Blood indices and its interpretation .pptx

Presentation on blood indices

1. Blood indices and its interpretation By : dr. nIDHI shah Guide : dr. shobhana prajapati

2. objectives To define & calculate the red blood cell indices To describe application of RBC indices in diagnosing various disorders To interpret indices along with histograms in brief Newer platelet indices Case scenarios

3. Wintrobe introduced calculations for determining the size, content and hb concentration of red cell. They are useful in the morphological characterization of anemias. They are calculated from the red cell count, hemoglobin concentration and hematocrit. They are called “red blood cell indices”.

4. What are Red blood cell indices? They are quantitative measurement of red blood cell, the amount and concentration of hemoglobin in them. Red cell indices are : -Mean cell volume(MCV) -Mean cell hemoglobin (MCH) - Mean cell hemoglobin concentration(MCHC). They are also called as “absolute values”. More recently R ed cell distribution width ( RDW ) and Platelet indices such as Mean platelet volume (MPV), Platelet distribution width (PDW) and Immature platelet fraction (IPF) has also been included.

5. Haematocrit - packed cell volume ( pcv )  

6. Hematocrit estimation MANUAL METHOD : anticoagulated whole blood is centrifuged in a wintrobe tube to completely pack the red cells. The volume of packed cells is read directly from the wintrobe tube . AUTMATION : Automated analyzers do not depend on centrifugation techniques to determine Hct , but instead calculate Hct by direct measurements of red cell number and red cell volume. Hct = Red cell number x Red cell volume

7. CAUSES OF HIGH AND LOW HEMATOCRIT Hematocrit Normal R ange : Males : 38.8-46.4 % Females : 35.4-44.4 % High Hematocrit is due to : Low Hematocrit is due to : Physiologically can be seen at high altitude Polycythemia vera Shock or dehydration Dengue hemorrhagic fever Cor pulmonale Blood loss ( Hemorrhage ) Hemolytic anemias Nutritional anemias Leukemia Bone marrow failure Erythropietin deficiency secondary to kidney disease.

8. Rule of 3 – correlating hemoglobin and hematocrit values Hemoglobin x 3 = hematocrit +/-3 For example : If patient’s hemoglobin is 14.8, then 14.8x3 = 44. (Actual hematocrit is 45%) The exception to this rule is in patients with hypochromic red cells. These patients will have hematocrits that are more than three times the hemoglobin.

9. MEAN CELL VOLUME ( Mcv ) MCV i s average volume of red blood cells. It is measured directly by automated instruments from the measurement of each red cell. With semi-automated instruments and by manual method, mcv is calculated by dividing the hematocrit by red blood cell counts. MCV = HCT (%) x 10 RBC count (millions / cmm )

10. MCV is expressed in femtoliters or FL ( of a liter ). Normal value is 80 to 96 fl. Red cell with decreased volume (< 80fl) is called “Microcytes”. Red cell with normal volume (80 – 96 fl ) is called “Normocytes”. Red cell with an increased volume (>96fl) is called “Macrocytes”.  

11. increased mcv - Macrocytic anemia CAUSES OF INCREASED MCV: MEGALOBLASTIC ANEMIA CHRONIC ALCOHOLISM LIVER DISEASE HYPOTHYROIDISM MYELODYSPLASTIC SYNDROMES APLASTIC ANEMIAS POST SPLENECTOMY DRUGS SUCH AS ANTI CONVULSANTS(PHENYTOIN) AND ANTI TUMOR AGENTS(METHOTRAXATE)

12. DECREASED MCV - MICROCYTIC ANEMIA CAUSES OF DECREASED MCV: IRON DEFICIENCY ANEMIA THALASSEMIA LEAD POSISONING ANEMIA OF CHRONIC DISEASE SIDEROBLASTIC ANEMIA

13. MEAN CELL HEMOGLOBIN (MCH) The MCH is the content (weight) of the hb of the average red cell. It is obtained by dividing hemoglobin value by red cell count. MCH = H emoglobin (in grams/dl) x 10 Red cell count(in millions/ cmm )

15. MEAN CELL HEMOGLOBIN CONCENTRATION MCHC is the average concentration of hb in a given volume of packed red cell. It is obtained by dividing hemoglobin value by hematocrit . It is expressed in grams/dl or grams/l. MCHC = Hemoglobin (in grams/dl) x 100 HCT in (%) MCHC is the most important parameter which will alert the user about the possibility of a spurious result since it is derived from multiple parameters. MCHC indicates whether population of red cell is normochromic or hypochromic.

