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Abstract Interpretation of different parameters reported on modern day analyzers is bit tricky and demand continuous monitoring and on-going learning. In present paper interpretation of different reported parameters has been discussed with approach to diagnosis of various abnormalities.
The CBC interpretation are useful in the diagnosis of various types of anemias. It can reflect acute or chronic infection, allergies, and problems with clotting. objectives
CBC- complete blood count • Component of the CBC: • • Red Blood Cells (RBCs)• Hematocrit (Hct)• Hemoglobin (Hgb)• Mean Corpuscular Volume (MCV)• Mean Corpuscular Hemoglobin Concentration (MCHC) • - Red cell distribution width (RDW) • • White Blood Cells (WBCs)• Platelet
RBC • RBC (varies with altitude): • M: 4.7 to 6.1 x10^12 /L • F: 4.2 to 5.4 x10^12 /L • Biconcave disc shape with diameter • of about 8 µm • Function: - transport hemoglobin which carries oxygen from the lung to the tissues • -acid –base buffer. • Life span 100-120 days.
Hemoglobin & Hematocrit • Hemoglobin : • M: 13.8 to 17.2 gm/dL • F: 12.1 to 15.1 gm/dL • Hematocrit : (packed cell volume) • It is ratio of the volume of red cell to the volume of whole blood. • M: 40.7 to 50.3 % • F: 36.1 to 44.3 %
MCV&MCHC • MCV = mean corpuscular volume HCT/RBC count= 80-100fL • small = microcytic • normal = normocytic • large = macrocytic • MCHC= mean corpuscular hemoglobin concentration HB/RBC count= 26-34% • decreased = hypochromic • normal = normochromic
MCH & RDW • MCH (mean corpuscular hemoglobin) • HB/HCT = 27-32 pg • RDW (red cell distribution width) • It is correlates with the degree of anisocytosis • _ Normal range from 10-15%
The Reticulocyte Count • This important value is needed in the evaluation of any anemia. • Normal range 1-2% • Retic count goes up with • Hemolytic anemia • Retic goes down with • Nutritional deficiencies • _ Diseases of the bone marrow itself
Definition of Anaemia Decrease in the number of circulating red blood cell mass and there by O2 carrying capacity Most common hematological disorder by far Almost always a secondary disorder As such, critical for all practitioners to know how to evaluate / determine its cause / treat
First Question The onset of Anaemia Acute versus chronic Clues Hemodynamic stability Previous CBC Overt blood loss
Screening Tests – Anaemia Clinical Signs and symptoms of Anaemia Look for bleeding – all possible sites Look for the causes for anemia Routine Hemoglobin examination Cut off marks for Hb – US < 13.5 g WHO < 12.5 g Subcontinent Less than 12 g%
Clinical Signs to be looked for Skin / mucosal pallor, Skin dryness, palmar creases Bald tongue, Glossitis Mouth ulcers, Rectal exam Jaundice, Purpura Lymphadenopathy Hepato-splenomegaly Breathlessness Tachycardia, CHF Bleeding, Occult Blood
PCV or Hematocrit 57% Plasma 1% Buffy coat – WBC 42% Hct (PCV)
The Three Basic Measures Measurement Normal Range RBC count 5 million 4 to 6 Hemoglobin 15 g% 12 to 17 Hematocrit 45 38 to 50 A x 3 = B x 3 = C - This is the rule of thumb Check whether this holds good in given results If not -indicates micro or macrocytosis or hypochromia.
Causes of Anaemia Decreased production of Red Cells - Hypoproliferative, marrow failure Increased destruction of Red Cells - Hemolysis (decreased survival of RBC) Loss of Red Cells due to bleeding - Acute / chronic blood loss (hemorrhagic)
Anaemia – First Test RETICULOCYTE COUNT % • ‘RBC to be’ or Apprentice RBC • Fragments of nuclear material • RNA strands which stain blue Normal Less than 2%
Reticulocytes Supravital Leishman’s
Anaemia Hb% < 12, Hct < 38% Hemolytic Hypoproliferative Retics < 2 Retics > 2
Workup – Second Test The next step is ‘What is the size of RBC’ ? MCV indicates the Red cell volume (size) Both the MCH & MCHC tell Hb content of RBC If the Retic count is 2 or less We are dealing with either Hypoproliferative anaemia (lack of raw material) Maturation defect with less production Bone marrow suppression (primary/ secondary)
Mean Cell Volume (MCV) RBC volume (rather) is measured by The Mean Cell Volume or MCV and RDW MCV Microcytic Normocytic Macrocytic < 80 fl 80 -100 fl > 100 fl < 6.5 µ 6.5 - 9 µ > 9 µ
Anaemia Workup - MCV MCV Microcytic Normocytic Macrocytic Iron Deficiency IDA Chronic Infections Thalassemias Hemoglobinopathies Sideroblastic Anemia Chronic disease Early IDA Hemoglobinopathies Primary marrow disorders Combined deficiencies Increased destruction Megaloblastic anemias Liver disease/alcohol Hemoglobinopathies Metabolic disorders Marrow disorders Increased destruction
Red cell Distribution Width - RDW RDW Normal High Population Uniform Population Double
Anaemia Workup - 4th TestPeripheral Smear Study Are all RBC of the same size ? Are all RBC of the same normal discoid shape ? How is the colour (Hb content) saturation ? Are all the RBC of same colour/ multi coloured ? Are there any RBC inclusions ? Are intra RBC there any hemo-parasites ? Are leucocytes normal in number and D.C ? Is platelet distribution adequate ?
