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INVESTIGATION OF RED BLOOD CELL DISORDERS. INVESTIGATION OF RED BLOOD CELL DISORDERS. Modification in the number of erythrocytes (polycythemia, anemia) Normal number with abnormal components. INVESTIGATION OF RED BLOOD CELL DISORDERS. Screening Tests DETERMINATION OF HEMATOCRIT (PCV)
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INVESTIGATION OF RED BLOOD CELL DISORDERS • Modification in the number of erythrocytes (polycythemia, anemia) • Normal number with abnormal components
INVESTIGATION OF RED BLOOD CELL DISORDERS Screening Tests DETERMINATION OF HEMATOCRIT (PCV) ESTIMATION OF HEMOGLOBIN TOTAL RED CELL COUNT RED CELL INDEXES EXAMINATION OF PERIPHERAL BLOOD SMEAR
Determination of hematocrit Ht – ratio of the volume of packed red cells to the total volume -most precise investigation with the smallest error Principle: anticoagulated blood is drawn into a hematocrit tube and centrifuged Macro-method: venous blood in Wintrobe tubes Micro-method: using capillary tubes. Values: men=45%+/-5% women=41%+/-5% children =38%+/-5% new born=54%+/-5%
Determination of hematocrit • Normal PVC with decreased absolute red cell volume in hemoconcentration after hemorrhages • Decresead PCV in anemias, hyperhidratation • Increased PCV polyglobulia, hypovolemia
Estimation of hemoglobin The Hb content can be estimated by: - Visual colorimetry (Sahli method with acid hematin) Photoelectric colorimetry: Hemoglobincyanide Oxyhemoglobin method - Spectrophotometry Normal values: men =14-17g/100ml women =12-15g/100ml children =12-14g/100ml new born=25-16g/100ml
- Hb and Ht are screening tests with which the investigation are begun. Hb under 12 g/100 in women or 14g/100 in men and Ht under 36% in women or 39% in men indicate olygocitemia. Next step is counting erythrocyte.
Total red cell count -automated counting -visual counting Thoma sau Burker-Turk counting chamber Normal -men = 4.7mil/mm3 -women =4.2mil/mm3 -new born=5.5mil/mm3 -children = 4.7mil/mm3 Increase: false polycythemia (decrease of plasma volume, stress) true (new born, polycythemia vera, COBP) Decrease: false in hemodilution or real in anemias
Red cell indexes - Mean cell volume MCV= PCV/RBC (Normal 82-92 fl) • Mean red cell hemoglobin MCH= Hb/RBCx10 (25-33pg) • Mean cell hemoglobin concentration MCHC= Hb/PCVx100 (30-35 g/dL)
Red cell indexes Macrocytic anemias: MCV increased, MHC increased, MCHC normal or diminished. Mycrocytic hypochromic anemias: MCV diminished, MCH diminished,MCHC diminished.
Examination of peripheral blood smear • Increase variation in size and shape anisocytosis and poikilocytosis (micro- iron deficency, hemolitic anemias, sideroblastic anemic; macro chronic - liver disease,megaloblastic anemias, aplastic anemias) • Reduced or unequal hemoglobin content hypochromasia (iron defincency, thalassemias) or hyperchromasia (megaloblastic anemias) • Shape changes: spherocytosis, sickle cells, acantocytosis
Analitical tests RETICULOCYTE COUNT BONE MARROW SMEAR EXAMINATION ANALITICAL TESTS FOR HEMOLYTIC ANEMIAS ANALITICAL TESTS FOR HYPOCHROMIC ANALITICAL TESTS FOR MEGALOBLASTIC ANEMIAS
RETICULOCYTE COUNT Juvenile red cells Counting the reticulocytes from blood sample corresponding for 500 erythrocytes, the normal range should be 0.5-1% (20-80.000) failure to produce ret. Inappropriate count, hyperproduction – hemolyasis Bone marrow biopsy with M/E ratio modified in infections, leukemoid reactions, neoplasic proliferation, erythroid hyperplasia, ineffective erythropoiesis.
Analytical tests for hemolitic anemia Increased red cell destruction: Extravascular: Hyperbilirubinemia Decreased or absent Haptoglobin (Hp) Increased plasma hemoglobin Intravascular: Methemalbumin Urine: Extravascular: increased urobilinogen,hemosiderinuria Intravascular hemoglobinuria Increased red cell production:increased reticulocyte, erythroid hyperplasia and polichromatophilia.
Analytical tests for mycrocytic hypochromic anemias Serum iron Total iron binding capacity Serum ferritin Bone marrow examination
Analytical tests for macrocytic anemias Bone marrow examination Serum vitamin B12 Serum folate Vitamin B12 absorbtion