cbp (3)complete blood picture

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  • 1.Complete blood count in primary care COMPLETE BLOOD PICTURE Dr.N.R.K.Anil Kumar, Ist Year Post Graduate, Vishnu Dental College.

2. INTRODUCTION CBP or hemogram: One of the most common lab investigations. It assesses: Red blood cells (RBC count, hemoglobin, ESR, PCV, MCV, MCH, MCHC) White blood cells (WBC, DC) Platelets (platelet count, BT, CT) Blood grouping 3. RBC 4. NORMAL COUNTS NORMAL VALUES Males Females RBC Count 4.5 6 million/cu.mm Hb% 14 18 gm% 11.5 16.5 gm% PCV 42 52 % 36 48 % ESR 1 7 mm/ 1st hr MCV 78 90 cu.microns MCH 27 32 pico gms MCHC 30 38 % 5. Anemia- when blood has low O2 carrying capacity; insufficient RBC or iron deficiency. -Due to blood loss -Due to nutritional deficiency -Due to destruction of RBC -Due to defects in bone marrow 6. Polycythemia- abnormal increase in the RBC count. -8-11 million cells/mm3 -Physiologically seen in people living in high altitudes. -Pathologically it can be primary or secondary. -Primary is polycythemia vera, a myeloproliferative disorder. -Secondary seen in conditions like - respiratory disorders like emphysema - congenital heart disease - chronic carbon monoxide poisoning - repeated mild heamorrhages. 7. Hb % AGE Hb% At birth 25 gm% After 3rd month 20 gm% After 1 year 17 gm% Adult male 15 gm% Adult female 14.5 gm% Hb often accompanied by PCV can reflect - Decreased plasma volume (eg: dehydration, alcohol, cigarette, smoking, diuretics) or - Increased red cell mass (eg polycythaemia) 8. HEMATOCRIT (PCV) % of blood volume consisting of erythrocytes (red blood cells) In Males 40 45 % In Female 38 42 % 9. ESR Normally, red blood cells remain suspended uniformly in circulation called suspension stability of RBC. When blood mixed with an anticoagulant is allowed to stand in a vertical tube, the red cells settle down due to gravity with a supernatant layer of clear fluid. The rate at which the cells settle down is called erythrocyte sedimentation rate. Methods 1) westergrens method : 2) wintrobes method : 10. Factors affecting ESR : specific gravity of RBC, rouleaux formation, size of RBC, viscosity of blood, RBC count. variations in ESR : - less in infants and children - more in females - from 3rd month until parturition increased upto 35mm per hr. 11. ESR INCREASED ESR DECREASED All types of anemias except sickle cell anemia Sickle cell anemia Tuberculosis Allergic conditions Malignant tumors Polycythemia Rheumatoid arthritis Extreme leukocytosis Rheumatic fever Peptone shock Liver diseases It is especially useful in assessing the chronic diseases and their prognosis during treatement 12. MCV MCV (Mean corpuscular volume) PCV in 100 ml of blood x 10 MCV = RBC count in million per cc This is the average volume of the RBC Useful to classify the anaemia Microcytic, MCV < 80 cu.microns Normocytic, MCV 80 100 cu.microns Macrocytic, MCV > 100 cu.microns 13. MCH MCH (Mean corpuscular hemoglobin) Hb% in 100 ml of blood x 10 MCH = RBC count in million per cc This is the quantity of hemoglobin present in one RBC. Useful to classify the anaemia Normochromic, MCH 27 33 pg Hypochromic, MCH < 27 pg 14. MCHC MCHC (Mean corpuscular hemoglobin concentration) Hb% in 100 ml of blood x 100 MCHC = PCV IN 100 ml of blood Indicates the concentration of hemoglobin in one RBC. Most important absolute value in diagnosis of anemia. Normal range is 30 to 38 %. 15. RETICULOCYTE COUNT Reticulocytes: immature RBCs Number helps to determine causes of anemia. Normal reticulocyte count is 1.0-2.0% Low reticulocyte 2.5% = indicates anemia caused by RBC loss 16. RDW RDW = Red blood cell distribution width Standard deviation of red cell volume 100 mean cell volume Normal value is 11-15% If elevated, suggests large variability in sizes of RBCs 17. Definition of Anemia Deficiency in the oxygen-carrying capacity of the blood due to a diminished erythrocyte mass. May be due to: Erythrocyte loss (bleeding) Decreased Erythrocyte production low erythropoietin Decreased marrow response to erythropoietin Increased Erythrocyte destruction (hemolysis) 18. Evaluating the Patient with Anemia Check Hemoglobin/Hematocrit If female, is Hgb < 12 or Hct < 36? If male, is Hgb < 13.5 or Hct < 41? If Yes, Patient has ANEMIA! If No, they are fine. 19. Evaluating the Patient with Anemia Are the other cell lines also low? If WBC and platelets are both low, consider APLASTIC ANEMIA! Check medication list NSAIDS (phenylbutazone), Sulfonamides, Acyclovir, Gancyclovir, chloramphenicol, anti- epileptics (phenytoin, carbamazepine, valproic acid), nifedipine Check parvovirus B19 IgG, IgM Consider hepatitis viruses, HIV If Platelets are low consider TTP or HUS! Must check smear for schistocytes (for sign of microangiopathic hemolytic anemia) If renal failure, E. Coli O157:H7 exposure HUS If renal failure, neurologic changes, fever TTP 20. ANEMIA RETICULOCYTE COUNT LESS THAN 2.5 RETICULOCYTE COUNT MORE THAN 2.5 RED CELL MORPHOLOGY NORMOCYTIC NORMOCHROMIC MARROW DAMAGE, DECREASED ERYTHROPOITIN MICROCYTIC OR MACROCYTIC NUCLEAR : B12 DEF, FOLATE DEF, DRUG TOXICITY CYTOPLASMIC : Fe DEF ANEMIA, THALASSEMIA, SIDEROBLASTIC HEMOLYTIC ANEMIA OR HEAMORRHAGE 21. Evaluating the Patient with Anemia If MCV < 80, then its a microcytic anemia The three most common causes for microcytic anaemia are: Iron deficiency Thalassaemia Anaemia of Chronic disease Check serum iron, ferritin, TIBC If iron-deficiency anemia, look for sources of chronic bleeding heavy menstrual bleeding, consider colonoscopy Consider lead poisoning, copper deficiency, thalassemias. 