Which osmotherapies are commonly used to reduce ICP in TBI?

• A. Mannitol and hypertonic saline
• B. Furosemide and acetazolamide
• C. Guaifenesin and mannitol
• D. Isotonic saline and D50

Answer: (A)

Osmotherapy lowers intracranial pressure by creating an osmotic gradient that pulls water out of swollen brain tissue into the bloodstream, thereby reducing brain edema and ICP. The two most commonly used osmotic agents in traumatic brain injury are mannitol and hypertonic saline. Mannitol works as an osmotic diuretic: it raises plasma osmolality, drawing water from the brain into the intravascular space and then out through the kidneys, which can rapidly reduce ICP. Hypertonic saline also increases serum osmolality, drawing water from brain tissue and can help shrink edema while supporting blood pressure in some patients. Both require careful monitoring of osmolality, sodium levels, and volume status to avoid complications like electrolyte disturbances, renal issues, or rebound ICP. The other options don’t provide the rapid osmotic effect needed to acutely lower ICP: decongestants like furosemide or acetazolamide are not first-line osmotic therapies; guaifenesin is not used for ICP; isotonic saline and D50 do not create the osmotic gradient necessary for immediate ICP reduction.