1. 1 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Assisting in the Analysis of Blood Chapter 54

2. 2 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Learning Objectives  Define, spell, and pronounce the terms listed in the vocabulary.  Apply critical thinking skills in performing patient assessment and care.  Name three main functions of blood.  Identify the role of the hematology laboratory in patient care.  Describe the appearance and function of erythrocytes.  Define the appearance and function of granular and agranular leukocytes.

3. 3 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Learning Objectives  Differentiate between T cells and B cells.  Describe the appearance and function of the thrombocyte.  Explain the process of clot formation.  Identify the anticoagulant of choice for hematology testing.  Explain the purpose of the microhematocrit test.  Accurately perform a microhematocrit.  Explain the role of hemoglobin in the body.

4. 4 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Learning Objectives  Perform a hemoglobin test.  Identify the tests included in a complete blood count (CBC) and their reference ranges.  Explain the principle behind automated blood cell counting.  Distinguish between normal and abnormal test results.  Describe the RBC indices and how they are calculated.  Explain the reasons for performing a WBC differential.  Discuss the Wright’s stain sequence.

5. 5 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Learning Objectives  Describe the appearance of the normal erythrocyte.  Describe the appearance of the five different types of leukocytes seen in a normal Wright-stained differential.  Cite the reasons for performing an erythrocyte sedimentation rate test.  Describe the sources of error for the erythrocyte sedimentation rate test.  Determine an erythrocyte sedimentation rate using a modified Westergren method.

6. 6 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Learning Objectives  Describe the tests performed to assess coagulation.  Differentiate between the ABO blood groupings and the Rh blood groupings.  Secure a capillary blood sample and determine the ABO and Rh grouping of the sample.  Discuss rare blood types and the implication of having a rare blood type when transfusion is necessary.  Describe the methodology behind the clinical chemistry testing methods used in the physician’s office laboratory.

7. 7 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Learning Objectives  Explain the reasons for testing blood glucose, blood cholesterol, hemoglobin A 1c, thyroid hormone levels, and liver enzymes.  Perform a cholesterol test using an FDA-approved cholesterol monitor.  Summarize typical chemistry panels, the reason for performing each panel, and the individual tests performed in those panels.

8. 8 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Hematology  Section of the laboratory that deals with:  Counting RBCs, WBCs, and platelets  Differentiating WBCs on a stained smear  Measuring the percentage of RBCs in blood  Determining the hemoglobin

9. 9 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Complete Blood Cell Count  Red blood cell count  White blood cell count  Hemoglobin determination  Hematocrit determination  Differential white blood cell count  Estimation of platelet numbers  Red cell indices

10. 10 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Critical Thinking Application  Dana will collect the specimen for Mr. Corrigan’s CBC. What tests are included in the CBC? Can any of these tests be performed by capillary puncture? Explain.  Which vacuum tube will Dana use to collect the CBC?

11. 11 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Whole Blood  Plasma  Clear yellow liquid portion  55% of blood by volume  Formed elements  45% of blood  Erythrocytes (RBCs), leukocytes (WBCs), and thrombocytes (platelets)

12. 12 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Erythrocytes  Red blood cells (RBCs)  Formed in red bone marrow  120-day life span  Lack nucleus, resulting in biconcave shape  Hemoglobin: transports oxygen

13. 13 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Leukocytes  White blood cells (WBCs)  Contain nucleus  Protect body against infection and disease  Granular or agranular leukocytes  Granular leukocytes – perform phagocytosis  Agranular leukocytes – produce antibodies

14. 14 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Granular Leukocytes  Polymorphonuclear leukocytes  Neutrophils, eosinophils, basophils  Granulated cytoplasm and segmented nuclei  Phagocytic function  Inflammation

15. 15 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Agranular Leukocytes  Lymphocytes and monocytes  Clear cytoplasm and a solid nucleus  Production of antibodies  T cells and B cells

16. 16 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. T Cells  Immune response to intracellular parasites, viruses, fungi, and bacteria.  Cytotoxic or killer T cells—kill foreign, virus-infected, and tumor cells.  Helper T cells—stimulate the activity of other T cells.  Suppressor T cells—inhibit the activity of other T cells.  Memory T cells—respond quickly to antigens at a later date.  Natural killer cells—kill cells infected with viruses and tumor cells without prior sensitization.

