Thrombosis and hemostasis testing

Thrombosis and hemostasis tests include capillary fragility test, bleeding time measurement, platelet count, clot shrinkage test, clotting time measurement, plasma prothrombin time measurement, and activated partial thromboplastin time measurement. In these trials, the first four trials primarily reflected the role of vessel walls and platelets in thrombosis and hemostasis. The remaining three are tests for the examination of endogenous coagulation, which is most sensitive to the determination of live partial thromboplastin time. Basic Information Specialist classification: cardiovascular examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Normal value: no Above normal: negative: Generally it is normal. Positive: Common in vascular diseases. Reminder: blood test specimens are best collected separately, otherwise the blood stays in the needle tube for a prolonged period due to the distribution, dispensing, etc. of the specimen. Normal value There was no positive reaction in the test results, and there was no abnormal data reaction, which was negative. Bleeding time measurement TBT method: (Simplate type II) 2.3 to 9.5 min. IVY method: 2 to 7 minutes. Duke method: 1 to 3 minutes (not more than 4 minutes). Platelet count Ordinary microscopic counting method (100 to 300) × 109L. The qualitative method began to shrink at 30-60 min and completely contracted at 24 h. Blood clot contraction test The quantitative method Macfarlane method is 48-60%. The plasma method is 40%. Coagulation time measurement Ordinary test tube method for 5 to 10 minutes. The silicon tube method is 15 to 32 min. Activated clotting time method 1.1 ~ 2.1min. Determination of calcium time Glass dish method 97 ~ 160s. The test tube method (PRP method) is 90 to 160 s. (PPP method) 90 to 200 s. (ART method) 50s. Plasma prothrombin time measurement The one-step prothrombin time is 11 to 13 s. The prothrombin ratio is 0.82 to 1.15. Clinical significance Abnormal result First, capillary fragility test Pathological CFT positive is seen in 1 capillary deficient disease such as hereditary hemorrhagic telangiectasia, this test is more valuable, as well as scurvy, allergic purpura, senile purpura, etc.; 2 platelet defective disease Idiopathic thrombocytopenic purpura (ITP), thrombocytopenia, von Willebrand disease (VWD), platelet disease; 3 other occasional severe coagulation abnormalities; diseases caused by capillary damage, such as sepsis, uremia, Liver disease, chronic hepatitis, thrombotic thrombocytopenic purpura. Second, the bleeding time determination BT extension (1) abnormal platelet count 1 primary thrombocytopenic purpura, thrombotic thrombocytopenic purpura (caused by drugs, poisoning, infection, immunity, etc.); 2 thrombocytopenia, such as essential thrombocytosis. (2) platelet function defects 1 congenital platelet diseases such as thrombocytopenia; 2 acquired platelet diseases such as drug-induced platelet disease, myelodysplastic syndrome. (3) Vascular hemophilia (VWD). (4) vascular wall and structural abnormalities (rare) hereditary hemorrhagic telangiectasia. (5) Occasionally, severe clotting factor deficiency such as clotting factor II, V, VIII, IX or fibrin deficiency; disseminated intravascular coagulation (DIC); also seen in patients after receiving a large number of blood transfusions. 2. BT shortening is mainly seen in some severe prethrombotic states and thrombosis. Such as pregnancy-induced hypertension syndrome, myocardial infarction, cerebrovascular disease, DIC hypercoagulable period, etc., can be caused by damage to the blood vessel wall, excessive activity of platelets or blood factors behind. Third, platelet count 1. Physiological normal human platelet count can change 6-10% in one day; the performance is lower in the morning, slightly higher; lower in spring, slightly higher in winter; lower in plains, higher in plateau; venous blood than capillary Blood is 10% higher; lowers before menstruation, rises after menstruation; rises in the middle and late pregnancy, decreases after delivery; rises after exercise, recovers after rest. 2. Pathological (1) Clinically, in addition to trauma, thrombocytopenia causes common causes of bleeding. The number of platelets is greater than 100 × 109 L, no abnormal bleeding; when less than 50 × 109 L, there may be bleeding symptoms. Common diseases include 1 thrombocytopenia, such as acute leukemia, aplastic anemia; 2 excessive platelet destruction, such as ITP, hypersplenism, systemic lupus erythematosus; 3 increased platelet consumption, such as DIC, thrombotic thrombocytopenic purpura. (2) thrombocytopenia (platelet count greater than 400 × 10L); 1 myeloproliferative disease chronic myeloid leukemia, polycythemia vera; 2 essential thrombocytosis; 3 acute massive hemorrhage, acute lysate, acute suppurative infection; 4 after splenectomy. Fourth, blood clot contraction test 1. Clot dysplasia or blood clot not shrinking is seen in 1 platelet dysfunction such as platelet weakness; 2 platelet count reduction when platelet count is less than 50 × 109L, clot shrinkage is significantly reduced, such as ITP; 3 fibrinogen, prothrombin serious Reduction; 4 primary or secondary polycythemia (due to the large number of red blood cells in the blood clot, large volume, limited clot contraction); 5 abnormal proteinemia such as multiple bone marrow. 