Anaemia Flashcards
What is the definition of anaemia? and what are the cut offs for men and women?
Low Hb concentration and may be due to:
- low red cell mass
- or, increased plasma volume
Men: <13.5g/dl
Women: <11.5g/dl
What are the symptoms of anaemia?
Asymptomatic if slow onset - patient able to compensate
Generalised:
Fatigue, dyspnoea, headache/faintness, papitations, tinnitus, anorexia, angina
What are the general signs of anaemia?
May be absent
Pallor, hyperdynamic circulatory signs - tachycardia, ejection systolic murmur, cardiac enlargement → heart failure and peripheral oedema
What is Microcytic anaemia? and what are the causes?
Low Mean Cell Volume (≤ 27pg)
Iron deficiency anaemia
Thalassaemia - abnormal Hb formation
Sideroblastic anaemia
What is normocytic anaemia and what are the causes?
Normal MCV
Acute blood loss
Anaemia of chronic disease (can ↓MCV)
BM failure - ↓WCC or ↓Plateletes
Renal failure, Hypothyroidism (can ↑MCV)
Haemolysis (can ↑MCV)
Pregnancy
What is a combination of normocytic anaemia with ↓WCC and ↓plateletes likely to be?
Bone Marrow Failure
What is macrocytic anaemia?
High MCV
Vitamin B12/Folate deficiency
Alcohol excess/liver disease
Reticulocytosis, cytotoxics (hydroxycarbamide), myelodysplastic syndromes, marrow infiltration, hypothyroidism, antifolate drugs - Phenytoin
What is haemolytic anaemia and what would lead to its suspicion?
Normocytic/Macrocytic
Reticulocytosis,
Mild macrocytosis
↓Haptoglobin
↑Bilirubin and ↑Urobilinogen
Mild Jaundice
What factors can cause decreased marrow production?
Stem cell defects/dysfunction
Hypoproliferation
Marrow infiltration
Nutritional deficiencies
What are the intrinsic and extrinsic causes of stem cell dysfunction?
Intrinsic - Stem cell aplasia, stem cell abnormalities (e.g. Leukaemia)
Extrinsic - Drugs, viruses, chemicals, radiation - kill/impair stem cell function
What are the causes of hypoproliferation which cause anaemia?
Hypostimulation - renal insufficiency → low EPO; endocrinopathies
Extrinsic inhibition of proliferation - Cytokine inhibition (anaemia of chronic disease), Viral infections, Autoimmune reactions
What causes marrow infiltration?
Functional marrow space reduced by cancers (metastasis, lymphomas, myelomas, or leukaemias), or fibrosis
What nutritional deficiencies can cause anaemia?
Iron
Folate and B12
Protein malabsorption
What are the intrinsic factors which cause Haemolysis?
Abnormal Hb
HbS (Sickle) polymerises → Damage to RBCs
β-Thalassaemia causes excess α-globin chain precipitation, binding and damage to cell membranes
Membrane protein defects
- Hereditary spherocytoses/elliptocytoses cause abnormally shaped cells → less compressible and more readily lysed in spleen etc.
What extrinsic factors may lead to haemolysis?
Autoimmune reactions - destroy RBCs. (Alloimune - destory transfused RBCs)
Hypersplenism - ↑RBC lysis rates
Microangiopathic disorders - TTP, DIC
Infections - Malaria, Clostridia may lyse RBCs
What are the causes of iron deficiency anaemia?
Blood loss - menorrhagia
Poor diet - babies or children, specific diet/poverty
Malabsorption - Coeliac’s
GI blood loss - parasites such as hookworm
What are the signs of iron deficiency anaemia?
Koilonychia
Atrophic Glossitis
Angular Cheilitis
What investigations should be done for iron deficiency anaemia?
FBC
- Microcytic, hypochromic anaemia
- Ferritin decreased (but increased in inflammation)
- Decreased serum iron
- Increased Total Iron Binding Capacity
What is the treatment for Iron deficiency anaemia?
Treat the cause
Oral iron e.g. Ferrous Sulphate 200mg/8h
S/E: Nausea, abdominal discomfort, diarrhoea/constipation, black stools
What is anaemia of chronic disease?
Associated with many diseases, including chronic infection, vasculitis, RA, malignancy, RF
- Cytokine driven inhibtion of RBC production
What would the FBC show for anaemia of chronic disease?
Mild, normocytic anaemia
Normal/increased ferritin
What is the treatment for anaemia of chronic disease?
Treat underlying disease
- Treat inflammatory condition
- Treat renal failure with EPO
