platelet aggregation function test

Under physiological conditions, the function of adhering to platelet granules or lumps between platelets and platelets is called platelet aggregation. The method for measuring platelet aggregation function is called platelet aggregation test (PAgT), which is commonly used for turbidimetry. (1) Platelet aggregation rate reduces platelet weakness, giant platelet syndrome, storage pool disease, May-Hegglin abnormality, and low (no) fibrinogenemia; uremia, cirrhosis, vitamin B12 deficiency, platelet inhibitors, etc. . (2) increased platelet aggregation rate, hypercoagulable state and thrombotic diseases, such as acute myocardial infarction, angina pectoris, diabetes, cerebrovascular disease, deep vein thrombosis, congenital purpura heart disease, high beta lipoproteinemia, antigen-antibody Complex reactions, prosthetic valves, oral contraceptives, smoking, etc. Basic Information Specialist classification: cardiovascular examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Tips: Blood collection should be smooth, avoiding repeated puncture and pumping tissue fluid into the syringe or mixing bubbles. Normal value See the table below (Table 1). Clinical significance (1) Decrease in platelet aggregation rate: platelet weakness, giant platelet syndrome, storage pond disease, May-Hegglin abnormality, and low (no) fibrinogenemia; uremia, cirrhosis, vitamin B12 deficiency, platelet inhibitory drugs Wait. (2) increased platelet aggregation rate: hypercoagulable state and thrombotic diseases, such as acute myocardial infarction, angina pectoris, diabetes, cerebrovascular disease, deep vein thrombosis, congenital purpura heart disease, high beta lipoproteinemia, antigen - Antibody complex reactions, prosthetic valves, oral contraceptives, smoking, etc. Precautions (1) Blood collection: Blood collection should be smooth, avoiding repeated puncture and pumping tissue fluid into the syringe, or mixing air bubbles. (2) Time: The experiment should be completed within 3 to 4 hours after blood collection. If the time is too long, the aggregation intensity and speed of platelets will be reduced. (3) Temperature: The specimen after blood collection should be placed at room temperature of 15 ~ 25 ° C, low temperature will cause platelet activation. (4) Plasma pH: plasma pH value of 6.8 ~ 8.5 can obtain the best aggregation effect, the pH value is less than 6.4 or greater than 10.0, aggregation is inhibited or disappeared. (5) Anticoagulant: Aggregation increases with the decrease of plasma sodium citrate concentration. Therefore, an an anticoagulant should be added to the anemia when it is more normal. Ethylenediaminetetraacetic acid and heparin are not suitable as anticoagulants. (6) drugs: aspirin, dipyridamole, heparin and oral anticoagulants can inhibit platelet aggregation, aspirin can last 1w. (7) PRP is mixed with other substances: mixed with red blood cells, hemolysis, high blood lipids and other factors can reduce the transmittance and mask the changes in platelet aggregation. (8) Contact surface: The use of uncoated silicon common test tubes or straws can affect platelet aggregation and even cause abnormal results in the original normal. (9) Inducing agent: ADP should be stored in a refrigerator at -20 °C after being formulated into a solution, generally not reducing activity within half a year; when applying adrenaline, it should be protected from light. Inspection process (1) 4.5 ml of blood was smoothly taken from the elbow vein with a silicified or plastic syringe, and a siliconized centrifuge tube containing 0.129 mol/L sodium citrate 0.5 ml was injected. (2) Centrifuge at 1000 r/min for 10 min, carefully remove the upper plasma (PRP), count the platelets and adjust to 250×109/L. (3) Centrifuge the remaining blood at 3000r/min for 20min. The relatively transparent liquid in the upper layer is PPP, and the platelets are adjusted to (10-20)×109/L. (4) Put the PRP specimen into the measuring well to adjust the transmittance to 10%, and add a stirring magnetic rod to preheat for 3 min at 37 °C. (5) An inducer was added to the PRP, and stirring was started (1000 r/min), and the aggregation waveform was recorded. 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. 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.