A client with subdural hematoma is given mannitol for which purpose?

A client with subdural hematoma is given mannitol for which purpose?

• A. To reduce intraocular pressure
• B. To prevent acute tubular necrosis
• C. To promote osmotic diuresis to decrease ICP
• D. To draw water into the vascular system to increase blood pressure

Answer: (C)

The main concept is using an osmotic diuretic to lower intracranial pressure. Mannitol raises the osmolality of the blood, so water is pulled out of swollen brain tissue into the vascular compartment. This reduces cerebral edema and, as a result, lowers intracranial pressure. The brain, in a subdural hematoma, is vulnerable to high pressure, so decreasing ICP improves cerebral perfusion and lowers the risk of herniation. The water that moves into the bloodstream is then eliminated by the kidneys, producing osmotic diuresis that further helps reduce brain water content. This isn’t about preventing acute tubular necrosis, and while mannitol can lower ocular pressure in other contexts, the purpose here is to decrease ICP. It’s also not aimed at raising blood pressure by pulling water into the circulation—the primary therapeutic goal is reducing intracranial pressure.

The main concept is using an osmotic diuretic to lower intracranial pressure. Mannitol raises the osmolality of the blood, so water is pulled out of swollen brain tissue into the vascular compartment. This reduces cerebral edema and, as a result, lowers intracranial pressure. The brain, in a subdural hematoma, is vulnerable to high pressure, so decreasing ICP improves cerebral perfusion and lowers the risk of herniation. The water that moves into the bloodstream is then eliminated by the kidneys, producing osmotic diuresis that further helps reduce brain water content.

This isn’t about preventing acute tubular necrosis, and while mannitol can lower ocular pressure in other contexts, the purpose here is to decrease ICP. It’s also not aimed at raising blood pressure by pulling water into the circulation—the primary therapeutic goal is reducing intracranial pressure.