Volume depletion in adults

Patient may note decreased urinary frequency or volume, or more concentrated urine.

Patients with frequent and severe diarrhoea may be unable to maintain adequate oral intake to compensate for these losses, and so become volume-depleted. Older people and children are especially vulnerable.

Patients with frequent and severe vomiting are often unable to maintain adequate oral intake to compensate for these losses and so become volume-depleted. Older people and children are especially vulnerable.

The passage of characteristic black, tarry, foul-smelling stool is indicative of blood from a gastric or duodenal haemorrhage that has passed through the ileum and colon. Such bleeds are a frequent cause of volume depletion.

The passage of significant amounts of bright red, bloody stool is an important indicator for the possibility of volume depletion.

Hospitalised patients may become volume-depleted due to large volume losses from nasogastric suction or enteral drainage if they do not receive appropriate maintenance or replacement fluids.

May be associated with uncontrolled diabetes and the presence of glucose in the urine, causing osmotic diuresis.

A sustained poor intake of fluids and solutes can result in volume depletion. Children and older people are especially vulnerable.

Prolonged heavy physical exertion in warm environments, with limited access to solute and water replacement, can quickly lead to volume depletion.

Likelihood depends on the size of the burn. If extensive, burns can quickly lead to volume depletion, as the fluid lost has a similar solute composition to plasma.

As much as 7-8 L of fluid can be sequestered in the bowel, especially when the obstruction is distal.

Substantial volumes may be sequestered in the retroperitoneum.

This can lead to blood and fluid being sequestered into a third-space, such as the thigh muscle compartment.

Substantial volumes may be lost into the abdominal cavity.

Non-specific; may be a manifestation of decreased tissue perfusion.

Non-specific; may be seen with volume depletion alone, but is greatest in settings of true water depletion (dehydration and hypernatraemia), with or without hypovolaemia. Volume depletion can stimulate thirst, but an increase in serum osmolality, as seen in dehydration, is the strongest stimulus of thirst.

Suggests volume depletion, and is more helpful in the setting of vomiting or diarrhoea. It is not very useful for blood loss.

May be a reflection of decreased tissue perfusion or electrolyte abnormalities.

In patients with significant atherosclerosis of the mesenteric vasculature, abdominal ischaemia due to severe volume loss can result in abdominal pain. However, it can also be a symptom of intra-abdominal bleeding, bowel obstruction, or pancreatitis.

Volume depletion in patients with coronary atherosclerosis can result in cardiac ischaemia and angina due to hypotension.

Non-specific; but may reflect poor cerebral blood flow or uraemia in the setting of impaired kidney function.

Can suggest decreased interstitial fluid volume, especially in younger adults. This sign is less helpful in older adults as they have decreased elasticity of their skin as part of ageing.