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