Whole blood viscosity

Whole blood specific viscosity not only detects changes in the blood itself (mainly red blood cells), but also changes in blood vessels and heart. The whole blood specific viscosity is divided into two kinds of viscosity: high shear and low shear. The high-viscosity viscosity reflects the deformability of red blood cells, and the blood with low red blood cell deformability has high shear viscosity; the low shear viscosity reflects the red blood cell aggregation ability, and the red blood cells gather blood, and the low shear viscosity increases. Basic Information Specialist classification: cardiovascular examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Tips: The time of compression of the cuff should be as short as possible. After the needle is inserted, the blood should be collected after the pressure pulse is released for 5 seconds. The force should not be too strong when drawing blood. Normal value Cone and plate blood viscosity meter test method: Gao cut male 2.70 ~ 5.20mPa · s. Female 1.64 ~ 4.78mPa · s. The medium cut male 5.03 ~ 6.67mPa · s. Female 4.36 ~ 5.88mPa · s; Low cut male 8.23 ​​~ 10.01mPa · s. Female 7.67 ~ 10.29mPa · s. Clinical significance (1) increased ischemic stroke, myocardial infarction, coronary atherosclerotic heart disease (coronary heart disease), pulmonary heart disease, thromboangiitis obliterans, arteriosclerotic embolism, tumor, multiple myeloma, original Macroglobulinemia, fibrinogen hyperplasia, polycythemia vera. (2) reduce hemorrhagic stroke, hematemesis and black feces (upper gastrointestinal bleeding), uterine bleeding, hemorrhagic shock. Precautions (1) Blood collection and anticoagulation: Improper blood collection can cause viscosity measurement errors. According to the recommendations of ICSH, the compression time of the cuff should be as short as possible. After the needle is inserted, the blood should be collected after the pressure pulse is released for 5 s. When the blood is drawn, the force should not be too strong. The anticoagulant should use a solid anticoagulant to prevent dilution of the blood. If liquid anticoagulation is used, the concentration of the anticoagulant should be increased to reduce the amount of liquid added, usually with heparin or dipotassium edetate or Disodium (EDTA-K: or EDTA-Na2) is anticoagulated, but potassium salt is preferred because of its high solubility. (2) Storage time of sample: It should be tested immediately after blood collection. If stored at room temperature for too long, the measurement result will be too high. It is best to complete the test within 4 hours. If stored in a refrigerator at 4 ° C can be extended to 12 h, blood specimens should not be stored below 0 ° C, because red blood cells will rupture under freezing conditions. (3) Influence of life rhythm: Some studies have pointed out that the blood viscosity of the human body changes regularly in one day, with two peaks at 11 am and 8 pm. Eating can cause changes in hematocrit and plasma composition, so blood collection time is appropriate for early morning fasting. (4) Reference value problem: blood viscosity is the macroscopic performance of internal factors such as plasma viscosity, hematocrit, aggregation and deformation of red blood cells, platelets and white blood cells under certain measurement conditions, and these factors fluctuate within a certain range, so Blood viscosity also has a certain range of fluctuations. Complex changes in blood rheology occur under pathological conditions. Therefore, it is necessary to have a reference value to evaluate whether the blood viscosity is normal. The reference value must be obtained by a person who has undergone strict examination and is in good health. However, the detection rate of diseases in the population depends on the age of the person, the medical knowledge and the level of detection technology, so the reference values ​​are relative. In addition, the living standards and habits of people in different regions have different effects on blood viscosity, so there is no universally applicable reference value, even with common instruments and standardized operation methods. Therefore, different regions and laboratories should have their own reference values. Inspection process (1) Turn on the instrument to warm up and let the constant temperature system reach the test temperature. (2) After the sample is kept at the test temperature for 5 minutes, mix well and add to the sample cup. (3) Press the measurement button and the shear rate is measured in descending order. In order to avoid the sinking of blood cells, the choice of shear rate should not be too much, and the retention time should not be too long. (4) After each sample is measured, the sample cup should be cleaned and dried. Not suitable for the crowd Generally no taboos. Adverse reactions and risks Dizziness or fainting: When blood is drawn, due to emotional overstress, fear, reflex caused by vagus nerve excitability, blood pressure drop, etc., the blood supply to the brain is insufficient to cause fainting or dizziness.