Traumatic Brain Injury

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Traumatic Brain Injury

• IMSURT Training 2006
• Eileen M. Bulger, MD
• Associate Professor of Surgery

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TBI The Problem

• 1.5 million cases of TBI/yr in U.S.
• 10 die prior to reaching the hospital
• Leading cause of death after injury
• 100,000 patients disabled each year

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Mechanism of Injury
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Mechanism of Fatal TBI
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TBI following Disasters

• Common Injury
• Flying Debris
• Falls
• Blast waves
• 60 of wounded soldiers in Iraq suffer TBI

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Patient Assessment

• AIRWAY
• Can patient protect his/her airway?
• GCS lt 8 INTUBATE!
• BREATHING
• Can the patient maintain adequate ventilation?
• CIRCULATION
• Is the patient in SHOCK?
• DISABLITY

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Initial Assessment

• Identify Mechanism of Injury
• ABCD
• Examine for signs of head trauma, pupillary
  response
• Determine GCS score
• Best predictor of Outcome
• Common language among care providers

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GCS Score

• Eye opening
• Spontaneous 4
• To Speech 3
• To Pain 2
• None 1
• Best Motor response
• Obeys commands 6
• Localizes Pain 5
• Withdraws from Pain 4
• Decorticate (abn flexion) 3
• Decerebrate (abn extension) 2
• None (flaccid) 1
• Verbal response
• Oriented 5
• Confused conversation 4
• Inappropriate words 3
• Incomprehensible sounds 2
• None 1

Best score 15 Worst score 3 Mild TBI GCS
14-15 Moderate TBI GCS 9-13 Severe TBI GCS
lt8 Must be assessed BEFORE sedation or
paralytics!
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Case study GCS 8

• 42y/o female s/p motor vehicle crash with open
  femur fracture. SBP 94/60, HR 144, RR 36.

• Eyes open briefly to painful stimuli
• Groans, no verbalization
• Pulls away from IV start, doesnt follow commands

E 2 V 2 M 4 GCS 8
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Case study GCS 8

• 27 y/o unhelmeted male, s/p motor cycle crash at
  highway speed. Deformity of L femur noted, L
  periorbital ecchymosis. SBP 138/74, HR 128, RR
  10.

• Eyes open to voice, but close without constant
  verbal stimuli
• Moaning, doesnt follow commands
• Flexes arms with sternal rub.

E 3 V 2 M 3 GCS 8
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Signs of Impending Herniation

• Unequal pupils
• Lateralizing motor signs

ONLY TIME WHEN HYPERVENTILATION SHOULD BE
CONSIDERED!
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Treatment of Impending Herniation

• Hyperventilation
• Mannitol
• 1.0gm/kg bolus
• DO NOT USE IF PATIENT IS HYPOVOLEMIC
• Patients need rapid surgical decompression

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Secondary Brain Injury

• Systemic hypotension due to associated injuries
• Hypoxia/Hypercarbia related to airway compromise
• Loss of autoregulation
• Cerebral edema
• Hyperventilation can lead to ischemia

Chesnut et al, 1993 SBP lt 90 increases mortality
2 fold!
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Cerebral autoregulation
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• Impaired autoregulation
• 30 with minor TBI
• 60 with severe TBI

Day 1 Impaired autoregulation
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Cerebral Perfusion Pressure
Do not treat hypertension in this group as it is
a compensatory response to preserve cerebral
blood flow
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Clinical ProblemSecondary Brain Injury

• Early deaths (2-7 days) from Traumatic Brain
  Injury
• Inadequate cerebral perfusion, which leads to
• Secondary Ischemic Injury
• AVOID HYPOTENSION
• AVOID HYPOXIA
• MAINTAIN NORMOCAPNEA
• High pCO2 leads to cerebral swelling
• Low pCO2 leads to vasoconstriction and decreased
  cerebral blood flow

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AIRWAY

• Can the patient protect his/her airway?
• Facial or neck trauma
• Blood or emesis in oropharynx
• Depressed LOC, loss of gag reflex GCS lt 8
• If NO then intubate
• BUT Avoid hypoxia and hyperventilation!

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Assessment of Facial stability

• Palpate midface
• Look for blood or teeth in airway
• Assess patient supine

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Facial Fractures

• Most patients can be orally intubated
• If midface unstable or significant bleeding into
  oropharynx than lower threshold to intubate (need
  good suction)
• If unable to intubate surgical cric is the most
  reliable alternative

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Breathing

• Can the patient maintain adequate ventilation
  oxygenation?
• If NO Intubate and monitor pulse ox
• Evaluate for tension pneumothorax
• Avoid hyperventilation unless signs of active
  herniation

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San Diego RSI Studies

• Enrolled patient with prehospital GCS lt8
• Increased intubation success rates with RSI
• Study stopped early due to increased mortality
  compared to historical controls
• Controls matched based on AIS not GCS
• Subsequent analysis revealed episodes of hypoxia
  high rate of hyperventilation
• Studies of patients transported by aeromedical
  service demonstrated improved outcome with
  intubation and lower rates of hyperventilation
• End tidal CO2 monitoring may be important to
  target prehospital and ED ventilation

