Nada Mohamed Ahmed, MD, MT (ASCP)i Introduction to anemia.
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Transcript of Nada Mohamed Ahmed, MD, MT (ASCP)i Introduction to anemia.
Nada Mohamed Ahmed ,MD, MT (ASCP)i
Introduction to anemia
contents
Introduction to RBC’s RBC cell indices and Haemeglobin Anemia- Definitionclassification of AnemiaSigns and symptoms of AnemiaDiagnosis
Introduction To RBC
The mature erythrocytes are non-nucleated cells and lack usual cell organelles.
The normal RBC is biconcave in shape,7.2µm in diameter and has a thickness of 2.4µm at the periphery and 1µm in the center.
The biconcave shape helps the RBC to pass through the smallest capillaries
90% of the RBC’s weight is concentrated in the red pigment hemoglobin and the RBC’s have a lifespan of 120±30 days.
Functions of RBC
• The most important function of an RBC
1- is the transportation of oxygen to tissues.
2- Another important function of RBC’s is the transportation of CO2
from the tissues to the lungs.
Normal Values
• Range of normal RBC count is:5.5±1.0 in Men and 4.8±1.0 ×1012/L in women
• Hemoglobin content being 15.5±2.5(13-18)g/dl in Men and 14.0±2.5(11.5-16.5)g/dl and Women.
• The packed cell volume (PCV) or the haematocrit is the volume of the erythrocytes per litre of whole blood is 40-54% in Men and 37-47% in Women
• Based on these normal values red cell indices have been calculated ,which are of diagnostic importance.
Haemoglobin
• Haemoglobin is a basic protein,GLOBIN and of iron-porphyrin complex HEME with a molecular weight of 68,000 dalton and consists of 4 polypeptides.
RBC Destruction and Recycling
History of Anemia
• The word "anemia" is composed of two Greek roots that together mean "without blood,“
• The ancients readily recognized the importance of blood as a life- giving substance, believing it to hold the body's vital force
Definition of Anemia :
Low Hb level less than normal range Less than 13.5 g/dl Adult male Less than 11.5 g/dl adult female Less than 15 g/dl neonate
Other definitions RBCs count less than normal range according to age group
Decreased in hematocrit level (Packed cell volume pcv) less than normal rang
Red cell indices
• MCV (mean corpuscular volume) – The average volume of RBC NR= 80-96 fl
= Hct 10 (fl) RBC count (m/µL)
e.g. Hct= 40%RBC=5.0 (m /µL)
MCV= 40/5.0 10 = 80 fl
• MCH (mean corpuscular hemoglobin)
– The average content of Hb in average RBC. – It is directly proportional to the amount of Hb
and RBC size.
Hb
RBC count (m/µL) 10 (pg)MCH =
e.g. Hb = 14 g/dlRBC = 4.8 (m/µL)
MCH= 14/4 10 = 29 pg
NR= 27-32 pg
• MCHC (mean corpuscular hemoglobin concentration)
• NR= 32-36%
– Express the average concentration of hemoglobin per unit volume of RBC.
– It defined as the ratio of the weight of hemoglobin to volume of RBC.
Hb (g/dl)
Hct (%)
100 (%)MCHC=
e.g. Hb = 14 g/dlHct = 45 %
MCHC 14/45 100 = 31%
Classification of Anemia
I. Etiologic Classification 1. Impaired RBC production 2. Excessive destruction 3. Blood loss
II. Morphologic Classification 1. Macrocytic anemia 2. Microcytic hypochromic
anemia 3. Normochromic normocytic
anemia
Impaired RBC Production
1. Abnormal bone marrow (Aplastic anemia)
2. Essential factors deficiency
3.Anemia in renal disease : Erythropoietin
Excessive Destruction of RBC(cont.)
Hemolytic anemia 1. Intracorpuscular defect(defect inside
the cell)
1.1 Membrane : Hereditary spherocytosis
Hereditary ovalocytosis, etc.
1.2 Enzyme : G-6PD deficiency, PK def., 1.3 Hemoglobin : Thalassemia,sickle
cell anemia
Excessive Destruction of RBC
2. Extracorpuscular defect1. Mechanical trauma : 2. Infection : Clostridium tetani,
malaria parasites.3.Antibodies : HTR (Hemolytic
transfusion reaction) , SLE(Systemic lupus erythematosus)
Blood Loss
1. Acute blood loss : Accident, GIbleeding2. Chronic blood loss : Hypermenorrhea
Macrocytic Anemia MCV > 94 fl
Megaloblastic anemia
1 . Vit. B12 deficiency2. Folic acid deficiency : Nutritional
megaloblastic anemia.
Microcytic Hypochromic Anemia MCV < 80 fl
1. Iron deficiency anemia 2. Thalassemia 3. Sidroblastic anemia 4. Anemia due to lead
poisoning.
Normocytic Normochromic Anemia
MCV 82 – 92 fl • 1. Blood loss• 2. Increased plasma volume : Pregnancy, • 3. Hemolytic anemia : depend on each cause• 5. Infiltrate BM : Leukemia, Multiple myeloma, Myelofibrosis, etc.• 6. Abnormal endocrine : Hypothyroidism, Adrenal • insufficiency, etc.• 7. Kidney disease / Liver disease / Cirrhosis
Signs and Symptoms
Diagnosis Haemoglobin EstimationPeripheral blood smear
examinationRed cell indicesReticulocyte countErythrocyte sedimentation
rate ESRSpecial test for special
type of AnemiaBone marrow examination