1. Dr Stephanie Tilston, Anaesthetic SpR KCH March 2007
Management of Severe Raised ICP in Traumatic Brain Injury & the Role of Decompressive Craniectomy
Dr Stephanie Tilston, Anaesthetic SpR
KCH March 2007

2. 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

3. 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.

4. 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

5. Relationship Between ICP and Intracranial Volume

6. Fundamental Pathophysiology

7. 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

8. Of these only barbitutates reached level of ‘guidance’
Others considered ‘options’
Brain Trauma Foundation Guidelines

9. 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.

10. 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.)

14. Classification Primary/Prophylactic decompression
Aim not to control refractory ICP but to avoid expected increases.
Secondary decompressive craniectomy-
Any decompressive surgery performed to control ICP refractory to maximal medical management

15. 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

16. 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 ?

17. 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

18. 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)

19. 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)

20. RescueICP Trial
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

21. Hypothesis
DC results in improved Extended Glasgow Outcome Score cf optimal medical management
DC results in improved surrogate endpoint measures cf optimal medical management

22. Rational of Trial Establish class I evidence
Establish incidence of complications
Recruit from centres experienced in ITU management of head injury

23. 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

24. 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

26. Power
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)

27. 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

28. Current Recommendations Servadei et al Curr Op Critical Care 2007, 13: (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

29. Exclude devastating neurological injury & predictable poor outcome
(signs of brainstem damage, very severe diffuse axonal injury)

30. 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