Approach To A Patient With AnemiaDr. Mohammad Usman ShaikhAssistant Professor,Aga Khan University Hospital.
Hematology• Study of blood forming tissue and circulating bloodcomponent• Clotting factors• Blood groups• CBC and smear examination regardless of specialty• Accessible, close proximity to tissues, often providesome information• Important for accurate diagnosis and therapeuticschoices
Manual Versus AutomationFeasibility:Workload:• Depend on number of samples per day• Less than 20 samples, prefer manual method• Tertiary care hospital setting in western hospitals,CBC is mandatory for consultation.• Rapid analysis• Require only an appropriate blood sample.• Measure 8-25 variables, no equivalent manually.
Principles of Automation• Electrical Impedance• Light scattering
Electrical ImpedanceDetection & measurement of changes inelectrical resistance produced by cells asthey passes via a small apertureElectrical resistance between two electrodes,or impedance in current leads to the formation ofpulses
A stream of cells passes through aperture across whichelectrical current is applied. Each cell that passes alterselectrical impedance and can thus be counted andsized.Good PulseDiluent stream
Sensing ZoneRed BloodCellsElectrical ImpedanceOscilloscopeOscilloscopeEach time a cell passes apulse is produced.The pulse height isproportional to CellvolumeAnimation by M.A.Ghauri
Light ScatteringO-3 deg(relative size)Light Scatter estimates relativecell size based on forwardscatter - that is a measurementof cross-sectional diameterLaser
Hemogram/ Histogram• Visual representation of what was counted at theaperture.• Verify a count that has a typical pattern according tothe reference ranges• Alert for possible interfering particles andabnormalities
Anemia– Definition: low Hemoglobin and hematocrit– Results from a wide variety of disorders
Anemia• Laboratory data is more informative whenconsidered in the context of history and physicalexamination
Approach to Anemia• History:– Family history– inherited causes such asthalassemia, sickle cell anemia, G6PD deficiencyand hereditary spherocytosis.– In most of these cases morphological findings ofsmear are diagnostic• B symptoms• Systemic or other chronic disorders
History• Drug history:• History of blood loss• Clinically: Degree of pallor, with or withouticterus, angular stomatitis andglossitis, koilonychia, lymphadenophathy andhepatoslenomegaly
KoilonychiaPhysical Examination:helps to direct theclinician to the cause ofanemiaIron deficiency:koilonychia, glossitis, angular stomatitis.
GlossitisB12 deficiency: decreasevibration and posturalsenseFolate deficiency:glossitis, sign ofmalabsorption, alcoholabuse and pregnancy
Angular stomatitisAngular stomatitis:non specific, can beseen in irondeficiency, B12 andfolate deficiency
Lymphadenophathy• Bone marrowfailure/infiltration: fever,Petechiae,lymphadenophathy,splenomegaly and sternaltenderness
Splenomegaly• Bone marrowfailure/infiltration:splenomegaly
Classification of Anemia on the Basis of MCVLess than 76fl --- microcyticIron deficiencyThalassemiaAnemia of chronic diseaseSideroblastic anemia and lead poisoningMCV between 76 to 96 flAnemia of chronic diseaseAcute blood lossChronic renal failureAnemia due to infiltrationAplastic anemia
Classification of Anemia on the Basis of MCV• MCV more than 96fl– Macrocytic anemia• Megaloblastic: B12 and folate deficiency• Non megaloblastic:– Hemolysis– MDS– Hypothyroidism– Liver disease
Etiological Classification of Anemia:• Increase destruction1-Hemolytic anemiainherited and acquired• Impaired Production2-Anemia due to bone marrow failure states3-Nutritional deficiencies4-Anemia due to infiltrative disorders5-Anemia of chronic disorders
Sickle Cell Disease• Rare in Pakistan (Balochistan), common in MiddleEast, and up to 40% trait in Central Africa• Qualitative globin chain defect; Homozygous inheritance• Deoxy Hb S--- tendency to aggregate--- sickle cell• Increase blood viscosity --- vascular stasis---tissuedamage + RBC membrane damage• Sickling depend on Hb S concentration• Hb S <50%, usually no symptoms• Hb F---confer protection• Hb: 5-11 g/dl, Normocytic normochromic, Targetcells, reticulocytosis, Increase WBC & Platelets
Reticulocyte• Reticulocyte: larger thannormal RBC• RNA and Golgi remnants,Ribosome, maturation takeanother 24 to 48 hours inthe blood circulation
Conclusions• Peripheral blood smear examination and reporting is oneof the most important aspect of hematology.• It is diagnostic in many hematological and nonhematological disorders.• It is cost effective and non invasive and helps theclinicians in further diagnostic workup