APPROACH TO ANEMIA Year 4 Internal Medicine Notes OmpathStudy

APPROACH TO ANEMIA Year 4 · Internal Medicine Collection: 4TH YEAR ALL NOTES / IMED / I MED BEAUTIFUL NOTES / CVS -- Slide 2 Update on (Approach to) Anemia How to efficiently and accurately work up the anemic patient 2 Dr Alex Mogere Consultant physician Slide 3 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 3 Slide 4 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 4 Slide 5 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 5 Slide 6 ANEMIA 6 Slide 7 7 Slide 8 Anemia History and Exam Reticulocyte count Blood film MCV Ferritin WBC, diff, platelets 8 Slide 9 Anemia Workup - 1st Test RETICULOCYTE COUNT 9 Slide 10 10 Slide 11 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 11 Slide 12 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 12 Slide 13 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 13 Slide 14 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) 14 Slide 15 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 15 Slide 16 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? 16 Slide 17 Mean Corpuscular Volume 17 Slide 18 Anemia Workup - MCV 18 Slide 19 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 19 Slide 20 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 20 Slide 21 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 21 Slide 22 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 22 Slide 23 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 23 Slide 24 24 Slide 25 Marrow Failure Normocytic Anemia (MCV 80-100 fl) 25 Slide 26 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 26 Slide 27 27 Slide 28 28 Slide 29 29 Slide 30 30 Slide 31 MCV, Retics, Blood film Ferritin Ferritin < 15 Ferritin ≥ 120 TIBC trial of Fe Rx anemia\ncorrected anemia\nnot corrected examine\nmarrow Fe stores Fe deficiency excluded Fe deficiency anemia Anemia Ferritin 15-