Case 1 Traumatic Brain Injury : Review, Update, and Controversies - - PDF document

5/30/2013 1

Traumatic Brain Injury :

Review, Update, and Controversies

Shirley I. Stiver MD, PhD

Case 1

32 year old male

• s/p high speed MVA
• Difficult extrication
• Intubated at scene

Case

• BP 75 systolic / palp
• GCS 3 (2T)
• Pupils 4 mm bilateral,

reactive

• Motor – nil
• Open femur fracture

First Management Steps ? A) Give Mannitol 0.5 g/kg iv bolus B) GCS 3 - donor ? C) Get stat CT scan D) Elevate sys BP > 90 mmHg

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Intracranial Pressure (ICP)

ICP = Brain + CSF + Blood vascular volume + Mass Lesion

Pressure Volume Curve

Compliance ∆V/∆P

• Small increase in

the intracranial volume

•  significantly

increase the ICP and ppt herniation

Low High

Raised Intracranial Pressure

Cerebral Herniation

Indications for Mannitol

• Signs of impending cerebral herniation

(Level III)

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Motor

Motor Score

1 Nil 2 Decerebrate posturing 3 Decorticate posturing 4 Withdrawal 5 Localizes 6 Obeys commands

Treatment Raised ICP

Mannitol

• Osmotic diuresis
• Reduces blood

viscosity

1-1.4gm/kg, bolus Watch for hypotension

Glasgow Coma Scale

Motor component of the GCS is most predictive

• f outcome

GCS Eyes 4 Verbal 5 Motor 6 Perform after resuscitation & before sedation or paralytics

Poor GCS  check Brainstem reflexes

Importance of testing

• Pupils
• Corneals,
• Cough and gag

Before Paralytics

• Often determines whether to take patient to OR

5/30/2013 4 Differentiating primary versus secondary injury

• Early GCS in the field – gives you

the closest assessment of the severity of the primary impact

– Resuscitated evaluation ; … hypoxia / hypotension – false positive – No drugs / alcohol on board

• Importance of the reports from

the emergency response team

• Importance of serial GCS &

neurological testing

Guidelines Blood Pressure – Level II

Hypotension strong predictor of

• utcome
• Single episode

sys BP<90 doubles mortality

• Avoid hypotension sys

BP < 90 mmHg

• Isotonic saline
• Fluid resuscitation a

balance:

• Maintain cerebral

perfusion ↔ avoid fluid

• verload, osmotic shifts,

brain edema

Case

Non –Contrast CT scan

Next ?

A) OR for decompressive craniectomy B) ICU observation C) ICU and ICP monitoring D) Ortho to OR femur repair

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Guideline for ICP Monitoring

GCS < 8 With Abnormal CT scan

Unresponsive with absence of a neurological exam that can be followed

Normal CT scan with

• age > 40
• unilateral or bilateral posturing
• systolic pressure < 90 mmHg
• ethanol intoxication

Guideline ICP Treat for threshold > 20mmHg

ICP Monitoring

Tiers of Therapy

Tier 1

• EVD drainage ; Sedation (Mannitol x 1)

Tier 2

• Osmotic therapy; Mannitol or Hypertonic N/S ;

pCO2 30-35 mmHg; paralysis

Tier 3

• Decompressive craniectomy ;
• Induced Barbiturate or propofol coma

Cerebral Perfusion Management

CPP = Mean arterial blood pressure – ICP

CPP goal > 60 mmHg Lund Therapy

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Advanced Monitoring ?

• What advanced

monitoring might best help you manage this patient ? A) Cerebral blood flow probe B) Brain tissue oxygen monitor C) SjVO2 –jugular venous saturation

Brain Tissue Oxygen

• Brain O2 probes placed in

white matter

• Normal values for white

matter 20-30mmHg

Brain Tissue Oxygenation

• Cerebral blood flow
• O2 content of blood
• Dissociation

& Diffusion of O2

BBB Normal values (white matter) 20-30 mmHg Critical values < 15

Jugular Venous Saturation

Global measure of cerebral metabolism: Measures total venous brain tissue oxygen in jugular bulb  Oxygen extraction by the brain

SjvO2 Normal values 50-75% Critical values < 50

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Case

ICP 18 MAP 86 FiO2 50% 7.4/35/141 PBrO2 18 SjVO2 90

UpDATES

• 1. “A Trial of Intracranial-Pressure Monitoring in

TBI” R. Chesnut et al. NEJM 367: 2471-81 (2012).

