The ABC Of CBC Interpretation Of Complete Blood...
A complete blood count (CBC) is a blood test. It helps healthcare providers detect a range of disorders and conditions. It also checks your blood for signs of medication side effects. Providers use this test to screen for diseases and adjust treatments.
The ABC of CBC Interpretation of Complete Blood...
Healthcare providers use complete blood counts to manage disease and help you stay healthy. With one sample of blood, CBCs can help screen for hundreds of disorders, conditions and infections. A CBC can detect conditions early, sometimes before you have symptoms, so treatment can start as soon as possible. CBCs are an essential tool in maintaining good overall health.
A complete blood count (CBC) is a test that counts the cells that make up your blood: red blood cells, white blood cells, and platelets. Your doctor may order a CBC as part of a routine checkup or to:
The complete blood count (CBC) is test, used to diagnose and monitor numerous diseases. It can reflect problems with fluid volume (such as dehydration) or loss of blood. It can show abnormalities in the production, life span, and destruction of blood cells. It can reflect acute or chronic infection, allergies, and problems with clotting. The CBC test identifies and counts the 7 types of cells found in the blood, red blood cell, neutrophil, eosinophil, basophil, lymphocyte, monocyte, and platelet.
All recently resettled refugees, regardless of age and ethnicity, should have a complete blood count (CBC) with red blood cell indices, white blood cell differential, and platelet count. These general, nonspecific tests may indicate common underlying conditions, including iron deficiency and inherited anemias. Additionally, these tests may reveal rarer conditions that if not treated or managed, may result in serious morbidity or mortality. Based on the results of these tests, additional, more focused laboratory testing may be warranted.
Common causes of anemia in refugee populations include primary iron deficiency, blood loss (e.g., menorrhagia, intestinal parasitosis, peri- and post-partum hemorrhage), inherited hematologic abnormalities (e.g., sickle cell disease, thalassemias, enzyme defects), and infectious diseases that cause pathology, such as bone marrow suppression, sequestration or hemolysis (e.g., malaria, visceral leishmaniasis). In many cases, the cause of anemia is multifactorial, and clinicians should consider multiple conditions if anemia is detected . The complete evaluation of anemia in refugees is beyond the scope of this document; common hematologic conditions encountered in refugees are discussed below.
Iron deficiency likely increases intestinal absorption of lead . Given the high prevalence of iron deficiency in refugee children and pregnant and breastfeeding persons, as well as the potential for lead exposure/development of elevated lead levels after US arrival, clinical management of iron deficiency should include testing for lead (see Screening for Lead during the Domestic Medical Examination for Newly Arrived Refugees for complete recommendations).
Improvement in technology and inclusion of new parameters in automated hematology analyzers allows for better and faster detection of anemias. These parameters along with histograms provide details and clues that help to diagnose the etiology of anemia and help bridge the time lag in detection and treatment. Timely and expert interpretation of complete blood counts should not be limited to the pathologist but should also interest the clinician to allow for efficient patient care.
The complete blood count, or CBC, is a lab test that provides information about these circulating cells. First, a sample of your blood is collected and sent to the lab. A lab instrument then automatically counts the number of each type of circulating cell. If results from the automated instrument are outside specified limits, a medical technologist will examine the cells closely so complete information about the cells can be provided.
A complete blood count (CBC), also known as a full blood count (FBC), is a set of medical laboratory tests that provide information about the cells in a person's blood. The CBC indicates the counts of white blood cells, red blood cells and platelets, the concentration of hemoglobin, and the hematocrit (the volume percentage of red blood cells). The red blood cell indices, which indicate the average size and hemoglobin content of red blood cells, are also reported, and a white blood cell differential, which counts the different types of white blood cells, may be included.
The CBC is often carried out as part of a medical assessment and can be used to monitor health or diagnose diseases. The results are interpreted by comparing them to reference ranges, which vary with sex and age. Conditions like anemia and thrombocytopenia are defined by abnormal complete blood count results. The red blood cell indices can provide information about the cause of a person's anemia such as iron deficiency and vitamin B12 deficiency, and the results of the white blood cell differential can help to diagnose viral, bacterial and parasitic infections and blood disorders like leukemia. Not all results falling outside of the reference range require medical intervention.
