Page 97 - 15Diarrhoeaandvomiting

Diarrhoea and vomiting caused by gastroenteritis in children under 5 years

children stated that fluid deficits should be replaced over a minimum of 24 hours. That alert
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was published with the intention of minimising the risk of hyponatraemia when administering
IV infusions to children. The GDG was conscious of the fact that opinions regarding the optimal
rate of IV fluid replacement in dehydration due to gastroenteritis are varied, and more rapid
rehydration regimens have been widely advocated. In 1996, the American Academy of Pediatrics
recommended a rapid rehydration model, for example giving 20 ml/kg or more over the first hour
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depending on the individual child’s clinical condition. For many years, the WHO has advocated
rapid IV rehydration for severe dehydration, recommending administration of 100 ml/kg over the
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first 6 hours, and even more rapid rehydration in older children. The GDG was aware of an
increasing trend towards the use of rapid IV rehydration regimens in children with gastroenteritis,
as illustrated by the studies listed in Table 5.4. It has been argued that rapid administration of
IV fluids may improve gastrointestinal perfusion so that oral feeding can be reinstituted earlier,
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and that improved renal perfusion may assist in correcting acidosis and electrolyte imbalances.
The GDG was aware of a study on rapid IV rehydration currently in progress at The Hospital for
Sick Children, Toronto, Canada (see www.clinicaltrials.gov/ct2/show/NCT00392145). In this trial,
children attending the emergency department with dehydration secondary to gastroenteritis and
requiring IV rehydration are being randomised to a 20 ml/kg 0.9% normal saline bolus over 1 hour
or to ‘rapid intravenous rehydration’ consisting of a 60 ml/kg 0.9% normal saline bolus over 1 hour.
The primary outcome measure in this study is the clinical rehydration status after 2 hours, and
secondary outcomes include duration of hospitalisation and ability to tolerate oral rehydration.
The GDG concluded that it was not currently possible to make a clinical recommendation on the
optimal rate of IV fluid administration in children with dehydration due to gastroenteritis. The GDG
considered that this was a crucially important matter, and a priority area for research. A research
recommendation was therefore made regarding rapid IV rehydration. Importantly, the GDG did
recommend early implementation of ORT to complete rehydration as soon as fluids are tolerated.
The GDG considered that it is essential that plasma electrolyte concentrations are measured
at baseline when commencing IVT, and regularly thereafter. The NPSA patient safety alert on
administering IV infusions to children emphasises the importance of monitoring the plasma
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sodium concentration regularly in order to avoid dangerous hyponatraemia or hypernatraemia.
The GDG did not consider that it could make precise recommendations on the frequency with
which blood testing should be undertaken, and this would depend both on the results of prior
tests and on the particular risk factors in individual cases. Moreover, it did not consider that it
should provide specific advice on the actions needed in the event of electrolyte disturbances
being present. Consideration should be given to including potassium supplementation in the
IV fluid solution following measurement of the plasma potassium concentration. The fluid
solutions recommended in this guideline are all available preconstituted with potassium, at
either 10 mmol/l or 20 mmol/l.
The GDG recognised the specific risks associated with hypernatraemic dehydration in
gastroenteritis and the importance of safe management. In such cases, expert advice on fluid
management should be sought. No high-quality evidence was found on the relative safety of
different fluid regimes. However, the GDG recognised that there is common agreement that in
those with clinically significant hypernatraemia (plasma sodium concentration > 160 mmol/l),
fluid deficit replacement should be delivered slowly (typically over 48 hours) using an isotonic
solution (0.9% sodium chloride solution). The NPSA advice on IV infusions is that plasma sodium
should be reduced at a maximum rate of 0.5 mmol/l per hour, or more slowly if it has prevailed
for more than 5 days. Frequent monitoring of the plasma concentration is therefore essential in
such patients.

Recommendations on intravenous rehydration therapy

Treat suspected or confirmed shock with a rapid intravenous infusion of 20 ml/kg of 0.9%
sodium chloride solution.
If a child remains shocked after the first rapid intravenous infusion:

• immediately give another rapid intravenous infusion of 20 ml/kg of 0.9% sodium chloride
solution and
• consider possible causes of shock other than dehydration.

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