Paediatric Gastroenteritis

Introduction

• Fever and vomiting without diarrhea = red flag
• Diarrhoea makes UTI much more unlikely

ABC Fluids In Fluids Out

• Alertness and activity
• Breathing – Tachypnoea
• Circulation – Mottled, cool peripheries
• Fluid intake <50%
• Urine output <50%

Shock

• Rapid thread pulse
• Delayed central capillary refill >2 seconds
• Agitation/lethargy/coma
• Do NOT wait for hypotension

Red flags

• <6mo
• Severe abdominal pain
• Bilious vomiting
• Ileostomy
• Short gut syndrome
• >10 days diarrhea
• Bloody diarrhea/vomitus
• Vomiting without diarrhea
• Chronic kidney/cardiac disease
• Poor growth
• Fortified feeds
• Hypertonic fluids e.g. lucozade

Degree of dehydration

• Mild – <4% – No signs
• Moderate – 4-6%
  • Delayed CRT
  • Increased RR
  • Mild decreased skin turgor
• Severe – >/7%
  • CRT >3s
  • Mottled
  • Tachycardia, hypotension, ALOC
  • Deep acidotic breathing
  • Decreased skin turgor
• Significance of dry mucous membranes, sunken eyes are unclear

Investigations

• BSL
• Urine MCS
  • Mandatory in infant with vomiting and fever
  • May be unnecessary if diarrhea and older
  • Symptoms in age >4
• Consider VBG, FBC, UEC, AXR, stool MCS, BC, CXR depending on circumstances
  • Electrolytes must be checked if severe dehydration, doughy skin, requiring IV rehydration, altered conscious state, renal/cardiac disease, hypertonic fluids, profuse or prolonged losses or ileostomy

Management

• Shock – 20mL/kg N/saline PRN targeting cap refill <2 seconds, mentation, MAP >40+Age x 1.5
• Treat hypoglycaemia – 2.5mL/kg 10% or 0.5mL/kg 50% dextrose
• No signs of dehydration – If tolerating fluids at all, with no red flags and not massive losses – Discharge
• Some signs of dehydration – Trial of fluid
  • Fails – NG or IV depending on preference/age
• Shock as above

Trial of fluid

• Gastrolyte 10mL/kg/hr over 1 hour in small aliquots q5min
• Significant ongoing losses usually mandates NG rehydration or at least SSW admission
• Freedman et al. JAMA 2016 showed use of dilute apple juice (half-strength) in children with mild dehydration was superior to ORS for composite primary outcome of treatment failure, IV rehydration, unscheduled return, symptoms >7 days, weight loss >3% and worsened dehydration
• No increase in diarrhea secondary to theoretical osmotic effect of glucose
• Applicable to developed countries (vs. ORS studies in developing countries)

NG rehydration

• Rapid
  • >6mo without significant abdominal pain or red flags
  • 25mL/kg/hr for 4 hours
  • Halve rate if not tolerated and give ondansetron if >2yo
• Regular rate
  • <6mo, comorbidities, significant abdominal pain
  • Replace deficit over 6 hours then maintenance for 18 hours + ongoing losses

IV rehydration

• Rapid IV rehydration
  • If >4yo and moderate dehydration without significant abdominal pain or electrolyte disturbance
  • 10mL/kg/hr N/saline + 5% dextrose for 4 hours
• Normal rate IV rehydration
  • Replace deficit over 6 hours (or longer if significant electrolyte disturbance or severe dehydration

Ondansetron

• Not recommended if <6mo or <8kg
• 8-15kg = 2mg
• 15-30kg = 4mg
• >30kg = 8mg

Last Updated on November 20, 2021 by Andrew Crofton