Page 89 - 15Diarrhoeaandvomiting

Diarrhoea and vomiting caused by gastroenteritis in children under 5 years

Table 5.1 Compositions of WHO ORS solution and of ORS solution products available in the UK

Product Osmolarity Glucose Sodium Chloride Potassium Citrate Bicarbonate
(mOsm/l) (mmol/l) (mmol/l) (mmol/l) (mmol/l) (mmol/l) (mmol/l)
WHO ORS solution 311 111 90 80 20 – 30
pre-2002
WHO ORS solution 245 75 75 65 20 10 –
post-2002
Dioralyte® (Sanofi-Aventis) 240 90 60 60 20 10 –
Electrolade® (Thornton & 251 111 50 40 20 – 30
Ross)
Rapolyte® (KoGEN) 110 60 50 20 10 –

There are no studies that compare the new (2002) WHO ORS solution with products currently
used in the UK. It is therefore unknown whether there are any clinically important differences
between these solutions, particularly in terms of rehydration failure, cessation of vomiting,
duration or volume of stool losses, or incidence of symptomatic hyponatraemia. Hyponatraemia
was important to consider as it has been suggested that low-sodium ORS solution might be
associated with hyponatraemia. While some studies suggested this might be so, the effect was
not statistically significant and there were no reports of clinically significant hyponatraemia with
adverse effects such as convulsions. There were no studies with hyponatraemia as a primary
outcome. The GDG therefore concluded that ORS solution products currently available in the
UK were appropriate for use in ORT.
Cereal-based ORS solution may have a beneficial effect in reducing diarrhoeal losses compared
with glucose-based ORS solution. However, the available evidence applied only to cholera and
was of low quality. Rice-based ORS solution is currently not available in the UK. The GDG did
not consider that there was evidence to support its use.

Clinical question
What oral fluid regimen should be used?
No studies were identified that compared the clinical effectiveness of various oral fluid regimens
in the treatment of dehydrated children with gastroenteritis. Likewise, there were no studies
that specifically addressed the optimal volume of fluid to be used for rehydration, the optimal
route of administration (bottle, beaker, cup, spoon, syringe or nasogastric), the frequency of
administration, the time interval over which rehydration should be attempted, or the indicators
for reintroduction of oral fluids after IVT.

Evidence overview
Since no study was identified directly answering the question, evidence was included from
three RCTs that had recruited children with dehydration for the primary purpose of comparing
different ORS solution products. The study populations in all three trials included some children
presenting with severe dehydration and/or shock, and all these children were started on ORT
following initial rehydration with IVT.

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In the first multicentre trial, the efficacy of reduced osmolarity ORS solution was compared
with that of the pre-2002 WHO ORS solution. Children presenting with severe dehydration
were initially rehydrated with IVT for 2 hours and then randomised to the two groups as soon
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as they were able to accept fluids orally. The second trial compared oral glucose electrolyte
solution with oral sucrose solution in equimolar concentrations using the WHO-recommended
electrolyte formula. In children with severe dehydration (fluid deficit ≥ 10% body weight), 70%
of their estimated fluid deficit was replaced within the first 2 hours by IVT and further rehydration
was achieved by ORT. The third trial evaluated the safety and efficacy of glycine-based ORS
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solution compared with ORS solution containing no glycine. Children with severe dehydration in
both groups were initially given IVT until blood pressure and pulse returned to normal, and then
rehydration was completed within 4 hours by giving either of the two ORS solutions.

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