Anaemia

INTRODUCTION

Anaemia is a label, not a specific diagnosis. Anaemia is defined as a haemoglobin (Hb) below the normal reference level for the age and sex of that individual. Symptoms include tiredness/fatigue, weakness, headache, faintness, effort angina and dyspnoea, palpitations, intermittent claudication.

Definition:

• Hb <130 g/L (♂)

• Hb <120 g/L (♀) <110 g/L—pregnant women, school-aged children

CLASSIFICATION OF ANAEMIA

The various types of anaemia are classified in terms of the red cell size—the MCV.

MICROCYTIC ANAEMIA—MCV ≤80 FL

The main causes of microcytic anaemia are iron deficiency and haemoglobinopathy, particularly thalassaemia.

Iron-deficiency anaemia

Iron deficiency is the most common cause of anaemia worldwide. The most common causes are chronic blood loss (haemorrhoids, menorrhagia, peptic ulcers, cancer, etc.), i.e. bleeding until proved otherwise, and poor diet.

Haemological investigations: typical findings

• Microcytic, hypochromic red cells

• Anisocytosis (variation in size), poikilocytosis (shape)

• Low s. iron

• ↑ Iron-binding capacity

• Low s. ferritin (NR: ♀ 15–200 mcg/L; ♂ 30–300 mcg/L, the most useful index)

• ↑ Soluble transferrin receptor factor

Treatment

• Correct the identified cause

• Iron preparations:

  • – oral iron (preferred method) daily up to 6 mths, e.g. Ferrograd C (avoid taking with milk), Ferro-Gradumet 325 mg (o)/d with orange juice or ascorbic acid until Hb is normal; can combine with folic acid

  • – parenteral iron is best reserved for special circumstances and with specialist advice. IM can cause a ‘tattoo’ effect. Give 0.5–1 g ferric carboxymaltose IV (consider cover with IV hydrocortisone 30 mins before)

Avoid blood transfusion if possible.

Response

• Anaemia responds after ~2 wks and is usually corrected after 2 mths

• Oral iron is continued for 3–6 mths to replenish stores

• Monitor progress with regular s. ferritin

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