17. 17 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. B Cells  Formed in bone marrow  Differentiate into plasma cells  Produce specific antibodies against an antigen Antibodies are protein molecules that attach to antigens  Complement system – series of reactions between plasma proteins that amplifies the immunological response to foreign molecules Activation causes lysis of microorganisms or their phagocytosis by neutrophils

18. 18 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. B Cells Three steps to destroying pathogens 1.Antigen processing – macrophages phagocytize antigens; break them down into smaller molecules that are displayed on the macrophage surface 2.Lymphocyte stimulation – T cells stimulate B cells to start antibody production 3.Antibody production – B cells have repeated cellular divisions, enlargement, and differentiation to create an effective number of plasma cells that secrete specific antibodies that bind to the antigen, making them easier to ingest by white cells or killing the bacteria directly

19. 19 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Thrombocytes  Cytoplasmic fragments of megakaryocyte  Smallest formed element

20. 20 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Clot Formation  Initiated by blood platelets.  Combines with calcium to form thromboplastin.  Then converts prothrombin into thrombin.  Thrombin converts fibrinogen to fibrin.  Blood cells and plasma are enmeshed in the network of minute threadlike structures called fibrils to form a clot.

21. 21 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Hemophilia  Bleeding disorder  Mutation of clotting factor genes  Hereditary, sex-linked disorder  Treatment:  Injection of purified clotting factor to prevent bleeding episode

22. 22 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Plasma  Liquid that is the carrier for formed elements and other substances  Proteins, carbohydrates, fats, hormones, enzymes, mineral salts, gases, and waste products  90% water, 9% protein, and 1% other  When plasma proteins and other components are used up during the clotting process, the remaining liquid is called serum

23. 23 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Collection of Blood Specimens  Capillary puncture can be used for most blood samples  Venipuncture is used when a larger sample is required  CBC – venous blood collected in an EDTA tube to prevent clotting

24. 24 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Hematocrit  Measurement of the percentage of packed RBCs in a volume of blood  Spun microhematocrit test – cellular elements separated from plasma by centrifugation  Capillary tubes are placed in a centrifuge  After centrifugation, RBCs will be at the bottom of the tube, WBCs and platelets in the center, and plasma on the top.  Percentage read with a microhematocrit reader

25. 25 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Centrifuge with Capillary Tubes

26. 26 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Hematocrit Test Results

27. 27 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Hemoglobin  A rough measure of the oxygen-carrying capacity of blood  Individual test or part of CBC  Hemoglobinometer – colorimeter that determines hemoglobin by measuring the amount of light absorbed by a sample of blood in which the hemoglobin has been released and chemically modified  HemoCue  Copper sulfate method – used to screen blood donors; a drop of blood with normal hemoglobin values falls rapidly to the bottom; if it drop falls slowly or not at all, the hemoglobin levels are low

28. 28 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Hemoglobin Machine Courtesy Stanbio Laboratory.  Hand-held instrument

29. 29 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Hemoglobin Determination  Copper sulfate method From Stepp CA, Woods MA: Laboratory procedures for medical office personnel, Philadelphia, 1998, Saunders.

30. 30 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Normal Hemoglobin Values From Stepp CA, Woods MA: Laboratory procedures for medical office personnel, Philadelphia, 1998, Saunders.

