A full blood count ( CBC ), also known as complete blood cell count , full blood count ( FBC ), or full blood test ( FBE ), is a panel of blood requested by a doctor or other medical professional who provides information about the cells in the patient's blood, such as the number of cells for each cell type and the concentration of various proteins and minerals. A scientist or laboratory technician performs the requested tests and provides a professional medical request with results from CBC.
Various blood counts have been used for clinical purposes since the 19th century. Automated equipment for full blood counting was developed in the 1950s and 1960s. Most of the current blood count includes the number of CBCs (ie: the number of complete blood cells) and the number of differential leukocytes (LDC) (ie, not only the total number of WBCs but also the per- formed percentages of each WBC type, such as neutrophils, eosinophils, basophils, monocytes, and lymphocytes).
Cells that circulate in the bloodstream are generally divided into three types: white blood cells (leukocytes), red blood cells (erythrocytes), and platelets (platelets). Very high or low numbers may indicate the presence of many forms of illness, and therefore blood count is one of the most frequently performed blood tests in medicine, as they can provide an overview of the general health status of patients. CBCs are routinely performed during annual physical examinations in some jurisdictions.
Video Complete blood count
Medical use
A complete blood count is performed to monitor overall health, to screen out several diseases, to confirm the diagnosis of several medical conditions, to monitor medical conditions, and to monitor changes in the body caused by medical treatment.
For patients who need blood transfusions, the amount of blood can be used to obtain data that will help plan a number of treatments. In such cases, the person should have only one blood count for the day, and a red blood cell or platelet transfusion should be planned on that basis. Some blood withdrawals and amounts throughout the day are excessive use of phlebotomy and may cause additional unnecessary transfusions, and unnecessary extra care will be beyond medical guidelines.
Maps Complete blood count
Procedures
A phlebotomist collects a sample through venipuncture, drawing blood into a reaction tube containing an anticoagulant (EDTA, occasionally citrate) to stop it from freezing. The sample is then transported to the laboratory. Sometimes a sample is pulled from a finger prick using a Pasteur pipette to be processed immediately by an automatic counter.
In the past, counting the cells in the patient's blood was done manually, by looking at slides prepared with a patient's blood sample (blood film, or peripheral smear) under a microscope. However, the number of manual cells becomes less common, and instead this process is generally automated by using an automated analyzer. As little as 10-20% of the sample is now checked manually.
Automatic
A sophisticated modern analytical tool can provide an expanded number of differentials, including hematopoietic progenitor cells, mature granulocytes, and erythroblasts.
Blood samples were well mixed (though not shaken) and placed on the shelf in analysis. This instrument has a flow of cells, photometers and apertures that analyze various elements in the blood. The cell counting component counts the number and type of different cells in the blood. The results are printed or sent to the computer for review.
The blood counting machine absorbs small quantities of specimens through a narrow tube followed by a hole and a laser flow cell. Laser eye sensors count the number of cells passing through the aperture, and can identify them; this is the flow of cytometry. The two main sensors used are light detectors and electrical impedances. This instrument measures blood cell types by analyzing data about the size and aspect of light as they pass through cells (called front and side scatter). Other instruments measure the characteristics of different cells to categorize them.
Because the sample cell counters are automated and count a lot of cells, the results are very precise. However, certain abnormal cells in the blood may not be correctly identified, requiring manual review of the instrument result and the identification of abnormal cells that can not be categorized by the instrument.
In addition to counting, measuring and analyzing red blood cells, white blood cells and platelets, automatic hematologic analyzers also measure the amount of hemoglobin in the blood and inside each red blood cell. This is done by adding diluents that lyse cells that are then pumped into a spectrophotometric measuring cuvette. Lysat color change is equivalent to blood hemoglobin level. This information can be very helpful to physicians who, for example, try to identify the cause of anemic patients. If the red blood cells are smaller or larger than normal, or if there are many variations in the size of red blood cells, this data can help guide the direction of further testing and speed up the diagnostic process so that patients can get the care they need. soon.
Manual
Hemositometers (counting chambers that hold diluted blood volume and dividing it with lattice stripes) are used to calculate the number of red and white blood cells per liter of blood. (Dilution and grid lines are needed because there are too many cells without the tool.)
To identify the number of different white blood cells, a blood film is made, and a large number of white blood cells (at least 100) are calculated. This gives the percentage of cells of each type. By multiplying the percentage by the number of white blood cells, the absolute amount of each type of white blood cell can be obtained.
