Transcript Management of Severe Raised ICP in Traumatic Brain Injury

Management of Severe Raised ICP in
Traumatic Brain Injury & the Role of
Decompressive Craniectomy
Dr Stephanie Tilston, Anaesthetic
SpR
KCH March 2007
Traumatic Brain Injury
 Major
cause of morbidity and
mortality worldwide
 Trauma is leading cause of death in
first 4 decades of life
 Head injury implicated in at least half
 Recent advances in care at several
levels
 But
morbidity and mortality remain
high
 High
ICP is the most frequent cause
of death and disability after severe
traumatic brain injury (TBI)
 controversy
continues about
fundamental treatment and specific
therapies.
Raised ICP
 Fundamental
principles credited to
Professors Monro (1783) and Kelly
(1824)
 States that
1) cranium is non-expandable
2) brain parenchyma is nearly incompressible
3) volume of blood therefore nearly constant
4) continuous venous outflow required for
continuous arterial flow
Relationship Between ICP and Intracranial Volume
Fundamental Pathophysiology
Management of raised ICP
Once first line measures fail only a few
therapeutic options are available unless
evacuable mass lesions are found at CT.
 Second tier management include:

–
–
–
–
–
–
High dose barbiturates
Hypertensive management
Mild/moderate hypothermia
Osmotherapy
?Intensive hyperventilation
Decompressive craniectomy
 Of
these only barbitutates reached
level of ‘guidance’
 Others
considered ‘options’
– Brain Trauma Foundation Guidelines
 However
Cochrane collaboration
found no evidence that barbiturates
improve outcome in severe TBI
 May
reduce ICP but this reduction
not associated with lower mortality
or improved outcome.
Decompressive Craniectomy
Increases cranial volume by removing
bone and opening duramater.
 Converting skull from
‘a closed box with finite volume into an
open one’
 First detailed report by Cushing in 1905
(used decompression to alleviate high ICP
secondary to inoperable brain tumours.)

Classification
 Primary/Prophylactic
decompression
Aim not to control refractory ICP but to avoid
expected increases.
 Secondary
decompressive
craniectomyAny decompressive surgery performed to
control ICP
refractory to
maximal medical management
Concerns About Decompressive
Craniotomy



May convert brain stem death into PVS
Confounding small observational studies
but no large RCT
Systematic review of >2000 patients
(Bazarian 2002) showed benefit but
heterogeniety of study
Controversies
 Variability
in surgical technique
– Extent of bone removed directly related
to fall in ICP. Should extend beyond
coronal suture
– Unilateral or bilateral
– Open the dura (or scarify?or keep
closed?)
– Sectioning of the falx ?
– Quality of teqnique and dissection
– Vascular tunnels ?
Complications of Craniectomy
– At surgery
– More commonly after bone replacement
Increased brain oedema
 Subdural collections
 CSF leakage
 Hydrocephalus
 Brain infarctions
 Epidural collections
 Infections
 Bone resorption

Decompressive Craniectomy For Refractory
ICP in TBI-Cochrane Systematic Review
(October 2005)
 Randomised/quasi
randomised trails
assessing patients over 12 months
 No evidence to support routine use
of secondary DC to reduce
unfavourable outcome in adults.
 But reduces risk of death and
unfavourable outcome in paediatric
population
(NB limitations of study)


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To date no RCT to confirm or refute
effectiveness of DC in adults
However results of non RCT and controlled
trails with historical controls involving
adults suggest DC may be useful option.
Two ongoing RCT may allow further
conclusions
– ResueICP
– DECRA (ANZICS)
RescueICP Trial

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International prospective multi-centre RCT
comparing efficacy of DC v optimal medical
management for treatment of refractory
intracranial hypertension following brain trauma
Collaboration between Cambridge
NeuroSx/NeuroITU and European Brain Injury
Consortium.
KCH is a recruiting centre
Hypothesis


DC results in improved Extended Glasgow
Outcome Score cf optimal medical
management
DC results in improved surrogate endpoint
measures cf optimal medical management
Rational of Trial

Establish class I evidence

Establish incidence of complications

Recruit from centres experienced in ITU
management of head injury
Inclusion Criteria
Patients aged 10-65
 Abnormal CT
 Requiring ICP monitoring
 ICP > 25mmhg for >1-12 hrs
 Refractory to initial medical measures
 May have initial op for mass lesion
 Hepato/renal/immuno compromise
included but type and extent documented

Exclusion Criteria
Bilateral fixed dilated pupils
 Bleeding diathesis
 Survival not expected >24hrs
 Follow up not possible
 ICPmonitoring not possible
 Patients treated on Lund Protocol
 Primary decompression
 Barbiturates pre randomisation
 Brainstem involvement

Power

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Originally 400 patients in total (200 each
arm) to detect 15% difference in outcome
Ie increase favourable outcome from 45%
to 60%
As a result of pilot study increased to 500
(due to crossover from medical to surgical
arm)
Outcome measures
 Primary
endpoints
Assessment of outcome at discharge
(Glasgow Outcome Score) and 6 months
(Extended Glasgow Outcome Score)
 Secondary
endpoints
SF-36 questionnaire
ICP control
Time in ITU
Time to discharge from ITU
Current Recommendations
Servadei et al Curr Op Critical Care 2007, 13:163-168 (WHO
Neurotrauma Collaboration)
Given dismal outcome of patients with
refractive high ICP, reasonable to include
DC as last resort in protocol driven Mx
 Conventional therapeutic measures failed
 Operable masses ruled out
 Patient has possibility of functional
outcome

 Exclude
devastating neurological
injury & predictable poor outcome
(signs of brainstem damage, very
severe diffuse axonal injury)
Recommendations - Technique
 Bifrontal
craniectomy with large
bilateral bone flap extending beyond
coronal suture and including most
basl part of temporal bone to base of
cranium
 Wide dural opening with anterior
division of the falx cerebri
 Vascular tunnels may be helpful to
protect veins at bony edges