plasma osmolality during ICH

Q: What is the goal of plasma osmolality with mannitol therapy during the management of intracranial hemorrhage (ICH)? 


Answer: 300 to 310 mosmol/kg

Mannitol continues to be the mainstay of treatment in acute management of ICH to quickly and effectively lowers Intracranial Pressure (ICP). But few basic tenets should be kept in mind. Firstly, the goal of mannitol therapy in ICH is to achieve plasma hyperosmolality to 300-310 mosmol/kg. This allows water to exit the brain. During this quest, the plasma osmolal gap should not be allowed to exceed 55 mosmol/kg. Moreover, the upper limit of total mannitol dose is 250 mg/kg every 4 hours. These boundaries have been set to avoid acute kidney injury which can be deadly due to loss of major volume regulator.

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#neurosurgery
#surgical-criticalcare


References:

1. Helbok R, Kurtz P, Schmidt JM, et al. Effect of mannitol on brain metabolism and tissue oxygenation in severe haemorrhagic stroke. J Neurol Neurosurg Psychiatry 2011; 82:378. 

2. Ropper AH. Management of raised intracranial pressure and hyperosmolar therapy. Pract Neurol 2014; 14:152. 

3. Dorman HR, Sondheimer JH, Cadnapaphornchai P. Mannitol-induced acute renal failure. Medicine (Baltimore) 1990; 69:153.