Detection of rheological properties of red blood cells

The erythrocyte rheological property test is to observe the flow and deformation of red blood cells in the blood, and provide a new basis for medical diagnosis, treatment and prognosis. Basic Information Specialist classification: cardiovascular examination classification: blood examination Applicable gender: whether men and women apply fasting: not fasting Tips: Do not eat too greasy, high-protein foods the day before, and avoid heavy drinking. Normal value Hematocrit (%) 35.66----44.12. The red blood cell aggregation index is 1.55----2.73. The red blood cell rigidity index is 3.71----5.61. The red blood cell deformation index is 0.65----0.96. Erythrocyte electrophoresis index 4.35----6.92. Clinical significance Abnormal results: (1) Erythrocyte sedimentation rate (ESR). Erythrocyte sedimentation rate is closely related to plasma viscosity, erythrocyte aggregation and erythrocyte ratio. It is often used as a red blood cell aggregation in blood rheology measurement. The surface charge of red blood cells and the common index of red blood cell electrophoresis are affected by the red blood cell product. It is more valuable to determine the K value of the ESR equation. (2) ESR equation (ESRK). That is to say, the effect of hematocrit (specific product) on the erythrocyte sedimentation rate, regardless of whether the erythrocyte sedimentation rate is fast or not, the high K value can reflect the increase of erythrocyte aggregation. Clinically, if the K value is normal and the blood sedimentation is fast, it may be due to the low red blood cell ratio, which causes the blood to sink quickly; the blood sedimentation is fast, the K value is the real blood sedimentation fast; on the contrary, the erythrocyte sedimentation rate and the K value are normal, it is the real blood sedimentation. normal. (3) Cell electrophoresis (EPM). The cells or microscopic particles are suspended in a medium, and under the action of a direct current electric field, an electrode movement opposite to that on its own surface occurs. Since this observation is performed by means of a microscope, it is also called microelectrophoresis. This technique is an effective method for studying the surface charge properties and amount of cells and microparticles, and because this electrical behavior is closely related to surface structure function, it is a tool for studying the biophysical characteristics of cell surfaces. It is important for the diagnosis and course of disease, as well as for biological and immunological diseases, such as coronary heart disease, ischemic stroke, myocardial infarction, thromboangiitis obliterans, central retinal artery or venous thrombosis. Red blood cells and platelets are slowed down by electrophoresis, suggesting that their surface charge drops, and they tend to aggregate or form thrombi. (4) TK value (erythrocyte flow coefficient). The viscosity value of whole blood at high shear rate was measured by a rotary or capillary viscometer, and the plasma viscosity was measured by a capillary viscometer. The TK value was calculated by the viscosity equation, which indicates that the red blood cell deformability was changed. Elevated TK values ​​indicate poor red blood cell deformability; red blood cell stiffness index is negatively correlated with deformability, and the higher TK value indicates deterioration of red blood cell deformability. (5) Red blood cell viscosity (ηi). Mainly affected by hemoglobin content and physical and chemical substances, the internal viscosity of normal red blood cells is 6 ~ 7mPa.s, when the average red blood cell hemoglobin rises to 37G / dL, the internal liquid viscosity can reach 15mPa.s; when hemoglobin rises to 45G / dL At the time, the internal viscosity is as high as 170 MPa?s; the viscosity of the red blood cell is increased, resulting in a decrease in red blood cell deformability. (6) In vitro thrombosis (EXT). According to the Chandler method, in the in vitro rotating environment, the formation of blood clots in the blood flow state is simulated. This artificially formed thrombus has a completely similar structure to the thrombus formed in the body, and it has a similar structure to coronary heart disease, cerebral thrombosis, and tumor. The diagnosis and prognosis of pulmonary heart disease and blood stasis have guiding significance, especially for the treatment effect, metastasis and postoperative recurrence of tumors. It has a differential significance for ischemic stroke and hemorrhagic stroke. In vitro thrombus length (EXTL), in vitro thrombus wet weight (EXTMW) and in vitro thrombus dry weight (EXTOW) have their special significance. (7) Red blood cell deformation index (RI). The ability of red blood cells