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Water comprises about 60% of the body weight in adult males, 50 to 55% in females and up to 75% in a newborn infant (1).
- in infants, extracellular compartment contains more water than intracellular space while in adults about two-thirds of total water is in the intracellular space, whereas one-third is extracellular water.
Dehydration can be defined broadly as the process of loosing body water which
leads eventually to hypohydration (1).
classification of dehydration
Dehydration can be classified according to the ratio of fluid to electrolyte
- characterised by isotonic loss of both water and solutes from the extracellular
fluid (ECF) e.g., - vomiting, diarrhoea or through inadequate intake
- no osmotic water shift from the intracellular fluid (ICF) to the ECF.
- water loss exceeds salt loss e.g. - through inadequate water intake, excessive
sweating, osmotic diuresis and diuretic drugs
- characterised by an osmotic shift of water from the ICF to the ECF
- sodium loss is higher than water loss e.g. in some instances of high sweat
or gastro-intestinal fluid losses or when fluid and electrolyte deficits
are treated with water replacement only
- characterised by an osmotic shift of water from the ECF to the ICF (1)
Dehydration is common in several types of patients:
The features of dehydration are:
- circulatory failure
- usually, hypernatraemia
Last reviewed 01/2018