Haemolytic Uraemic Syndrome



Haemolytic uraemic syndrome (HUS) occurs when there is thrombosis within small blood vessels throughout the body. This is usually triggered by a bacterial toxin called shiga toxin. It leads to the classic triad of:

  • Haemolytic anaemia: anaemia caused by red blood cells being destroyed
  • Acute kidney injury: failure of the kidneys to excrete waste products such as urea
  • Thrombocytopenia: low platelet count

The most common cause is a toxin produced by the e. coli 0157 bacteria, called the shiga toxin. Shigella also produces this toxin. The use of antibiotics and anti-motility medications such as loperamide to treat gastroenteritis caused by these pathogens increases the risk of developing HUS.

 

Presentation

E. coli 0157 causes a brief gastroenteritis, often with bloody diarrhoea. The symptoms of haemolytic uraemic syndrome typically start around 5 days after the onset of the diarrhoea.

Signs and symptoms of HUS may include:

  • Reduced urine output
  • Haematuria or dark brown urine
  • Abdominal pain
  • Lethargy and irritability
  • Confusion
  • Oedema
  • Hypertension
  • Bruising

 

Management

HUS is a medical emergency and has a 10% mortality. It needs to be managed by experienced paediatricians under the guidance of a renal specialist. The condition is self limiting and supportive management is the mainstay of treatment:

  • Urgent referral to the paediatric renal unit for renal dialysis if required
  • Antihypertensives if required
  • Careful maintenance of fluid balance
  • Blood transfusions if required

70 to 80% of patients make a full recovery.

 

Last updated August 2019