The document discusses various components of a basic blood test. It provides details on the normal composition and functions of blood, as well as procedures for blood specimen collection. It also explains the clinical implications and reference ranges for various components analyzed in a complete blood count test, including red blood cells, white blood cells, platelets, hematocrit, hemoglobin, and sedimentation rate.

1. Nur Aisyah Aziz Pathology Practical 15.12.2010

2. BASIC Composition of Blood 5L (1/13 of body weight): 3L plasma + 2L cells Plasma: intestine & lymphatic system Blood cells: RBCs (erythrocytes), WBCs (leucocytes) & platelets (thrombocytes) Hematopoeisis: Liver (before birth) Spleen & lymph nodes (minor role – midfetal life) BM (after birth) Blood test Basic screening for disorders of Hb and cell production, synthesis & functions Specimen collection: Capillary skin punctures (finger, toe, heel) Dried blood samples Arterial or venous sampling BM aspiration

3. Specimen Collection Procedures Capillary puncture (skin puncture) Preferred for peripheral blood smear Clinical alert: Do not squeeze the site to obtain blood – alters blood compositions & invalidates test values Warming extremities or placing it in a dependent position – may facilitate specimen collection

15. Venipuncture Allows procurement of larger quantities of blood Vein of choice: antecubital vein Blood values remain constant – regardless of venipuncture site, not arterial blood Venipuncture errors: Pretest, Procedure & Posttest Specimen Collection Procedures

16. Preventions for venipuncture errors:

17. 3. BM aspiration BM is located within cancellous bone & bone marrow cavities BM consists of pattern of vessels and nerves, differentiated hemopeitic cells, RE cells & fatty tissues Important to evaluate a number of hematologic disorders & infectious ds. Presence of suspicious of a blood disorder not always an indication for BM studies  decision on individual basis Before BM procedure: blood smear should be obtained from pts & diff. leukocyte count done Specimen Collection Procedures

18. 3. BM aspiration: Clinical Implications Clues for many ds. – presence, absence, ratio of cells Abnormal cell patterns: Multiple myeloma, plasma cell myeloma, macroglobulinemia Chronic or Acute leukemias Anemia (megaloblastic, macrocytic & normocytic) Toxic states that cause BM depression & destruction Neoplastic ds. – BM invaded by tumour cells Agranulocytosis –  white cell production Platelet dysfunction Infectious ds – histoplasmosis & tubercuklosis Def. of body iron stores, microcytic anemia Lipid or glycogen storage ds.

19. Normal Hypoplastic Hyperplastic Bone Marrow

23. Basic blood tests: Complete blood count (CBC) Basic screening test – most frequent ordered laboratory procedures Valuable diagnostic test: hematologic and other body systems, prognosis, response to treatment and recovery Consist of series of tests – no., variety, percentage, concentrations & quality of blood cells: White blood cell count (WBC): leukocytes fight infection Diff. white blood cell count (Diff.): specific pattern of WBC Red blood cell count (RBC): Hematocrit (Hct): measures of RBC mass Hemoglobin (Hb): main component of RBCs and transport O 2 and CO 2 RBC indices: calculated values of size and Hb content of RBCs – important in anemia evaluations Mean corpuscular volume (MCV) Mean corpuscular hemoglobin concentration (MCHC) Mean corpuscular hemoglobin (MCH) Stained red cell examination (film or peripheral blood smear) Platelet count (often included in CBC) Red cell distribution width (RDW): degree of variability and abN cell size Mean platelet volume (MPV): index of platelet production

24. Adult Reference Ranges for Red Blood Cells Measurement (units) Men Women Hemoglobin (gm/dL) 13.6–17.2 12.0–15.0 Hematocrit (%) 39–49 33–43 Red cell count (10 6 /µL) 4.3–5.9 3.5–5.0 Reticulocyte count (%) 0.5–1.5 Mean cell volume (µm 3 ) 82–96 Mean corpuscular hemoglobin (pg) 27–33 Mean corpuscular hemoglobin concentration (gm/dL) 33–37 RBC distribution width 11.5–14.5