31. 31 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Red Blood Cell Count  Approximates the number of circulating RBCs  Anemia: oxygen-carrying capacity of blood is below normal limits  Elevated during dehydration, polycythemia vera, or severe burns and in people who live at high altitudes  Normal RBC values range from four million to six million cells/mm 3

32. 32 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. White Blood Cell Count  Approximation of the total number of leukocytes in blood  Aids in determining whether an infection is present and in diagnosing leukemia  Used to measure response to treatment  Average adult range is between 4,000 and 11,000 cells/mm 3  Elevation of WBCs is called leukocytosis.  Decrease in the WBC count is called leukopenia

33. 33 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Critical Thinking Application Distinguish between normal and abnormal test results in the following patients:  Maggie McGuire, age 6 years, has a hematocrit of 38%. Is that normal?  Carlos Santiago, age 54 years, has a WBC count of 13,000/mm 3 and Dr. Fischbach asks to see his previous blood work. Why?  Angelina Washington, age 23 years, has an Hct of 32% and Hbg of 10. Why would she be diagnosed with anemia?  Rose Conrad has a platelet count of 142,000/mm 3. Why is Dr. Fischbach concerned about a bleeding disorder?

34. 34 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Red Cell Indices  Calculations performed using information from the CBC  Provide information about RBC disorders  Mean corpuscular volume (MCV)  Mean corpuscular hemoglobin (MCH)  Mean corpuscular hemoglobin content (MCHC)  Red cell distribution width (RDW)

35. 35 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Differential Cell Count  Purpose is to analyze and quantitate the types of WBC  Manually stained blood smear  Automated instrument

36. 36 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Preparation of Blood Smears for the Differential  Blood smear enables a view of cellular components of blood  Morphology of leukocytes, erythrocytes, and platelets  Size, shape, and maturity  Prepared by spreading a drop of blood on a clean glass slide

37. 37 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Blood Smears  Three kinds of smears  Coverglass smear, spun smear, and wedge smear  Should cover ½ to ¾ of the slide

38. 38 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Blood Smears  Gradual transition from thick to thin end  Smooth appearance, dried, labeled  Cells should be distributed evenly

39. 39 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Stains  Polychromatic stains – contain dyes that will stain various cell components different colors  Methylene blue, eosin  Wright’s stain

40. 40 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Normal Blood Cells  Observe and evaluate cell size, nuclear appearance, and cytoplasmic characteristics  Results of observing these three features will allow for cell identification  Examined using oil-immersion objective  RBCs – most numerous blood cells; biconcave disks that have no nuclei; appear pinkish tan  Thrombocytes – smallest cellular element; round or oval without a nucleus; stain blue; normal platelet count is 150,000 to 400,000/mm 3. An increase in platelets is thrombocytosis and a decrease is thrombocytopenia

41. 41 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Red Blood Cell Morphology From Stepp CA, Woods MA: Laboratory procedures for medical office personnel, Philadelphia, 1998, Saunders.

42. 42 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Blood Cells  Leukocytes – largest of blood cells; five types have a characteristic appearance  Granulocytes – neutrophils, eosinophils, and basophils; contain distinctive granules in their cytoplasm and may have segmented nuclei  Agranulocytes – lymphocytes and monocytes; few, if any, granules and nonsegmented nuclei  Neutrophils – most numerous WBCs in circulation; perform phagocytosis  immature form of a neutrophil is called a band or stab; increase seen in infections

43. 43 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Blood Cells  Eosinophils – phagocytic; elevated with allergies such as hay fever and asthma  Basophils – associated with the immediate immune response to external antigens  Lymphocytes – second most numerous type of WBC in adults and most numerous in children; recognize foreign antigens and produce antibodies; increased numbers with viruses, bacterial infections, leukemias  Monocytes – largest WBC; called macrophages when they enter tissues and ingest bacteria and debris of cellular breakdown

44. 44 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Differential Examination Normal values vary with age. Adult reference ranges:  Neutrophils: 40% to 60%  Lymphocytes: 20% to 40%  Monocytes: 2% to 8%  Eosinophils: 1% to 4%  Basophils: 0.5% to 1%  Band: 0% to 3%

45. 45 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Erythrocyte Sedimentation Rate (ESR)  Measures the rate at which erythrocytes gradually separate from plasma and settle to the bottom of a specially calibrated tube in an hour  General indication of inflammation  Increases are found in chronic infections, rheumatoid arthritis, tuberculosis, hepatitis, cancer, multiple myeloma, rheumatic fever, and lupus

46. 46 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Wintrobe ESR From Stepp CA, Woods MA: Laboratory procedures for medical office personnel, Philadelphia, 1998, Saunders.

