Your initial clinical assessment will stratify the child into minimal, mild to moderate, or severe dehydration (see Table 2) [1, 2]. This translates roughly into <5% loss in body weight, 5-10% loss of body weight and >10% loss of body weight and is essential for guiding treatment.
Scoring systems exist, but have not been adequately validated in clinical settings.
Consider also if hypernatraemic dehydration could be present (Na+ >145mmol/L). It is rare during gastroenteritis, with a frequency of <4% of all cases [2], but should be suspected if:
Other neurological signs: increased muscle tone, hyperreflexia, convulsions, drowsiness, coma