The most rapid means of decreasing cerebral oedema is via osmotherapy. Mannitol is used clinically to reduce acute raised intracranial pressure by drawing water out of the brain by an osmotic gradient and to decrease blood viscosity.

Mannitol is thought to decrease brain volume by decreasing overall water content, to reduce blood volume by vasoconstriction, and to reduce CSF volume by decreasing water content.

Clinicians should be cautioned about prolonged use of mannitol, as this may cause electrolyte imbalances.

For more information on mannitol, check out mannitol as diuretic and mannitol in oedema. The TRC topic osmotic diureticsgives a general overview of this group's effects.


Which of the following statements about mannitol is FALSE?