ObjectivesObjectives

Describe basic intracranial physiology.Describe basic intracranial physiology.Recognize the importance of limiting Recognize the importance of limiting

secondary brain injury.secondary brain injury.Perform a focused neurologic exam.Perform a focused neurologic exam.Stabilize and arrange for definitive care.Stabilize and arrange for definitive care.

Key QuestionsKey Questions

What are the unique features of brain What are the unique features of brain anatomy and physiology and how do they anatomy and physiology and how do they affect patterns of brain injury?affect patterns of brain injury?

What is a focused neurologic exam?What is a focused neurologic exam?What is optimal management of the What is optimal management of the

brain-injured patient?brain-injured patient?How do I diagnose brain death?How do I diagnose brain death?

Anatomy and physiology effects?Anatomy and physiology effects?

Rigid, nonexpansile skull filled with Rigid, nonexpansile skull filled with brain, CSF, and blood brain, CSF, and blood

CBF autoregulation CBF autoregulation Autoregulatory compensation Autoregulatory compensation

disrupted by brain injurydisrupted by brain injuryMass effect of intracranial hemorrhageMass effect of intracranial hemorrhage

Intracranial Pressure (ICP)

10 mm Hg10 mm Hg== Normal Normal > 20 mm Hg> 20 mm Hg == AbnormalAbnormal> 40 mm Hg> 40 mm Hg == SevereSevereMany Pathologic Processes affect outcomeMany Pathologic Processes affect outcomeSustained Sustained ↑ ICP lead to ↓ brain function and ↑ ICP lead to ↓ brain function and

outcomeoutcome

AutoregulationAutoregulation

If autoregulation is intact, CBF is If autoregulation is intact, CBF is maintained with a mean BP of 50 to maintained with a mean BP of 50 to 160 mm Hg.160 mm Hg.

Moderate or severe brain injury: Moderate or severe brain injury: Autoregulation often impairedAutoregulation often impaired

Brain more vulnerable to episodes of Brain more vulnerable to episodes of hypotension hypotension secondary brain injury secondary brain injury

Classification of Brain injuryClassification of Brain injury

Blunt: High and Blunt: High and low velocitylow velocity

Penetrating: Penetrating: GSW and otherGSW and other

By MechanismBy Mechanism

Classification of Brain InjuryClassification of Brain Injury

• Depressed / nondepressedDepressed / nondepressed• Open / ClosedOpen / Closed

By Morphology: Skull FracturesBy Morphology: Skull Fractures

VaultVault

•With / without CSF leakWith / without CSF leak

•With / without cranial With / without cranial

palsypalsy

BasilarBasilar

Classification of Brain InjuryClassification of Brain Injury

• Epidural (extradural)Epidural (extradural)• SubduralSubdural• IntracerebralIntracerebral

• ConcussionConcussion• Multiple contusionsMultiple contusions• Hypoxic / ischemic injuryHypoxic / ischemic injury

By Morphology: BrainBy Morphology: Brain

Focal Focal

DiffuseDiffuse

Diffuse Brain InjuryDiffuse Brain Injury

Mild concussionMild concussion Severe, ischemic insult Severe, ischemic insult

Epidural HematomaEpidural Hematoma

Associated with skull fractureAssociated with skull fractureClassic: Middle meningeal artery tearClassic: Middle meningeal artery tearLenticular / biconvexLenticular / biconvexLucid intervalLucid intervalCan be rapidly fatalCan be rapidly fatalEarly evacuation essentialEarly evacuation essential

Subdural HematomaSubdural Hematoma

Venous tear / brain lacerationVenous tear / brain lacerationCovers cerebral surfaceCovers cerebral surfaceMorbidity / mortality due to Morbidity / mortality due to

underlying brain injuryunderlying brain injuryRapid surgical evacuation Rapid surgical evacuation

recommended, especially if > 5 mm recommended, especially if > 5 mm shift of midlineshift of midline

Contusion / HematomaContusion / Hematoma

Coup / contracoup injuriesCoup / contracoup injuriesMost common: Frontal / temporal lobes Most common: Frontal / temporal lobes CT change usually progressiveCT change usually progressiveMost conscious patient: No operationMost conscious patient: No operation

Mild Brain InjuryMild Brain Injury

GCS Score = 14-15GCS Score = 14-15HistoryHistoryExclude systemic Exclude systemic

injuriesinjuriesNeurologic examNeurologic exam

X-rays as indicatedX-rays as indicatedAlcohol / drug Alcohol / drug

screens as indicated screens as indicated Liberal use of head Liberal use of head

