911e4ece-6a8a-466e-b5b5-42027aef60e2.doc, Page 1 of 9 List blood tests performed as part of a CBC. WBC WBC with differential RBC Hct Hgb Platelets RBC indices: mean corpuscular volume [MCV], mean corpuscular hemoglobin [MCV], mean corpuscular hemoglobin concentration [MCVC]. Recognize the influence of the patient’s hydration status on accurate CBS results. Overhydration overexpands the plasma compoenet of blood, diluting the % of formed blood cell elements. Dehydration causes hemoconcentration, resulting in a deceptively inflated number of formed elements in the blood. State normal adult values for CBC test results. RBC Newborns: 4.8 – 7.2 million Adult Male: 4.6 - 6.0 million Adult Female: 4.2 – 5.0 million Pregnancy: slightly lower than adult values Children: 3.8 – 5.5 million Reticulocyte Men 0.5% - 1.5% of the total number of RBCs Women 0.5% - 2.5% Hematocrit (% of RBCs in plasma) Newborns: up to 60% Adult Male: 40% – 54% Adult Female: 36% - 46% Pregnancy: decreased as plasma volume increases Children: varies with age Hemoglobin Adult Male: 13.5 – 17 g/dl Adult Female: 12 – 15 g/dl Pregnancy: 11- 12 g/dl Children: 11 – 16 g/dl Erythrocyte Indices MCV: (mean or average size of individual red blood cells) Men: 80 – 98 fl (femoliters) Women: 96 – 108 fl MCH: 17 – 31 pg (picograms) [the amount or mass of hemoglibn present in one RBC] 911e4ece-6a8a-466e-b5b5-42027aef60e2.doc, Page 2 of 9 MCHC: 32% – 36% (proportion of each cell taken up by hemoglobin) WBC Total WBC: 4,500 - 10,000 Bands or stabs: 3 - 5 % Granulocytes (or polymorphonuclears) Neutrophils (or segs): 50 - 70% relative value (2500-7000 absolute value) Eosinophils: 1 - 3% relative value (1 00-300 absolute value) Basophils: 0.4% - 1% relative value (40-100 absolute value) Agranulocytes (or mononuclears) Lymphocytes: 25 - 35% relative value (1 700-3500 absolute value) Moncytes: 4 - 6% relative value (200-600 absolute value) Lymphocytes Cells Percent Number of Cells /microL T Cells 60-95% 800-2,500/microL T-helper [CD4] Cells 60-75% 600-1,500/ microL T-Suppressor [CD8] Cells 25-30% 300-1,000/ microL B-Cells 4-25% 100-450/ microL NK Cells 4-30% 75-500/ microL CD4/CD8 Rauo >1 Platelets 150,000-350,000 Describe two physiologic reasons and two pathological reasons for an increase in red blood cells. Physiologic: 1. High altitudes; less atmospheric pressure pushing oxygen into lungs 2. After strenuous exercise; muscle mass demands more oxygen Pathologic: 1. Polycythemia vera is a disease of unknown origin that result in anbanormal in RBCs not caused by physiologic need. Treated by radioactive phosphorus to slow down bone marrow overproduction of RBCs. 2. Hemolysis – each result in stepped up production of RBCs in the bone marrow a. hemolytic anemias: RBCs are destroyed at a faster rate than normal b. erythroblastosis fetalis: immune-mediated destruction of RBCs 3. Hemorrhage [3-4 days later] Describe four reasons for a decrease in red blood cells. 1. Massive RBC loss, i.e. hemorrhage 2. Abnormal destruction of RBCs 3. Lack of substances need for RBC production (e.g. B12 or folate deficiency) 4. Chemotherapy or radiation 911e4ece-6a8a-466e-b5b5-42027aef60e2.doc, Page 3 of 9 Explain the clinical significance of a low reticulocyte count. Useful in classifying anemias. Also, the reticulocyte count is a test for determining bone marrow function and evaluating eruthropoietic activity; it gives an indication of RBC production by the bone marrow. A reticulocyte is an immature RBC. Low reticulocyte counts are seen with cirrhosis, folic acid deficiency, and bone marrow failure. A low or normal count in a patient with anemia indicates the marrow response to anemia is inadequate and perhaps is contributing to or is the cause of the anemia. A high count indicates that the bone marrow is responding to the need for RBC production, either for anemia or in response to ongoing loss of RBC, as in hemolysis or hemorrhage. Explain the purpose of the reticulocyte index. To get a true idea of the reticulocyte count – and the appropriateness