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Head Trauma. Dr. Roberts. Epidemiology. 1.1 million annual ED visits Highest < 5 yo & >85 yo 80% minor head trauma (GCS 14-15) 10% moderate (GCS 9-13) & 10% severe (8 & below) 200,000 deaths, most under 25 yo & 40% firearm related & 34% MVC. Anatomy.
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Head Trauma Dr. Roberts
Epidemiology • 1.1 million annual ED visits • Highest < 5 yo & >85 yo • 80% minor head trauma (GCS 14-15) • 10% moderate (GCS 9-13) & 10% severe (8 & below) • 200,000 deaths, most under 25 yo & 40% firearm related & 34% MVC
Anatomy • Brain covered in multiple layers: 1. dura 2. arahnoid 3. pia • Subarchnoid space contains 150cc CSF; 500 cc made each day • Normal CSF pressures 5-15 mmHg • Scalp 1. skin 2. subcutaneous, 3. galea, 4. areolar 5. pericranium • rich blood supply
What is the goal when treating TBI • To prevent secondary injury caused by ischemia and hypoxia • Primary injury occurs as a direct result of the force of the injury and cannot be reversed
MS How do you calculate CPP • CPP=MAP-ICP • MAP represent blood flow into the brain • ICP represents blood flow out of the brain, normal <15 • Autoregulation is functional with CPP 50-150. • Normally under control of Pco2, BP, pH • When autoregulation is lost due to increased ICP, CBF follows a linear pressure relationship to CPP
Pathopphysiology • Two main mechanisms of injury • Primary: initial mechanical trauma (irreversible) • Secondary: hypotension; hypoxia; anemia (our job) • Cushings Reflex:Hypertension; bradycardia; respiratory irregularity (mostly kids) • Cerebral herniation: 4 Types • Central Transtentorial-expanding lesion at frontal or occipital poles; AMS, pinpoint pupils, bi-muscle weakness • Cerebellotonsillar-cerebellar tonsils herniate through foramen magnum due to cerebellar mass; Pinpoint pupils, quadriplegia and cardiorespiratory collapse • Upward Transtentorial-expanding posterior fossa lesion; pinpoint pupils, absence of vertical eye movements • Uncal-most common, usually due to hematoma, 3rd nerve compression (anisocoria, ptosis, sluggish pupil, CN III defects)
Types of herniation • Upward Transtentorial • Central Transtentorial • Uncal • Cerebellotonsillar
Initial ED Evaluation & Tx • History: • High Risk – prolonged amnesia, anticoagulation, coagulopathy, progressive vomiting, post injury seizure • Physical Exam-Neuro Exam (GCS) • High Risk – focal neuro findings, distracting injury, signs of skull fracture, large extracranial hematoma, intoxication • ABCs (consider lidocaine if RSI) • Maintain PO2 & MAP • Watch for cushings • CT if GCS < 14, high risk Hx or Exam
What agents can be used during RSI to prevent increases in ICP • Pre-induction • Lidocaine • Defasciculating dose of succs, vec • Induction • Barbituates (thiopental) • Propofol, etomidate? • NMB • Succs-shortest acting, allowing for monitoring of neurologic changes and repeat exams
Further ED Management • Indications for Seizure Prophylaxis • Depressed skull fracture • Paralyzed & Intubated patient • Seizure at time of injury • Seizure in ED • Penetrating brain injury • GCS <9 • Acute Subdural/Epidural hematoma • Intracranial hemorrhage • Prior history of seizure
How are TBI classified • Based on GCS • Mild-GCS 14-15 • Low risk-GCS 15 without LOC, amnesia, vomiting, diffuse headache, no CT • Mod risk-GCS 15 plus one of the above, CT or skull x-rays if no CT avail (if xray + move into high risk) • High risk-GCS 14 or 15, skull fx, and/or neurologic deficit; coagulopathy, drug or etoh use, previous NS procedure, epilepsy, >60 yr old regardless of clinical presentation, CT • Mod-GCS 9-13, admit for monitoring, intubate, NS consult, 50% long term disability • Severe-GCS <9, mortality 40%, usually within 48hr
Glasgow Coma Scale • EYES • - Opens Eyes spontaneously 4 • - Opens eyes when told to do so 3 • - Opens eyes after painful stimuli 2 • - No response 1
Glasgow Coma Scale • VERBAL • Speaks and makes sense (oriented) 5 • - Speaks but is confused (disoriented) 4 • - Speaks but makes no sense 3 • - Makes only sounds 2 • - No speech 1
Glasgow Coma Scale • MOTOR • - Obeys verbal commands to move 6 • To painful stimulus: • - Localizes pain 5 • - Flexion-withdrawl from pain 4 • - Abnormal flexion (decorticate rigidity) 3 • - Extension (decerebrate rigidity) 2 • - No response to pain 1
Which is worse decerebrate or decorticate posturing • Decerebrate • arm extension, internal rotation; wrist and finger flexion, leg extension with internal rotation • Lesion below the midbrain • Decorticate • UE flexion and LE extension • Injury above midbrain • Better outcome
Specific Head Injuries • Scalp Lac: direct pressure, lido with epi, explore wound, suture/staples
Skull Fractures • Linear & simple comminuted fx: irrigate, suture, antibiotics per neuro surg consult • Basilar:
What are signs of increasing ICP • Uni or B/L dilated pupils, hemiparesis, motor posturing, progressive neurologic deterioration
Specific Injuries • Cerebral Contusion:
Subarachnoid Hemorrhage • Disruption of small subarachnoid vessels • Only detected 33% on initial CT • Most common abnormality on Head CT • Show signs of photophobia & headache • Marks significant increase morbidity/mortality in severe head injury
Subdural Hematoma • Blood clot between dura and brain • Seen in acceleration-deceleration injuries • Common in alcoholic & elderly • Rupture of superficial bridging vessels • Acute-symptoms in 1st 24 hrs (lucid interval) • Subacute-symptoms between 24 hrs-2 wks • Chronic-symptoms after 2 wks
Epidural Hematoma • Collection of blood between skull & dura due to blunt trauma causing rupture of middle meningeal artery • May have a lucent period following immediate LOC • Due to arterial bleeding, herniation occurs quickly
Concussion • Temporary & brief interruption of neurologic function after minor trauma • Symptoms-headache, confusion, & amnesia • Should not return to play until resolution of symptoms for 1 week
Pediatric Head Trauma • <2yo consider abuse • Higher mortality in children • <3months asymptomatic, no scalp hematoma then no CT • 3months-2yrs: scalp hematoma present then skull films, if fracture CT • >2yrs CT if high risk PE or history
Penetrating Head Injuries • ABCs • Antibiotics & Td proph • CT & Neurosurgery