Haemolytic Uraemic Syndrome

Disclaimer

These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline. 

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Aim 

To guide staff with the assessment and management of haemolytic uraemic syndrome.

Background

Haemolytic Uraemic Syndrome (HUS) is a disease characterised by:
  • Microangiopathic haemolytic anaemia (destruction of red blood cells).
  • Acute renal failure.
  • Thrombocytopaenia.

Typical haemolytic uraemic syndrome

  • Is among the commonest causes of acute renal failure in children.
  • Mortality of 5-10%.
  • In the majority of cases it follows gastrointestinal tract infection with verotoxin producing E. coli, but it also can be induced by Shigella, Campylobacter and various viruses. In most of these there is preceding diarrhoea, which is frequently bloody (D+HUS).

Atypical haemolytic uraemic syndrome

  • Represents 5-10% of cases.
  • May develop without a diarrhoea prodrome.

Causes:

  • Complement defects
  • Familial cases
  • Drug toxicity (e.g. chemotherapy, Tacrolimus, Cyclosporin, oral contraceptives, Valacyclovir)
  • Immune mediated (e.g. Quinine, Clopidogrel)
  • Malignancy
  • Hereditary (e.g. inborn error of cobalamin deficiency)
  • Connective tissue disease (e.g. SLE, scleroderma, antiphospholipid antibody syndrome)
  • Other glomerunephritides (e.g. APIGN, membranoproliferative GN).

Assessment

History

Most children with HUS present 5-10 days after the onset of a bloody diarrhoea with:
  • Oliguria
  • Haematuria
  • Anaemia
  • Oedema
  • Renal failure
  • Hypertension.
Myocardial infarction, stroke, pancreatitis, liver necrosis, encephalopathy and seizure have also been described.

Examination

  • Full system examination
  • Assessment of cardiovascular and intravascular volume status is very important.
Assess:
  • Thirst, restlessness and confusion
  • Capillary refill
  • Skin turgor
  • Oliguria
  • Fontanelle tension
  • Blood pressure
  • Heart rate
  • Evidence of oedema.

Investigations

  • FBC, film and differential
  • UEC
  • Liver function tests
  • CRP
  • Blood glucose level (BGL)
  • Coagulation profile
  • Group and hold
  • Blood cultures if Pneumococcal cause suspected
  • Stool microscopy, culture and sensitivity (MC&S)
  • Stool - Shiga-toxin producing E-Coli PCR 
  • Urinalysis and urine MC&S
  • Other investigations as clinically indicated (e.g. CXR, renal US, ECG, head CT or MRI, EEG).

Differential diagnoses

  • Sepsis
  • Acute post-Streptococcal glomerulonephritis
  • Disseminated intravascular coagulation
  • Immune thrombocytopaenic purpura (ITP)
  • Thrombotic thrombocytopaenia purpura
  • Systemic lupus erythematosis (SLE)
  • Vasculitis.

Management

Fluid management
  • Establish IV access
  • Hypovolaemia should be treated with 0.9% saline boluses, or packed red blood cells, depending on the clinical status (usually 0.9% saline in the ED setting)
  • In the presence of oligo-anuria and fluid overload, fluid should be administered cautiously and should not exceed insensible fluid losses plus urine output (or less)
    • Insensible fluids:
      • 0-10kg weight - give 25mL/kg/day
      • 10-20kg weight - give 12.5mL/kg/day
      • Then 5mL/kg/day for each additional kg over 20kg weight
  • Hyponatremia is treated with fluid restriction
  • Electrolyte abnormalities: please discuss with paediatric renal team
Altered consciousness/focal neurological signs
  • If these develop, immediate discussion should be undertaken with a senior colleague (e.g. ED consultant, renal consultant or PICU consultant)
Hypertension
  • Usually secondary to volume overload
  • If unresponsive to diuretics, try vasodilator treatment (e.g. Nifedipine)
Abdominal pain and vomiting
  • Due to colitis in post-diarrhoeal HUS
    • Treat initially with paracetamol
    • May require opiate analgesia (but this will decrease bowel motility and should be avoided if possible)
    • Do not prescribe NSAID's such as ibuprofen
Antibiotics
  • Indicated in pneumonia related HUS (not in typical D+HUS)

Further management

Indications for dialysis

  • Fluid overload resistant to diuretic therapy
  • Hyperkalaemia
  • Intractable acidosis
  • Symptoms of uraemia
  • Likely progression of one of the above

Patients needing dialysis (most) will usually be placed on peritoneal dialysis (PD). Exceptions are those with severe colitis, cerebral HUS or profound metabolic abnormalities (where haemodialysis or haemofiltration techniques may be considered).

All patients diagnosed with HUS must be admitted.

The paediatric renal team (and general surgical team for PD catheter / line placement) should be consulted early.

Bibliography

  1. AMH Children’s Dosing Companion (2015) Australian Medicines Handbook Pty Ltd
  2. Textbook of Paediatric Emergency Medicine 2nd Edition Cameron Elesevier 2012
  3. Nelson Textbook of Pediatrics: 20th Edition Robert M. Kliegman, Bonita M.D. Stanton, Joseph St. Geme, Nina F Schor Publisher: Elsevier 
  4. Textbook of Pediatric Emergency Medicine, Fleisher, Gary R. Ludwig, Stephen.  6th Edition. 2010

Endorsed by:  Director, Emergency Department   Date:  Feb 2018


 Review date:   Feb 2021


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