Basics
Description
- Classification of subdural hematoma (SDH):
- Acute: Diagnosis within the 1st 3 days
- Subacute: Diagnosis 3 days " 3 wk
- Chronic: Diagnosis after 3 wk
- CT description:
- Rarely crosses midline
- Does cross suture lines
- Inner margins are often seen to be irregular.
- Acute:
- Most commonly due to acceleration " deceleration forces and less commonly from direct trauma
- Sagittal movement of the head causes stretch of parasagittal bridging veins.
- Other bleeding sites include:
- Laceration of dura
- Venous sinus injury
- Cortical arteries
- Nontraumatic injuries: Intracerebral aneurysm rupture, arteriovenous malformation, coagulation disorder, arterial HTN, drug or alcohol abuse
- Chronic:
- Encapsulated hematoma most likely caused by repeated small hemorrhages of bridging veins.
Etiology
- Acute:
- Most common type of intracranial hematoma (66 " 70%)
- Occurs most commonly at cerebral complexities > falx cerebri > tentorium cerebelli
- Peak incidence 15 " 24 yr, 2nd peak >75 yr
- Represents 26 " 63% of blunt head injury
- Motor vehicle crash (MVC) is most common cause overall.
- Falls and assault more commonly result in isolated SDH (72%) than do MVCs (24%).
- Elderly patients and those with seizure disorders are at increased risk.
- Mortality is related to presenting signs and symptoms as well as comorbidities:
- Mortality is 50% for age >70
- Less than 1/2 present as simple extra-axial collection (22% mortality rate)
- ’ Ό40% of patients will have complicated SDH: Parenchymal laceration or intracerebral hematoma (mortality rate >50%)
- 3rd group associated with contusion (30% mortality rate with functional recovery of 20%)
- Coagulopathy: INR >2 increases risk of bleed 2, INR >3 is associated with larger initial volume and increased expansion
- Chronic:
- Most common in babies or elderly with atrophy:
- Associated with infarction in underlying brain
- 75% of patients are >50
- <50% have history of trauma
- 50% are alcoholic
- Epilepsy and shunting procedures
- May occur secondary to trauma at birth
- Nonaccidental trauma more common
Diagnosis
Signs and Symptoms
- Acute:
- 1/5 have diagnosis discovered at autopsy.
- Most commonly misdiagnosed as intoxication or cerebrovascular accident (CVA)
- Headache and altered mental status:
- 50% unconscious at discovery
- Subacute/chronic:
- Headaches, nausea, vomiting, and seizures are frequent symptoms.
- Presentation varied:
- Fluctuating mental status
- Unsteady gait
- Slow progression of deficits
Imaging is necessary in infants with persistent vomiting, new seizures, lethargy, irritability, bulging, or tense fontanels.
Physical Exam
- Acute:
- Headache and altered mental status
- Most common clinical signs are hemiparesis or hemiplegia:
- Seen in 40 " 65%
- SDH opposite motor deficit in 60 " 85%
- Pupillary abnormality seen in 28 " 79%:
- SDH will be on same side of pupillary abnormality in 70 " 90%.
- Seizures may be seen in ’ Ό10% initially.
- Papilledema in <1/3
- Chronic:
- Presentation is varied and mimics other diseases.
Essential Workup
Obtain directed history:
- Mechanism of injury kinetics
- Neurologic status: Baseline and at-scene
- Complicating factors:
- Past medical history, medications
- Allergies, drug use
- Rapid neurologic assessment:
- Glasgow Coma scale ([GCS] after fluid resuscitation most important)
- Brainstem reflexes:
- Anisocoria
- Pupillary light reflex
- Corneal, gag, oculocephalic/oculovestibular
- Head imaging
Diagnosis Tests & Interpretation
Lab
- ABG, CBC, electrolytes with glucose, prothrombin time (PT), partial thromboplastin time (PTT)
- Blood ethyl alcohol, drug screen
Imaging
- Head CT in coordination with other necessary trauma workup
- Acute:
- Characteristic CT finding is crescent-shaped clot overlying hemispheric convexity.
