1a Update on (Approach to) Anemia-1 Year 4 Internal Medicine

1a Update on (Approach to) Anemia-1 Year 4 · Internal Medicine Collection: 4TH YEAR ALL NOTES / IMED / IMED 4.2 / Mogere -- Slide 1 Update on (Approach to) Anemia HOW TO EFFICIENTLY AND ACCURATELY WORK UP THE ANEMIC PATIENT <number Dr Alex Mogere Consultant physician Slide 2 Anemia - Definition Decrease in the number of circulating red blood cells Most common hematologic disorder by far Almost always a secondary disorder As such, critical for doctors to know how to evaluate/determine cause <number Slide 3 Anemia - Causes Blood loss Decreased production of red blood cells (Marrow failure/hypoptoliferative) Red cell maturation defects(ineffective erythropoiesis) Increased destruction of red blood cells Hemolysis <number Slide 4 Anemia Workup - Exaggerated Iron/TIBC/Ferritin Folate/B12 LDH/Bilirubin Haptoglobin/Urine for hemosiderin Coombs Test – Direct & indirect Hemoglobin electrophoresis Acid hemolysis(PNH) Osmotic fragility(rbcs resistance to hemolysis-thalassemia /hereditary spherocytosis) Rx iron/folate/B12 Type & Cross Transfuse 2-4 units GI Consult Hematology Consult – Bone Marrow <number Slide 5 ANEMIA <number Slide 6 <number Slide 7 Anemia History and Exam Reticulocyte count Blood film MCV Ferritin WBC, diff, platelets <number Slide 8 Anemia Workup - 1st Test RETICULOCYTE COUNT <number Slide 9 <number Slide 10 Reticulocyte Count - Absolute Value Retic % x RBC Count eg 0.01 x 5,000,000 = 50,000 Normal retic count,1-4% of the circulating RBCs in adults Normal up to 120,000/μl More accurate way to assess body’s response to anemia A retic count prdn index 2.5 indicates hemolysis is most likely Retic count < 2 implies hypoproliferative anemia or maturation disorder <number Slide 11 Anemia Workup If retic count is elevated, following tests not needed: Iron/Iron Binding Capacity/Ferritin Folate/Vitamin B12 Acid Hemolysis GI Consult Bone Marrow <number Slide 12 Hypoproliferative anemias No erythroid hyperplasia is noted in bone marrow At least 75 % of all cases of anemia are hypoproliferative Majority due to ida or inflammation Can result from marrow damage, iron def, inadequate epo stimulation,\n+/- Microcytic, hypochromic in mild ida or chronic inflammation <number Slide 13 Maturation disorders Characteristics include: Anaemia with inappropriately low retic prdn index Macro or microcytosis on smear,abnormal red cell indices 2 broad categories: Nuclear maturation defects(associated with macrocytosis) Cytoplasmic maturation defects(associated with microcytosis and hypochromia) <number Slide 14 Blood loss/hemolytic anaemia Hemolysis is associated with red cell prdn index / 2.5 times normal PBF –polychromatophilic macrocytes Acute blood loss not associated with retic change <number Slide 15 Anemia –PBF findings Look for size and shape of RBC’s - esp for variability in sizes & shapes\nIs there polychromasia present? (Often implies reticulocytosis) Is there a dimorphic population of RBCs(rbc transfusions, RA with ringed sideroblasts)? Are there platelet and WBC abnormalities? <number Slide 16 Mean Corpuscular Volume <number Slide 17 Anemia Workup - MCV <number Slide 18 Anemia – Normocytic (MCV 80-100) Most commonly caused by anemia of chronic disease Early iron deficiency often causes normocytic anemia as well Anemia of chronic investigation – particular hazard of ICU patients Combined deficiencies <number Slide 19 Anemia of Chronic Disease Common Develops over 1 to 2 months Non-progressive\nUsually mild to moderate but hematocrit < 0.20 occasionally 30% mildly microcytic(low Fe, TIBC low, transferrin saturation low) WBC, platelets normal or increased <number Slide 20 Anemia of Chronic Disease - Pathophysiology Cytokine effects (eg, IL-1, TNF) DNA & RNA iron-response elements  erythropoietin responsiveness (& production)\n transferrin synthesis  Fe mobilization from macrophages  Fe re-utilization in erythropoiesis  serum Fe despite adequate stores  serum ferritin Reticulocytopenia Anemia <number Slide 21 Effects of Interleukin-1 (IL-1) Stimulates fever granulopoiesis thrombopoiesis synthesis of: ferritin Ig fibrinogen, VIII CRP IL-2, IL-6 Inhibits erythropoiesis\n\nsynthesis of: transferrin albumin <number Slide 22 ANEMIA OF CHRONIC DISEASE - Causes Thyroid disease Collagen Vascular Disease Rheumatoid Arthritis Systemic Lupus Erythematosus Polymyositis Polyarteritis Nodosa Inflammatory Bowel Disease Ulcerative Colitis Crohn’s Disease Malignancy Chronic Infectious Diseases Familial Mediterranean Fever Renal Failure <number Slide 23 <number Slide 24 Marrow Failure Normocytic Anemia (MCV 80-100 fl) <number Slide 25 ANEMIA - Microcytic (MCV < 80) Iron Deficiency - High RDW (Red cell distribution width) (normal in human rbcs 11.5-14.5%) Thalassemia minor - Normal RDW Rare Sideroblastic anemia Metal poisoning (esp lead, aluminum) Occasional hemoglobinopathies Thalassemia major <number Slide 26 <number Slide 27 <number Slide 28 <number Slide 29 <number Slide 30 MCV, Retics, Blood film Ferritin Ferritin < 15 Ferri