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Download The anaemic patient Basics and pitfalls
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The anaemic patient Basics and pitfalls Bettie Oberholster 2013 Day to day “Working” definition of anaemia Hb too low for age and gender at a given altitude Journey DESTINATION STARTING POINT Effective treatment Establishing the underlying cause Presence of an anaemia 1. PRODUCTION 2. PERIPHERAL LOSS Bone marrow Lack of nutritients (iron, vit B12, folate) Bleeding Primary BM disorders ↓ Thropic hormones (EPO, thyroid, androgens) Bone marrow suppression by e.g. drugs, virus infections Hemolysis BM Infiltration ↑Plasma volume Potential causes Which route ? Cause & Effective treatment DETOUR: waste time and may be expensive Anaemic Patient SHORT CUT: may land up at wrong destination or get lost Best Route ? GPS Route Guidance GPS: “History and clinical findings” • Obvious blood loss • Drug history e.g chemotherapy, ARV’s • Chronic disease e.g. renal disease, SLE, malignancy • Organomegaly • Family history GPS: “Reticulocyte count” Do not use the % count RPI: RETICULOCYTE PRODUCTION INDEX Blood loss Response to hematinics Bone marrow production defect Red cell indices RPI <2.0 RPI ≥2.5 HEMOLYSIS Hemolysis SCREEN: confirm the presence of hemolysis • Raised unconjugated bilirubin • Raised LDH • Decreased haptoglobin • Increased urinary urobilinogen • Haemosiderin in the urine (IV) You still need to find out WHY the patient is hemolysing Examination of blood smear is important for clues Direct coombs Red cell membrane studies Micro-angiopathic hemolytic anaemia DIC, TTP/HUS, PET/HELP GPS: “Red cell parameters” • MCV = mean corpuscular volume (mean size of a red cell) • MCH = mean corpuscular hemoglobin (mean Hb per red cell) Normochromic Normocytic Hypochromic Microcytic Macrocytic MCV and MCH normal MCV and MCH low MCV high Blood loss Iron deficiency Chemotherapy Anaemia of Chronic disease Megaloblastic Vit B12/folate def Drugs e.g MTX, AZT Haemolysis (RPI ≥2.5) Anaemia chronic disease Thalassaemia Bone marrow failure Hemoglobinopathy Mixed nutrient deficiencies (RDW high) Sideroblastic anaemia Lead poisoning Early iron deficiency Iron studies Renal functions Iron studies Non-megaloblastic Liver disease Alcohol ARV’s Hypothyroidism Myelodysplasia Reticulocytosis Vit B12 and RBC folate, TSH, LFT Important Iron, vit B12 and red cell folate studies BEFORE any blood transfusion GPS: “Iron studies” Serum Iron Transferrin % Transferrin saturation S-Ferritin ↓ ↑ ↓ ↓ Typical ↓ anaemia of Chronic disease ↓ ↓ Normal to raised Typical Iron Deficiency Normal ferritin does not exclude iron deficiency Ferritin: 30-100 and % sat < 16% May be iron deficiency in presence of an acute phase Soluble serum transferrin receptor assay (sTfR) Not all hypochromic microcytic anaemias are iron deficiencies or anaemia of chronic disease !! Thalassaemia or hemoglobinopathy (RBC count normal to high) Hb electrophoresis/abnormal hemoglobin screen (HPLC) Make sure that iron status is normal DNA testing to exclude alfa thalassaemia, lead levels and possible BM for sideroblastic anaemia Macrocytic anaemia Normal Vit B12/folate Normal LFT Normal TSH No drug history Do not miss underlying Myelodysplastic disorder GPS: “Phone a friend: Local Pathologist” • Clues blood smear findings • Advice further investigations GPS: “Bone marrow” Unexplained anaemia with low RPI FBC: pancytopenia, bicytopenia or abnormal WBC Abnormal cells on blood smear e.g. blasts, dysplasia Leuco-erythroblastic reaction BM not always the best route Unexplained Iron Deficiency ? Celiac disease • Antibodies •Small bowel biopsy •HLA-DQ2 and HLA-DQ8 •PNH Right destination Take home message
