Hemorheology is a new medical analysis discipline which specializes in blood flow and blood cell deformation. What people usually call hemorheology examination is mainly to study the fluidity and viscosity of blood and the aggregation and deformability of red blood cells and platelets in blood. In recent ten years, the detection of hemorheology has been widely used in clinic, which is of great significance to the diagnosis, treatment, development and prevention of diseases. Its specific content and clinical significance are as follows:
1, whole blood viscosity test
Whole blood viscosity is a parameter reflecting the basic characteristics of hemorheology and an important index reflecting the degree of blood viscosity. The main factors affecting whole blood viscosity are hematocrit, erythrocyte aggregation and deformability and plasma viscosity. According to the different shear rate, it is generally divided into high, medium and low shear viscosity. The whole blood viscosity at high shear rate reflects the deformability of red blood cells, while the whole blood viscosity at low shear rate reflects the aggregation of red blood cells.
[Clinical significance]
Blood viscosity is an important parameter of hemorheology, which plays an important role in the diagnosis, treatment and prevention of prethrombotic state and thrombotic diseases. When the blood viscosity increases, the blood rheology is abnormal, which can directly affect the blood perfusion of the tissue, leading to the lack of water and oxygen in the tissue, metabolic disorder and dysfunction of the body, thus producing a series of serious consequences.
The increase of whole blood viscosity will lead to the following diseases:
1. circulatory system diseases: arteriosclerosis, hypertension, coronary heart disease, angina pectoris, myocardial infarction, peripheral arteriosclerosis, hyperlipidemia, heart failure, pulmonary heart disease, deep vein embolism, etc.
2. Diabetes
3. Cerebrovascular diseases: stroke, cerebral thrombosis, cerebrovascular sclerosis, etc.
4. Tumor diseases: Common diseases include liver, lung and breast tumors.
(5) polycythemia vera, multiple myeloma and primary macroglobulinemia.
6. Others: shock, burns, pre-eclampsia, etc.
The decrease of whole blood viscosity can be seen in various anemia and massive blood loss.
2, plasma viscosity
Plasma viscosity is another important index reflecting the degree of blood viscosity. The factors affecting plasma viscosity are fibrinogen, globulin, albumin, blood lipid and blood sugar. Clinical significance]
The higher the plasma viscosity, the higher the whole blood viscosity. The increase of clinical plasma viscosity can be seen in hereditary spherocytosis, some ischemic cardiovascular and cerebrovascular diseases, diabetes, macroglobulinemia and so on.
3. Hematocrit
Hematocrit, also known as red blood cell volume and hematocrit, refers to the ratio of compacted red blood cell layer to blood volume after anticoagulant that does not change red blood cell volume is placed in winch tube or capillary tube and centrifuged by centrifugal force for a certain period of time.
[Clinical significance]
Increased hematocrit: seen in normal people's strenuous exercise or emotional excitement, blood concentration is caused by a variety of reasons, such as massive vomiting, diarrhea, and a large amount of wound exudates after extensive burns. Polycythemia vera can sometimes be as high as about 80%. Secondary polycythemia is a compensatory reaction caused by insufficient oxygen supply, such as newborns, mountain residents and chronic cardiopulmonary diseases.
Decreased hematocrit: found in normal pregnant women, patients with various anemia and those who use interferon, penicillin, indomethacin, vitamin A and other drugs.
4. Detection of reduced viscosity of whole blood
The whole blood viscosity refers to the whole blood viscosity when the hematocrit is 65438 0, also known as the unit hematocrit viscosity.
[Clinical significance]
The decrease of whole blood viscosity reflects the contribution of rheological properties of red blood cells to blood viscosity.
1. If the whole blood viscosity and the whole blood reduced viscosity are high, it means that the blood viscosity is high, which is related to the change of rheological characteristics of red blood cells and has reference significance.
2. If the whole blood viscosity is high and the whole blood reduced viscosity is normal, it means that high hematocrit (blood viscosity) leads to high blood viscosity, but the rheological characteristics of red blood cells are not abnormal (the contribution to viscosity is small).
3. If the whole blood viscosity is normal and the whole blood reduced viscosity is high, it means that the hematocrit is low (blood is thin), but the rheology of red blood cells is abnormal (the contribution to viscosity is too large), which means that the whole blood viscosity is still high, which is also of reference significance.
4. If the whole blood viscosity and the whole blood reduced viscosity are normal, the blood viscosity is normal.
5. Erythrocyte aggregation index
Red blood cell aggregation refers to the ability of red blood cells to form so-called "money-like" aggregates when the shear force of blood is reduced to a certain extent.
[Clinical significance]
Many clinical diseases are accompanied by elevated erythrocyte aggregation, such as acute myocardial infarction, cerebral infarction, cor pulmonale, diabetes, hyperlipidemia, peripheral vascular diseases and so on.