Blood is composed of a fluid portion, called plasma, and a cellular portion that contains red blood cells, white blood cells and platelets.[note 1] The complete blood count evaluates the three cellular components of blood. Some medical conditions, such as anemia or thrombocytopenia, are defined by marked increases or decreases in blood cell counts. Changes in many organ systems may affect the blood, so CBC results are useful for investigating a wide range of conditions. Because of the amount of information it provides, the complete blood count is one of the most commonly performed medical laboratory tests.
The complete blood count has specific applications in many medical specialties. It is often performed before a person undergoes surgery to detect anemia, ensure that platelet levels are sufficient, and screen for infection, as well as after surgery, so that blood loss can be monitored. In emergency medicine, the CBC is used to investigate numerous symptoms, such as fever, abdominal pain, and shortness of breath, and to assess bleeding and trauma. Blood counts are closely monitored in people undergoing chemotherapy or radiation therapy for cancer, because these treatments suppress the production of blood cells in the bone marrow and can produce severely low levels of white blood cells, platelets and hemoglobin. Regular CBCs are necessary for people taking some psychiatric drugs, such as clozapine and carbamazepine, which in rare cases can cause a life-threatening drop in the number of white blood cells (agranulocytosis). Because anemia during pregnancy can result in poorer outcomes for the mother and her baby, the complete blood count is a routine part of prenatal care; and in newborn babies, a CBC may be needed to investigate jaundice or to count the number of immature cells in the white blood cell differential, which can be an indicator of sepsis.
The reference ranges for the complete blood count represent the range of results found in 95% of apparently healthy people.[note 2] By definition, 5% of results will always fall outside this range, so some abnormal results may reflect natural variation rather than signifying a medical issue. This is particularly likely if such results are only slightly outside the reference range, if they are consistent with previous results, or if there are no other related abnormalities shown by the CBC. When the test is performed on a relatively healthy population, the number of clinically insignificant abnormalities may exceed the number of results that represent disease. For this reason, professional organizations in the United States, United Kingdom and Canada recommend against pre-operative CBC testing for low-risk surgeries in individuals without relevant medical conditions. Repeated blood draws for hematology testing in hospitalized patients can contribute to hospital-acquired anemia and may result in unnecessary transfusions.
Most analyzers take less than a minute to run all the tests in the complete blood count. Because analyzers sample and count many individual cells, the results are very precise. However, some abnormal cells may not be identified correctly, requiring manual review of the instrument's results and identification by other means of abnormal cells the instrument could not categorize.
Point-of-care testing refers to tests conducted outside of the laboratory setting, such as at a person's bedside or in a clinic. This method of testing is faster and uses less blood than conventional methods, and does not require specially trained personnel, so it is useful in emergency situations and in areas with limited access to resources. Commonly used devices for point-of-care hematology testing include the HemoCue, a portable analyzer that uses spectrophotometry to measure the hemoglobin concentration of the sample, and the i-STAT, which derives a hemoglobin reading by estimating the concentration of red blood cells from the conductivity of the blood. Hemoglobin and hematocrit can be measured on point-of-care devices designed for blood gas testing, but these measurements sometimes correlate poorly with those obtained through standard methods. There are simplified versions of hematology analyzers designed for use in clinics that can provide a complete blood count and differential.
Reticulocytes are immature red blood cells, which, unlike the mature cells, contain RNA. A reticulocyte count is sometimes performed as part of a complete blood count, usually to investigate the cause of a person's anemia or evaluate their response to treatment. Anemia with a high reticulocyte count can indicate that the bone marrow is producing red blood cells at a higher rate to compensate for blood loss or hemolysis, while anemia with a low reticulocyte count may suggest that the person has a condition that reduces the body's ability to produce red blood cells. When people with nutritional anemia are given nutrient supplementation, an increase in the reticulocyte count indicates that their body is responding to the treatment by producing more red blood cells. Hematology analyzers perform reticulocyte counts by staining red blood cells with a dye that binds to RNA and measuring the number of reticulocytes through light scattering or fluorescence analysis. The test can be performed manually by staining the blood with new methylene blue and counting the percentage of red blood cells containing RNA under the microscope. The reticulocyte count is expressed as an absolute number or as a percentage of red blood cells. 041b061a72