This is an updated guideline from Nice on anaemia in chronic kidney disease. The main changes relevant for us are the tests which should be used to diagnose it and the targets for treatment.
This guideline seems to be for any patient with CKD and GFR less than 60. I am not covering children, patients on erythropoietic stimulating agent (ESA) therapy or patients on dialysis in this summary as their care is generally managed in hospital, but they are covered in the guideline.
If the GFR is over 60, anaemia is unlikely to be due to CKD.
When to investigate
Investigate if the patient has Hb ≤ 11g/L or symptoms of anaemia.
How often to investigate
NICE advises to "carry out testing to diagnose iron deficiency and determine potential responsiveness to iron therapy and long term iron requirements every 3m". This seems a bit ambiguous to me. I can't imagine investigating all our CKD patients every 3m, even those with Hb of 11 or less, but that does seem to be what they are advising.
What tests to do
Just using ferritin and transferrin to diagnose iron deficiency isn't very accurate, because CKD is an inflammatory state. This is why NICE has advised different tests.
Use hypochromic red blood cells (HRC) < 6% (if sample will be tested within 6hrs which isn't likely for most of us).
If HRC isn't possible, use reticulocyte Hb content (CHr) ≤ 29pg.
If these are not possible, or if the patient has thalassaemia or thalassaemia trait, then use a combination of transferrin saturation <20% and serum ferritin < 10 mcg/L.
NB - this only applies if the patient is not on ESA therapy.
Serum ferritin shouldn't go above 800mcg/L, so review treatment doses if levels go over 500mcg/L.
If treatment hasn't helped after 3m, or if they are intolerant of oral iron supplementation, they should be considered for intravenous iron therapy.