of the RBC marrow response – by controlling for the possibility of a low RBC count in a patient with anemia. Reticulocyte values are a % of the total number of RBCs, so a low RBC count can make a normal or low number of reticulocytes look high. Identify panic values for hematocrit, hemoglobin, WBCs, and platelets. Hematocrit < 15% can result in cardiac failure > 60% may result in spontaneous blood clotting Hemoglobin <5 g/dL may cause heart failure >20 g/dL may cause clogging of capillaries due to hemoconcentration Recognize the purpose of hemoglobin in RBCs The oxygen-carrying capacity of the blood is determined by the Hgb concentration; Hgb serves as a vehicle for oxygen and carbon dioxide transport. The oxygen carrying ability of blood is directly proportional to its hemoglobin concentration. Describe the calculation relationship between hematocrit and hemoglobin. If a person’s RBC and hemoglobin are both normal, estimate the hematocrit as being approximately 3x the hemoglobin. If Hct = 30%, Hgb = 10g Identify the purpose of erythrocyte indices. When a patient has a lower than normal hemoglobin it important to determine whether RBCs are of normal size and if they have a normal concentration of hemoglobin. These indices provide information about the size [MCV and RDW], weight [MCH], and hemoglobin concentration [MCHC] of RBCs. 911e4ece-6a8a-466e-b5b5-42027aef60e2.doc, Page 4 of 9 Describe classifications of anemia based on the results or erythrocyte indices. 1. Normocytic, normochromic anemia: most often caused by acute blood loss. Normal MCV, MCH and MCHC 2. Microcytic, hypochromic anemia: most often caused by iron deficiency, thalassemia, lead poisoning. MCV, MCH, and MCHC. 3. Macrocytic anemia: most often caused by vitamin B12 and folic acid deficiency. MCV, MCH, and MCHC List five types of white blood cells and state the function of each type of cell. 1. Basophils Least common type of granulocyte Non-phagocytic Contain proteins and chemials such as heparin, histamine, bradykinin Tend to appear during inflammatory responses, particlalty allergic reactions Imortant source of Interleukin-4, which is critical in the development of allergies and the production of IgE antibodies Basoophil counts are used to analyze allergic reaction. 2. Eosinophils Responsible for combating infection by parasites in the body Found in large numbers in the respiratory and GI tract Play a role in the allergic response Allergic reactions (hay fever, asthma) increase eosinophil count Corticosteroid drug decrease eosinophil count 3. Neutrophils Most plentiful of granuloctyes Phagocytic cells They are the body’s primary defense against bacterial infection and physiologic stress. 4. Lymphocytes Primary component of the body’s immune system Protect the body from microorganisms, foreign tissue and cell alterations and also monitor the body for cancerous cells. Primary function is to fight chronic bacterial infection and acute viral infections. Are the source of serum immunoglobulins and cellular immune response. 5. Monocytes Largest leukocyte/blood cell Monocytes are immature WBCs; released by bone marrow and circulate for 1-2 days in the blood Once in tissue they mature into macrophages Act as scavengers, secrete a variety of powerful chemicals and activate T-cells Body’s second line of defense; identify and present foreign antigens to lymphocytes State the implications of a “shift to the left” on a white blood cell differential. A shift to the left indicates an increase in the amount of bands or stabs (immature WBCs) in the blood, indicating an infection in progress. Identify common patterns of white blood cell increase or decrease in disease processes. 