2. Excessive contraction of blood clots is seen in 1 congenital or acquired factor VIII deficiency; 2 severe anemia (increased contraction of red blood cells with less clots). V. Determination of clotting time 1. CT prolongs 1 significant VIII, IX reduction of hemophilia A, B clotting factor deficiency; 2 von Willebrand disease; 3 severe factor V, X, fibrin anticoagulant, application of heparin and low Fibrinogenemia; 4 secondary or primary fibrinolytic activity; 5 anti-intensity in circulating blood, such as anti-Factor VIII antibody factor, SLE and so on. 2. CT shortens 1 pre-thrombotic state DIC hypercoagulable period, etc. 2 thrombotic diseases such as myocardial infarction, unstable angina pectoris, cerebrovascular disease, effective tuberculosis of urinary tract disease, pulmonary infarction, deep vein thrombosis, pregnancy-induced hypertension , nephrotic syndrome and high blood stasis, high blood lipids and so on. Six. Determination of calcium time Same as clotting time. However, it is more sensitive, and some patients with mild hemophilia can be extended. Seven, plasma prothrombin time measurement 1. PT prolongs PT over normal control for more than 3 seconds or prothrombin ratio exceeds normal range is prolonged, mainly seen in 1 reduction of congenital factors II, V, VII, X and fibrinogen deficiency (low or no fibrin blood) 2) acquired coagulation factor deficiency, such as DIC, primary fibrinolysis, obstructive jaundice and vitamin K deficiency in liver disease, and increased anticoagulant substances in the blood circulation. 2. PT shortens 1 increased congenital factor V; 2DIC early (hypercoagulated state); 3 oral contraceptives, other prethrombotic states and thrombotic diseases (increased blood coagulation factors and platelet activity, vascular injury can not be the basis of thrombosis) . Eight, activated partial thromboplastin time determination 1. APTT prolongs APTT results beyond the normal control for more than 10s is normal extension. APTT is the most reliable screening test for endogenous clotting factor deficiency and is primarily used to detect mild hemophilia. Although factor VIIIC levels of less than 25% of hemophilia A can be detected, subclinical hemophilia (factor VIII greater than 25%) and hemophilia carriers are less preferred. The prolonged results are also seen in factors XI (hemophilia B), XII and VII deficiency; when blood anticoagulants such as coagulation factor inhibitors or heparin levels are elevated, when prothrombin, fibrinogen and factors V, X are absent It can also be extended, but the third sex is slightly worse; other liver diseases, DIC, and a large amount of imported blood are included. 2. APTT shortening is seen in DIC, prethrombotic state and thrombotic disease. 3. Heparin treatment monitoring APTT is a widely used laboratory monitoring index for plasma heparin concentration. At this point, it should be noted that the APTT measurement results must be linear with the plasma concentration of the heparin treatment range, otherwise it should not be used. Generally, during heparin treatment, the APTT is preferably maintained at 1.5 to 3.0 times of the normal control. Need to check the crowd of people with angina, limb numbness, lack of movement, speech, vertigo, blurred vision and other symptoms. Positive results may be diseases: thrombosis, hemophilia, immune thrombocytopenic purpura in the elderly, generalized idiopathic telangiectasia Contraindications before examination: bleeding, hematoma and ulcers on the upper arm. Requirements for inspection: blood test specimens are best collected separately, otherwise the blood stays in the needle tube for a prolonged period due to the distribution, dispensing, etc. of the specimen. Inspection process It is generally recommended to use a stoppered test tube when collecting blood coagulation samples. The blood and anticoagulant should be mixed upside down 10 times in the test tube, but avoid shaking with force. NCCLS advocates the use of high-quality plastic or polyethylene test tubes to collect specimens. This tube should be sufficiently transparent, designed according to blood volume, and should have sufficient space for blood to mix with anticoagulant. After the blood is taken, the remaining space in the tube should be no less than 15% of the volume of the pumped blood, and sent for inspection in time. Not suitable for the crowd 1. Patients who have taken contraceptives, thyroid hormones, steroid hormones, etc., may affect the results of the examination and prohibit patients who have recently taken the drug history. 2, special diseases: patients with hematopoietic function to reduce disease, such as leukemia, various anemia, myelodysplastic syndrome, etc., unless the examination is essential, try to draw less blood. 3. There is no need to do this test when there are obvious signs of skin bleeding. 4, the patient's vital signs are unstable, in an endangered state, it is not appropriate to do this test. Adverse reactions and risks 1, subcutaneous hemorrhage: due to pressing time less than 5 minutes or blood draw technology is not enough, etc. can cause subcutaneous bleeding. 2, discomfort: the puncture site may appear pain, swelling, tenderness, subcutaneous ecchymosis visible to the naked eye. 3, dizzy 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. 4. Risk of infection: If you use an unclean needle, you may be at risk of infection.

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