Fluid/Electrolyte/Acid-base abnormalities
Volume depletion, commonly referred to as dehydration, occurs whenever water and salt losses exceed intake. If oral intake remains adequate, dehydration is usually avoided. Infants are especially prone to dehydration because they have higher proportional body fluid turnover than older children or adults. If an infant develops anorexia or vomiting, dehydration develops sooner than in the older child because of the higher proportion of obligatory losses. Diarrhoea in conjunction with vomiting is the most common cause of dehydration in children. Dehydration can also occur from increased sweating produced by fever; acute infections that decrease oral intakes, such as pneumonia or meningitis; or conditions that cause increased renal losses of salt and water such as pyelonephritis or excess diuretic use.
