head injuries

Common major trauma4 million people experience head trauma

annually Severe head injury is most frequent cause of trauma death

At Risk population Males 15-24 years Infants Young Children Elderly

INTRODUCTION TO HEADINJURIES

TIME IS CRITICAL Intracranial Hemorrhage Progressing Edema

Increased ICP Cerebral Hypoxia Permanent Damage

Severity is difficult to recognize Subtle signs Improve differential diagnosis

Improves survivability

INTRODUCTION TO HEAD INJURIES

Mechanism of Injury Blunt Injury

Motor vehicle collisions Assaults Falls

Penetrating Injury Gunshot wounds Stabbing Explosions

PATHOPHYSIOLOGY OFHEAD INJURY

Head InjuryCranial InjuryBrain Injury

DIFFERENT TYPES OF INJURY

HEAD INJURY

Open • Skull compromised

and brain exposed

Closed• Skull not compromised

and brain not exposed

5Head Trauma -

Contusions

Lacerations

Avulsions

Significant Hemorrhage

SCALP INJURY

HEAD INJURIES

Scalp wound

• Highly vascular, bleeds briskly Shock: child may develop Shock: adult another cause

• Management No unstable fracture:

direct pressure, dressings Unstable fracture: dressings, avoid direct pressure

7Head Trauma -

Skull fracture• Linear nondisplaced

• Depressed

• Compound

Suspect fracture• Large contusion or darkened swelling

Management• Dressing, avoid excess pressure

HEAD INJURIES

8Head Trauma -

Trauma must be extreme to fracture Linear Depressed Open Impaled Object

CRANIAL INJURY

Basal Skull Unprotected Spaces weaken

structure Relatively

easier to fracture

Basal Skull Fracture Signs Battle’s Signs

Retroauricular Ecchymosis Associated with fracture of

auditory canal and lower areas of skull

Raccoon Eyes Bilateral Periorbital

Ecchymosis Associated with orbital

fractures

CRANIAL INJURY

BASILAR SKULL FRACTURE

Battle’s sign Raccoon eyes

12Head Trauma -

Basilar Skull Fracture May tear dura

Permit CSF to drain through an external passageway May mediate rise of ICP Evaluate for “Target” or “Halo” sign

CRANIAL INJURY

CRAINIAL INJURIES

Penetrating trauma

14Head Trauma -

Bullet fragments

Head Trauma - 15

Forces that cause skull fracture can also cause brain injury.

As defined by the National Head Injury Foundation “a traumatic insult to the brain capable of producing physical,

intellectual, emotional, social and vocational changes.”

BRAIN INJURY

BRAIN INJURY

Response to injury

• Swelling of brain Vasodilatation with increased blood volume Increased ICP

• Decreased blood flow to brain Perfusion decreases Cerebral ischemia (hypoxia)

17Head Trauma -

Altered Mental Status Altered orientation Alteration in personality Amnesia

Retrograde Antegrade

Cushing’s Reflex Increased BP Bradycardia Erratic respirations

SIGNS & SYMPTOMS OF BRAIN INJURY

Vomiting Without nausea Projectile

Body temperature changes

Changes in pupil reactivity

Decorticate posturing

Pathophysiology of Changes Frontal Lobe Injury

Alterations in personality Occipital Lobe Injury

Visual disturbances Cortical Disruption

Reduce mental status or Amnesia Retrograde

Unable to recall events before injury Antegrade

Unable to recall events after trauma “Repetitive Questioning”

Focal Deficits Hemiplegia, Weakness or Seizures

SIGNS & SYMPTOMS OF BRAIN INJURY

ClassificationDirect

Primary injury caused by forces of trauma Indirect

Secondary injury caused by factors resulting from the primary injury

BRAIN INJURY

Direct brain injury

• Immediate damage due to force

• Coup and contracoup

• Fixed at time of injury

Management

• Directed at prevention

21Head Trauma -

Coup Injury at site of impact

Contrecoup Injury on opposite side

from impact

DIRECT BRAIN INJURY TYPES

BRAIN INJURY

Indirect brain injury

• Results from hypoxia or decreased perfusion

• Response to primary injury

• Develops over hours

Management

• Good prehospital care can help prevent

23Head Trauma -

Focal Occur at a specific location in brain Differentials

Cerebral Contusion Intracranial Hemorrhage

Epidural hematoma Subdural hematoma

Intracerebral HemorrhageDiffuse

Concussion Moderate Diffuse Axonal Injury Severe Diffuse Axonal Injury

DIRECT BRAIN INJURY CATEGORIES

Cerebral Contusion Blunt trauma to local brain tissue Capillary bleeding into brain tissue Common with blunt head trauma