IDA Summary Microcytic MCV < 80 fl, RBC < 6 µ RDW Widened with low MCV Hypochromic MCH < 27 pg, MCHC < 30% RI < 2 Serum ferritin Very low < 30 (p mols/L) TIBC Increased > 400 (µg/dL) Serum Iron Very low < 30 (µg/dL) BM Fe Stain Absent Fe Response to Fe Rx. Excellent
IDA- Some Nuggets Look for occult blood loss – 2 days non veg. free Pica and Pagophagia – Ice sucking Absorption of Haem Iron > Fe ++ > Fe+++ Food, Phytates, Ca, Phosphate, antacids ↓absorption Ascorbic acid ↑absorption Oral iron Rx. always is the best, ? Carbonyl Fe FeSO4 is the best. Reserve parenteral Rx. Packed cell transfusion in emergency Continue Fe Rx at least 2 months after normal Hb 1 gram ↑in Hb every week can be expected Always supplement protein for the Globin component
Macrocytic Anaemias A. Megaloblastic Macrocytic – B12 and Folate↓ B. Non Megaloblastic Macrocytic Anaemias Liver disease/alcohol Hemoglobinopathies Metabolic disorders, Hypothyroidism Myelodystrophy, BM infiltration Accelerated Erythropoesis -↑destruction Drugs (cytotoxics, immunosuppressants, AZT, anticonvulsants)
Anemia - Macrocytic (MCV > 100) Premature gray hair – consider MBA Macrocytic anemias may be asymptomatic until the Hb is as low as 6 grams MCV 100-110 fl must look for other causes of macrocytosis MCV > 110 fl almost always folate or B12 deficiency
Basophilic Stippling - MBA BS occurs in Lead poisoning also
Pernicious Anaemia - Tongue Bald, smooth, lemon yellowish red tongue
Normocytic Anaemias Chronic disease Early IDA Hemoglobinopathies Primary marrow disorders Combined deficiencies Increased destruction Anaemia of investigations -ICU
Anaemia of Chronic Disease Thyroid diseases Malignancy Collagen Vascular Disease Rheumatoid Arthritis SLE Polymyositis Polyarteritis Nodosa • IBD • – Ulcerative Colitis • – Crohn’s Disease • Chronic Infections • – HIV, Osteomyelitis • – Tuberculosis • Renal Failure
‘Dimorphic’ Anaemia Folate & Fe deficiency (pregnancy, alcoholism) B12 & Fe deficiency (PA with atrophic gastritis) Thalassemia minor & B12 or folate deficiency Fe deficiency & hemolysis (prosthetic valve) Folate deficiency & hemolysis (Hb SS disease) Peripheral smear exam is critical to assess these RDW is increased very much
Target Cells • Liver Disease • Thalassemia • Hb D Disease • Post splenectomy
WBC • WBCs are involved in the immune response. • The normal range: 4 – 11x10^9 /L • Two types of WBC: • 1) Granulocytes consist of: • Neutrophils: 50 - 70% • Eosinophils: 1 - 5% • Basophils: up to 1% • 2) Agranulocytes consist of: • - Lymphocytes: 20 - 40% • Monocytes: 1 - 6%
WBC • The type of cell affected depends upon its primary function: • In bacterial infections, neutrophils are most commonly affected • In viral infections, lymphocytes are most commonly affected • In parasitic infections, eosinophils are most commonly affected.
Neutrophil • polymorphneuclear leukocytes (PMN,s) • Nucleus 3-5 lobes. • Diameter 10-14 µm • 50-70% WBC • =2.5-7.5x10^9/ L • Function: Phagocytosis of bacteria and cell debris • Numbers rise with all manner of stress, especially bacterial infections