Mannitol Concentration in a 20% Solution
In a 100 mL of 20% mannitol solution, there are 20 grams of mannitol. 1
Understanding Mannitol Concentration
Mannitol is commonly available as a 20% solution, which means:
- 20% concentration equals 20 grams of mannitol per 100 mL of solution 1
- This concentration is specifically formulated for clinical use in reducing intracranial pressure 2
Clinical Applications of 20% Mannitol
Mannitol is primarily used for:
- Reduction of intracranial pressure and brain mass 1
- Treatment of threatened intracranial hypertension or signs of brain herniation 3
- Reduction of high intraocular pressure 1
- Diagnostic measurement of glomerular filtration rate 1
Dosing Considerations
For intracranial pressure reduction:
- Adult dosing: 0.25 to 2 g/kg body weight as a 15% to 25% solution administered over 30-60 minutes 1
- Pediatric dosing: 1 to 2 g/kg body weight or 30 to 60 g/m² body surface area over 30-60 minutes 1
- Small or debilitated patients: 500 mg/kg 1
- Recommended administration: 250 mOsm dose, infused over 15-20 minutes 3, 2
Administration Guidelines
When administering mannitol:
- It should be given intravenously only 1
- Infusion should typically occur over 15-20 minutes for treating intracranial hypertension 3
- Do not add mannitol to whole blood for transfusion 1
- Monitor serum osmolality to ensure it remains below 320 mOsm/L 2, 4
Comparative Efficacy
- At equiosmolar doses, mannitol and hypertonic saline have comparable efficacy in treating intracranial hypertension 3, 5
- Some studies suggest hypertonic saline may have longer duration of effect than mannitol 6
- Among therapies that decrease ICP, mannitol has been associated with improved cerebral oxygenation 3
Precautions and Monitoring
- Mannitol induces osmotic diuresis and requires volume compensation 3
- Serum osmolality should be monitored every 12 hours during mannitol therapy 4
- Excessive use can result in hyperosmolar states, hypernatremia, and renal failure 4
- Consider limiting therapy to 48 hours if facilities for measuring serum osmolality are not available 4