General Management

The aim of treatment is to replace fluid and electrolytes. Most children with gastroenteritis can be safely managed at home with advice and support from a healthcare professional if necessary. [1]

The main questions to consider in each case are:

1. Does this child need immediate resuscitation?
2. What way should I give replacement fluids?
3. What fluid should I use?
4. How much fluid should I give, and how quickly?
5. Should I give any other treatment in addition to fluids?
6. Which children are safe to let home, and what should I tell their parents?

Choice of fluid replacement route

Oral rehydration is generally the first-line treatment for all children with acute gastroenteritis who are not clinically shocked. For every 25 children (95% CI 14 to 100) treated with oral rehydration, it is estimated one would fail and require IV rehydration. [13] It is less invasive than IV rehydration with no evidence of any important clinical difference. [14]

Where oral rehydration is not feasible, nasogastric fluid replacement is preferred ahead of IV rehydration, [2] though local practice may vary.

IV rehydration is required in cases of shock; dehydration with altered level of consciousness; worsening of dehydration or lack of improvement despite attempts at oral rehydration; persistent vomiting despite appropriate fluid administration; and severe abdominal distension and ileus. [2]

Choice of fluid

For oral or NG rehydration, reduced osmolarity oral rehydration solution (ORS) is recommended (50/60mmol/L of sodium). [2] Lemonade, sports drinks or homemade ORS are not appropriate.

For IV rehydration, during the initial phase of restoring fluid volume, isotonic fluid (usually 0.9% NaCl) is recommended. Hypotonic solutions are associated with an increased risk of developing hyponatraemia. [2]

Once fluid volume has been restored, glucose should be added to the saline solution in the maintenance phase of IV rehydration (0.9% NaCl with 5% dextrose).

Volume and rate of fluid replacement

• Oral rehydration: Aim for 10-20ml/kg of ORS in frequent small amounts. [15] Replace deficit over 4 hours.
• NG rehydration:
  • Two regimes have been described
    • Rapid NG replacement: 25ml/kg/hr of ORS over 4 hours [15]
    • Standard NG replacement: replace the deficit over the first 6 hours, then give maintenance fluids over next 18 hours. This slower regime is preferred in infants <6 months, in the presence of significant comorbidities, or for children with significant abdominal pain.
  • IV rehydration:
    • Resuscitation phase: If the child is clinically shocked, 20ml/kg boluses of 0.9% NaCl should be given. If shock persists after a second, and certainly after a third bolus, consider contacting the paediatric ICU team.
    • Standard IV rehydration regime
      • Calculate child’s total deficit and maintenance requirement and replace over 24hrs
    • Rapid IV rehydration regime
      • Rapid IV rehydration with 20ml/kg/hr of 0.9% saline for 2 to 4 hours, followed by oral rehydration is now recommended [2]. The WHO recommends that IV rehydration should be completed within 3 to 6 hours depending on age. [1]
    • These regimes do NOT apply to children requiring fluids for another clinical reason (e.g. pneumonia)

Calculating deficit and maintenance

• Replacing child’s deficit
  • Estimate if the child has a 5% or 10% deficit (see “assessment of dehydration” section above)
  • Estimated deficit (in ml) is 5% (or 10%) X child’s weight in kg X 10
• Replacing child’s daily maintenance requirements (Holliday – Segar method) [2]
  • 100ml/kg for first 10kg of body weight, then
  • 50ml/kg for next 10kg of body weight, then
  • 20ml/kg for each subsequent kg of body weight
  • Divide this total by 24 to get the hourly maintenance fluid requirements
• Total fluid replacement rate
  • Decide over how many hours you want to replace the estimated deficit and add the calculated hourly maintenance requirement.