Hematology Lecture PDF

HEMATOLOGY LECTURE LEARNING POINTS  INCREASED  Be able to differentiate blood components and explain  congenital heart disease their functions.  COPD  Per...

HEMATOLOGY LECTURE LEARNING POINTS  INCREASED  Be able to differentiate blood components and explain  congenital heart disease their functions.  COPD  Perform Peripheral Blood Smear Procedure.  Kidney Failure  Perform Manual Microhematocrit Procedure. WHITE BLOOD CELLS HEMATOLOGY  ROLE AND FUNCTION  Hematology came from the Greek word “haima”  White blood cells are a key part of the immune meaning blood and “logy” meaning study. system. They fight off pathogenic diseases and  Hematology, the discipline that studies the infections. They are made in the bone marrow. development and diseases of blood.  Do not have a fixed shape. Can change their form.  CORRELATIONS BLOOD  DECREASED  Viral infections (neutrophil)  In vivo, blood is in fluid form; in vitro, it coagulates 5-  Dengue 10mins  Bone marrow damage  Thick and viscous 3.5-4.5 times thicker than water  HIV  Blood pH: 7.35-7.45 (avg 7.40)  Lupus  Color:  INCREASED  Arterial: oxygenated (bright red)  Bacterial infections (neutrophils)  Venous: deoxygenated (dark purplish red)  Allergic and parasitic infections (eosinophils)  75 to 85 ml blood per kg of body weight 7%-8% of the total  Leukemia body weight  Inflammation SERUM VS. PLASMA PLASMA  ROLE AND FUNCTION  The plasma carries the red blood cells, white blood cells and platelets around the body.  It also contains hormones, glucose, enzymes and waste products.  DESCRIPTION  Pale yellow  Liquid  PERCENTAGE BLOOD COMPONENTS  55% of the blood is plasma 1. Red blood cells PLATELETS 2. White blood cells 3. Plasma  ROLE AND FUNCTION 4. Platelets  Platelets form scabs to stop cuts from bleeding  They are made in the bone marrow. RED BLOOD CELLS  CORRELATIONS  DECREASED  ROLE AND FUNCTION  Dengue  Red blood cells carry oxygen from the lungs, around  Chronic bleeding the body to every cell.  Sepsis  They contain a chemical called haemoglobin which  INCREASED binds to oxygen in order to carry it in the blood.  Splenectomy Biconcave disc shape, No nucleus.  Recovering from a recent injury  CORRELATIONS  Birth control pills  DECREASED  bone marrow disorder  thyroid function  iron deficiency  anemia 1  PERIPHERAL BLOOD SMEAR 1. Cover glass smear (Ehrlich)  Two cover glass smears  Used for bone marrow samples 2. Cover glass and slide (Beacom)  Used for bone marrow samples 3. Wedge smear MICROHEMATOCRIT  Uses 2 slides; angle between the 2 slides → 25 / 30- 40 / 30-450-degree angle (PREFERRED) ADAM’S MICROHEMATOCRIT METHOD  Easiest to master Most convenient, and most  Capillary tube: commonly used  Length: 7-7.5cm or 70-75 mm  Bore: 1-1.2 mm in diameter  Can hold up to 0.05mL of blood  5cm filled portion with blood (2/3 filled portion)  Plug: 4 to 6 mm long  Two types: With red band (with anticoagulant heparin) and with blue or green band (without anticoagulant) MICROHEMATOCRIT  Trapped plasma (microhematocrit) may cause the Hct to be falsely increased by as much 1% to 3% (0.01 to 0.03 L/L) higher than the value obtained using automated instruments.  Trapped plasma- small amount of plasma that remains in the RBC portion of the spun Hematocrit even when properly centrifuged.  Trapped plasma increased in conditions such as Sickle cell anemia, Hypochromic anemia, Spherocytosis, Macrocytosis and Thalassemia.  Excess anticoagulant / Short draw/underfilled tubes = decrease hematocrit results.  The values of duplicate hematocrits should agree within 1%.  Specimens for microhematocrit determination should be centrifuged within 6 hours of collecting. 2  MICROHEMATOCRIT  RULE OF THREE  Used for checking the validity of test results.  Works only on Normocytic, Normochromic specimens.  The value of the hematocrit should be three times the value of the hemoglobin plus or minus 3.  It should become habit for the analyst to multiply the hemoglobin by 3 mentally for every specimen; a value discrepant with this rule may indicate abnormal RBCs, or it may be the first indication of error.  3 x RBC Count = Hemoglobin  3 x Hb = Hct ± 3 (%) 3