Which scenario describes the use of mannitol?

• A. For chronic edema
• B. For diuretic hypertension management
• C. For routine hydration
• D. For emergent treatment of intracranial pressure

Answer: (D)

Mannitol lowers intracranial pressure quickly by acting as an osmotic agent. When given IV, it raises plasma osmolality, pulling water out of swollen brain tissue into the bloodstream, which reduces brain edema and intracranial pressure. This makes it particularly useful in emergent situations where there is acute ICP elevation and a need to prevent herniation. It isn’t used for chronic edema, routine hydration, or as a diuretic for hypertension management. Chronic edema care relies on longer-term strategies, routine hydration aims to maintain balanced fluids without osmotic shifts, and hypertension management uses other diuretics for sustained effect rather than the rapid, hyperosmolar action of mannitol. Use requires caution in renal impairment or dehydration, and monitoring of electrolytes, fluid status, and kidney function is important.