcutaneous hemorrhage due to less than 5 minutes of compression time or blood draw technique.