Research guru and PI for the ARISE study, college examiner and semi-professional forrest-based carpenter, Anthony always gives a fascinating talk. This time he gives an intelligent and considered breakdown on the nebulous topic of cerebral protection.
Call Girls Kochi Just Call 9907093804 Top Class Call Girl Service Available
Delaney on Cerebral protection
1. CEREBRAL PROTECTION
Anthony Delaney MBBS MSc FACEM FCICM
Staff Specialist in Intensive Care, Royal North Shore Hospital
Senior Lecturer, Sydney Medical School, University of Sydney
5. Decompressive craniectomyin diffuse traumatic
brain injury
Population:
Aged 15-59
Severe non penetrating brain injury (GCS 3-8),
Class III Marshall score
Exclusion: mass lesion on CT, dilated unreactive
pupils, spinal cord injury, cardiac arrest
ICP > 20 for 15 minutes within an hour after;
Sedation, Normal CO2, osmotic therapy, NM blockade
and CSF drainage
Within 72 hours of injury
6. Decompressive craniectomyin diffuse traumatic
brain injury
Intervention:
Standardised large bifrontotemperoparietal
craniectomy with opening of the dura
8. Decompressive craniectomyin diffuse traumatic
brain injury
Allocation concealment:
Yes, automated telephone system
Blinding:
Outcome assessment by telephone by blinded assessors
Complete follow-up:
Yes
Intention-to-treat analysis:
Yes
Baseline balance:
More patients in DC group had bilateral unreactive pupils
Concommittant interventions:
Different between the 2 groups
18. Decompressive craniectomyin diffuse traumatic
brain injury
However the adjusted analysis
Age, last GCS before intubation, GCS post
resuscitation, Marshall score;
GOSe 1.66 (95% CI 0.94 to 2.94, p=0.08)
Good v Evil OR 2.31 (95% CI 1.10 to 4.83, p=0.03)
And non reactive pupils
GOSe 1.53 (95% CI 0.86 to 2.73, p=0.15)
Good v Evil OR 1.9 (95% CI 0.95 to 3.79, p=0.07)
19. Decompressive craniectomyin diffuse traumatic
brain injury
So…….
RESCUE ICP
ICP>25 for 1-12 hours
Abnormal CT
Primary decompression excluded but prior
surgery not an exclusion
Recruitment commenced 2005
334/400 recruited as of 18/9/12
20. Hypothermia for cerebral protection
Pathophysiology:
Reduction of CMRO2 of 6-7% per 1o drop in temp
Reduction in ICP
Decreases excitatory amino acids and lactate in
ischaemia/reperfusion injury
Reduces intracellular Ca++ sequestration
Reduces neutrophil adhesion
Reduces apoptosis
Reduces free radical production
• Induced hypothermia in critical care medicine: A review. Bernard et al CCM 2003;31:2041-2051
• Application of therapeutic hypothermia in the ICU: opportunities and pitfalls of a promising
treatment modality. Part 1: indications and evidence. Polderman. ICM 2004;30:556-575
23. Hypothermia for neuroprotection in adults after
cardiopulmonary resuscitation
Question:
To assess the effectiveness of therapeutic hypothermia in
patients after cardiac arrest
Studies:
Randomised and quasi-randomised studies
Population:
Adult patients who suffered cardiac arrest (in or out of hospital)
Intervention:
Temperature target <35oC
Control:
Standard treatment
Outcome:
Neurological recovery
Cerebral performance category
27. Hypothermia for neuroprotection in adults after
cardiopulmonary resuscitation
Conventional cooling methods to induce
mild therapeutic hypothermia seem to
improve survival and neurological outcome
after cardiac arrest. Our review supports
the current best medical practice as
recommended by the International
Resuscitation Guidelines
28.
29.
30.
31.
32. Higher risk of bias in existing trials ->
overestimation of treatment effect
Low inclusion rate (8%) -> poor
generalisability
Or better signal to noise ratio
Target population
Early stopping and no power calculation
More of a type II error problem
Non-standard change to palliative treatment
Dude ?!?
Adverse effects of hypothermia
33.
34. Adverse effects of hypothermia
Prospective observational study
22 centres
36. Most published research findings are
false
Complicated statistical argument
Prior probability
Power of the study
Level of significance
Bias
Flexibiilty in design
Definition
Outcomes
Analysis
37.
38. Contradicted research
Original clinical research cited more than
1000 times 1990-2003
Compared to subsequent studies bigger
and/or better
49 studies
45 claimed a treatment effect
16% contradicted
16% lesser treatment effect
44% replicated
24% not challenged
39. So, wherefore hypothermia
Dilemma
Hypothermia has a good physiological
rationale
Supported by at least
reasonable trials