16. Causes of increased and decreased mchc Reference range is 33 to 36 g/dl. Decreased MCHC is due to : Increased MCHC due to : Microcytic Hypochromic Anemias such as Iron deficiency anemia , Anemia of chronic inflammation, Thalassemias Plasma : Cold agglutinins, Hyperlipidemia , Hyperbilirubinemia, Hyperprotinemias Red cell : Spherocytosis, Sickle cell disease, Autoimmune hemolytic anemia Technical error : Artifactual due to improper mixing of blood.

17. Red cell distribution width ( rdw ) It is a quantitative measure of variation in size of red cells. It is helpful in differential diagnosis of hemolytic anaemias. Normal reference range of rdw -cv in human red blood cells is 11.5 %-14.5 %.

18. Causes of high rdw Along with normal mcv : Early iron deficiency anemia, Early vitamin b12 and folate deficiency, Hemoglobinopathies like sickle cell anemia ALONG WITH HIGH MCV : Vitamin b12 and folate deficiency Liver disease Autoimmune hemolytic anemias Alcoholism ALONG WITH LOW MCV : Iron deficiency anemia RBC fragmentation Thalassemia Intermedia

19. Histograms ALONG WITH RED BLOOD CELL INDICES:

20. NORMAL RBC HISTOGRAM

21. MICROCYTOSIS RBC graph has shifted to the left and is starting from close to the Y-axis. This indicates that maximum number of cells are smaller in size (MCV is low). RBC graph shifted to the left

22. MACROCYTOSIS RBC graph has shifted to the right and is extends beyond 100 fL This indicates that maximum number of cells are larger in size (MCV is high ). RBC graph shifted to the right

23. Dimorphic picture RBC histogram shows two peaks, which indicate a dimorphic population of rbc’s . This could be seen in transfused patients, in recovering iron deficiency patients, sideroblastic anemia. MCV is generally normal. Low RBC count, high RDW.

24. Red cell distribution width Red cell distribution width (RDW) is a quantitative measure or numerical expression of anisocytosis. It is a coefficient of variation of the distribution of individual RBC volume, as determined by automated blood cell counters. The rdw value reflects size variability in red cell. • High rdw values mirror a large range in red cell size.

25. The RDW-CV is a calculation based on both the width of the distribution curve and the mean cell size. It is calculated by dividing the standard deviation of the mean cell size by the MCV of the red cells and multiplying by 100 to convert to a percentage. A normal range for the RDW-CV is approximately 11.0% - 15.0%. Because it is a calculation, the RDW-CV is dependent not only on the width of the distribution curve but also the MCV of the red cell population and may not always reflect the actual variation in red cell size. A homogenous population of red cells with a narrow distribution curve and low mcv may have an elevated RDW-CV . A heterogeneous population of red cells with a broad distribution curve and a high MCV may have a normal RDW-CV.

26. PLATELET INDICES Mean platelet volume (MPV) Platelet distribution width (PDW) Immature platelet fraction (IPF)

27. Mean platelet volume ( mpv ) MPV : is a measurement that describes average size of platelet in the blood This parameter provides an indicator as to whether the bone marrow is manufacturing platelets normally or there is some kind of production pressure from the periphery like excessive destruction. MPV is inversely proportional to degree of platelet maturity. Normal range : 7.4-10.4 fl Increased MPV Decreased MPV It means platelets are larger than normal  Megathrombocytes . Idiopathic thrombocytopenic pupura Sepsis (Recover Phase) DIC, TTP Myeloproliferative disorders, CML It means platelets are smaller than normal  Microthrombocytes . Aplastic anemia Megaloblastic anemia Chemotherapy

28. Platelet distribution width ( pdw ) It is analogous to the red cell distribution width. It compares the uniformity and heterogenecity of platelet size. Normal values : 9-13 fL It is a good tool to distinguish between essential thrombocythemia (PDW increased) and reactive thrombocytosis (PDW normal). Increased values seen in : - Aplastic anemia -Essential thrombocythemia -Chemotherapy -Sepsis False elevation of PDW ?? --- RBC fragmentation

