Niels Van Regenmortel

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Niels Van Regenmortel
IAP The Brain
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Introduction
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Guy
Ineke
Joost
Malbrain. Current Opinion Crit Care 2004 10(2)
132-145
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Monroe-Kellie Doctrine 75 brain 10
blood 10 CSF
Vasoconstriction
Movement of CSF
Intracranial volume constant
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Slide by S. DAmours
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Autoregulation
CPP MAP - ICP
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Traumatic Brain Injury

• Strong association between high ICP and outcome
• Monitoring and treatment of ICH is widespread

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Todays QuestionsWhat is the effect of
abdominal hypertension on the brain?What are
we going to do about it?
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The Evidence
Treatment options ?
Relationship IAP and ICP ?
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Relationship IAP - ICP

• Birth of an idea
• Morbid obesity data
• Idiopathic intracranial hypertension rates higher
  than general population
• Resolution of signs and symptoms associated with
  weight loss (and ? IAP)
• Laparoscopy data
• ? IAP leads to ? ICP (in normal setting)

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Relationship IAP - ICP

• Animal studies
• Josephs, J Trauma, 1994
• Pneumoperitoneum in pigs IAP ?
• ICP ?, but CPP
• Explanation reduction of venous outflow

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Relationship IAP - ICP

• Animal studies
• Bloomfield, J Trauma, 1996
• Intraperitoneal balloon in swine IAP ?
• CVP ? ICP ? CI ? MAP ? CPP ?
• Statistically significant CPP ? , even without
  head injury
• Volume resuscitation ICP ? CPP ?
• Conclusion mechanical problem by reduction of
  venous outflow

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Relationship IAP - ICP

• Animal studies
• Bloomfield, Crit Care Med, 1997
• Group 1 as previous study
• Group 2 sternotomy pleuropericardiotomy

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Relationship IAP - ICP

• Clinical studies
• Citerio, Crit Care Med, 2001
• Weight on abdomen of TBI patient
• IAP ? CVP ? ICP ? within seconds
• MAP ? CPP

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Treatment options
Small numbers Uncontrolled Differences between
groups Conclusion ??

• Abdominal decompression
• Joseph, J Trauma, 2004
• 17 pts with ICH unresponsive to maximal therapy
• Decompression IAP ? ICP ?
• 6 pts transient effect ?
• 11 pts persistent effect survived
• Neuromuscular blockade
• Deeren, ICM, 2005
• 10mg cisatracurium

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Treatment options
Ertel, Crit Care Med, 2000
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Practical Considerations
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Perform well on both sides of the problem!

• ABDOMINAL
• Low threshold for IAP monitoring
• Prevention of IAH in each patient with ICH
• Avoid laparoscopy in pts with ICH
• Treat IAH, especially when ICH is present
• Lower threshold for decompression?

• NEUROLOGICAL
• Monitoring of neurological status in patients
  with IAH
• Stepwise treatment of ICH

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Which patient need ICP monitoring?

• Mild head injury (GCS 14-15)
• Low risk for ICH - 3 will deteriorate to coma
• Sequential neurological examination
• Moderate head injury (GCS 9-13)
• Relatively low risk for ICH - 10 will
  deteriorate to coma
• Sequential neurological examination
• Severe head injury (GCS 3-8)
• High risk for ICH
• CT scan
• Abnormal always ICP monitoring
• Normal ICP monitoring if gt2 risk factors
• Age gt 40y
• Uni- or bilateral motor posturing
• Systolic BP lt 90 mmHg

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Stepwise treatment of ICH
www.braintrauma.org

• Revised guidelines Brain Trauma Foundation 2003
• Cerebral perfusion pressure should be maintained
  at a minimum of 60 mmHg
• In the absence of cerebral ischemia, aggressive
  attempts to maintain CPP above 70 mm Hg with
  fluids and pressors should be avoided because of
  the risk of adult respiratory distress syndrome.

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Stepwise treatment of ICH

• First Line
• Avoid hypotension (MAP 90)
• Only treat excessive hypertension
• Avoid hypoxemia (pO2 gt60mmHg, Sat gt90)
• Avoid hypercapnia
• 30 head of bed elevation
• If filling status and haemodynamics are OK
• Sedation
• Cave blood pressure
• Awake patients neuroleptics
• MV patients propofol opiates. No routine
  curare

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Stepwise treatment of ICH

• First Line
• Drainage of CSF
• Absolute threshold is unlikely to exist
• 20-25 mmHg is usually considered the upper
  threshold to initiate therapy
• Hypertonic saline
• Osmotic, haemodynamic, immunomodulatory and
  neurochemical effects
• Bolus vs. continuous
• Different schemes
• Central line!
• Sodium levels 145-155 mEq/L
• Monitor fluid status avoid hypovolemia

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Stepwise treatment of ICH

• First Line
• Mannitol (?)
• 0.25-1 g/kg
• 15 15g/100ml
• Osmotic gradient transient hypervolemia
• Risk for renal failure, especially with
  osmolarity gt320
• Cochrane review
• Beneficial on ? when compared to pentobarbital
• Detrimental compared to hypertonic saline
• Insufficient data on prehospital use
• No diagnosis of diabetes insipidus based on
  urinary osmolarity after mannitol treatment!

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Stepwise treatment of ICH

• Second Line
• Hyperventilation
• Cerebral vasoconstriction ? CBF ?
• Risk for cerebral ischemia (CBF lt15-50cc/100g/)
• Rebound effect?
• Avoid chronic prolonged hyperventilation paCO2
  lt25 mmHg in the absence of increased ICP
• Avoid prophylactic hyperventilation lt 35 mmHg
  especially in first 5d and particularly during
  first 24h
• May be necessary for brief periods if acute
  neurological deterioration or for longer periods
  if refractory to first line measures.

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Stepwise treatment of ICH

• Second Line
• Barbiturates (Pentobarbital)
• Loading dose 5mg/kg ? 1-5 mk/kg/h until burst
  suppression on EEG
• Efficacious is lowering ICP in refractory ICH
• Adverse effects!
• Cardiac depression
• Immune depression
• Hypernatremia
• Central line!
• No prophylactic use

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Stepwise treatment of ICH

• Third Line
• Hypothermia
• 32-34
• Ice application, wind tunnel, Coolguard
• Blocks neurotoxic neurotransmitters
• No rebound effect
• Decompressive craniotomy
• Steroids are NOT useful

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Open Questions
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Open questions?

• Effect of ACS on  normal brain  or  possible 
  brain injury
• Thresholds to decompress

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Conclusions
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Conclusions

• Evidence that IAH has a detrimental effect in the
  setting of TBI.
• Decompression surgically or medically can
  improve the outcome
• Monitor IAH and if necessary ICH
• Prevent IAH
• Treat IAH and ICH
• Open questions still work to do!

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