Hematology The study of blood and blood forming
Hematology • The study of blood and blood forming tissues Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hematology • Bone Marrow – Where most blood cells are formed • Some can be formed in the liver and spleen – Long bones, skull, pelvis, and sternum (flat bones) produce most of the cells • Hematopoiesis • Blood cell production • Begins with very young, immature cells within the marrow – Influenced by hormones, needs nutrients (iron) to make – The cells form here and are pushed out when mature • Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hematologic Tests • Second most common type of tests performed in POL • Cellular components of blood affected by changes in organs or tissues of body Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Types of Blood Tests • Hemoglobin • Hematocrit • White blood cell (WBC) count • Red blood cell (RBC) count • Platelet count • Differential WBC count • Erythrocyte sedimentation rate (ESR) • Prothrombin time Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hematologic Tests • Results of tests provide valuable information for diagnosis, evaluating patient’s progress, or regulating further treatment Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Complete Blood Count • • • Hemoglobin determination Hematocrit determination WBC count RBC count Differential WBC count Erythrocyte indices Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hemoglobin and Hematocrit • Hemoglobin – Major component of erythrocyte and carrier of oxygen in body; 85 percent of dry weight of RBC – Synthesis of heme requires iron – Adult male requires 0. 5 mg/day of iron – Menstruating female requires 2 mg/day of iron – Iron is found in raisins, kidney beans, egg yolks, oysters, turnips. NOT iceburg lettuce. Iron supplements are available also. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hemoglobin and Hematocrit • Hemoglobin – Carries 95 percent of oxygen to cells – Transports 27 percent of carbon dioxide back to lungs for removal – Acts as buffer system Normal hemoglobin values or reference ranges by age or sex Newborn Age 3 months Age 10 months Adult woman Adult man 15 -20 g/d. L 9 -14 g/d. L 12 -14. 5 g/d. L 12 -16 g/d. L 13 -18/d. L Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hemoglobin and Hematocrit • Hematocrit – Separation of blood into liquid portion and solid portion by process of centrifugation – Erythropoietin • Hormone that triggers production of new red cells – Hemoglobinopathies • Group of diseases; abnormal forms of hemoglobin • Hgb S is most common- causes Sickle cell anemia (therefore it is the most common type of hemoglobin disease seen in ambulatory setting) Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hemoglobin and Hematocrit • Hematocrit – Iron deficiency anemia • Near-normal hematocrit with low hemoglobin value; hypochromic RBC lack hemoglobin (they are pale in color due to lack of hemoglobin) • • Most common type of anemia seen in ambulatory setting Other anemias • Hemorrhagic anemia- anemia due to a bleeding problem • Congenital defects • Industrial toxins Aplastic anemia- diseases of bone marrow Determining hemoglobin values – Cyanmethemoglobin Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hemoglobin and Hematocrit • Normal hematocrit values or reference ranges by age or sex Newborn Year old child Adult female Adult male 45 -60% 27 -44% 36 -46% 40 -55% Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hemoglobin and Hematocrit • Microhematocrit – Centrifuge for 5 min – Packed cell column showing separation of cellular components >> Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Hemoglobin and Hematocrit • Hgb X 3 = Hct • WBC count can be estimated by measuring buffy coat thickness- 0. 1 mm = approximately 1, 000 WBCs/mm 3 Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
WBC Counts – Automated method- not a waived test • • • Function of the leukocyte: To provide the main line of defense against foreign invaders (infections including bacteria and viruses) Leukopenia – a decreased number of leukocytes Leukocytosis – increased number of leukocytes Cancer of the wbc – Leukemia Both leukopenia and leukocytosis can be found in infections and some drugs. However, if a patient has leukopenia, their risk of further infections is greatly increased due to the fact that they have no line of defense against the infection. Age Newborn 1 year old toddler 6 year old child Adult Average 18, 000 11, 000 8, 000 7, 000 Reference Range 9, 000 -30, 000 6, 000 -14, 000 4, 500 -12, 000 4, 500 -11, 000 Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
RBC Count Function: Transport gases between the lungs and tissues – Oxygen and carbon dioxide. This is called internal respiration. Structure: Biconcave disk containing hemoglobin • Allows them to exchange gases in the tissues and lung fields • Measurements of RBCs and associated parameters are useful guides for detecting anemia • Anemia could be from low iron, blood loss or increased destruction of rbc. Anemia = dec number of rbc Polycythemia = inc number of rbc • Men, 4. 6– 6. 2 million/mm 3 (higher in men) • Women, 4. 2– 5. 4 million/mm 3 Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
