What is the typical dosing range for mannitol when used as an osmotic therapy in TBI?

What is the typical dosing range for mannitol when used as an osmotic therapy in TBI?

• A. 0.25-1 g/kg IV
• B. 2-4 mg/kg IV
• C. 10-20 mg/kg IV
• D. 0.05-0.1 g/kg IV

Answer: (A)

Mannitol works as an osmotic therapy by creating a gradient that pulls water out of swollen brain tissue into the intravascular space, rapidly lowering intracranial pressure. For an initial osmotic bolus in traumatic brain injury, the typical dosing range is 0.25 to 1 g per kilogram given IV, usually as a bolus over about 15–20 minutes. This range is broad enough to achieve a meaningful osmotic effect without delivering an excessively large osmolar load at once. In practice, many clinicians use roughly 0.25–0.5 g/kg, with allowances up to 1 g/kg depending on ICP response and patient factors. Careful monitoring is essential: track serum osmolality (keep it under around 320 mOsm/kg) and watch for signs of dehydration, renal dysfunction, or electrolyte shifts. Re-dosing is guided by ongoing ICP elevation and osmolality, typically every 4–6 hours if needed. The other dosing options are outside this usual range and would be either too small to achieve the desired effect or carry greater risk of hyperosmolar complications.

Mannitol works as an osmotic therapy by creating a gradient that pulls water out of swollen brain tissue into the intravascular space, rapidly lowering intracranial pressure. For an initial osmotic bolus in traumatic brain injury, the typical dosing range is 0.25 to 1 g per kilogram given IV, usually as a bolus over about 15–20 minutes. This range is broad enough to achieve a meaningful osmotic effect without delivering an excessively large osmolar load at once. In practice, many clinicians use roughly 0.25–0.5 g/kg, with allowances up to 1 g/kg depending on ICP response and patient factors.

Careful monitoring is essential: track serum osmolality (keep it under around 320 mOsm/kg) and watch for signs of dehydration, renal dysfunction, or electrolyte shifts. Re-dosing is guided by ongoing ICP elevation and osmolality, typically every 4–6 hours if needed. The other dosing options are outside this usual range and would be either too small to achieve the desired effect or carry greater risk of hyperosmolar complications.