911e4ece-6a8a-466e-b5b5-42027aef60e2.doc, Page 5 of 9 Leukopenia (WBC < 4,000) Common causes include: viral infections; overwhelming bacterial infections; and bone marrow disorders. Leukocytosis (WBC > 10,000) Common causes include: acute infections trauma imflammation leukemia and other bone marrow disorders Recognize the function of platelets in normal coagulation. Platelets form the initial plug in a broken blood vessel, which stems the loss of blood until clotting factors and fibrinogen can form a clot. A dearth of platelets can result in prolonged and potentially life-threatening bleeding. Formulate nursing diagnoses and describe interventions for a patient with an elevated RBC count, a hematocrit, a neutrophil count, and a platelet count. STUDY POINTS - RBCs What is the clinical significance of high reticulocyte count? This indicates that the bone marrow is responding to the need for RBC production. What should the reticulocyte index be for a patient with a positive bone marrow response to anemia? 1. What clinical situations would you expect a decreased reticulocyte count? Cirrhosis, folic acid deficiency, and bone marrow failure. What does a normal or low reticulocyte count indicate in a patient with anemia? A low reticulocyte count could be either an indication of anemia – that the bone marrow response is inadequate – or the cause of it. STUDY POINTS – HEMATOCRIT What does the term hematocrit mean? It’s a measure of the percentage of RBCs in blood. State the normal value for the adult. Males: 40%-54%, Females: 36%-46% What can affect the hematorcit value? Fluid status, abnormalities in RBC size, extreme elevation in WBC count, some drugs, pregnancy, high altitudes, hemorrhage (3-4 days later). 911e4ece-6a8a-466e-b5b5-42027aef60e2.doc, Page 6 of 9 What is the clinical significance of low hematocrit? Anemia Hemoglobinopathy – hemoglobin disorders Cirrhosis – chronic fluid overload hemodilution Hct Hemolytic anemia – premature RBC destruction Hemorrhage – plasma levels return to normal faster than RBCs are produced Dietary deficiency – iron deficiency most often Bone marrow failure Prosthetic valves – cause mechanical trauma to RBCs RBC lifespan Renal disease – erythropoietin is made in the kidney and is a strong stimulant of RBC production Arthritis and chronic diseases – associated with Hct What is the clinical significance of high hematocrit? Erythrocytosis - RBCs due to illness or external factors CHD – chronically low PO2 RBC production Polycythemia vera – bone marrow dysfunction; inappropriate production of RBCs Server dehydration; burn injury – in proportion to plasma, Hct appears high Severe COPD – same as CHD If the RBC and hemoglobin are both normal, is it possible to determine the hematocrit? Yes. All things being normal, the Hct is generally 3x the Hgb. If Hgb = 10g, what would the Hct be? 30%. STUDY POINTS – HEMOGLOBIN What is the significance of Hgb? Hgb is the oxygen and CO2 transport component of RBCs. State the normal Hgb value for the adult. Adult male: 13.5–17 g/dL; Adult female: 12–15 g/dL What can affect the Hgb value? Diurnal variations Pregnancy – hemodilution = Hgb Smoking – RBC production High altitudes - RBC production Drugs that Hgb: gentamicin, methyldopa Drugs that Hgb: antibiotics, chemotherapy, aspirin, indomethacin rafampin, sulfonamides What is the clinical significance of low Hgb? Blood loss and bone marrow suppression Abnormal hemoglobin or hemoglobinopathies (RBCs with these are usually fragile) o Thalassemia 911e4ece-6a8a-466e-b5b5-42027aef60e2.doc, Page 7 of 9 o Sickle cell anemia What is the clinical significance of high Hgb? Erythrocytosis - RBCs due to illness or external factors CHD – chronically low PO2 RBC production Polycythemia vera – bone marrow dysfunction; inappropriate production of RBCs Server dehydration; burn injury – in proportion to plasma, Hct appears high Severe COPD – same as CHD If the RBC and Hgb are both normal, is it possible to determine the Hgb? Yes. The Hgb value will generally be 1/3 of the Hct value. If a person’s Hct = 30%, what would the Hgb be? 10g. STUDY POINTS – ELECTROLYTE INDICES What is the clinical significance of the erythrocyte indices? These indices proved information about the size, weight and Hgb concentration of RBCs. Diagnostic test used in the treatment of anemia. When would the erythrocyte indices be ordered? When a patient