Mark Wilson and John Myburgh discuss intracranial pressure. Some fundamentals, some history to put it all in perspective and all the issues with focusing on just one number. Fascinating insights from two true experts. For more head to: codachange.org/podcasts

1. ICP
@JAMyburgh @MarkHWilson

2. ICP
Variable to be targeted?
Or Marker of Severity of Disease?

3. 1783 1824 18421828 1846 1926
“for, as the substance of the brain, like
that of the other solids of our body, is
nearly incompressible the quantity of
blood within the head must be the
same, or very nearly the same, at all
times, whether in health or disease, in
life or after death, those cases only
excepted, in which water or other
matter is effused or secreted from the
blood-vessels; for in these, a quantity of
blood, equal in bulk to the effused
matter, will be pressed out of the
cranium. ”

4. What Makes Intracranial Pressure

5. Idiopathic
Intracranial
Hypertension

6. W H E N I T C O M E S T O I C P
T H I N K I N A N D O U T S I D E O F T H E B O X

7. Inputs:
RCT - 15 centres, Aus, NZ + Saudi Arabia
n = 155
ICP of > 20mmHg for > 15 minutes
DC = 75 vs no DC in 82
Extended GOS at 6 months, favourable
outcome
Outputs:
At 6 months:
GOS-E worse in DC (Odds Ratio 1.8)
Mortality DC = 19%, `standard care = 18%
Post hoc adjustments for pupils —> no
difference
Mean ICP DC = 14.4 vs 19.1 and fewer ICU
days.
More fixed pupils in DC group (27% vs 12%)-
removed statistically significant benefits when
analysed.
Conclusion: Crainectomy associated with more
unfavrouable outcomes
DECRA - 2002 -2010

9. Inputs: 52 centres in 12 countries
n = 408 patients ICP >25mmHg for > 12 hours
201 surgery vs 188 medical
Extended GOS at 6 months, favourable
outcome
Outputs at 6 months:
Death: 26.9% in surgery vs 48.9% medical
Veg State: 8.5% in surgery vs 2.1% medical
Lower sever disability: 21.9% vs 14.9%
Upper severe disability: 15.4 vs 8%
Moderate severe disability: 23.4 vs 19.7%
Good recovery 4.0 vs 6.9%
Outputs at 12 months:
Death: 30.4% in surgery vs 52% medical
Veg State: 6.2% in surgery vs 1.7% medical
Lower sever disability: 18% vs 14%
Upper severe disability: 13.4% vs 3.9%
Moderate severe disability: 22.2 vs 20.1%
Good recovery 9.8 vs 8.4%
RESCUE ICP - 2004 TO 2014

10. 100 patients treated with
decompressive craniectomy
rather than medical intent, there
were 22 more survivors; of
these 22 patients, 6 were in a
vegetative state (27%), 8 were
categorised as having lower
severe disability (36%), and 8
were categorized as having
upper severe disability or
better (36%)

12. WHEN?

14. HOW?

15. Robba: Int Care Med 2017

16. ΔP(mmHg)
ΔV (ml)
1783, 1824
Alexander Monro
1733-1817
George Kellie
1720-1779

19. Rat / human model 20th century
Take a young male rat.
Infuse alcohol or ice until intoxicated.
Throw rat at high speed into brick wall
Break its femur and pelvis.
Leave it lying in the corner for 1 hour.
Get resident to resuscitate it using albumin and ketamine
Include an oesophageal intubation and hypoxia for 20m.
Get orthopod to fix femur and lose 20% blood volume.
Do a CT head, but don’t tell the researcher the results.
Get a resident to put in ICP monitor 6-36 hours after injury.
Do the intervention.
Random use of mannitol, hyperventilation, hypothermia, barbs
Count how many rats are dead after 1 week.

20. www.braintrauma.org

21. Rat / human model 21th century
Take a rat of any age.
If young, infuse alcohol or speed until intoxicated.
If old, give warfarin and aspirin
Early intubation and resuscitation
Pan-scan and damage control surgery
Standardise ICP monitoring
Do the intervention.
Flog CPP with noradrenaline
Use hypothermia, barbiturates to keep ICP<20
Decompressive craniectomy if these don’t work
Keep going until the rat’s family tells you when to stop
Count how many rats are dead after 6 months.

22. Noradre
But you said…… “Keep the CPP above 70!??”

24. Cooper: New Eng J Med 2011
Unfavourable Favourable
70% 51%
OR: 2.21 95%CI 1.14 to 4.26; P=0.0219 vs 18% mortality

26. Chesnut: NEJM 2012
ICP monitoring group
Imaging/exam group
P=0.60

27. Outcome from ABI is primarily determined by geography…
… and genetics
ICP is primarily an indicator of severity of injury
Treating ICP comes at a cost …
… saving the head, but killing the body…
… and those who care for the patient

28. Beware the relentless therapeutic imperative to do what we can…
… and not what we should

29. ICP
Treat the cause not the number

30. ICP
GAME OVER
?