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4 Assessing dehydration

and shock

4.1 Clinical assessment

Introduction
Dehydration is the primary serious complication of gastroenteritis. To manage gastroenteritis
safely and effectively it is necessary to be able to recognise the presence of dehydration based
on clinical assessment. Those with dehydration require fluid administration to replace the fluid
and electrolyte deficit. Many have suggested criteria for determining the degree of dehydration in
order to try to accurately estimate the deficit replacement to be administered. Some children with
gastroenteritis may develop hypovolaemic shock, requiring specific emergency treatment. It is
critically important that the manifestations of shock are immediately recognised. In this chapter,
these matters are addressed in detail.
Recognising the child with a lesser degree of dehydration is not as easy as identifying the
presence of advanced dehydration or hypovolaemic shock. In practice, when assessing a
child with gastroenteritis, the clinician should first consider whether there are risk factors for
dehydration, i.e., how likely it is that the child is or may soon become dehydrated. Second, the
clinician should decide whether there are symptoms and signs present that indicate the presence
of dehydration. The GDG therefore considered both of these matters as important elements in the
assessment for dehydration.

4.1.1 Risk factors for dehydration

Clinical question
What factors are associated with an increased risk of dehydration?

In total, 40 papers of potential importance were retrieved after the literature search, of which 35
were excluded after being assessed. Thus four case–control studies describing risk factors for the
development of dehydration and published in five papers have been included. 69–73 Since all the
studies were conducted in developing countries, efforts have been made to describe clinical risk
factors relevant to the UK paediatric population.

Evidence overview
The first paper was a case–control study from India with a study sample of 379 infants with
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acute gastroenteritis of less than 24 hours’ duration. Cases were defined as infants with moderate
or severe gastroenteritis (n = 243), while controls had no or mild dehydration (n = 136). Various
factors were evaluated for the risk of dehydration: aetiology, feeding practices, management of
diarrhoea, hygiene practices, history of measles and clinical features on admission. Univariate
analysis identified various risk factors associated with increased risk. However, after controlling
for confounding variables during multivariate analysis, only two factors were found to be
significantly associated with an increased risk of dehydration: withdrawal of breastfeeding during
diarrhoea (OR 6.8; 95% CI 3.8 to 12.2; P < 0.001) and not giving oral rehydration salt (ORS)
solution during diarrhoea (OR 2.1; 95% CI 1.2 to 3.6; P = 0.006). Age, severity of symptoms and
nutritional status were identified as major confounding variables. There was a significant risk of
dehydration if the child was younger than 12 months (OR 2.7; 95% CI 1.5 to 5.0; P = 0.001), had
increased frequency of stool > 8 per day (OR 4.1; 95% CI 2.4 to 7.0; P < 0.00001), had increased
frequency of vomiting > 2 per day (OR 2.4; 95% CI 1.4 to 4.0; P = 0.001) or was severely
malnourished with weight for age < 60th centile according to the Indian Academy of Paediatrics
(IAP) classification (OR 3.1; 95% CI 1.6 to 5.9; P = 0.001). [EL = 2+]

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