II. Indications
- Acute Severe Intracranial Pressure Management (cereral edema with Brainstem Herniation)
- Narrow Angle Glaucoma
III. Contraindications
- Congestive Heart Failure (transient increase in CVP)
- Hypertension
- Pulmonary Edema
IV. Mechanism
- Mannitol is a sugar Alcohol found naturally in fruits and vegetables
- Six-carbon sugar Alcohol
- Formed from reduction of mannose or fructose
- Mannitol acts as an osmotic Diuretic
- Freely filtered by glomerulus, but poorly reabsorbed at renal tubule
- Increases osmolarity of glomerular fluid, resulting in diuresis (water, Sodium, chloride)
- Increases plasma osmolarity
- Draws water from cells into plasma and interstitial fluid
- Transiently reduces tissue edema and increases plasma volume and Blood Pressure
- Later, fluid and Electrolyte redistribution results in Hypotension and Electrolyte abnormalities
VI. Precautions
- Filter solutions with concentration >20% (due to risk of crystallization)
- Monitor serum electolytes (e.g. basic chemistry panel) and fluid status
VII. Dosing
- Available as solution concentrations: 15% , 20% , 25%
- Intracranial Hypertension
- Dose: 0.25 to 1 g/kg IV over 20 minutes every 4-6 hours as needed
- Single dose of 1-2 g IV may be given over 30-60 minutes
VIII. Resources
- Mannitol Injection Solution
IX. References
- Olson (2020) Clinical Pharmacology, Medmaster, Miami, p. 62-3
- Hamilton (2010) Tarason Pocket Pharmacopeia, p. 224