Final answer:
Mannitol (Osmitrol) is administered in neurological procedures to reduce brain swelling, acting as an osmotic diuretic. It draws water out of brain tissue, thereby decreasing intracranial pressure. Such osmotic effects are also observed with high glucose levels in poorly controlled diabetes mellitus.
Step-by-step explanation:
Mannitol (Osmitrol) is used in neurological procedures to reduce brain swelling after head injury. This therapeutic effect is due to its function as an osmotic diuretic, which promotes water loss through osmosis. Mannitol, being an indigestible sugar, pulls water out of the brain tissue, which subsequently reduces intracranial pressure and swelling, improving the outcome for patients.
Osmotic diuretics like mannitol are not the only substances that can cause diuresis. In cases of poorly controlled diabetes mellitus, high glucose levels also lead to an osmotic diuretic effect because glucose that is not reabsorbed attracts water into the urine, causing polyuria. Therefore, the presence of glucose in the urine is indicative of diabetes mellitus, which historically was recognized by symptoms like polyuria, polydipsia, and polyphagia. It is paramount to understand that sodium (Na+) plays a significant role in the regulation of plasma osmolarity, and high levels of sodium can lead to hypertension and contribute to systemic edema.