47. 47 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Coagulation Testing  Prothrombin time (PT) is tested with a hand-held instrument  Method of measuring how well the blood clots  PT used to monitor anticoagulant therapy  Results reported as number of seconds blood takes to clot when mixed with a thromboplastin reagent  International Normalized Ratio (INR) – standard unit for reporting PT results rather than the time in seconds; normal PT values are 10 to 13 seconds or an INR value of 1 to 1.4; anticoagulant is adjusted so INR values are 2 to 3

48. 48 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Immunohematology  Formerly called the blood bank  Responsible for blood typing or cross-matching of blood types  Prevents problems caused by incompatibility of blood types

49. 49 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Blood Grouping  Two major blood antigen systems: ABO and Rh; four major blood groups: A, B, O, and AB; person is either Rh positive or Rh negative  About 85% of U.S. population is Rh positive  Blood type is inherited

50. 50 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Blood Grouping

51. 51 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Blood Compatibility  Type O – no antigens; anti-A and anti-B antibodies; universal donors  Type A – type A antigen; anti-B antibodies; O and A donors  Type B – type B antigen; anti-A antibodies; O and B donors  Type AB – type AB antigen; no plasma antibodies; universal recipients

52. 52 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Rh Factor  Rh factor – first discovered in rhesus monkeys  Test detects presence of proteins (D antigens) on the surface of RBCs  Rh + blood agglutinates in the presence of anti-D antiserum; Rh – does not agglutinate in the presence of anti-D antiserum  If an Rh – mother is exposed to the Rh + blood of her infant during pregnancy, miscarriage, abortion, or delivery she develops antibodies against the D antigen that cross the placenta and destroy the RBCs of the fetus in a subsequent pregnancy  Rho(D) immune globulin is given to Rh – mothers to prevent the infant’s Rh + cells from stimulating the mother’s immune system

53. 53 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Blood Glucose Testing  Blood glucose tolerance test.  Self-monitoring of blood glucose.  Urine reagent strips  Blood glucose monitors using electrochemisty  The medical assistant can perform glucose testing.  Blood glucose is routinely monitored for diabetes.

54. 54 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Glycosylated Hemoglobin  Provides information about the average blood sugar level during the past 2 or 3 months.  Glucose binds to hemoglobin molecules within RBCs; amount of glucose that is bound to hemoglobin is directly tied to the concentration of glucose in the blood.  Measuring the amount of glucose bound to hemoglobin can provide an assessment of average blood sugar control during the 60 to 90 days preceding the test.  Normal HbA 1c levels between 4 and 6%; goal for diabetic patients are levels less than 7%.

55. 55 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Cholesterol Testing  Recommended that adults over the age of 20 years have a cholesterol test at least once every 5 years  Total cholesterol  HDL – “good” cholesterol; high level protects against heart attack; carries cholesterol away from arteries and back to the liver for excretion  LDL – high levels reflect an increased risk of heart disease; called “bad” cholesterol  Recommendations – total cholesterol levels under 200 mg/dl; over 240 mg/dl indicates high-risk category for coronary heart disease

56. 56 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. Thyroid Hormone Testing  Thyroid produces T 3 and T 4 ; affect metabolism, growth, and development  Pituitary produces TSH – stimulates thyroid to produce hormones; first test is to measure TSH levels  Screen patients for hypothyroidism

57. 57 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved. ALT and AST Testing  Certain drugs can impair liver function; liver damage releases enzymes that can be tested.  Drugs include statins (lower blood cholesterol), certain antidiabetic drugs, and antihypertensives  Monitor liver function during therapy with drugs that have a potential for causing liver malfunction

58. 58 Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Automated blood chemistry analyzer.  Several analytes may be tested at once.  Renal or liver panel.  Typical panels are shown in Table 54-9. Chemistry Panels