Volume depletion in children

Volume depletion is a common condition encountered in paediatric practice. Early signs and symptoms in infants and children are often non-specific and frequently under-recognised.

Signs and symptoms vary by age and specific aetiology but can include generalised irritability, thirst, decreased activity, tachycardia, delayed capillary refill, dry mucous membranes, sunken eyes, decreased skin turgor, and decreased urination. Specific causes of volume depletion such as diabetic ketoacidosis and acute tubular necrosis may present with increased urination. A meticulous general paediatric history and physical examination is the most sensitive means of determining that a child is in a state of volume depletion.

Hypotension is a late sign of volume depletion in children and often heralds overt circulatory collapse.

Initial management of children with mild or moderate volume depletion is with oral rehydration therapy. Regardless of aetiology, children with severe hypovolaemia and shock should be treated promptly with intravenous isotonic crystalloid solution.

With timely recognition and appropriate intervention, volume depletion in children is readily reversible, with an excellent prognosis.

Volume depletion is a deficit in water and solutes from the extracellular component of total body fluid that results in decreased blood volume. This is distinct from dehydration, which more specifically indicates a total body water deficit. In children, the most common cause of dehydration is gastroenteritis, which can lead to severe volume depletion. Volume depletion can also be secondary to haemorrhage, excessive renal fluid and solute losses, increased insensible losses, and redistribution of body fluid into extravascular tissue (third spacing). Symptoms of volume depletion can range from thirst (with mild depletion) to irreversible shock and death in severe cases.