Management of Epidural Hematoma with Mannitol

Introduction to Mannitol Use

The American Association of Neurological Surgeons recommends mannitol 20% at a dose of 250 mOsm (0.25-0.5 g/kg IV) infused over 15-20 minutes for treating threatened intracranial hypertension or signs of brain herniation in EDH patients after controlling secondary brain insults 1

Post-evacuation ICP monitoring is critical, as 50-70% of patients develop postoperative intracranial hypertension after EDH evacuation, with over 40% experiencing uncontrollable intracranial hypertension 1
High-risk features requiring aggressive management include preoperative Glasgow Coma Scale motor response ≤5, anisocoria, or hematoma volume >25 mL 1
Mannitol serves as a temporizing measure before definitive surgical evacuation or in the postoperative period when ICP remains elevated 2
Clinical signs of herniation, such as mydriasis, anisocoria, or acute neurological deterioration, are indications for mannitol administration 1, 2
Directly measured ICP >20 mmHg in monitored patients is also an indication for mannitol use 3

The initial dose of mannitol is 0.25-0.5 g/kg IV (approximately 250 mOsm) over 15-20 minutes 1, 2
Repeat dosing is every 6 hours as needed 2
The maximum daily dose of mannitol is 2 g/kg 2

Serum osmolality should be monitored continuously, and mannitol discontinued when serum osmolality exceeds 320 mOsm/L to prevent renal failure 2, 3
Effective ICP reduction is associated with serum osmolality increases ≥10 mOsm 2
Contraindications to mannitol use include severe pulmonary congestion or frank pulmonary edema, and severe dehydration 3

At equiosmotic doses (250 mOsm), mannitol and hypertonic saline have comparable efficacy for ICP reduction 1
Mannitol should be used in conjunction with head-of-bed elevation 20-30 degrees, neutral neck position, sedation and analgesia, and brief hyperventilation 1, 2, 4

Given the 50-70% incidence of postoperative intracranial hypertension after EDH evacuation, readiness for mannitol administration should be maintained in the immediate postoperative period 1, 2
Monitoring for secondary bleeding, new extra-axial collections, or increased brain edema is crucial as causes of ICP elevation 1