Chapter 41 Hematology.

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1 Chapter 41 Hematology

2 Hematologic Tests Second most common type of tests performed in POL
Cellular components of blood affected by changes in organs or tissues of body Watch the animation

3 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

4 Hematologic Tests Results of tests provide valuable information for diagnosis, evaluating patient’s progress, or regulating further treatment

5 Complete Blood Count Hemoglobin determination Hematocrit determination
WBC count

6 Complete Blood Count RBC count Differential WBC count
Erythrocyte indices

7 Hemoglobin and Hematocrit
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

8 Hemoglobin and Hematocrit
Carries 95 percent of oxygen to cells Transports 27 percent of carbon dioxide back to lungs for removal Acts as buffer system

9 Hemoglobin and 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

10 Hemoglobin and Hematocrit
Iron deficiency anemia Near-normal hematocrit with low hemoglobin value; hypochromic RBC lack hemoglobin Determining hemoglobin values Cyanmethemoglobin

11 Hemoglobin and Hematocrit
Normal hemoglobin values or reference ranges by age or sex Normal hematocrit values or reference ranges by age or sex

12 Hemoglobin and Hematocrit
Microhematocrit Centrifuge Packed cell column showing separation of cellular components >>

13 WBC and RBC Counts WBC and RBC counts WBC differential
Automated method WBC differential Normal leukocyte counts

14 Leukocyte Identification Guide

15 Leukocyte Differentiation
Groups Myelocytic or granulocytic series Lymphocytic Monocytic

16 Leukocyte Differentiation
Granulocytic group Neutrophil Eosinophil Basophil Differential leukocyte count Normal values for a differential leukocyte count in adults

17 Erythrocyte Indices Include: Mean corpuscular volume (MCV)
Mean corpuscular hemoglobin (MCH) Mean corpuscular hemoglobin concentration (MCHC)

18 Erythrocyte Indices Provide information about size of RBC and hemoglobin content Normal values

19 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

20 Erythrocyte Sedimentation Rate
Measures rate at which RBC fall toward bottom when placed in vertical tube >>

21 Erythrocyte Sedimentation Rate
Also called “sed rate” Used in diagnosis and treatment of many diseases Inexpensive Accurate Easy to perform

22 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

23 Erythrocyte Sedimentation Rate
Westergren method Mix blood sample with 3.8 percent sodium citrate solution before filling tube Normal values for Westergren method of ESR Sediplast ESR system

24 Erythrocyte Sedimentation Rate
Guidelines for Wintrobe and Westergren ESR procedures to measure accurate results Rouleaux >>

25 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

26 Coagulation Studies Prothrombin Time (PT)
“Protime” Measures time it takes a patient’s blood to clot Normal blood clots in seconds International Normalized Ratio (INR) Can be universally applied

27 Automated Hematology Instrumentation and Quality Control
Hematology instruments that require sample dilutions Hematology instruments that do not require sample dilutions

28 Automated Hematology Instrumentation and Quality Control
CLIA ’88 regulation for quality control in automated hematology

29 Automated Hematology Instrumentation and Quality Control
Required procedures Calibration Control samples Proficiency testing Check manufacturer’s recommendations for particular piece of equipment