Question of the Week, 21.3.2011
Severe dehydration is a common finding in sick children. It is either due to a decreased intake of water, since children commonly refuse to drink in this situation or due to increased losses of water due to sweating, polyuria e.g. in diabetes mellitus, or losses by diarrea or vomiting in gastrointestinal infections. Clinical findings like dry skin, dry mouth, low blood pressure and increased heart rate can often help to evaluate the severity of dehydration.
Many lab findings like hypernatremia, increased haematocrit or an increased base excess are used to objectify the clinical evaluation in order to justify either an invasive rehydration or a wait and see strategy, but a single valid lab result has not been established for this purpose.
Johannes Heymer