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DATAALL TRAUMA
N 490
pCO2
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DATAHead AIS gt3
N 216
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OUTCOMEHead AIS gt3
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Take Home Message

• Intubation often required for airway protection
  or to provide adequate ventilation/oxygenation
• How you intubate is important!
• Avoid hypoxia, pre-oxygenate when possible
• How you ventilate is important!
• Avoid hyperventilation unless there are active
  signs of herniation
• 10 breaths/ min in an adult
• Monitor O2 sat and end tidal CO2 if available

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Circulation

• Is the patient in SHOCK?
• Monitor vital signs
• Control external bleeding
• Excessive scalp bleeding is common
• Give fluids to keep SBP gt 100mmHg
• RAPID triage to surgical support

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Fluid Resuscitation

• 2 large bore IVs
• Isotonic fluids Normal saline
• Hypertonic fluids
• Investigational for initial resuscitation
• 3 saline used for persistent elevations in ICP

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Hypertonic Saline/Dextran

• 8 clinical trials for hypovolemic shock
• 6 prehospital , 2 ED
• No adverse events
• All prehospital trials demonstrated a survival
  advantage for HSD but sample size too small or
  too many penetrating patients
• Meta-analyses, Wade et al
• 1395 pts Improved survival to hosp discharge (OR
  1.47)
• Severe brain injury had a 2 fold increase in
  survival

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Hypertonic saline (/- dextran)

• Potential advantages
• Rapid restoration of tissue perfusion
• Restoration of cerebral perfusion while
  attenuating ICP
• Immunomodulation
• Transient inhibition of innate immune response
• Enhanced T cell response
• Decreased risk of ARDS/MOFS??
• Decreased risk of nosocomial infection??

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Advantages of Hypertonic Saline for TBI patients

• Improved hemodynamics plasma volume expansion
• Decreased cerebral edema reduced ICP
• Vasoregulation reduction of vasospasm
• Immunomodulation
• Neurochemical effects

Doyle et al, J Trauma 2001
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How does HS work?

• Pulls fluid into vessels
• Increases serum
• osmotic pressure
• Redistributes
• fluid from the
• interstitial to the
• intravascular space

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What does HS do?

• Rapidly restores intravascular volume
• with a smaller volume of fluid
• decreased accumulation of extravascular volume

Rizoli, J Trauma 2003
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Resuscitation Outcomes Consortium

• Multicenter trial
• 7.5 saline /- dextran vs. control
• Target populations
• Trauma w/ Hypovolemic shock
• Severe TBI
• Outcomes
• Survival to Hosp D/C
• Neurologic outcome 6 months after injury

NIH NHLBI, DOD, CIHR
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TBI in the Elderly

• Fall related TBI increases with age
• Anticoagulation is a major risk factor for
  progression of disease
• Apparent minor mechanism of injury can lead to
  severe injury

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San Diego Talk Die Study

• Large database study
• 7,443 patients w/ TBI and verbal GCS gt3
• 6.1 mortality
• Anticoagulation and advanced age were major risk
  factors for mortality

Davis et al, AAST 2005
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Summary of Key Points

• Priorities are ABCD
• Use the GCS score to assess TBI
• Intubation if unable to protect airway or support
  adequate ventilation/oxygenation
• Look for signs of herniation, if present then
  hyperventilate, consider mannitol
• Monitor and avoid hypoxia and hyperventilation
• Treat shock with control of visible bleeding,
  aggressive volume resuscitation, and early
  surgical intervention
• High index of suspicion in the elderly especially
  if on coumadin
• Rapid triage to definitive care

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Assess ABCs
Guideline for Initial Management of Traumatic
Brain Injury
AIRWAY Provide supplemental oxygen Consider
intubation for hypoxia, hypercapnea,
respiratory distress, facial/neck injuries, GCS
lt8
BREATHING Assess treat chest injuries Avoid
hyperventilation unless signs of active
herniation
CIRCULATION Evaluate and treat for
hypovolemia Identify control hemorrhage Use
isotonic fluids
When ABCs stable then Examine for signs of
impending herniation Unilateral or bilateral
dilated pupils, lateralizing motor signs or
posturing
YES
NO
Document GCS score neuro exam GCS lt8
Severe TBI GCS 9-13 Moderate TBI GCS
13-15 Mild TBI Avoid hyperventilation
(pCO235-40mmHg) Use short acting sedatives Obtain
Head CT scan Arrange transfer to neurosurgeon
Place in reverse trendelenberg Hyperventilate
(pCO2 25-30mmHg) Administer Mannitol (if not
hypovolemic) Arrange rapid transfer to
neurosurgeon Head CT only of it does not delay
transfer
20 solution, bolus 1g/kg over 5 min