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.

Read the full CAHS clinical disclaimer.

Aim

To guide Emergency Department (ED) staff with the assessment and management of haemolytic uraemic syndrome.

Background^1,2

Haemolytic Uraemic Syndrome (HUS) is a disease characterised by:

Microangiopathic haemolytic anaemia (destruction of red blood cells).
Acute renal failure.
Thrombocytopaenia.
HUS is among the commonest causes of acute renal failure in children.
Mortality of 5-10%.

Causes¹:

Infectious:

Post diarrhoeal illness (usually bloody):
- Shiga toxin producing Escherichia coli (STEC), accounts for 90% of cases.
- Shigella, Campylobacter and other viruses.
Non-diarrhoeal
- Streptococcus pneumoniae, Approximately 10% of all paediatric HUS.
- Usually present with pneumonia with effusion.

Non-infectious:

Complement defects.
Familial cases.
Medications (e.g. chemotherapy, tacrolimus, ciclosporin, oral contraceptives, valaciclovir, quinine).
Immune mediated.
Malignancy.
Hereditary (e.g. inborn error of cobalamin deficiency).
Connective tissue disease (e.g., systemic lupus erythematosus (SLE), scleroderma, antiphospholipid antibody syndrome).
Other glomerulonephritides (e.g., acute post-infectious glomerulonephritis (APIGN), membranoproliferative glomerulonephritis (GN)).

Assessment^2,3

History

Most children with HUS present 5-10 days after the onset of a bloody diarrhoea with:

Oliguria
Haematuria
Anaemia
Oedema
Renal failure
Hypertension.

Pneumococcal associated HUS usually presents with pneumonia.

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.

Consider:

Thirst, restlessness and confusion
Capillary refill
Skin turgor
Oliguria
Fontanelle tension
Blood pressure
Heart rate
Evidence of oedema.

Investigations

Full blood picture
Electrolytes, Urea and Creatinine (EUC)
Liver function tests (LFT)
C-Reactive Protein (CRP)
Blood glucose level (BGL)
Coagulation profile
Group and hold
Blood cultures if pneumococcal cause suspected
Stool microscopy, culture and sensitivity (MC&S)
Stool – Shigella-toxin producing E-Coli PCR
Urinalysis and urine MC&S.
Other investigations as clinically indicated (e.g. Chest X-ray, renal ultrasound, electrocardiogram (ECG), head computerised tomography (CT) or magnetic resonance imaging (MRI), electroencephalogram (EEG)).

Differential diagnoses

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

Management^1,4

Fluid management

Establish IV access
Hypovolaemia should be treated with sodium chloride 0.9% saline boluses, or packed red blood cells, depending on the clinical status (usually sodium chloride 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
Hyponatraemia 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 Paediatric Critical Care (PCC) consultant)

Hypertension

Usually secondary to volume overload
If unresponsive to diuretics, try vasodilator treatment (e.g. Isradipine, clonidine).

Abdominal pain and vomiting

Due to colitis in post-diarrhoeal HUS
- Treat initially with paracetamol (refer to Paracetamol Monograph – Medication Management Manual (internal WA health only)
- May require opiate analgesia (but this will decrease bowel motility and should be avoided if possible)
- Do not prescribe non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.

Antibiotics

Indicated in pneumonia related HUS. Refer to Acute Respiratory Tract Infection – Empiric Guidelines - ChAMP.

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.

Nursing

Complete and record a full set of observations on the Observation and Response Tool and record additional information on the Clinical Comments chart.
Complete a full set of neurological observations if clinically indicated.
Maintain an accurate record of fluid balance
Obtain an accurate patient weight.

Bibliography

Niaudet P & Boyer OG, UpToDate: Overview of hemolytic uremic syndrome in children. 2021 Overview of hemolytic uremic syndrome in children - UpToDate (health.wa.gov.au)
Textbook of Paediatric Emergency Medicine 3rd Edition Cameron P, Browne GJ, Mitra B, et al (2018) Publisher: Elsevier Edition updated
Nelson Textbook of Pediatrics: 21st Edition Robert M. Kliegman, St Geme JW, Blum MJ et al. 2020 Publisher: Elsevier
Fleisher and Ludwig’sTextbook of Pediatric Emergency Medicine, 8th Edition. Shaw K and Bachur RG (2020) Publisher: Wolters Kluwer

Endorsed by:	Nurse, Co-director, Surgical Services	Date:	Apr 2024
		Review date:	Apr 2022

This document can be made available in alternative formats on request for a person with a disability.