Osmotic diuretics are a type of medication that can be used to manage cerebral edema. 

Cerebral edema is a condition where an excess of cerebral water accumulates due to primary neurological or non-neurological causes. This excess fluid can cause additional injury often in excess of the original neurological insult.

MOA

Osmotic diuretics work by increasing the osmolality of the blood. This increase in osmolality draws water out of the brain’s cells and interstitial spaces and into the bloodstream. This shift of fluid helps to decrease the intracranial pressure (ICP), which is often elevated in cases of cerebral edema.

One commonly used osmotic diuretic is mannitol. Although the osmotic diuresis seen with mannitol does facilitate reduction in cerebral edema, redistribution of the cerebral plasma volume ultimately leads to increased cerebral blood flow and a concomitant vasoconstrictive response of the intracerebral vasculature that decreases intracerebral pressure.

DOSE 

• Oral -0.5 to1g per kg
• Bolus or infusion -5ml per kg

MONITORING: Proper monitoring is needed as the serum osmolarity get increased to 320 mosm cause renal injury

In summary, osmotic diuretics can be a useful tool for managing cerebral edema by drawing excess fluid out of the brain and into the bloodstream, thereby reducing intracranial pressure.