In the practice of hematology, many medical students feel that hematology is too abstract, and entering the department of hematology is like a cloud of smoke. In addition, the internship time of hematology is short and often time passes by.
The most common symptoms of hematological diseases are mainly anemia, infection and bleeding caused by the disease affecting red blood cells, white blood cells and platelet cells. Differential diagnosis from symptoms alone is difficult, so the diagnosis of hematological diseases is more dependent on laboratories than other internal medicine specialties. . Among many laboratory examinations, blood routine is the door-to-door examination of the department of hematology, and it is also a window for various blood diseases, and is an important basis for the diagnosis and treatment of blood diseases.
It is very important to memorize the normal value of blood routine and understand its clinical significance.
1. Red blood cell system inspection:
(1) Hemoglobin (Hb):
Normal value: 12-16 g/L for men and 11-15 g/L for women. Hemoglobin lower than this value is anemia, and patients will experience dizziness, fatigue, insomnia and dreaminess. The types of anemia include iron deficiency anemia, megaloblastic anemia, aplastic anemia, etc., which must be comprehensively diagnosed in combination with clinical manifestations and other auxiliary examinations.
Excessive hemoglobin is not a good sign. When Hb is higher than 18 g/L in men and 17 g/L in women, after excluding polycythemia caused by chronic hypoxia and tumors, polycythemia vera must be considered. (PE) diagnosis. The disease can be combined with cerebral thrombosis and hypertension, and the patient is often misdiagnosed as cerebral infarction and admitted to the neurology ward. However, the characteristics of patients with conjunctival hyperemia, lips and facial features, and palms crimson are conducive to the differential diagnosis of cerebrovascular disease.
(2) Mean Red Blood Cell Volume (MCV):
Normal value: 80-100fL. If the MCV of anemia patients is lower or higher than this value, the diagnosis of microcytic hypochromic anemia (the most common disease is iron deficiency anemia) or megaloblastic anemia should be considered.
Iron-deficiency anemia and megaloblastic anemia are the most common benign anemias in hematology, and the anemia can be corrected within 2-3 weeks after regular treatment. Attention should be paid to the population with special disease when diagnosing. For example, iron deficiency anemia is common in gastritis, peptic ulcer, hemorrhoids, uterine fibroids or chronic blood loss patients, and also seen in children or pregnant women during the period of vigorous growth; megaloblastic anemia is seen in people with partial eater ( Eat vegetables or too little meat and eggs) or children, pregnant women. If these two types of anemia occur in elderly patients, they must be admitted to the hospital for detailed examination to rule out the cause of malignant tumors. After the cause is found, the cause of these two types of anemia must be treated. Otherwise, anemia is easy to recur.
(3) Percentage of reticulocytes (RET%):
Normal value: 0.5-1.5%. If the patient has increased RET with anemia, jaundice, especially indirect bilirubin increase, be aware of the existence of hemolytic anemia, and further examinations such as bone puncture, acid hemolysis test, anti-human immunoglobulin test, etc. are required to further confirm whether hemolysis is possible The existence of anemia is classified as paroxysmal nocturnal hemoglobinuria or autoimmune hemolytic anemia.
If the patient has reduced RET and pancytopenia, clinical examination of the liver and spleen lymph nodes is not enlarged, bone biopsy, chromosome, stem cell culture and other tests are required to confirm whether the diagnosis is consistent with the diagnosis of aplastic anemia.
2. White blood cell count and percentage:
Normal white blood cell value: 4.0-10.0×109/L, of which neutrophils account for 50-70%, lymphocytes 20-40%
, The median cell is about 10%.
When the white blood cell count is lower than 4.0×109/L, it is called leukopenia; when the white blood cell count is lower than 0.5×109/L, it is called agranulocytosis. The patient feels fatigue and is prone to infection. When normal people have upper respiratory tract virus infection, they are also prone to leukopenia.
When the number of white blood cells increases and the proportion of neutrophils is greater than 70%, the patient has symptoms such as fever, and the diagnosis of bacterial infection needs to be considered. The increase in the number of white blood cells at this time is the body's compensation mechanism for pathogenic microorganism infection, and the function of bone marrow stem cells is normal, and leukemia-like reactions can occur, but the number of white blood cells generally does not exceed 50×109/L, mainly due to the increase in neutrophils . When the infection is severe, the nucleus shifts to the left, and a small amount of rod-shaped nucleus granulocytes or late myelocytes appear in the peripheral blood, unlike leukemia.
When the number of white blood cells increases (a few normal or lower), the median cells in the classification are higher than normal, and manual classification of white blood cells is required. If an increase in the percentage of blasts or early immature cells is found, the diagnosis of myelodysplastic syndrome (MDS) or acute leukemia should be vigilant. The percentage of immature cells exceeds 20%, combined with acute course, fever, anemia, hemorrhage, liver and spleen lymphadenopathy Examination of manifestations, bone marrow chromosomes and immunophenotyping to confirm acute leukemia.
When the number of white blood cells increases, the number of myelocytes and late myelocytes in the classification is mainly increased. The patient is generally in good condition and the spleen is obvious. Pay attention to the diagnosis of chronic myeloid leukemia; if the number of white blood cells increases, the proportion of mature lymphocytes in the classification More than 50%, the general condition of the patient is good, lymph nodes are enlarged, and the spleen is obvious. Pay attention to the diagnosis of chronic lymphocytic leukemia
Normal value: 100-400×109/L. Below 100×109/L, it is called thrombocytopenia. When the platelet is lower than 20×109/L, the patient is prone to visceral hemorrhage and should stay in bed, stay in the emergency room or be admitted to hospital for treatment. Excluding the diagnosis of secondary factors such as drugs, viral infections, leukemia, and early aplastic anemia, if only thrombocytopenia, hemoglobin and white blood cell counts are normal, the most common disease is the diagnosis of idiopathic thrombocytopenic purpura, which should be combined with bone marrow And platelet antibody tests confirm the diagnosis.
When the platelets are higher than 400×109/L, it is called thrombocytosis. When platelets are higher than 800-1000×109/L, the diagnosis of idiopathic thrombocytosis should be considered. However, secondary factors such as inflammation, iron deficiency, and tumors should be routinely excluded.
Therefore, the normal value of blood routine is very important, higher or lower than the normal value will lead to different blood diseases. For medical students, memorizing these normal values and understanding their clinical significance can expand their horizons, reduce missed diagnosis and misdiagnosis of diseases, and gradually accumulate clinical experience.