25. White blood cell count (WBC; Leukocyte count) Leukocytosis vs Leukopenia ??? Clinical Implications

26. Leukocytosis Leukopenia Increase of only one type of leukocyte Rarely caused by a proportional increase in leukocytes of all types Of a temporary nature (leukemoid reaction) must be distinguish from leukemia In leukemia: permanent & progressive Acute infection: depends on severity of infection, pts resistence, age and marrow efficiency & reserve Other causes: Leukemia, Myeloproliferative disorder, Trauma, Tissues injury, Malignant Neoplasm, Toxins, Drugs, Acute hemolysis, Hemorrhage, After splenectomy, Polycythemia vera & Tissue necrosis No eveidence of clinical ds.: Physiologic leukocytosis (excitemnt, stress, exercise, pain, cold or heat, anesthesia), Sunlight, UV irradiation, Nausea, Seizures & Vomitting. Viral & bacterial infection Hypersplenism Bone marrow depression caused by heavy-metal intoxication, ionizing radiation, drugs Primary BM disorder: Leukemia, Aplastic anemia, Pernicious anemia, Myelodisplastic syndromes, congenital disorder etc. Immune-associated nuetropenia Marrow-occupying ds (fungal infection, metastatic tumour) Pernicious anemia.

27. 2. Diff. white blood cell count (Diff; Differential Leukocyte Count) Total count of circulating WBC, differentiated according to 5 types of leukocytes – each with specific fx. Percentage of the total number of leukocytes (WBC) The distribution (number & types) of cells and the degree of increase or decrease are dx significant. Neutrophils Pyogenic infections (bacterial) Eosinophils Allergic disorders & parasitic infections Basophils Parasitic infection, some allergic disorder Lymphocytes Viral infections (measles, rubella, chicken pox) Monocytes Severe infections, by phagocytosis

28. 3. Red cell count Important in evaluation of anemia or polycythemia Determines the total number of erythrocytes in a microliter of blood Clinical Implications:  RBC values vs. Erythrocytosis

29.  RBC values Erythrocytosis Anemia Hodgkin’s ds & other lymphoma Multiple myeloma Leukemia Myeloproliferative disorder Acute & chronic hemorrhage Lupus erythematous Addison’s ds Rheumatic fever Subacute endocarditis Chronic infection Primary erythrocytosis (PV, erythemic erythrocytosis) Secondary erythrocytosis (Renal ds, extrarenal tumours, High altitude, pulmonary ds, cardiovascular ds, alveolar hypoventilation, Hemoglobinopathy, tobacco, carboxyhemoglobin Relative erythrocytosis (dec. in plasma volume): dehydration – vomiting & diarhea

30. 4. Hematocrit (Hct); Packed cell volume (PCV) Important measurement for anemia & polycythemia Hematocrit – ‘to separate blood’ Test mechanism: plasma & cells are separated by centrifugation Measures the RBC mass Percentage of volume of packed RBCs in whole blood (PCV) Clinical implications:  Hct vs  Hct = ?????????

31.  Hct  Hct Anemia Leukemias Lymphomas Hodgkin’s ds Adrenal insufficiency Chronic ds. Acute & Chronic blood loss Hemolytic reaction: transfusion of incompatible blood, reactions to chemicals or drug, infectious agents or physical agents such as severe burns, prosthetic heart valves. Erythrocytosis Polycythemia vera Shock – when hemoconcentration rises considerably.

32. HOWEVER…. Hct may or may not be reliable immediately after even a moderate loss of blood or after transfusion Hct may be N after acute hemorrhage Hct is parallels the RBC when the cells are of N size Pts with microcytic or macrocytic anemia – NOT TRUE Iron def. anemia with small RBCs  Hct decreased …due to microcytic cells pack to a smaller volume

33. 5. Hemoglobin; Hb Main component of erythrocytes Vehicle for O 2 and CO 2 transportation The O 2 -combining capacity is directly proportional to [Hb] Hb determination is important Evaluation of anemia Determine severity of anemia Treatment response monitoring Evaluation of polycythemia Clinical implications: DECREASED vs INCREASED

34. Variation in Hb level: Occurs after transfusions Hemorrhage Burns Hb and Hct provide valuable information in an emergency situation if they are interpreted not in an isolated fashion but in conjunction with other pertinent laboratory data  Hb  Hb Anemia states (Hb must be evaluated along with Hct and RBC; Iron-def., thalassemia, pernicious anemia, hemoglobinopathies, liver ds., hypothyrodism, hemorrhage-chronic & acute, Hemolytic anemia) Polycythemia vera Congestive heart failure COPD

