The anaemic patient Basics and pitfalls
description
Transcript of The anaemic patient Basics and pitfalls
The anaemic patient
Basics and pitfalls
Bettie Oberholster2013
Day to day “Working” definition of anaemia
Hb too low for age and gender at a given altitude
Journey
STARTING POINT
DESTINATION
Presence of an anaemia
Effective treatment
Establishing the underlying cause
Potential causes
Bone marrowLack of nutritients (iron, vit B12, folate)
Bone marrow suppression by e.g. drugs, virus infections
Bleeding
Hemolysis
↑Plasma volume
Primary BM disorders
BM Infiltration
1. PRODUCTION 2. PERIPHERAL LOSS
↓ Thropic hormones(EPO, thyroid, androgens)
Anaemic Patient
Cause & Effective treatment
Fast and cost-effective
DETOUR: waste time and may be expensive
SHORT CUT: may land up at wrong destination or get lost
Which route ?
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
RPI <2.0
RPI ≥2.5
Blood lossResponse to hematinics
Bone marrow production
defectHEMOLYSIS
Red cell indices
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 NormocyticMCV and MCH normal
Hypochromic Microcytic
MCV and MCH low
Macrocytic
MCV high
Blood lossChemotherapyHaemolysis (RPI ≥2.5)
Anaemia chronic diseaseBone marrow failureMixed nutrient deficiencies (RDW high)Early iron deficiency
Iron deficiencyAnaemia of Chronic disease
ThalassaemiaHemoglobinopathySideroblastic anaemiaLead poisoning
MegaloblasticVit B12/folate defDrugs e.g MTX, AZT
Non-megaloblastic Liver diseaseAlcoholARV’sHypothyroidismMyelodysplasiaReticulocytosis
Iron studiesRenal functions
Iron studies 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 Iron Deficiency
↓ ↑ ↓ ↓
Typical anaemia of Chronic disease
↓ ↓ ↓ Normal to raised
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
Do not miss underlying Myelodysplastic disorder
Macrocytic anaemia
Normal Vit B12/folateNormal LFTNormal TSHNo drug history
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