Confusion Neurologic deficit

Personality changes Vision changes Speech changes

Results from Coup-contrecoup injury

FOCAL BRAIN INJURY

BRAIN INJURIES

Cerebral contusion

• Bruising of brain tissue Swelling may be rapid and severe

• Level of consciousness Prolonged unconsciousness,

profound confusion or amnesia

• Associated symptoms Focal neurological signs May have personality changes

26Head Trauma -

Epidural Hematoma Bleeding between dura mater

and skull Involves arteries

Middle meningeal artery most common

Rapid bleeding & reduction of oxygen to tissues

Herniates brain toward foramen magnum

FOCAL BRAIN INJURYINTRACRANIAL HEMORRHAGE

INTRACRANIAL HEMORRHAGE

Acute epidural hematoma • Arterial bleed

Temporal fracture common Onset: minutes to hours

• Level of consciousness Initial loss of consciousness “Lucid interval” follows

• Associated symptoms Ipsilateral dilated fixed pupil, signs of increasing ICP, unconsciousness, contralateral

paralysis, death

28Head Trauma -

Subdural Hematoma Bleeding within meninges

Beneath dura mater & within subarachnoid space

Above pia mater Slow bleeding

Superior sagital sinus Signs progress over several days

Slow deterioration of mentation



Acute subdural hematoma• Venous bleed

Onset: hours to days

• Level of consciousness Fluctuations

• Associated symptoms Headache Focal neurologic signs

• High-risk Alcoholics, elderly, taking anticoagulants

30Head Trauma -


Intracerebral hemorrhage

• Arterial or venous Surgery is often not helpful

• Level of consciousness Alterations common

• Associated symptoms Varies with region and degree Pattern similar to stroke Headache and vomiting

31Head Trauma -

Intracerebral Hemorrhage Rupture blood vessel within the brain Presentation similar to stroke symptoms Signs and symptoms worsen over time


Due to stretching forces placed on individual nerve cellsPathology distributed throughout brainTypes

Concussion Moderate Diffuse Axonal Injury Severe Diffuse Axonal Injury

DIFFUSE BRAIN INJURY

Mild to moderate form of Diffuse Axonal Injury (DAI) Nerve dysfunction without anatomic damage

Transient episode of Confusion, Disorientation, Event amnesia

Suspect if patient has a momentary loss of consciousness

Management Frequent reassessment of mentation ABC’s


CONCUSSION

BRAIN INJURIES

Concussion

• No structural injury to brain

• Level of consciousness Variable period of unconsciousness or confusion Followed by return to normal consciousness

• Retrograde short-term amnesia May repeat questions over and over

• Associated symptoms Dizziness, headache, ringing in ears, and/or nausea

35Head Trauma -

“Classic Concussion”Same mechanism as concussion

Additional: Minute bruising of brain tissue

UnconsciousnessMay exist with a basilar skull fractureSigns & Symptoms

Unconsciousness or Persistent confusion Loss of concentration, disorientation Retrograde & Antegrade amnesia Visual and sensory disturbances Mood or Personality changes


MODERATE DIFFUSE AXONAL INJURY

BRAIN INJURIES

Diffuse axonal injury

• Diffuse injury Generalized edema No structural lesion Most common injury from

severe blunt head trauma

• Associated symptoms Unconscious No focal deficits

37Head Trauma -

Brainstem InjurySignificant mechanical disruption of nerve

cells Cerebral hemispheres and brainstem

High mortality rateSigns & Symptoms

Prolonged unconsciousness Cushing’s reflex Decorticate or Decerebrate posturing


SEVERE DIFFUSE AXONAL INJURY

BRAIN ANATOMY

Intracranial volume

• Brain

• CSF

• Blood vessel volume Dilatation with high pCO2

Constriction with low pCO2

Slight effect on volume

39Head Trauma -

Cranial volume fixed 80% = Cerebrum, cerebellum & brainstem 12% = Blood vessels & blood 8% = CSF

Increase in size of one component diminishes size of another Inability to adjust = increased ICP

INTRACRANIAL PERFUSION

Compensating for Pressure Compress venous blood vessels Reduction in free CSF Pushed into spinal cord

Decompensating for Pressure Increase in ICP Rise in systemic BP to perfuse brain

Further increase of ICP

INTRACRANIAL PERFUSION

ICP BP

Vasculature ConstrictionCerebral EdemaSystolic Blood Pressure

Low BP = Poor Cerebral Perfusion High BP = Increased ICP

Carbon DioxideReduced respiratory efficiency

FACTORS AFFECTING ICP

Role of Carbon Dioxide Increase of CO2 in CSF

Cerebral Vasodilation Encourage blood flow Reduce hypercarbia Reduce hypoxia

Contributes to ICP Reduced levels of CO2 in CSF

Cerebral vasoconstriction Results in cerebral anoxia

INTRACRANIAL PRESSURE

Increased pressure Compresses brain tissue

Herniates brainstem Compromises blood supply Signs & Symptoms

Upper Brainstem Vomiting Altered mental status Pupillary dilation

Medulla Oblongata Respiratory Cardiovascular Blood Pressure disturbances

PRESSURE & STRUCTURAL DISPLACEMENT

Upper Brainstem Compression Increasing blood pressure Reflex bradycardia

Vagus nerve stimulation Cheyne-Stokes respirations Pupils become small and reactive Decorticate posturing