- May have irregular medial border of hematoma
- Mixed density of clot may represent active bleeding
- Most (60%) associated with other intracranial lesions
- Intracranial volume of hematoma >2% predicts poor prognosis
- Chronic:
- MRI is a better choice, as lesion may be isodense on CT from 2 " 3 wk.
- MRI volume in diffusion-weighted images correlates with Rankin disability score.
- CT may show hypodense lesion after 3 wk.
- Spinal radiographs
US can be used to visualize cerebral structures if fontanelles are patent.
Differential Diagnosis
- Acute:
- Diffuse axonal injury
- Cerebral contusion
- Intracerebral bleed
- Subdural hygroma
- Epidural hematoma
- Shaken baby/battered child syndrome
- Chronic:
- Pseudotumor cerebri
- Brain tumor
- Dementia
- Meningitis
- CVA/transient ischemic attack
- Cerebral atherosclerosis
- Toxic, metabolic, respiratory, or circulatory causes
Treatment
Initial Stabilization/Therapy
- Manage airway and resuscitate as indicated:
- Hypoxia is a strong predictor of outcome.
- Maintain SaO2 >95%.
- Rapid-sequence intubation (RSI) is indicated for GCS <9 or for evidence of increased intracranial pressure (ICP).
- RSI for PaCO2 >45, anisocoria, drop of GCS by 3, loss of gag reflex, C-spine injury
- Routine hyperventilation is no longer recommended due to resultant diminished cerebral perfusion pressure.
- Controlled ventilation to maintain PCO2 35 " 40 mm Hg:
- NS to maintain mean arterial pressure (MAP) 100 " 110 is necessary:
- A single episode of systolic BP <90 is associated with poor outcome.
- Spine precautions
- Elevate head of bed 20 " 30 ° (only after adequate fluid resuscitation to avoid resultant decrease in cerebral blood flow [CBF]).
- Not considered helpful:
- Steroids
- Antibiotic prophylaxis
- Hyperventilation (unless herniation is imminent)
- Fluid restriction
- Calcium channel blockers
- Hypothermia not proven
- NaCl 3% not yet proven helpful
Ed Treatment/Procedures
- Acute
- Early neurosurgical intervention (<4 hr) in comatose patients shows reduced mortality:
- Burr holes may be used as temporizing measure in deteriorating patients.
- ICP monitoring is indicated for patients with abnormal CT who are intubated.
- Subdural evacuating port system has been shown to be equivalent to Burr hole for acute treatment of SDH
- Nonoperative treatment may be indicated for small SDH:
- <20 mL of blood, <1 cm, midline shift <5 mm, no mass effect, no neurologic deficit
- This requires frequent neurologic reassessment.
- 10% go on to require operative intervention.
- Maintain euvolemic state with isotonic fluids:
- Arterial line placement to monitor MAP, PO2, and PCO2
- Foley catheter to monitor I/O status
- Control ICP:
- Prevent pain, posturing, and increased respiratory effort:
- Sedation with benzodiazepines
- Neuromuscular blockade with vecuronium or rocuronium in intubated patients
- Etomidate is a good induction agent.
- Mannitol may be used once euvolemic:
- Shown to increase MAP > cerebral perfusion pressure and CBF as well as decrease ICP
- Keep osmolality between 295 and 310.
- Use furosemide (Lasix) as an adjunct only if normovolemic.