CTCT

Observe or discharge based on findingsObserve or discharge based on findings

Moderate Brain InjuryModerate Brain Injury

GCS Score = 9-13GCS Score = 9-13Initial evaluation Initial evaluation

same as for mild same as for mild injuryinjury

CT scan for allCT scan for all

Admit and observe Admit and observe • Frequent Frequent

neurologic examsneurologic exams• Repeat CT scanRepeat CT scan

Deterioration: Deterioration: Manage as severe Manage as severe head injuryhead injury

Severe Brain InjurySevere Brain Injury

GCS Score = 3-8GCS Score = 3-8Evaluate and resuscitateEvaluate and resuscitateIntubate for airway protectionIntubate for airway protectionFocused neurologic exam Focused neurologic exam Frequent reevaluation Frequent reevaluation Identify associated injuriesIdentify associated injuries

PrioritiesPriorities

ABCDEABCDEMinimize secondary brain injuryMinimize secondary brain injury

• Administer OAdminister O22

• Maintain blood pressure Maintain blood pressure (systolic > 90 mm Hg)(systolic > 90 mm Hg)

Focused Neurologic Exam?Focused Neurologic Exam?

GCS score GCS score Pupils Pupils Lateralizing signsLateralizing signs

Consult neurosurgeon earlyConsult neurosurgeon early

Medical ManagementMedical Management

Intravenous fluidsIntravenous fluids• Euvolemia Euvolemia • IsotonicIsotonic

Controlled ventilation Controlled ventilation • Goal: PaCOGoal: PaCO22 at 35 mm Hg at 35 mm Hg

Indications for CT Scan?Indications for CT Scan?

All patient with All patient with suspicion of brain suspicion of brain

injuryinjury

Medical ManagementMedical Management

MannitolMannitol• Use with signs of tentorial herniationUse with signs of tentorial herniation• Dose: 1.0 g / kg IV bolusDose: 1.0 g / kg IV bolus• Consult with neurosurgeon firstConsult with neurosurgeon first

Medical ManagementMedical Management

Other medicationsOther medications• Anticonvulsants Anticonvulsants • SedationSedation• ParalyticsParalytics

Surgical ManagementSurgical Management

Scalp Injuries Scalp Injuries Possible site of major blood lossPossible site of major blood lossDirect pressure to control bleedingDirect pressure to control bleedingOccasional temporary closureOccasional temporary closure

Surgical ManagementSurgical Management

Intracranial Mass LesionIntracranial Mass LesionMay be life-threatening if expanding May be life-threatening if expanding

rapidlyrapidlyImmediateImmediate neurosurgical consult neurosurgical consultHyperventilation / MannitolHyperventilation / MannitolDamage control craniotomy: Transfer Damage control craniotomy: Transfer to neurosurgeon (rural / austere areas)to neurosurgeon (rural / austere areas)

Diagnose brain death?Diagnose brain death?

Clinical Clinical GCS Score = 3 GCS Score = 3 Nonreactive pupilsNonreactive pupilsAbsent brainstem Absent brainstem

reflexesreflexesNo spontaneous No spontaneous

ventilatory effortventilatory effort

Ancillary Studies Ancillary Studies EEG: No activy EEG: No activy Brain scan: No flow Brain scan: No flow ICP > Map x 3 ICP > Map x 3

hourshoursNo cardiac response No cardiac response

to atropineto atropineRemember, organ donationRemember, organ donation

: What should I do?: What should I do?

Maintain mean BP > 90 mm HgMaintain mean BP > 90 mm HgMaintain PacoMaintain Paco22 near / at 35 mm Hg near / at 35 mm HgUse isotonic solution for euvolemiaUse isotonic solution for euvolemiaFrequent neurologic examsFrequent neurologic examsLiberal use of CT scansLiberal use of CT scansEarlyEarly neurosurgical consult neurosurgical consult

: What should I : What should I notnot do? do?

Allow patient to become hypotensiveAllow patient to become hypotensiveOver-aggressively hyperventilateOver-aggressively hyperventilateUse hypotonic IV fluidsUse hypotonic IV fluidsUse long-acting paralyticsUse long-acting paralyticsParalyze before performing complete exam Paralyze before performing complete exam Depend on clinical exam aloneDepend on clinical exam alone