Mannitol Administration for Increased Intracranial Pressure in Cerebral Infarction

Indications and Administration

The American College of Cardiology recommends administering mannitol 0.25 to 0.5 g/kg IV over 20 minutes when there are clinical signs of elevated ICP or impending herniation, repeated every 6 hours as needed, with a maximum daily dose of 2 g/kg 1
Mannitol should only be given when specific clinical signs indicate elevated ICP or brain herniation, such as declining level of consciousness, pupillary changes, decerebrate posturing, and clinical deterioration suggesting herniation 1, 2

The standard dose of mannitol is 0.25 to 0.5 g/kg IV as a 15% to 25% solution, administered over 20-30 minutes, with a maximum daily dose of 2 g/kg 1
Smaller doses (0.25 g/kg) are as effective as larger doses (0.5-1 g/kg) for acute ICP reduction, with ICP decreasing from approximately 41 mm Hg to 16 mm Hg regardless of dose 1

Serum osmolality should be monitored frequently and mannitol discontinued if >320 mOsm/L 1, 3
Fluid status, electrolytes, and neurological status should be monitored closely during treatment 1, 3

Mannitol must be used in conjunction with other ICP control measures, such as head elevation, avoiding hypoosmotic fluids, correcting aggravating factors, and considering sedation, analgesia, and CSF drainage if appropriate 1, 2, 4

Hypertonic saline has comparable efficacy to mannitol at equiosmolar doses and may be preferred in certain situations, such as hypovolemia or hypotension 1, 2

Mannitol is only a temporizing measure and does not improve long-term outcomes in ischemic brain swelling, with mortality remaining 50-70% despite intensive medical management 1, 2, 4
Decompressive craniectomy performed within 48 hours is the most definitive treatment for large hemispheric infarcts with mass effect and results in reproducible large reductions in mortality when medical management fails 1, 2, 4