Neural pathway disruption

SIGNS & SYMPTOMS OF BRAIN INJURYPHYSIOLOGICAL CHANGES

Middle Brainstem Compression Widening pulse pressure Increasing bradycardia CNS Hyperventilation

Deep and Rapid Bilateral pupil sluggishness or inactivity Decerebrate posturing


Lower Brainstem Injury Pupils dilated and unreactive Ataxic respirations

Erratic with no pattern Irregular and erratic pulse rate ECG Changes Hypotension Loss of response to painful stimuli


Physiological Issues Indicate pressure on

CN-III (Oculomotor Nerve) Pressure on nerve causes eyes to be sluggish, then dilated, and finally fixed

Reduced peripheral blood flow

Pupil Size & Reactivity Reduced Pupillary Responsiveness

Depressant drugs or Cerebral Hypoxia Fixed & Dilated

Extreme Hypoxia

SIGNS & SYMPTOMS OF BRAIN INJURYEYE SIGNS

HEAD TRAUMA ASSESSMENT Initial Assessment

Rapid Trauma Exam

Limit patient agitation, straining• Contributes to elevated ICP

Airway• Vomiting very common within first hour• Endotracheal intubation

50Head Trauma -

Head Trauma - 51

Decreased level of consciousnessis an early indicator of

brain injury or rising ICP.

Reactive: ICP increasing

Nonreactive (altered LOC): increased ICP

Nonreactive (normal LOC): not from head injury

PUPILS

Both dilated Nonreactive: brainstem Reactive: often reversible

Unilaterally dilated

52Head Trauma -

Eyelid closure• Slow: cranial nerve III

• Fluttering: often hysteria

Anisocoria

GLASGOW COMA SCALE

Suspect severe brain injury GCS <9

53Head Trauma -

*Decorticate posturing to pain**Decerebrate posturing to pain

EXTREMITY POSTURING

Decorticate• Arms flexed

and legs extended

Decerebrate• Arms extended

and legs extended

54Head Trauma -

INCREASING ICP

55Head Trauma -

Vital Sign Change with Increasing ICP

Respiration Increase, decrease, irregular

Pulse Decrease

BP Increase, widening pulse pressure

Cushing’s response• As ICP increases, systolic BP increases• As systolic BP increases, pulse rate decreases

Head Trauma - 56

Early effortsto maintain brain perfusion

can be life-saving.

THE INJURED BRAIN

Hypoxia• Perfusion decrease causes cerebral ischemia• Hyperventilation increases hypoxia

significantly more than it decreases ICP

Assist ventilation• High-flow oxygen• One breath every 6–8 seconds• SpO2 >95%

• Maintain EtCO2 at 35 mmHg

57Head Trauma -

THE INJURED BRAIN

Hypotension• Single instance increases mortality

Adult (systolic <90 mmHg) 150% Child (systolic < age appropriate) worse

Fluid administration for traumatic brain injury, GCS <9• Titrate to 110–120 mmHg systolic

with or without penetrating hemorrhage to maintain CPP

58Head Trauma -

THE INJURED BRAIN

Cerebral herniation syndrome

• Brain forced downward CSF flow obstructed, pressure on brainstem

• Level of consciousness Decreasing, rapid progression to coma

• Associated symptoms Ipsilateral pupil dilatation, out-downward deviation Contralateral paralysis or decerebrate posturing Respiratory arrest, death

59Head Trauma -

CEREBRAL HERNIATION

Is ICP severe enoughto outweigh cerebral ischemia?

60Head Trauma -

HYPERVENTILATION

Cerebral herniation syndrome• Herniation danger outweighs hypoxia

Indications for hyperventilation• TBI GCS <9 with decerebrate posturing• TBI GCS <9 with dilated or nonreactive pupils• TBI initial GCS <9, then drops >2 points

If signs resolve, stop hyperventilation.

61Head Trauma -

HYPERVENTILATION RATES

Capnography • Maintain EtCO2 <30 mmHg, but >25 mmHg

62Head Trauma -

Age Group Normal Rate Hyperventilation

Adult 8–10 per minute 20 per minute

Children 15 per minute 25 per minute

Infants 20 per minute 30 per minute

THANK YOU

head injuries

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