Wednesday, 10 November 2010

MRCP revision battle 45.2: Anaemia in chronic renal failure

Anaemia is common in chronic renal failure and is usually due to:
  • decreased production of erythropoetin
  • iron deficiency

Treatment should be considered when Hb <11
The target for treatment should be Hb between 10.5 and 12.5

Correct any iron deficiency first; note that oral iron is often not enough and IV iron therapy may be needed.

If there is still anaemia the likely eryropoetin deficiency must be addressed.  Options are:
  • Eryropoetin replacement with either epoetin (=recombinant human erythropoetin) or 
  • darbepoetin (=hyperglycosylated derivative of epoetin with a longer half life)

Side effects of epoetin include:
  • hypertension (25%)
  • bone aches
  • 'flu'
  • rashes, urticaria
  • pure red cell aplasia 
    • low reticulocyte count
    • anaemia
    • antibodies
  • increased risk of DVT as increased PCV

If no response to epoetin consider if the patient has an infection, inflammatory condition or aluminium toxicity, all of which can impair epoetin's effectiveness.

Note that blood transfusions are generally avoided in renal patients as they would make matching for transplants more difficult

Cross your legs as we move on to a battle of diuretics...