Page 73 - 15Diarrhoeaandvomiting

Diarrhoea and vomiting caused by gastroenteritis in children under 5 years

GDG translation from evidence to recommendation

The GDG noted that there was a lack of evidence on this topic, No evidence was found for the
often described phenomenon of ‘doughy skin’, and so it was concluded that this finding could not
be relied on to clinically identify patients with hypernatraemic dehydration. The GDG also noted
that in some publications from North America the term ‘doughy skin’ was used with a different
meaning – seemingly being synonymous with ‘reduced skin turgor’, a sign of dehydration more
generally. Therefore GDG consensus was that the term ‘doughy’ was not helpful and hence it
has not been used in this guideline. On the other hand, it was the experience of GDG members
that hypernatraemic dehydration is associated with neurological signs such as an altered level
of consciousness, ‘jitteriness’ or muscle hypertonicity, and the presence of these signs should
prompt laboratory investigation.

Recommendation on assessment of hypernatraemic dehydration
Suspect hypernatraemic dehydration if there are any of the following:
• jittery movements
• increased muscle tone
• hyperreflexia
• convulsions
• drowsiness or coma.

4.2 Laboratory investigations for assessing dehydration

Introduction

There are potential biochemical complications associated with gastroenteritis that can only be
identified through blood testing. For example, electrolyte disturbances such as hypernatraemia
and hyponatraemia may occur. Hypoglycaemia may occur in some cases. Children with
gastroenteritis may become acidotic. Dehydration may lead to pre-renal failure or even acute
renal failure. To suggest that all children with gastroenteritis should undergo blood testing would
be inappropriate, and yet the clinician must consider the possibility that in some cases clinically
important biochemical abnormalities may occur that could require specific treatment. Evidence
was therefore sought on the incidence of such biochemical disturbances in children presenting
with gastroenteritis, and their accuracy in detecting severity of dehydration. An attempt was
made to determine whether the incidence of such complications was increased in specific and
clinically identifiable categories of patient.

Clinical questions
How common are biochemical abnormalities in children with gastroenteritis and dehydration?
How accurate are laboratory tests in detecting varying degrees of dehydration?
Evidence overview

After the primary screening, 40 papers were retrieved for reviewing. Most of the retrieved studies
had been published in the 1980s and 1990s, used a non-comparative study design and did not
give adequate data to calculate the incidences. In the end, five studies were included to provide
data on the incidence of biochemical disturbances in children with acute gastroenteritis. For
the second part of the question relating to diagnostic accuracy, two studies were included – a
systematic review of diagnostic studies and a prospective diagnostic study.

Incidence of biochemical abnormalities
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There were three prospective cross-sectional studies from the UK, 53,57,58 one from Turkey and
one retrospective case series from the USA. All three studies from the UK have already been
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included previously under Section 3.2.1.
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The first UK study included 1148 children younger than 16 years admitted to a sub-regional
infectious disease hospital with a diagnosis of gastroenteritis over a 1 year period. Of the
admitted children, 55% (635/1148) were younger than 1 year while 5% were over 5 years of age.

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