ATI Neurosensory Practice Test 2025 – Comprehensive Exam Prep

Mannitol is an osmotic diuretic often used in the management of increased intracranial pressure (ICP). Its therapeutic effect primarily results from its ability to create an osmotic gradient that draws fluid out of the brain tissue and into the bloodstream, thereby reducing cerebral edema and lowering ICP.

A serum osmolarity of 310 mOsm/L indicates that mannitol is effectively causing osmotic changes in the body. Normal serum osmolarity typically ranges from 280 to 300 mOsm/L, so an increase to 310 mOsm/L suggests that mannitol is active and has successfully elevated the osmolarity, which is essential for its function in treating increased ICP.

While stabilized blood pressure, reduction in headache, and normal temperature may be beneficial outcomes in a patient treated for increased ICP, they do not specifically correlate with the pharmacological effectiveness of mannitol. The key indicator of mannitol's therapeutic effect lies in the osmolarity changes it induces, which directly impacts the management of increased intracranial pressure.