RBC Morphology is the physical size and shape of the red blood cells • Variations in size and shape. Poikilocytosis - variations in shape (not biconcave disk) Anisocytosis - Variations in size (both large and small) – Example: Sickle cell anemia (genetic disease) and iron deficiency Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Leukocyte Identification Guide Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Leukocyte Differentiation • Groups – Myelocytic or granulocytic series – Agranulocytic series • Lymphocytic • Monocytic Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Leukocyte Differentiation • Granulocytic group – meet the ‘phils’ – Neutrophil – fight bacteria – Eosinophil – increased in allergic reactions and parasitic infections, neutralize histamine – Basophil – important in inflammation, release histamine, release heparin to inhibit clotting Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Leukocyte Differential • Agranulocytic group Lymphocytes - immunity, makes antibodies, matures in lymphatic system, attack viruses. Monocytes- phagocytosis to clean up Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Leukocyte Differential • Normal values for a differential leukocyte count in adults WBC Band Neutrophil Lymphocytes Monocytes Eosinophils Basophils Normal Range Increased In 3 -5% Bacterial infections, appendicitis 54 -62% Bacterial infections, appendicitis 25 -33% Viral infections, mononucleosis 3 -7% Tuberculosis, mononucleosis 1 -3% Allergic reactions, parasitic infections 0 -1% Polycythemia vera, chicken pox, ulcerative colitis Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Erythrocyte Indices • Include: • Mean corpuscular volume (MCV) = Hct/RBC X 10 MCV tells you about the SIZE of the rbc • Mean corpuscular hemoglobin (MCH) = Hgb/RBC X 10 MCH tells you about the HEMOGLOBIN in the cells • Mean corpuscular hemoglobin concentration (MCHC) = • Hgb/Hct X 10 MCHC tells you about the hemoglobin in reference to the hematocrit . Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Erythrocyte Indices Normal values MCV 80 -100 f. L (femtoliters) MCH 27 -33 pg (picograms) MCHC 32 -36 g/d. L (grams/deciliter) MCV <80 is microcytic anemia (small rbcs) MCV >100 is macrocytic anemia (large rbcs) MCH <27 is hypochromic anemia (pale rbcs) MCH >33 is hyperchromic (really red rbcs) MCHC decreased is very small, very pale rbcs. MCHC increased is very large, very round, very red cells called spherocytes. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Erythrocyte Indices • Using erythrocyte indices to diagnose – MCH and MCV increased in megaloblastic anemias – MCH and MCV decreased in hypochromic and microcytic anemias – MCHC increased in hereditary spherocytosis – MCHC normal in macrocytosis – MCHC decreased in iron deficiency anemia Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Thrombocytes – Made in bone marrow and important in clotting – Cell fragments of megakaryocyte cells (pieces of cytoplasm) – Essential to hemostasis – the body’s ability to form a clot Forms a “platelet plug” that aids in sealing wounds to stop bleeding until a clot can form • Help initiate clotting factors to form the more stable fibrin clot – Normal range, 140, 000– 400, 000/ml of blood – Thrombocytopenia – decrease in platelets • Results in bleed problems – unable to clot quickly – Thrombocytosis – increase in platelets Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Erythrocyte Sedimentation Rate • Measures rate at which RBC fall toward bottom when placed in vertical tube >> Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Erythrocyte Sedimentation Rate • Also called “sed rate” • Used in diagnosis and treatment of many diseases – Inexpensive – Accurate – Easy to perform Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Erythrocyte Sedimentation Rate • Wintrobe method – – – – EDTA venous blood sample mixed Blood transferred with Pasteur pipette to Wintrobe tube No air bubbles Place tube vertically in rack to stand for 60 minutes Read number of millimeters red cells settled Normal values for Wintrobe method of ESR Male patients Female patients 0 -9 mm/hr 0 -20 mm/hr Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Erythrocyte Sedimentation Rate • Westergren method – Mix blood sample with 3. 8 percent sodium citrate solution before filling tube – Sediplast ESR system – Normal values for Westergren method of ESR Male patients younger than 50 years Male patients older than 50 years Female patients younger than 50 years Female patients older than 50 years 0 -15 mm/hr 0 -20 mm/hr 0 -30 mm/hr Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Erythrocyte Sedimentation Rate • Guidelines for. Wintrobe and Westergren ESR procedures to measure accurate results • • The tube must remain exactly vertical during the 1 -hour test time The test must be read at exactly 60 minutes (1 hour) The counter on which the rack is placed must be free of vibrations The test should be set up within 2 hours after the blood is drawn The test should be conducted at room temperature The tube should not be placed in a draft, and it should not be exposed to direct sunlight The column of blood must be free of bubbles Rouleaux >> Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Erythrocyte Sedimentation Rate • Using the ESR to diagnose – ESR increased in infections and inflammatory diseases, tissue destruction, and other conditions leading to increased plasma fibrinogen – ESR increased with anemia, menstruation, pregnancy, malignant neoplasms, and multiple myeloma – ESR normal in osteoarthritis, some cases of cirrhosis, and malaria – ESR decreased in polycythemia, spherocytosis, and sickle cell anemia Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Coagulation Studies • Prothrombin Time (PT) – “Protime” – Measures time it takes a patient’s blood to clot – Normal blood clots in 11 -13 seconds – Primary monitor of Coumadin anticoagulant therapy • International Normalized Ratio (INR) – Can be universally applied – Goal is PT 16 -18 seconds INR 2. 0 -2. 6 Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Automated Hematology Instrumentation and Quality Control • Hematology instruments that require sample dilutions • Hematology instruments that do not require sample dilutions Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Automated Hematology Instrumentation and Quality Control • CLIA ’ 88 regulation for quality control in automated hematology Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
Automated Hematology Instrumentation and Quality Control • Required procedures – Calibration – Control samples – Proficiency testing • Check manufacturer’s recommendations for particular piece of equipment Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.
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