Chronic kidney disease: anaemia

Chronic kidney disease: anaemia

Patients with chronic kidney disease (CKD) may develop anaemia due to a variety of factors, the most significant of which is reduced erythropoietin levels

Chronic Kidney Disease often leads to anaemia due to reduced levels of erythropoietin

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Importance: 41

. This is usually a normochromic normocytic anaemia and becomes apparent when the GFR is less than 35 ml/min (other causes of anaemia should be considered if the GFR is > 60 ml/min). Anaemia in CKD predisposes to the development of left ventricular hypertrophy - associated with a three fold increase in mortality in renal patients

Causes of anaemia in renal failure

• reduced erythropoietin levels
  Chronic Kidney Disease often leads to anaemia due to reduced levels of erythropoietin
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  Importance: 41
  • the most significant factor in CKD causing anaemia
  • CKD is associated with a decrease in the production of erythropoietin, a hormone produced by the kidneys that stimulates erythropoiesis in the bone marrow
  • reduced erythropoietin levels → diminished red blood cell production
• reduced absorption of iron
  • hepcidin is an acute-phase reactant
  • in CKD, hepcidin levels are often increased due to inflammation and reduced renal clearance
  • elevated hepcidin levels
    Elevated hepcidin levels in patients with CKD are a contributory factor to the development of iron-deficiency anaemia
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    Importance: 96
    lead to decreased iron absorption from the gut and impaired release of stored iron from macrophages and hepatocytes, reducing the iron available for erythropoiesis
  • additionally, metabolic acidosis, a common condition in CKD, can inhibit the conversion of ferric iron (Fe³) to its absorbable form, ferrous iron (Fe²), in the duodenum → reduced iron absorption.
• reduced erythropoiesis due to toxic effects of uraemia on bone marrow
• anorexia/nausea due to uraemia
• reduced red cell survival (especially in haemodialysis)
• blood loss due to capillary fragility and poor platelet function
• stress ulceration leading to chronic blood loss

Management

• the 2011 NICE guidelines suggest a target haemoglobin of 10 - 12 g/dl
  10 - 12 g/dl
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• determination
  determination
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  and optimisation of iron status
  optimisation of iron status
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  should be carried out prior to the administration of erythropoiesis-stimulating agents (ESA)
  erythropoiesis-stimulating agents (ESA)
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  .
  • oral iron should be offered for patients who are not on ESAs or haemodialysis
    Oral iron is first-line therapy for CKD patients not on ESAs or haemodialysis if Hb < 10 g/dL
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    Importance: 100
    . If target Hb levels are not reached within 3 months then patients should be switched to IV iron
  • patients on ESAs or haemodialysis generally require IV iron
    IV iron
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• ESAs such as erythropoietin and darbepoetin should be used in those 'who are likely to benefit in terms of quality of life and physical function'

+PassMedicine Notes

Patients with chronic kidney disease (CKD) may develop anaemia due to a variety of factors, the most significant of which is reduced erythropoietin levels. This is usually a normochromic normocytic anaemia and becomes apparent when the GFR is less than 35 ml/min (other causes of anaemia should be considered if the GFR is > 60 ml/min). Anaemia in CKD predisposes to the development of left ventricular hypertrophy - associated with a three fold increase in mortality in renal patients

Causes of anaemia in renal failure

• reduced erythropoietin levels
• the most significant factor in CKD causing anaemia
• CKD is associated with a decrease in the production of erythropoietin, a hormone produced by the kidneys that stimulates erythropoiesis in the bone marrow
• reduced erythropoietin levels --> diminished red blood cell production
• reduced absorption of iron
• hepcidin is an acute-phase reactant
• in CKD, hepcidin levels are often increased due to inflammation and reduced renal clearance
• elevated hepcidin levels lead to decreased iron absorption from the gut and impaired release of stored iron from macrophages and hepatocytes, reducing the iron available for erythropoiesis
• additionally, metabolic acidosis, a common condition in CKD, can inhibit the conversion of ferric iron (Fe³) to its absorbable form, ferrous iron (Fe²), in the duodenum --> reduced iron absorption.
• reduced erythropoiesis due to toxic effects of uraemia on bone marrow
• anorexia/nausea due to uraemia
• reduced red cell survival (especially in haemodialysis)
• blood loss due to capillary fragility and poor platelet function
• stress ulceration leading to chronic blood loss

Management

• the 2011 NICE guidelines suggest a target haemoglobin of 10 - 12 g/dl
• determination and optimisation of iron status should be carried out prior to the administration of erythropoiesis-stimulating agents (ESA).
• oral iron should be offered for patients who are not on ESAs or haemodialysis. If target Hb levels are not reached within 3 months then patients should be switched to IV iron
• patients on ESAs or haemodialysis generally require IV iron
• ESAs such as erythropoietin and darbepoetin should be used in those 'who are likely to benefit in terms of quality of life and physical function'