Manual counting is useful in cases where automated analysis can not reliably account for abnormal cells, such as cells that are absent in normal patients and seen only in peripheral blood with certain haematological conditions. Manual calculations are subject to sampling errors because very few cells are counted compared to automated analysis. The manual count will also provide information about other cells that are not usually present in peripheral blood, but may be released in the course of certain diseases.
Medical technologists check blood films through a microscope for some CBCs, not only to find abnormal white cells but also because variations in the form of red blood cells are an important diagnostic tool. Although automated analysis provides fast and reliable results regarding the number, size, size and size of red blood cells, they do not detect cell shape. Also, some normal patient platelets will clot in the EDTA anticoagulant blood, which causes automated analysis to give incorrect platelet counts. The person viewing the slide in the case will see a platelet clot and can estimate if there is a low, normal, or high platelet count.
The included test
A full blood count will usually include:
White cell
The number of white blood cells is reported, and the differential report of all types of white blood cells as a percentage and as an absolute amount per unit volume. High WBC may indicate infection.
Neutrophils: Can indicate bacterial infection. It can also be increased in acute viral infections. Because of the appearance of segmented nuclei, neutrophils are sometimes referred to as "segs". The underutilized neutrophil nucleus is not segmented, but has shapes such as stems or stems. Undercooked neutrophils - those who have recently been released from the bone marrow into the bloodstream - are known as "bands" or "stabbing". Stab is the German term for the stick.
Lymphocytes: Higher with some viral infections such as glandular fever. Raised in chronic lymphocytic leukemia (CLL). May be inherited by HIV infection. In adults, lymphocytes are the second most common type of WBC after neutrophils. In children under 8 years of age, lymphocytes are more common than neutrophils.
Monocytes: May be raised in bacterial infections, tuberculosis, malaria, Rocky Mountain spotted fever, monocytic leukemia, chronic ulcerative colitis, and regional enteritis.
Eosinophils: Increased parasitic infections, asthma, or allergic reactions.
Basophils: May increase in bone marrow related conditions such as leukemia or lymphoma.
The red cells
Total red blood cells: The number of red blood cells is given as an absolute amount per liter. Iron deficiency anemia appears as a low RBC count.
Hemoglobin
Hemoglobin: The amount of hemoglobin in the blood, expressed in grams per deciliter. Low hemoglobin levels are a sign of anemia.
Hematocrit
Haematocrit or packed cell volume (PCV): This is an intact blood volume fraction composed of red blood cells.
Index of red blood cells
MCV
Mean corpuscular volume (MCV): the average volume of red blood cells, measured in femtolites. Anemia is classified as either microcytic or macrocytic if the MCV values ​​are above or below the expected normal range; anemia is classified as normocytic if MCV is within the expected range. Other conditions that may affect MCV include thalassemia, reticulocytosis, alcoholism, chemotherapy, vitamin B12 deficiency, and/or folic acid deficiency.
MCH
Means corpuscular hemoglobin (MCH): the average number of hemoglobin per red blood cell, in the pictogram.
MCHC
Means the concentration of corpuscular hemoglobin (MCHC): the average concentration of hemoglobin in cells.
RDW
Red cell distribution width (RDW): This reflects the degree of variation in the size of red blood cells.
The determination of RDW in relation to the number of RBC and MCV is useful in the interpretation of some haematological disorders.
RDW is measured as the coefficient of variation in red blood cell size distribution (RDW-CV)
(CV = SD/Mean.100)
RDW is expressed as RDW-CV and RDW-CV. While most hematologic instruments report RDW-CV.
Platelets
The number of platelets is given, as well as information about the size and size range in the blood.
Means platelet volume (MPV): measurement of platelet average size.
Results
Example report formats for a complete blood count. Note that test names, measurement units, and reference ranges may vary between countries and laboratories. Patient outcomes should always be interpreted using units and reference ranges from laboratories that produce results.
Interpretation
The state of a particular disease is defined by an absolute increase or decrease in the number of specific cell types in the bloodstream. As an example:
Many diseases are expressed by changes in blood count: leukocytosis can be a sign of infection; thrombocytopenia may occur as a result of drug toxicity; pancytopenia is commonly referred to as a result of reduced production of bone marrow, and is a common complication of cancer chemotherapy
References
External links
- Blood Group and Red cell Antigen - Free online book at NCBI ID Bookshelf: NBK2261
Source of the article : Wikipedia
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