– Treatment based on ICP monitor vs Clinical Exam

• 2. Protect Study – Methylprednisolone
• 3. Pharmacologic DVT Prophylaxis in TBI

ICP versus Clinical Exam

324 severe TBI patients

• Randomly assigned to
• 1. ICP monitor group
• 2. Clinical group

– Outcome measures : survival, functional and neuropsychological outcome at 6 months No randomized trial to show that treatment based on monitored ICP improves outcome

• R. Chesnut NEJM 367: 2471-81 (2012)

ICP versus Clinical Results

At 6mo ICP Clinical p value 1° Outcome score 56 53 0.5 Mortality 39% 44% 0.4 Favorable Outcome 44% 39% Unfavorable Outcome 17% 17%

Conclusions

Management guided by ICP Monitoring NOT > Clinical Exam

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DVT Prophylaxis after TBI

The controversy :

• TBI : enoxaparin has the potential to

iatrogenically exacerbate intracranial hemorrhage

• View that hemorrhage stabilizes with time
• Is there an early prohibitive period, but once

hemorrhage stabilizes, anticoagulation is safe -

• Timing ?

Recent Studies Pharmacologic DVT Prophylaxis in TBI

Importance of hemorrhage stability before starting prophylaxis

• Worsening of hemorrhage between 1st and 2nd

CT scan followed by enox  13-fold increase in rate of continued hemorrhage

• Stable scan – no hemorrhage expansion
• A. Levy et al, J. Trauma 68: 886-94 (2010)

Recent Studies Pharmacologic DVT Prophylaxis in TBI

• Risk stratification by injury patterns
• different lesions have different risks of hemorrhage

progression  different time frames for stabilization, and  different times for starting prophylaxis Low risk for enox at 24h :

• SDH < 9mm
• EDH < 9mm
• Contusion < 2cm
• Single contusion per lobe
• S. Norwood J Trauma 65: 1021-27 (2008)

Parkland Model Risk Stratification for Starting Enoxaparin

Low Risk

Repeat CT at 24h Stable ? Start Enox at 24 h

Moderate Risk

Repeat CT at 72 h Stable ? Start Enox at 72 h

High Risk

Consider IVC filter

• H. Phelan, J Neurotrauma 29: 1821-28 (2012)

yes yes no no

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Controversy

Does Decompressive Craniectomy Improve Outcome ? DECRA Study

Decra: Study Methods

• Severe TBI (GCS 3-8) with Diffuse injury
• Tier 1 therapy: osmotics, sedation, paralytics, EVD

drainage

• Refractory ICP defined as >20mmHg for > 15min

Bifrontal decompressive craniectomy

Continued ICU Care Tier 2 & 3 therapy :

• mild hypothermia to 35’
• Barbiturate coma

DECRA Study Results : GOSE @6mo

DC 5 10 15 20 25 Die Veg LS US LM UM LG UG DC MC

• DC shifted survivors from favorable  unfavorable
• utcome (dependent for ADLs)

Hemi- Craniectomy

RescueICP

• www.rescueicp.com

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Conclusions

Basic Principles

– Once ICP  already used up compensatory reserves – Mannitol for impending herniation – Poor GCS  brainstem exam – Distinguish primary v secondary injury – Hypoxia / hypotension / drugs & ethanol may mask GCS – ICP monitoring for unresponsive without neuro exam

DECRA: Study Design

• 155 adults, aged 15-59 yrs
• Severe TBI (GCS 3-8) with Diffuse injury
• Randomized Standard Care vs Bifrontal

craniectomy for Refractory ICP

• Outcome : GOS-E @ 6mo ‡

Exclusions

• Dilated, unreactive pupils
• Mass lesions (unless small)
• Cardiac arrest at scene

History Pharmacologic DVT Prophylaxis in TBI

History

• No role for pharmacologic prophylaxis in TBI before

2000

• Gearhart 2000 –

– DVT prophylaxis in 102 trauma patients – 26 TBI with intracranial blood  no instance of TBI worsening

• Kim 2002 -

– 76 severe TBI, unfrac heparin; groups <72 h and > 72 h ; – no increase in intracranial bleeding between groups

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Decra: Study Methods

• Severe TBI (GCS 3-8) with Diffuse injury
• Tier 1 therapy: osmotics, sedation, paralytics, EVD

drainage

• Refractory ICP defined as >20mmHg for > 15min

Bifrontal decompressive craniectomy

Continued ICU Care Tier 2 & 3 therapy :

• mild hypothermia to 35’
• Barbiturate coma

Life saving DC >72 h after admission

DECRA: Study Results

• Icp control