has a lower than normal Hgb. What does the MCV, MCH and MCHC measure? MCV [Mean Corpuscular Volume] measures the RBC size. MCH [Mean Corpuscular Hgb] measures the amount (mass) of Hgb in one RBC. MCHC [Mean Corpuscular Hgb Concentration] measure the % of each RBC taken up by Hgb. What are the normal ranges for RBC indices? MCV - Men: 80-98 fl; Women: 96-108 fl MCH – 7-31 pg MCHC – 32-36% What changes in RBC indices would you most likely see in acute blood loss? All normal. What changes in RBC indices would you most likely see in iron deficiency anemia, Thalassemia, and lead poisoning? MCV, MCHC, MCH What changes in RBC indices would you most likely see in pernicious (B12) anemia and folic acid deficiency? MCV, variable MCHC and MCH Define the following terms: 911e4ece-6a8a-466e-b5b5-42027aef60e2.doc, Page 8 of 9 normocytic – RBC is normal size microcytic - RBC is undersized macrocytic - RBC is oversized normochromic - RBC is normal color hypochronic - RBC is pale ( Hgb conent) STUDY POINTS – WBC: NEUTROPHILS What is the normal WBC count? Total WBC: 4,500 - 10,000 What is the purpose and function of the neutrophils? They are the body’s primary defense against bacterial infection and physiologic stress; first phagocytic cell to arrive on the scene. What is the normal range for neutrophils? 50%-70% relative value (2,500-7,000 absolute value) Identify and describe five  characteristics of neutrophils? 1. Most plentiful granulocyte 2. Phagocytic cells 3. They are the body’s primary defense against foreign invaders 4. After release from the bone marrow they circulate for 8 hours before settling into tissue, where they live for about one week; the most short-lived in circulation of all leukocytes. 5. Also play a key role in inflammation What are "bands"? Immature WBCs. What are “segmented" neutrophils? Mature WBCs and one of the three types of granulocytes. What is the clinical significance of increased neutrophil count? infection in progress inflammatory processes physical stress severe burn or a MI leukemia What is the clinical significance of decreased neutrophil count? Viral infections (influenza, mumps) and some bacterial infections (typhoid) Overwhelming infection Chemotherapy Some antibiotics, lithium, tricyclic antidepressants 911e4ece-6a8a-466e-b5b5-42027aef60e2.doc, Page 9 of 9 STUDY POINTS – WBC: EOSINOPHILS What is the purpose and function of the eosinophils? Eosinophils are responsible for combating infection by parasite in the body; found in large numbers in respiratory and GI tract. What is the normal range for eosinophils? 1%-3% relative value (100-300 absolute value) Identify and describe five  characteristics of eosinophils? 1. A type of granulocyte accounting for 1-4% of total leukocyte count 2. Phagocyte cells, but less effective than neutrophils 3. Eosinophils contain histamine and other chemicals toxic to parasites and host tissue 4. Play a role in the allergic response 5. Are considered the main effector in asthma pathogenesis What is the clinical significance of increased eosinophil count? Parasitic infections Allergic reactions, i.e. hay fever, asthma, drug hypersensitivity What is the clinical significance of decreased eosinophil count? Patient receiving corticosteroids STUDY POINTS – WBC: BASOPHILS What is the purpose and function of the basophils? What is the normal range for basophils? Identify and describe five  characteristics of basophils? What is the clinical significance of increased basophil count? What is the clinical significance of decreased basophil count? STUDY POINTS – WBC: LYMPHOCYTES What is the purpose and function of the lymphocytes? What is the normal range for lymphocytes? Identify and describe five  characteristics of lymphocytes? Identify and describe the three  types of lymphocytes? What is the purpose and function of B-Cells? What is the purpose and function of T-Cells? What is the purpose and function of NK-Cells? Compare and contrast CD-4 Count; CD-4% and CD4:CD8 Ratio.
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