A subdural hematoma (SDH) is a collection of blood between the dura mater and the arachnoid mater, two protective layers surrounding the brain. This accumulation places pressure on brain tissue, causing severe neurological symptoms and damage. Treatment is highly specific, depending primarily on the hematoma’s size, location, and speed of development—classified as acute (within three days), subacute (four days to three weeks), or chronic (more than three weeks). Approaches range from close observation for small, stable bleeds to immediate, aggressive surgery for rapidly expanding ones.
Emergency Triage and Initial Stabilization
Immediate management focuses on life-saving measures to prevent secondary brain injury. Initial steps follow trauma resuscitation principles, ensuring the patient’s airway, breathing, and circulation are secure. Patients with a significantly depressed level of consciousness, typically a Glasgow Coma Scale (GCS) score of eight or less, generally require immediate intubation to protect the airway and ensure adequate oxygenation.
Controlling intracranial pressure (ICP) is a primary concern, as rising pressure can lead to dangerous brain herniation. The head of the bed is often elevated to 15 to 30 degrees to optimize cerebral perfusion pressure. Medications like mannitol or hypertonic saline may be administered to temporarily reduce brain swelling by drawing fluid out of the brain tissue. Maintaining the patient’s systemic blood pressure within a specific range is also important to ensure adequate blood flow to the injured brain.
Conservative Medical Management
Conservative management is reserved for patients with small subdural hematomas who are asymptomatic or present with only mild symptoms, such as a minor headache. This strategy is most commonly applied to chronic SDHs that are not causing a significant mass effect or shift of the brain’s midline structures. Management involves close monitoring of the hematoma’s size and the patient’s neurological status over time.
Serial imaging studies, typically computed tomography (CT) scans, are performed regularly to track whether the hematoma is shrinking, remaining stable, or expanding. A critical intervention is the reversal or temporary discontinuation of any blood-thinning agents the patient may be taking, such as anticoagulants or antiplatelet medications, to prevent further bleeding. Conservative therapy is considered successful if the hematoma resolves without the need for surgical evacuation, which occurs in the majority of mildly symptomatic patients.
Minimally Invasive Surgical Procedures
When a subdural hematoma is causing symptoms or is too large for observation, but is not immediately life-threatening, minimally invasive techniques are often preferred. These procedures are primarily used for chronic or subacute hematomas, especially in older patients. The most common approach is the Burr Hole Trephination, which involves drilling one or two small holes, usually 12 millimeters in diameter, into the skull over the hematoma.
Through these small openings, the fluid is drained. A central element of this technique is the placement of a closed-system drain, which is left in the subdural space for 24 to 72 hours following the procedure. This continuous drainage significantly lowers the rate of hematoma recurrence and improves the overall clinical outcome. A similar, less invasive variation is the twist-drill craniostomy, which uses a smaller hole and is sometimes performed at the bedside under local anesthesia, further reducing procedural risk for fragile individuals.
Definitive Open Surgery
A craniotomy is the most aggressive treatment, typically reserved for acute, large, or rapidly expanding subdural hematomas that pose an immediate threat to life. This procedure is necessary when the hematoma causes significant pressure on the brain, particularly if there is a substantial midline shift of brain structures.
The craniotomy involves making a large incision in the scalp and using a surgical saw to temporarily remove a section of the skull, known as a bone flap. This larger opening allows the neurosurgeon direct access to the subdural space to evacuate the blood clot using suction and irrigation. The craniotomy permits the surgeon to identify and control any active bleeding from torn bridging veins or other vessels, which is essential in acute cases. Once the hematoma is cleared and bleeding is stopped, the bone flap is typically replaced and secured, though it may be temporarily left out in cases of severe brain swelling, a procedure called a decompressive craniectomy.
Post-Treatment Monitoring and Recovery
Following surgical intervention or conservative management, monitoring and recovery are essential. Patients who undergo surgery often spend time in the intensive care unit for close observation of their neurological status and vital signs. A follow-up CT scan is routinely obtained within 24 hours of surgical evacuation to confirm complete hematoma removal and check for residual blood or signs of recurrence.
Recurrence of the subdural hematoma is a known complication that may necessitate a repeat procedure. Recovery often involves a multidisciplinary approach, particularly for those who experienced significant neurological impairment before treatment. Rehabilitation services, including physical, occupational, and speech therapy, are often required to help patients regain lost function and manage symptoms like weakness, cognitive issues, or speech problems.