- Treat HTN:
- Labetalol, nicardipine, or hydralazine
- Treat coagulopathy
- Use fresh frozen plasma 4+ units
- Use prothrombin complex concentrate
- Treat hyperglycemia if present:
- Associated with increased mortality in traumatic brain injury
- Treat and prevent seizures:
- Diazepam and phenytoin (Dilantin), levetiracetam: Prophylactic anticonvulsants not indicated
Medication
- Diazepam: 5 " 10 mg (peds: 0.2 " 0.3 mg/kg) IV/IM q10 " 15min PRN; max. 30 mg (peds: 10 mg)
- Dilantin: Adults and peds: Load 18 mg/kg at 25 " 50 mg/min
- Etomidate: 0.3 mg/kg IV for induction of RSI
- Fentanyl: 2 " 4 Όg/kg
- Hydralazine: 10 " 20 mg (peds: 0.1 " 0.5 mg/kg IV) q2 " 4h PRN
- Labetalol: 20 mg IV bolus, then 40 " 80 mg q10min; max. 300 mg; follow with IV continuous infusion 0.5 " 2 mg/min; (peds: 0.4 " 1 mg/kg/h IV continuous infusion; max. 3 mg/kg/h)
- Lasix: Adults and peds: 0.5 mg/kg IV
- Levetiracetam: 1,500 mg PO/IV q12h
- Lidocaine: As preinduction agent, 1.5 mg/kg IV
- Mannitol: Adults and peds: 0.25 " 0.5 g/kg IV q4h
- Midazolam: 1 " 2 mg (peds: 0.15 mg/kg IV 1) IV q10min PRN
- Nicardipine: 5 " 15 mg/h IV continuous infusion (peds: Safety not established)
- Pentobarbital: 1 " 5 mg IV q6h
- Prothrombin complex concentrate: 50 U/kg IV
- Rocuronium: 1 mg/kg for induction
- Thiopental: As induction agent, 20 mg/kg IV
Follow-Up
Disposition
Admission Criteria
- Acute SDH patients should be admitted to the operating room or ICU by the neurosurgical service.
- Subacute subdurals should be admitted to a monitored setting.
Discharge Criteria
Patients with chronic SDH often can be managed as outpatients in conjunction with neurosurgery, adequate home resources, and appropriate follow-up.
Issues for Referral
All patients need neurosurgical evaluation immediately.
Pearls and Pitfalls
The following factors predict prognosis:
- GCS on admission
- Time to treatment
- Pupil abnormalities
- CT volume of hematoma and presence of midline shift
- Midline shift > hematoma volume
Additional Reading
- Beslow LA, Licht DJ, Smith SE, et al. Predictors of outcome in childhood intracerebral hemorrhage: A prospective consecutive cohort study. Stroke. 2010;41(2):313 " 318.
- Chittiboina P, Cuellar-Saenz H, Notarianni C, et al. Head and spinal cord injury: Diagnosis and management. Neurol Clin. 2012;30(1):241 " 276, ix.
- Huh JW, Raghupathi R. New concepts in treatment of pediatric traumatic brain injury. Anesthesiol Clin. 2009;27(2):213 " 240.
- Krupa M. Chronic subdural hematoma: A review of the literature. Part 2. Ann Acad Med Stetin. 2009;55(3):13 " 19.
- Kubal WS. Updated imaging of traumatic brain injury. Radiol Clin North Am. 2012;50:15 " 41.
- Zhu GW, Wang F, Liu WG. Classification and prediction of outcome in traumatic brain injury based on computed tomographic imaging. J Int Med Res. 2009;37(4):983 " 995.
Codes
ICD9
- 432.1 Subdural hemorrhage
- 767.0 Subdural and cerebral hemorrhage
- 852.20 Subdural hemorrhage following injury without mention of open intracranial wound, unspecified state of consciousness
ICD10
- I62.00 Nontraumatic subdural hemorrhage, unspecified
- P10.0 Subdural hemorrhage due to birth injury
- S06.5X0A Traum subdr hem w/o loss of consciousness, init
- P52.8 Other intracranial (nontraumatic) hemorrhages of newborn
- I62.01 Nontraumatic acute subdural hemorrhage
- I62.02 Nontraumatic subacute subdural hemorrhage
- I62.03 Nontraumatic chronic subdural hemorrhage
- I62.0 Nontraumatic subdural hemorrhage
SNOMED
- 95453001 subdural intracranial hematoma (disorder)
- 262952002 Traumatic intracranial subdural hematoma (disorder)
- 281864001 Non-traumatic intracranial subdural hematoma (disorder)
- 206191000 Local subdural hematoma due to birth trauma (disorder)
- 304831001 Chronic intracranial subdural hematoma (disorder)