Which drug is used to treat vasogenic edema by stabilizing cell membranes and improving cerebral blood flow?

• A. Dexamethasone
• B. Mannitol
• C. Oxygen administration
• D. Pentobarbital

Answer: (A)

The key idea is using a medication that specifically reduces vasogenic edema by strengthening the blood-brain barrier and decreasing capillary permeability, which in turn improves cerebral blood flow.

Dexamethasone is a corticosteroid that decreases capillary permeability and stabilizes the blood-brain barrier. By doing so, it reduces the extracellular fluid accumulation characteristic of vasogenic edema, especially around tumors or inflammatory lesions, and this reduction in edema often leads to better cerebral perfusion and lower intracranial pressure.

Mannitol acts by creating an osmotic gradient that pulls water out of the brain tissue, lowering ICP, but it doesn’t stabilize cell membranes or directly improve blood flow the way steroids do. Oxygen administration and pentobarbital provide other supportive or metabolic effects rather than addressing the edema mechanism described.