35.  RBC, Hct, and/or Hb Relative polycythemia:  Hb-Hct or RBC caused by  plasma volume Dehydration Absolute or True polycythemia: Primary (PV, erythemic erythrocytosis) Secondary: Appropriate vs Inappropriate Appropriate: Physiologic conditions – altitude, cardiopulmonary disorder. Increased affinity to O 2 Inappropriate: Renal tumor or cyst, Hepatoma, Cerebral hemangioblastoma Clinical implications of POLYCYTHEMIA :

36.  RBC, Hct, and/or Hb Clinical implications of ANEMIA : Pathophysiology states: Examples: Hypoproliferative anemia Marrow aplasia, Myelopthisic anemia, Anemia of chronic ds, etc Maturation defect anemias Cytoplasmic – hypochromic anemias Nuclear – Megaloblastic anemia Combined: Myelodisplastic syndromes Hyperproliferative anemias Hemorrhagic – Acute blood loss Hemolytic – a premature, accelerated destruction of RBCs Dilutional anemias Pregnancy Splenomegaly

37. RBC indices Define the size & Hb content of the RBC Consist of MCV, MCHC and MCH To differentiate anemias: by cell size: Macrocytic, Microcytic & Normocytic by colour: Hypochromia, Hyperchromia, Anisochromasia, Polychromasia

38. Microcytic red cells (MCV 62fl) Normocytic red cells Macrocytic red cells (MCV 105 fl)

39. Hyperchromic cells (  MCHC) Normochromic cells (N MCHC) Hypochromic cells (  MCHC)

40. Mean Corpuscular Volume (MCV) – index of single erythrocyte volume (fL) MCV (fL) = Hct (%) X 10 RBC (10 12 /L) Mean Corpuscular Hemoglobin Concentration (MCHC) – average [Hb] in RBCs MCHC (g/dL) = Hb (g/dL) X 100 Hct (%) Mean Corpuscular Hemoglobin (MCH) – average Hb weight per RBC MCH (pg/cell) = Hb (g/dL) X 10 RBC (10 12 /L)

41. Red Cell Size Distribution Width (RDW) – indication of the degree of anisocytosis RDW (CV%) = Standard deviation of RBC size X 100 MCV

42. Sedimentation Rate (Sed Rate); Erythrocyte Sedimentation Rate (ESR) The rate for which erythrocytes settle out of anticoagulated blood in 1 hour Sedimentation – occurs when the erythrocytes clump or aggregate together in a column-like manner ( ROULEAUX FORMATION ) Changes are related to alterations in plasma proteins N state : erythrocytes settle slowly – N RBCs do not form rouleaux

43. The test is based on the fact that inflammatory and necrotic processes cause an alteration in blood proteins, resulting in aggregation of RBCs, which makes them heavier and more likely to fall rapidly when placed in a special vertical test tube. The faster the settling of cells, the higher the ESR ESR is used in diagnosis of temporal arthritis, rheumatoid arthritis and polymyalgia rheumathica, also useful in monitoring the progression of inflammatory ds. ESR

44. 1 = Normal ESR 2 = Normal ESR with reddish plasma in hemolysis (disease or artifact) 3 = Blurring of the plasma-erythrocyte border in reticulocytosis 4 = White turbidity and blurring in severe leukocytosis of leukemia 5 = Accelerated ESR and lipemic plasma after a fatty meal 6 = Accelerated ESR and icteric plasma 7 = "Zero" ESR in polycythemia 8 = Severely accelerated ESR in multiple myeloma

45. Normal ESR  ESR PV, eryhthrocytosis SC anemia, Hb C ds. Congestive heart failure Hypofibrinogenemia PK def. Hereditary spherocytosis Anemia – N ESR in iron-def. ; abN ESR in anemia of chronic ds alone or in combination with iron-def. Etc. All collagen ds. (SLE) Infections, pneumonia, syphilis, TB Inflammatory ds. (acute pelvic inf. Ds) Carcinoma, Neoplasms, Lymphoma Acute-heavy metal posioning Cell or tissue destruction, MI Toxemia, pregnancy Nephritis, Nephrosis Anemia – acute or chronic ds. Rheumatoid arthritis Etc.