22. Differentiating Microcytic Anemias Type of Anemia Ferritin TIBC Iron Other Features IDA Fe/TIBC18% Sideroblastic Normal Ringed Sideroblasts 23. Iron Deficiency Anemia Lab Findings Serum Iron LOW (< 60 micrograms/dL) Total Iron Binding Capacity (TIBC) HIGH ( > 360 micrograms/dL) Serum Ferritin LOW (< 20 nanograms/mL) Can be falselynormal in inflammatory states 24. Thalassemia Microcytic anemia Smear shows microcytosis with target cells 25. Anemia of Chronic Disease Usually normocytic, normochromic (but can become hypochromic, microcytic over time) Occurs in people with inflammatory conditions such as collage vascular disease, malignancy or chronic infection. 26. Evaluating the Patient with Anemia If MCV 80-100, then its a normocytic anemia Any inflammatory conditions that could result in anemia of chronic disease? Consider checking indirect bili, LDH, haptoglobin, reticulocyte count 27. Normocytic anaemia The causes of normocytic anaemia include: Bleeding Early nutritional anaemia (iron, B12, folate deficiencies) Anaemia of renal insufficiency Anaemia of chronic disease/chronic inflammation Haemolysis Primary bone marrow disorder 28. Evaluating the Patient with Anemia If MCV > 100, then its a macrocytic anemia Check Vit. B 12, folate Consider liver disease, alcoholism, myelodysplastic syndrome Check medications: hydoxyurea, AZT, methotrexate 29. Macrocytic anaemia Common causes: Alcohol Liver disease B12 or folate deficiency Thyroid disease Some drugs (especially hydroxyurea) 30. Cobalamin (Vitamin B12) Deficiency anemia Macrocytic anemia Lab Values Cobalamin level < 200 pg/mL Elevated serum methylmalonic acid Elevated serum homocysteine 31. Pernicious anemia: -ANTIBODIES TO intrinsic factor - diagnosed by checking antibody levels -Schilling test -Smear shows macrocytosis with hypersegmentattion of -Polymorphonuclear cells, with possible basophilic stippli 32. Folate Deficiency Macrocytic anemia Lab Values Low folate Increased serum homocystine NORMAL methylmalonic acid Smear shows macrocytosis with hypersegmented neutrophils 33. Vitamin B12 Deficiency Versus Folate Deficiency Vitamin B 12 Deficiency Folate Deficiency MCV > 100 > 100 Smear Macrocytosis with hypersegmented neutrophils Macrocytosis with hypersegmented neutrophils Pernicious anemia Yes NO Homocystine Elevated Elevated Methylmalonic Acid Elevated NORMAL 34. Evaluating the Patient with Anemia Any jaundice, elevated bilirubin, suspicious for hemolysis? Check for increased indirect bilirubin, increased LDH, decreased haptoglobin, increased reticulocyte count Any sign of infection? Malaria? Babesiosis? Is Coombs test positive? If yes, may be warm antibody hemolytic anemia; Consider drug as cause 35. hemolytiicbs LDH: elevated Indirect bilirubin: elevated (due to catabolism of Hgb) Haptoglobin: decreased Binds to Hgb and taken up by liver In a series of reports: Elevated LDH, low Haptoglobin was 90% specific Normal LDH, Haptoglobin >25 was 92% sensitive for ruling out hemolysis Reticulocyte Count: elevated Normal is 0.5-1.5% Anemia leads to increase Epo production leading to a reticulocytosis (4-5% increase above baseline) Positive Direct Antiglobulin Test (Coombs) 36. Anemia due to Destruction of Red Blood Cells Hemoglobinopathies Sickle Cell Anemia Hemolytic Anemia Hereditary spherocytosis Glucose-6-phosphate dehydrogenase (G6PD) Deficiency Thrombotic Thrombocytopenic Purpura (TTP) Hemolytic Uremic Syndrome Autoimmune Hemolytic Anemia Warm-antibody mediated Cold agglutinin Disease Infections Malaria Babesiosis Sepsis Trauma Includes some snake, insect bites 37. Lab Analysis in Hemolytic Anemia Increased indirect bilirubin Increased LDH Increased reticulocyte count Normal reticulocyte count is 0.5 to 1.5% > 3% is sign of increased reticulocyte production, suggestive of hemolysis Reduced or absent haptoglobin < 25 mg /dL suggests hemolysis Haptoglobin binds to free hemoglobin released after hemolysis 38. Special Considerations in Determining Anemia Acute Bleed Drop in Hgb or Hct may not be shown until 36 to 48 hours after acute bleed (even though patient may be hypotensive) Pregnancy In third trimester, RBC and plasma volume are expanded by 25 and 50%, respective