Anaemia

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• Blood Components

1. Reduction in haemoglobin concentration causing decrease in oxygen carrying capacity
2. It is not a diagnosis - is an abnormal clinical finding
3. RBCs
   1. 8 um diameter, biconcave, flexible oval
   2. 10^12 made in bone marrow everyday - erythropoiesis
      1. 120 day lifespan - destroyed by macrophages in spleen
4. Haemaglobin
   1. 640 million molecules per RBC
   2. Tetrameric structure - 2 pairs of different polypeptide chains, 1 haem molecule
      1. Globin (polypeptide chains)
         1. Permits variability in oxygen affinity
         2. Protects haem from oxidation
         3. Makes the molecule soluble
   3. HbF has higher affinity for oxygen, HbS has lower affinity (than normal)
   4. 3 Main types
      1. HbA - alpha2beta2
         1. 96-98% in blood
      2. HbA2 - alpha2delta2
         1. 1.5-3.2% in blood
      3. HbF - alpha2gamma2
         1. 0.5-0.8% in blood
   5. Contains 65% of body iron
      1. 30% is ferritin and haemosiderin
         1. Rest is myoglobin, haem enzymes (cytochromes), transferrin

1. May not be any - depends on speed of onset, severity and age
2. Tiredness/Lethargy
3. Shortness of breath
4. Palpitations
5. Headaches
6. In old people
   1. Cardiac failure
   2. Angina
   3. Intermittent claudication - muscle pain
   4. Confusion
7. Signs
   1. General
      1. Pallor of mucous membranes - if Hb <9-10 g/dL
      2. Hyperdynamic circulation
         1. Tachycardia
         2. Bouncing pulse
         3. Cardiomegaly
         4. Systolic flow murmur
      3. Signs of heart failure
   2. Specific
      1. Koilonychia (spoon nails) - iron deficiency
      2. Jaundice - Haemolytic/megaloblastic anaemia
      3. Leg ulcers - sickle cell disease
      4. Bone deformities - thalassaemia major
      5. Associated infetions/bruising - bone marrow failure

1. Microcytic - MCV <80 fl
   1. Iron deficiency
   2. Thalassaemia trait
   3. Anaemia of chronic disease
2. Normocytic - 80-95 fl
   1. After acute blood loss
   2. Haemolytic anaemias
   3. Bone marrow failure
3. Macrocytic - >95 fl
   1. Megaloblastic - vitamin B12/folate deficiency
   2. Non-megaloblastic - alcohol, liver disease, myelodysplasia

1. In all cases
   1. Full blood count - red cell indices, white cell/platelet count
   2. Blood film
2. Depending on Blood Count/Film
   1. Reticulocyte count
   2. Hb electrophoresis
   3. Bone marrow biopsy
      1. Taken from pelvis
         1. Short needle for aspirate
         2. Long needle for core
   4. Bilirubin/LDH/haptoglobin test
   5. Haematinics
      1. Ferritin, iron studies, vitamin B12, folate

1. Most common - 500 million people affected
2. Caused by limited ability to absorb iron
   1. Excess loss due to bleeding common
   2. Iron requirement goes up in pregnancy, adolescence and menstruation
3. Average daily intake of iron - 10-15 mg (best source is meat)
4. Clinical features
   1. General signs/symptoms
   2. Painless glossitis (tongue inflammation)
   3. Angular stomatitis (corners of mouth)
   4. Koilonychia
   5. Children
      1. Irritability
      2. Poor cognitive function
      3. Decline in psychomotor development
5. Reticuloendothelial stores (haemosiderin and ferretin) depleted before anaemia develops
6. Causes
   1. Chronic Blood Loss
      1. Uterine
      2. Gastrointestinal
         1. Peptic ulcer disease
         2. Aspirin/NSAIDs
         3. Malignancy
         4. Inflammatory bowel disease
         5. Hookworm
      3. Haematuria
   2. Increased demand
      1. Prematurity
      2. Pregnancy
      3. Growth
   3. Malabsorption
      1. Coeliac disease
      2. Gastrectomy
   4. Poor diet