to deform during the flow. In the blood vessels, especially in the microcirculatory system, when the diameter of the blood vessel is equal to or smaller than the diameter of the red blood cells, the red blood cells are subjected to a large shear force, and a large deformation occurs to pass the micro blood vessels, and the red blood cell deformability is lowered to cause an increase in blood viscosity. Microcirculatory disorders and shortened red blood cell life, these changes play an important role in the development of many diseases. The deformation of red blood cells is mainly determined by the viscoelasticity of erythrocyte membrane, the geometry of red blood cells (surface area to volume ratio) and the internal viscosity of red blood cells. Three internal factors, the elasticity of the erythrocyte membrane is mainly determined by the structure of the bilayer membrane phospholipid and membrane skeleton protein, such as hyperlipidemia, diabetes and cirrhosis, due to the high ratio of cholesterol to phospholipid content in the bilayer membrane phospholipid. To reduce the deformability of the cell membrane. (8) Erythrocyte aggregation index and erythrocyte aggregation are one of the main causes of blood viscosity increase at low shear rate. Increased erythrocyte aggregation is one of the risk factors for thrombosis in vivo. Especially in the low-cut flow state, red blood cells form a squall-like aggregate under the bridge of macromolecular plasma proteins, and form a three-dimensional structure. The blood flow resistance is increased, and the greater the aggregation of red blood cells, the larger the aggregates are, and the blood viscosity is increased. (9) RBC rigidity index (IR). It is the corresponding word of red blood cell deformability, "rigid", that is, the shape of red blood cells is not easy to change, it is not a physical quantity, and there is no unified standard to describe the rigidity of cells. The so-called stiffness index is the blood reduction viscosity under specific conditions of high shear rate. (10) Hematocrit (red blood cell volume, HCT). The ratio of red blood cells in whole blood reflects the concentration of red blood cells, which directly determines the viscosity of whole blood and blood rheology. The data show that high red blood cell specific product is closely related to vascular occlusion, which has certain significance for predicting the onset of cardiovascular and cerebrovascular diseases. People who need to be examined are suspected of having a blood disease, middle-aged and elderly. Precautions Inappropriate crowd: None. Taboo before the test: Do not eat too greasy, high-protein foods the day before the test, to avoid heavy drinking. The alcohol content in the blood directly affects the test results. After 8 pm on the day before the medical examination, you should fast. Requirements for examination: When taking blood, you should relax your mind to avoid the contraction of blood vessels caused by fear and increase the difficulty of blood collection. Inspection process Vascular blood collection was used for testing. Before venous blood collection, carefully check that the needle is securely installed and that there is air and moisture in the syringe. The needle used should be sharp, smooth, ventilated, and the syringe should not leak. Firstly, the skin was disinfected from the inside to the outside and clockwise from the selected venipuncture with a 30g/L iodine swab. After the iodine was volatilized, the iodized trace was wiped out in the same way with a 75% ethanol swab. Fix the lower end of the venipuncture site with the thumb of the left hand, hold the syringe syringe with the thumb and middle finger of the right hand, and fix the needle lower seat with the index finger, so that the bevel of the needle and the scale of the syringe are upward, and the needle is inclined along the vein to make the needle and the skin obliquely penetrate the skin at an angle of 30°. Then, through the vein wall, enter the venous cavity forward at an angle of 5°. After seeing the blood return, the needle will be probed into the spot to avoid the needle slipping out when the blood is collected; but it is not possible to use a deep puncture to avoid hematoma, and immediately remove the cuff. Needle plug can only be pumped out, can not be pushed in, so as to avoid injecting air into the vein to form a gas plug, causing serious consequences. Remove the syringe needle and slowly inject the blood into the anticoagulation tube along the tube wall to prevent hemolysis and foam. Not suitable for the crowd Hemophilia and diffuse intravascular coagulation. Adverse reactions and risks Infection: Do not touch the dirt after blood collection. Do not wash your hands immediately to avoid infection.