29. Immature platelet fraction ( ipf ) It is a parameter used to assess thrombopoiesis . IPF or Reticulated platelets, contains RNA and can be detected using nucleic acid dyes. Reference range : 1.1-6.1% It is a sensitive marker for assessing regenerating bone marrow. It is found to be increased approximately 1-2 days before platelet recovery. IPF have a clinical utility in assessing disease activity, predicting treatment response in : Sepsis with thrombocytopenia ITP, DIC , TTP Dengue : attainment of peak and rise in ipf helps to predict platelet recovery within 1-2 days and can be used to rationalize platelet transfusion in dengue.

30. CASE SCENARIOS

31. CASE : 1 A case of 35 year old female presented in OPD with complains of Weakness, Fatigue ,Breathlessness

32. The decreased Hb level indicates anemia . The decreased MCV indicates the Microcytosis . The decreased MCHC indicates the Hypochromia . The increased RDW indicates the variation of red cell size or anisocytosis . For this patient wbc and platelets were normal and non contributory to diagnosis, This all goes toward the “Iron Deficiency Anemia ”.

33. CASE : 2 A patient presents with pallor, frontal bossing and leg ulcers. Values:- Hb : 6.2 gm/dl RBC : 5.31* 10^6/ cmm PCV : 32.3 % MCV : 62fL MCH : 18 pg MCHC : 24 gm/dl RDW : 18 % TC : 8000 / cmm Platelets : 10000 / cmm

34. The decreased HB level indicates anemia . The decreased MCV indicates the Microcytosis . The decreased MCHC indicates the Hypochromia . The increased RDW indicates the variation of red cell size or anisocytosis . But here look at the RBC count – it is increased which goes towards “ Thalassemia ”

35. Mentzer index The Mentzer index ,described in 1973 by william C. Mentzer , is the MCV divided by the RBC count. It is said to be helpful in differentiating Iron deficiency anemia from Beta thalassemia . Formula : MCV RBC COUNT Interpretation: if it is <13 --- Beta thalassemia . If it is > 13 ---- IDA

36. Case : 3 A 60 year old male patient presented with complaints of tingling, numbness and weakness since 1 month. Values:- hb : 4.5 gm/dl RBC : 2.45 * 10^6 / cmm WBC : 5100 / cmm Platelets: 48000 / cmm MCV : 110fL MCH : 34.3 pg MCHC : 33.6 gm/dl RDW : 18%

37. The decreased HB indicates anemia . The increased MCV indicates Macrocytosis . The MCH and MCHC normal indicates Normochromic cells. The increased RDW indicates anisocytosis . The smear shows Hypersegmented neutrophils . Along with sign, symptoms and lab findings diagnosis goes towards “MEGALOBLASTIC ANEMIA”.

38. Case : 4 A 30 year old male patient who had road traffic accident and has been given 2 units of blood Blood picture

39. Limitations of rbc indices Though the test for RBC INDICES is cost effective and simple,it has own limitation. Such as,   It is a screening test not a diagnostic test MCV is not reliable when anisocytosis is present In combine or dimorphic anemia again MCV is not reliable MCV does not reflect the diameter of the RBC, it is a volume of RBC False high or false low value, which should be evaluated further.

40. Reference ranges Indices Normal Range RBC Count Males : 4-5.9 Million/ uL , Females :3.8-5.2 Million/ uL Hematocrit or PCV Males : 38.8-46.4 %, Females : 35.4-44.4 % Mean Cell Volume (MCV) 80-96 fL Mean Cell Hemoglobin (MCH) 27-33 pg Mean Cell Hemoglobin Concentration (MCHC) 33-36 g/ dL Red cell distribution Width (RDW) 11.0% - 15.0%. Platelet Count 1.5-4.5 Lakhs / uL Mean platelet volume (MPV) 7.4-10.4 fl Platelet Distribution Width (PDW) : 9-13 fL Immature Platelet Fraction (IPF) 1.1-6.1%

41. references Dacie and L ewis Practical Hematology 12 th edition Kawthalkar Essential of Clinical Pathalogy 2 nd edition Atlas and Text of Hematology by Tejindar singh 4 th edition The ABC of CBC interpretation of CBC and Histogram by DP Lokwani 2 nd edition

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