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MLAB 1415- Hematology Keri Brophy-Martinez Anemia Part One.

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Presentation on theme: "MLAB 1415- Hematology Keri Brophy-Martinez Anemia Part One."— Presentation transcript:

1 MLAB Hematology Keri Brophy-Martinez Anemia Part One

2 Anemia Anemia is the inability of the blood to supply the tissue with adequate oxygen for proper metabolic function. Clinically, anemia is defined as a decrease in the normal concentration of hemoglobin or erythrocytes. Anemia is not a disease, but an expression of an underlying disorder or disease.

3 Development of Anemia Anemia occurs if: Erythrocyte loss or destruction exceeds the maximum capacity of bone marrow erythrocyte production OR Bone marrow erythrocyte production is impaired or abnormal

4 Causes of anemia Acute blood loss (hemorrhage) Accelerated destruction of RBC’s (immune or non-immune) Nutritional deficiency (iron, folate or B12) Bone marrow replacement (e.g. cancer) Infection Toxicity Hematopoietic stem cell arrest or damage Hereditary or acquired defect

5 Anemia Classifications Functional Uses absolute and corrected retic count, RPI, and serum iron for classification Types  Survival Defects(Increased Destruction)  Proliferation Defects(Decreased production)  Maturation Defects

6 Anemia Classifications Morphologic Uses erythrocyte indices (MCV) for classification Types  Macrocytic, Normochromic  Causes: Folate or B12 deficiency, liver disease, alcoholism  Normocytic, Normochromic  Causes: bone marrow failure, hemolytic anemia, chronic renal failure, leukemia, metastatic malignancy  Microcytic,Hypochromic  Most common anemia  Causes: iron deficiency, sideroblastic anemia, thalassemia, chronic diseases

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8 Diagnosis of anemia Clinical history Physical signs such as pallor, fatigue, weakness and shortness of breath Laboratory tests CBC Examination of the blood smear Reticulocyte - measures effective erythropoiesis Bone marrow examination Iron studies - iron, total iron-binding capacity (TIBC), ferritin Vitamin B12 and folate Erythropoietin level

9 Laboratory Tests for Measurement of Anemia

10 Lab Tests Hemoglobin Reference values  Male: g/dl  Female: g/dl Moderate anemia: 7-10 g/dl Severe anemia: <7 g/dl Hematocrit Reference values Male: 42-52% Female: 36-46%

11 Parameters of the CBC (complete blood count) Red Blood Count or RBC Hemoglobin Hematocrit Note: the approximate relationship of the hemoglobin to the hematocrit is 1:3. This may vary with the cause of the anemia and the effect on the RBC indices, especially the MCV. RBC indices MCV - mean cell volume Normal: fL (femtoliters) Measured directly on automated cell counters Used to classify RBCs as normocytic, microcytic or macrocytic Indicates the average volume of the red cells Calculation: Hct x 10 RBC

12 RBC Indices con’t MCH - mean cell hemoglobin weight Normal: pg A measurement of the hemoglobin content in RBC’s Calculation: Hgb x 10 RBC MCHC - mean cell hemoglobin concentration Normal: % Used to classify RBCs as normochromic, or hypochromic A measure of the concentration of hemoglobin in the average RBC Calculation: Hgb x 100 Hct

13 Parameters of the CBC (complete blood count) RDW -Red Cell Distribution Width Calculated index used to identify anisocytosis Normal: % Calculation: Standard deviation of MCV x100 Mean MCV

14 Reticulocyte Adult reference range: % Useful in determining the response to the anemia and the potential of the bone marrow to manufacture RBC’s. Expressed as a percentage of the RBC’s. When anemia is present, it is helpful to correct the retic using the patient’s hematocrit in order to assess appropriate bone marrow response A supravital stain called New Methylene Blue is used to stain reticulocytes. On a Wright’s stained smear, reticulocytes appear as bluish red cells. The term used for retics on Wright’s stain is polychromasia. Corrected retic% = retic % X Patient hct Normal hct* based on age and sex [*Normal female hct = 42%] [*Normal male hct = 45%]

15 Reticulocyte Prematurely released retics remain in the blood and take from ½ to 1 ½ days longer to mature. This will cause even the “corrected” retic to be elevated, so a calculation must be performed to correct for this situation to obtain the reticulocyte production index (RPI). A maturation time table is used for this calculation. Indicator of the adequacy of the bone marrow response in anemia RPI>2: good bone marrow response RPI<2: inadequate response RPI = corrected retic maturation time in days

16 Adult Reference Ranges Red Blood CellsMale: x 10 6 /µl Female: x 10 6 /µl HemoglobinMale: g/dl Female: g/dl HematocritMale: 42-52% Female: 36-46% MCV fL MCH28-34 pg MCHC32-36 % Reticulocyte % RDW %

17 References Harmening, D. M. (2009). Clinical Hematology and Fundamentals of Hemostasis. Philadelphia: F.A Davis. McKenzie, S. B., & Williams, J. L. (2010). Clinical Laboratory Hematology. Upper Saddle River: Pearson Education, Inc.


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