Epidural Hematoma
A rapid, life-threatening bleed between the skull and the brain's tough outer covering, usually from a torn artery after a severe blow to the head.
Emergency Management: Rapid neurologic decline requiring immediate field or ER intubation, administration of hypertonic saline, and direct transport to the operating room bypassing further imaging if uncal herniation is clinically obvious (in some extreme triage situations).
An epidural hematoma (EDH) is a traumatic accumulation of blood in the potential space between the inner table of the skull and the dura mater covering the brain. It is considered a life-threatening neurosurgical emergency due to the risk of rapid expansion causing elevated intracranial pressure and brain herniation.
Detailed Overview
EDH is classically caused by a forceful blow to the head that results in a skull fracture and tearing of an underlying artery, most commonly the middle meningeal artery. The arterial bleed rapidly pushes the tightly adherent dura away from the skull. The classic presentation includes a brief loss of consciousness followed by a 'lucid interval' where the patient appears normal, only to rapidly deteriorate into a coma as the hematoma expands and compresses the brainstem. Prompt surgical evacuation is highly curative with excellent outcomes.
Epidemiology & Demographics
Occurs in 1-2% of all traumatic brain injury (TBI) patients and up to 10% of those presenting in a traumatic coma. It is most common in adolescents and young adults (mean age 20-30 years) and rare in the elderly and infants, because the dura mater is tightly fused to the skull in those extremes of age. Male predominance (M:F 4:1).
Etiological Mechanism
Head trauma, usually from motor vehicle collisions, falls, or direct blows to the head (e.g., assault or sports injuries).
Primary Causes
Rupture of the middle meningeal artery (approx. 85% of cases). Less commonly, tearing of the middle meningeal vein or dural venous sinuses.
Blunt force trauma deforms the skull, often fracturing the squamous part of the temporal bone. This bony disruption lacerates the adjacent middle meningeal artery. Due to arterial pressure, blood dissects the dura from the skull, forming a biconvex (lens-shaped) hematoma. Expansion of the hematoma causes mass effect, leading to midline shift, elevated intracranial pressure (ICP), and eventually uncal herniation (compression of cranial nerve III and the brainstem).
Diagnostic Criteria & Guidelines
Emergent Non-contrast CT of the head demonstrating a hyperdense, biconvex (lenticular) extra-axial fluid collection that respects cranial sutures but can cross the midline via venous sinuses. Associated with skull fracture in 70-90% of cases.
Medical management for elevated ICP: Elevate head of bed to 30 degrees, intubation with mild hyperventilation (target PaCO2 30-35 mmHg), and osmotic therapy with Mannitol (1 g/kg IV) or Hypertonic Saline (3% or 23.4% push) as a bridge to the operating room. Ensure patent airway (ABCs).
Second-Line & Adjunctive Therapy
For small, asymptomatic hematomas (<30 cm3 volume, <15 mm thickness, <5 mm midline shift): Conservative management with strict ICU observation and serial CT scans every 6-8 hours to ensure non-expansion.
Surgical & Procedural Management
Emergent Craniotomy and Hematoma Evacuation. A large opening is made in the skull to evacuate the clot, identify the bleeding middle meningeal artery, coagulate it, and secure the dura to the skull (tacking sutures) to prevent re-accumulation.
Patient Counseling & Advice
For families: Explain that if surgery is performed rapidly before irreversible brainstem damage occurs, full functional recovery is highly probable, unlike other forms of brain injury.
Follow-Up & Monitoring Schedule
Post-operative ICU care, serial neurological exams, repeat CT head within 24 hours post-op, and neurorehabilitation if deficits persist. Monitoring for post-traumatic seizures.
Preventive Strategies
Primary prevention of trauma: mandatory use of helmets for bicycles, motorcycles, and extreme sports. Seatbelt use in motor vehicles.
Excellent if evacuated prior to bilateral pupillary dilation and coma (mortality <5%). Poor if surgery is delayed and brainstem herniation is established (mortality can approach 15-20%, with severe neurologic morbidity in survivors).