Gastroenteritis

Question 1

What is your impression and goals of management?

• A previously well 2½ year old girl presents to the Emergency Department with vomiting, watery diarrhoea, and fevers for 48 hours. Her father is currently unwell with vomiting and diarrhoea. She was sent home from childcare yesterday with several other children who reportedly having similar symptoms.*
• OR*
• An 18-month-old boy presents with 24 hours of diarrhoea and vomiting. He has reduced feeding to <50% of normal intake and his mother is concerned he is lethargic.*

Answer 1

Impression: gastroenteritis given the triad of diarrhoea, vomiting and fever. I am concerned about possible hypovolaemic shock given the lethargy in the context of fluid losses, and I would perform a rapid bedside assessment using the paediatric assessment triangle and proceed to a complete A-E assessment as appropriate.

There are a number of causes of gastroenteritis including:

• Viral (most common) → rotavirus, norovirus, adenovirus, astrovirus
• Colonising bacterial → Campylobacter spp., Shigella spp., Salmonella spp., E. coli
• Non-colonising bacterial → Staphylococcus aureus, Bacillus cereus, vibrio cholerae
• Parasitic → Giardia lamblia, Cryptosporidium parvum, Amoeba Histolytica

Differentials

• GIT → appendicitis, obstruction (intussusception, hernia, other), Hirschprung disease, IBD, FTT, cows milk protein intolerance
• Non-GIT → sepsis, meningitis, UTI, DKA

Goals of management

1. Initial assessment according to paediatric assessment trial and A-E. If necessary, emergency resuscitation and stabilisation
2. Targeted history, examination and investigations to: 1) confirm gastroenteritis, 2) assess severity of dehydration + complications, 3) exclude DDX
3. Management: supportive (replace fluids and electrolytes), parental education

Question 2

Gastroenteritis: history

Answer 2

History

• Classical presentation → diarrhoea, vomiting, fever (high fever usually non-viral cause), abdominal pain, anorexia, headache, myalgia
• Targeted history to exclude differentials
• Fluid status assessment
  
  • Output (character, volume, frequency) → diarrhoea (blood, mucus), vomiting (bilious?), urine
  • Input → feeding (well/not well, breastfeeding/formula/solids)
• Risk factors → unvaccinated (esp. rotarix), immunosuppressed, infectious contacts (day care, travel)
• Paediatric history → PMHx (short gut, Hirschsprung’s, ileostomy, FTT), FHx, medications/allergies/vaccinations, SHx, developmental

Question 3

Gastroenteritis: examination

Answer 3

A-E: Rapid assessment to exclude severe dehydration or electrolyte imbalances. If required, urgent resuscitation with 20mls/kg boluses of IV NS

Examination

• Vitals
• General → pallor, irritability, altered consciousness, decreased activity (red flags)
• Fluid status assessment
• Abdominal examination → focal vs. diffuse tenderness, signs of peritonism, bowel sounds, distension
• General → growth parameters, developmental milestones

Question 4

Gastroenteritis: investigations

Answer 4

Investigations

Clinical diagnosis so no investigations usually required. Indications: bloody stools, significant abdominal pain, neonates, immunocompromised

• Bedside → stool MCS/OCP (only if bloody diarrhoea, returned travellers, immunocompromised), U/A, BSL
• Bloods → FBC, EUC + BSL (prior to IVF), blood cultures
• Imaging → only indicated where there are red-flags, such as suggestion for bowel obstruction (AXR), intussusception (abdominal US), appendicitis (CT)

Question 5

Gastroenteritis: management

Answer 5

Disposition

• Consult paediatrics and admit if → shock, severe volume depletion, failed oral rehydration, electrolyte abnormalities, intractable or bilious vomiting, neurological abnormalities, possibility of alternate severe diagnosis (e.g. obstruction), complex comorbidities
• Consider transfer to PICU if → severe electrolyte disturbance, shock requiring more than 40 mL/kg in fluid boluses

Supportive

• Rehydration
  
  • Oral rehydration → ORS e.g. gastrolyte/hydralyte/pedialyte and aim for 10 mL/kg/hr
    
    • Stop any feed fortifications (such as extra scoops of formula or Polyjoule)
    • Continue breastfeeding, but more often to maintain hydration
    • Early feeding + usual diet once rehydrated
  • Nasogastric rehydration → use for moderate dehydration, can be administered rapid or slow depending on context.
  • IV rehydration → if not tolerating oral rehydration, severe dehydration, failed NG rehydration, already have IV in situ
• ± Anti-emetics → if vomiting continues; ondansetron wafers recommended (not for children <6 months or <8kg)
• Not recommended → probiotics, antibiotics (except for specific bacterial pathogens in selected cases)
• Monitoring
  
  • Bare weigh patients 6 hourly in moderate and severe dehydration, who are receiving NGFR or IV fluids
  • Reassess fluid status (input/output and adjust rehydration)

Follow up care

• Discharge criteria → diagnosis of gastroenteritis, child rehydrated and ongoing GI losses are not profuse, passed urine in ED or within last 4 hours
• Education and follow-up
  
  • Parent education + factsheet
  • GP review within 48 hours
  • Safety net seek medical advice for deteriorating clinical status or worrying signs/symptoms