Certified Medical-Surgical Registered Nurse Practice Test

Why would a physician order mannitol for a patient with a subdural hematoma?

1. To reduce intraocular pressure

2. To prevent acute tubular necrosis

3. To promote osmotic diuresis to decrease ICP

4. To draw water into the vascular system to increase blood pressure

The correct answer is: To promote osmotic diuresis to decrease ICP

Mannitol is a type of osmotic diuretic commonly used to reduce intracranial pressure by promoting osmotic diuresis. When mannitol is administered, it increases the osmolarity of the blood plasma which draws fluid from the tissues, including the brain, into the bloodstream. This mechanism helps decrease intracranial pressure (ICP) by reducing the amount of fluid in the brain parenchyma and cerebrospinal fluid compartments. Therefore, in the case of a subdural hematoma, the physician may order mannitol to help decrease ICP and improve the patient's neurological status. Options A, B, and D are not the correct reasons for prescribing mannitol in the scenario of a subdural hematoma.