6, erythrocyte deformation index
Red blood cell deformability refers to the deformability of red blood cells in blood flow, that is, the characteristics of red blood cells changing shape under the action of external force.
[Clinical significance]
Clinically, the reduction of erythrocyte deformability is mainly seen in some hemolytic anemia, myocardial infarction, cerebral thrombosis, coronary heart disease, hypertension and peripheral vascular diseases, diabetes, pulmonary heart disease and so on.
1. Erythrocyte deformability decreased in patients with acute myocardial infarction, and changed obviously on the third day.
2. Erythrocyte deformation in patients with cerebral thrombosis is significantly lower than that in healthy people. Diabetic patients also have similar changes, especially those with vascular complications.
3. Hyperlipidemia can increase the cholesterol content of erythrocyte membrane, increase the membrane area, make red blood cells prickly and reduce the deformability.
4. Multiple arteriosclerosis, chronic renal failure, Raynaud's disease, hypertension and tumor can reduce the deformability of red blood cells, and smoking can also reduce the deformability of red blood cells.
7.ESR
Erythrocyte sedimentation rate (ESR) refers to the sedimentation rate of red blood cells under certain conditions.
[Clinical significance]
Pathological acceleration:
1. The erythrocyte sedimentation rate (ESR) in active period of pulmonary tuberculosis and rheumatism often rises rapidly, and gradually returns to normal after the condition improves or stabilizes;
2. Used to distinguish myocardial infarction from angina pectoris; Gastric cancer and gastric ulcer; In pelvic inflammatory mass and ovarian cyst without complications, the erythrocyte sedimentation rate of the former increased significantly, while the erythrocyte sedimentation rate of the latter increased normally or slightly.
3. A large number of abnormal globulins appear in the plasma of multiple myeloma, and the erythrocyte sedimentation rate is obviously accelerated.
8. K value of 8.ESR equation
By calculating the k value of erythrocyte sedimentation rate equation, erythrocyte sedimentation rate is transformed into an index unrelated to hematocrit, so that the k value of erythrocyte sedimentation rate equation can reflect the change of erythrocyte aggregation more objectively than erythrocyte sedimentation rate.
9, erythrocyte hardness index
Under normal circumstances, the quantity and quality of red blood cells in the blood remain relatively stable. No matter what causes the abnormal production and destruction of red blood cells, it will cause changes in the quantity and quality of red blood cells, which will lead to diseases.
[Clinical significance]
The greater the rigidity index of red blood cells, the smaller the deformability of red blood cells, which is one of the reasons for the high blood viscosity at high shear rate.
10, erythrocyte electrophoresis time
The time required for red blood cells to move a certain distance under the action of DC electric field is called erythrocyte electrophoresis time. The factors affecting electrophoresis time are mainly related to the increase of blood lipid, globulin, fibrinogen and plasma viscosity.
[Clinical significance]
Patients with ischemic stroke, coronary heart disease, cor pulmonale, myocardial infarction, hypertension, chronic bronchitis and systemic lupus erythematosus have low erythrocyte electrophoresis rate and long electrophoresis time.
1 1, fibrinogen
Fibrinogen in plasma, that is, coagulation factor ⅰ, is an important coagulation factor in coagulation system. The increase of fibrinogen content is an important risk factor of thrombotic diseases, which is of great significance to the diagnosis, treatment and prognosis of cardiovascular and cerebrovascular diseases, diabetes and tumors.
[Clinical significance]
1. Fibrinopenia is found in congenital low fibrinogen, newborns and premature infants, disseminated intravascular coagulation, severe hepatitis, liver cirrhosis, severe anemia, primary fibrinolysis, malignant tumors and some obstetric emergencies.
2. Increased fibrinogen was found in pregnancy-induced hypertension, senile diabetes, atherosclerosis, acute infectious diseases, connective tissue diseases, acute nephritis and uremia, burns, radiation sickness, multiple myeloma, shock, postoperative, myocardial infarction and strenuous exercise.
Second, who is suitable for hemorheology examination?
The determination of hemorheological indexes plays an extremely important role in the research, diagnosis, differential diagnosis, development and prognosis judgment, treatment and prevention of various diseases.
1. Normal or sub-healthy people: such as people with heavy work pressure, psychological imbalance, overnutrition or unhealthy life, and healthy people over 30 years old.
2. Pathological population: such as diabetes, hypertension, coronary heart disease, angina pectoris, myocardial infarction, atherosclerosis, cerebral infarction, pulmonary heart disease, pregnancy-induced hypertension syndrome, stroke, malignant tumor, hematopathy, burn, severe anemia, severe hepatitis, liver cirrhosis, hyperlipidemia and other patients.