Anaemia (Guidelines)

Audience

• Highland HSCP 

The haemoglobin concentration reference range for most men is 130 to 170g/L and women is 120 to 150 g/L. The cause of anaemia can often be separated by trends in the MCV – see separate sections on microcytosis or macrocytosis. However the MCV is not completely sensitive or specific and there may be more than one cause of anaemia occurring together so detailed investigation is often required.

Causes

• Iron deficiency and bleeding
• Anaemia of chronic disease/inflammation
• Testosterone deficiency – common in elderly men
• Thyroid dysfunction
• Vitamin B12 or folate deficiency
• Alcohol and liver disease
• Renal failure especially if eGFR less than 30 mL/min or associated with diabetes
• Pregnancy
• Medications especially chemotherapy, anti-androgens and immunomodulatory drugs – check British National Formulary (BNF
• Malignancy including myeloma
• Haemolysis; including drug-induced
• Thalassaemia and haemoglobinopathy
• Bone marrow failure e.g. aplastic anaemia, myelodysplasia
• Bone marrow infiltration e.g. leukaemia, non-haematological cancer

History and examination 

Look at causes and work through systematically. Look at older blood counts.

Suggested investigations
See sections on microcytosis and macrocytosis. If the anaemia is normocytic (for the patient) then all causes should be excluded.

• Check inflammatory markers
• Renal and liver function
• Immunoglobulins

Management

This depends on the underlying cause. If the above causes have been excluded then the most likely explanations are anaemia of chronic disease or a bone marrow failure syndrome. The latter is frequently associated with other cytopenia or changes on the blood film. In patients with otherwise normal full blood count and for whom there are no concerning features we suggest monitoring the full blood count in general practice. In anaemia of chronic disease the treatment is that of the underlying cause and if you are concerned then a referral to the appropriate specialty should be made.

If there is haemolysis or concerns about myelodysplasia then a Clinical Dialogue/referral to haematology is required.

If there is no evidence of inflammation please consider referring to haematology if the haemoglobin is persistently less than 100 g/L in men or less than 90 g/L in women for evaluation into possible myelodysplasia. If there is uncertainty of whether referral is required especially when the haemoglobin concentration is greater than 90 g/L please discuss via Clinical Dialogue. If the patient is not referred to haematology then continued monitoring for any changes is likely to be appropriate.

For cases of renal anaemia refer to nephrology.