Role of Mannitol in Managing Increased Intracranial Pressure in Brain Abscess

Mechanism of Action and Indications

Mannitol creates an osmotic pressure gradient across the blood-brain barrier, causing water displacement from brain tissue to the hypertonic environment 3

The recommended dosage of mannitol is 0.5-1 g/kg IV administered as a bolus over 15-20 minutes, according to the American College of Hepatology 1, 2, 3
The usual maximal dose is 2 g/kg, as recommended by the American Heart Association 4, 5

Mannitol has been shown in controlled trials to effectively correct episodes of elevated ICP and its use has been associated with improved survival, according to the American College of Hepatology 2, 6
Maximum effect is observed after 10-15 minutes and lasts for 2-4 hours, as reported in Anaesthesia 3

Mannitol should be administered when there are obvious neurological signs of increased ICP, such as decerebrate posturing or pupillary abnormalities, as recommended by the American College of Hepatology 1, 2
Direct ICP monitoring showing elevated pressure (>20-25 mmHg) is also an indication for mannitol administration, according to the American College of Hepatology 1, 6

Serum osmolality should be monitored to ensure it remains below 320 mOsm/L, as recommended by the American College of Hepatology 1, 2
Volume overload is a risk with mannitol use in patients with renal impairment, and may require dialysis to remove excess fluid, according to the American College of Hepatology 2

Despite intensive medical management including mannitol, mortality in patients with increased ICP remains high (50-70%), so these interventions should be considered temporizing measures, as reported in Stroke 4, 5
No evidence indicates that mannitol alone improves outcome in patients with ischemic brain swelling, according to the American Heart Association 4, 5, 7
Cerebral perfusion pressure (CPP) should be maintained above 50-60 mmHg while treating elevated ICP, as recommended by the American College of Hepatology 1