Lecture 7Erythrocyte Indices Important in assessing border-line of anemia Should be interpreted only in the light of otherfindings i.e. appearance or RBCs on fixed smears Computed using: RBC count, Hemoglobin (Hgb), and haematocrit (Hct) 5. (MCHC) Color Index (CI) Volume Index (VI) Saturation Index (SI) Mean corpuscular Diameter (MCD) Mean Corpuscular Thickness (MCAT) .Types of RBC Indices 1. Mean Corpuscular Volume (MCV) 2. 6. 7. Mean Corpuscular Hemoglobin (MCH) 3. Mean Corpuscular Hemoglobin Concentration 4. 8. 1.X10 = cubic micra or femtoliter RBC in million = NV = 82 -92 cubic micra (u3) Interpretation: 95 – 160 u3 = macrocytic anemia 72 – 79 u3 = microcytic anemia 50 – 71 u3 = microcytic. MCV (Mean corpuscular volume) – average volume of individual blood cell Volume % Hct = ---------------------. hypochromic . RBC count = 5.000 / mm3 46 MCV = --------.Example: Given: Hct = 46 vol%.000.X 10 = 92 mm3 5 NV = 82 -92 cubic micra (u3) Normocytic . X 10 = micromicrogram (uug) or*picogram RBC in Million *pictogram = millionth part of microgram or gram x 10 -12 Normal Value: 27 – 33 uug or pg Interpretation: >33 uug = macrocyte <27 uug = microcyte <22 uug = microcytic hypochromic . MCH (Mean Corpuscular Hemoglobin) =ratio of hgb to red cell count =average weight or amount of Hgb in an individual RBC Gm Hgb = ------------.2. 2. MCH (Mean Corpuscular Hemoglobin) Example: Given: Hgb = 16 gm/100 ml.X 10 RBC in Million 16 MCH = --------. RBC count = 5.500.5 Normochromic Normal Value: 27 – 33 uug or pg .000/mm3 Gm Hgb MCH = ------------.x 10 = 29 uug 5. X 100 = 34.7% 46 .X 100 = % Vol % Hct Normal Value = 32 – 38% Example: Given: Hgb = 16gm/100 ml. Mean Corpuscular hemoglobin Concentration (MCHC) =mean concentration of Hgb in the average RBC Gm Hgb MCHC = ------------.3. Hct = 46 vol% 16 MCHC = ------. Whereas. . MCHC indicates concentration of Hgb in the average red cell reported in %.** MCH measures the weight of Hgb in the average red cell and is reported in uug or pictogram. MCHC are called red cell indices.Use of Erythrocyte Indices: The MCV. MCH. gives accurate picture of RBC morphology in fixed smears . Hgb = 13.5 MCHC = -----. the hgb concentration is normal (normochromic) .5 13.5 MCH = ----.X 100 = 33.Example1: Given: RBC = 4.8% 40 Normal Value: MCV= 82 -92 cubic micra (u3) MCH= 27 – 33 uug or pg MCHC = 32 – 38% Therefore.5 gm/100ml.X 10 = 89 cubic micra 4.5 mil/mm3.X 10 = 30 uug 4. Hct = 40 vol% 40 MCV = ------.5 13. the RBCs are normal in size (normocytic). 8 % Normal Value: MCV= 82 -92 cubic micra (u3) MCH= 27 – 33 uug or pg MCHC = 32 – 38% .5 uug. MCHC = 28. MCH = 25. hemoglobin weight and hemoglobin concentration. Given: MCV = 89 cubic micra.Example 2: Describe the cell size. Low MCHC shows to be hypochromic. RBCs are normal in size or Normocytic.Describe the cell size. hemoglobin weight and hemoglobin concentration.8 % Therefore. . MCH = 25. but contain less hgb than normal. MCHC = 28. Given: MCV = 89 cubic micra.5 uug. 2 uug. MCHC = 31.2% Normal Value: MCV= 82 -92 cubic micra (u3) MCH= 27 – 33 uug or pg MCHC = 32 – 38% Describe the cell size.Example 3: Given: MCV = 71 cubic micra. MCH = 22. . hemoglobin weight and hemoglobin concentration. I.) = average amount of haemoglobin in each erythrocyte as compared with the average amount in a normal erythrocyte % hemoglobin CI = ------------------------------% RBC . COLOR INDEX (C.Other Blood Indices: 1. 6 gm/100 ml So: % hemoglobin CI = ------------------------% RBC Given Hgb (9.= 0.90 to 1. Hgb = 9.000. 200.Example: RBC = 3.000/mm3. (5.6) % Hgb = ---------------------------.000) Therefore: 60 Color Index = ----------.200.000) % RBC = --------------------------------Standard RBC ct.94 64 Normal Value: 0.10 X 100 = 64% .X 100 = 60% Standard Hgb (16) Given RBC Ct (3. COLOR INDEX (C.I.) Note: Increased in pernicious anemia due to macrocytes and megalocytes Decreased in secondary anemia and chlorosis . 2. = ------------------------------Percent RBC (%RBC) .I. VOLUME INDEX (V.I.) = average size of RBC as compared with the average size of a normal RBC Percent Hct (% Hct) V. 000) %RBC = ------------------------------------.000) Therefore: 68 Volume Index = ------. (3.000.X 100 = 68% Standard Hct (47) Given RBC c t.X 100 = 60% Standard RBC (5.000/mm3.10 .000.13 60 Normal Value: 0. = ------------------------------Percent RBC (%RBC) Given Hct (32) % Hct = --------------------------.= 1. Hct = 32 vol% So: Percent Hct (% Hct) V.I.000.90 – 1.Example: RBC count= 3. usually lower than adult .I. VOLUME INDEX (V.) Note: Increased in infants during the first few weeks of life.2. Decreased in older children. = --------------------.I.3.) = average amount of haemoglobin per unit volume of cell in relation to the normal Color index %Hgb S.I.or ------------Volume Index % Hct . SATURATION INDEX (S. 500.94 70 .Example: RBC ct.= 0.I. = 3.07 70 66 Volume Index = -----.000/ mm3 (3. = --------------------Volume Index %Hgb or ------------% Hct 75 Color Index = ------.= 1.5/5) = 70% Hgb = 12gm/100ml (12/16)= 75% Hct = 31vol% (31/47) = 66% Color index S. 94 Or: 75 Saturation Index = ------.20 . SATURATION INDEX (S.07 Saturation Index = --------.= 1.3.) Therefore: 1.80 to 1.14 0.I.14 66 Normal value: 0.= 1. MEAN CORPUSCULAR DIAMETER (MCD) = mean or average diameter of the rbc in terms of micron 5.4. MEAN CORPUSCULAR AVERAGE THICKNESS (MCAT) = mean or average thickness of rbc MCV MCAT in micron = -----------(MCD)2 _________ 2 **The thickness is obtained by dividing the MCAT by the normal MCAT . Thank You .