Effects of Hyperbaric Oxygenation Therapy on Cerebral Metabolism and Intracranial Pressure in Severely Brain Injured Patients

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Effects of Hyperbaric Oxygenation Therapy on
Cerebral Metabolism and Intracranial Pressure in
Severely Brain Injured Patients

• Rockswold SB et al.
• J Neurosurgery 94403-411, March 2001
• Presented by Ri ???
• Supervisor Vs???
• 91-8-11

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Its Hyperbaric Oxygenation Therapy

• What is Hyperbaric Oxygen Therapy?
• entirely enclosed chamber
• breathing oxygen,
• greater than one atmosphere

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How Does HBO Work?

• 1. Hyperoxygenation
• a. Dissolves extra oxygen into the blood
• b. Angiogenesis in wound areas
• c. Sufficient oxygenation to ischemic
• tissues
• _at_ Useful in the treatment of anemias,
• ischemias and some poisonings

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How Does HBO Work?

• 2. Mechanical effect of increased pressure
• Any free gas trapped in the body will decrease
  in volume as the pressure on it increases
• _at_Successfully applied to air embolism
• and decompression sickness

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How Does HBO Work?

• 3. Gas wash out effect
• The flooding of the body with any one gas tends
  to "wash out" all others.
• _at_Treatment for CO intoxication
• and cyanide poisoning

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How Does HBO Work?

• 4. Vasoconstriction
• Causes vasoconstriction without creating
• hypoxia which decreases edema
• decreases ICP
• _at_Useful in burns, crush injuries and
• interstitial bleeding
• _at_Acute brain and spinal cord injuries

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How Does HBO Work?

• 5. Bacteriostasis
• Inhibits growth of anaerobic as well as some
  aerobic organisms
• _at_Useful in conditions such as dysvascular
• conditions and disorders of
• immunosuppression

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Indications
HBO is generally used as an adjunctive therapy
it does not compete with or replace other
treatment methods

• Selected refractory anaerobic infections
• Gas gangrene
• Necrotizing soft tissue infections
• Refractory osteomyelitis
• Radiation Necrosis
• Compromised Skin Grafts or Flaps
• Thermal Burns

• Air or gas embolism
• CO poisoning
• Cyanide poisoning
• Crush injury and other acute traumatic ischemias
• Decompression sickness
• Enhancement of healing in selected problem wounds
  
• Exceptional blood loss anemia

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What are the risk factors

• Oxygen Toxicity
• (cerebral and pulmonary
• toxicity)
• Cisplatinum, Doxorubicin
• COPD
• Pnumothorax
• History of seizures
• History of middle ear disorders/surgery

• Optic Neuritis
• Pregnancy
• High Fever
• URI Viral infection
• Asthma
• Congenital Spherocytosis

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About the Study
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• Introduction
• HBO therapy has been shown to reduce mortality
• by 50 in a prospective randomized trial of
• severely brain injured patients
• Objectives
• Determine the effects of HBO on CBF, cerebral
• metabolism, and ICP, and to determine the
• optimal HBO treatment paradigm

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• Materials and Methods
• GCS 3-8, head injury
• N37, 10 F, 27M,
• 1. Oxygen (100 O2, 1.5 ATA) was delivered to
  pts in hyperbaric chamber for 60 mins q24h
• 2. CBF, AVDO2, CMRO2, ventricular CSF lactate,
  and ICP values were obtained 1 hour before and 1
  hour and 6 hours after a session

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• Exclusion criterias
• Unstable pulmonary status
• Pregnancy
• Unstable fracture
• lt4 y/o
• Barbiturate-induced coma

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• Patients were assigned to 3 categories
• A) Reduced CBF before HBO
• B) Normal CBF before HBO (32.9-55.3ml/100g/min)
• C) Raised CBF before HBO

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About the Parameters

• Cerebral Blood Flow (CBF)
• nitrous oxide saturation method
• Cerebral Metabolism
• 1. CMRO2AVDO2 X CBF
• 2. CSF lactate level
• Intracranial Pressure (ICP)
• ventriculostomy with ICP monitor

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Results
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CBF

• Group A, CBF was raised 1 hour and 6 hours after
  HBO (p lt 0.05)

Group A
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CBF

• Group B, CBF was increased at 1 hour (p lt 0.05),
  but decreased by 6 hours after HBO

Group B
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CBF

• Group C, CBF was reduced 1 hour and 6 hours after
  HBO (p lt 0.05)

Group C
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AVDO2

• In all patients AVDO2 remained constant both
  before and after HBO
• HBO may normalize the coupling of CBF and
  cerebral metabolism

Session 1
Session 2-7
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CMRO2

• Group A, CMRO2 was raised 1 hour post-treatment

Group A
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CMRO2

• Group B, CMRO2 was raised 1 hour post-treatment

Group B
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CMRO2
Group C

• The CMRO2 was not affected when patients began
  with a raised CBF

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ICP

• ICP higher than 15 mm Hg before HBO were
  decreased 1 hour and 6 hours after HBO (p lt 0.05)
  
• Stimulation-induced increase in ICP

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CSF lactate level

• The CSF lactate levels were consistently
  decreased 1 and 6 hours post-treatment,
  regardless of the pre-treatment CBF

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Conclusions
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Conclusions

• 1. The increased CMRO2 and decreased CSF lactate
  levels after treatment indicate that HBO may
  improve aerobic metabolism in severely brain
  injured patients

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Conclusions

• 2. Elevated levels of ICP and CBF were
• reduced after HBO treatment
• HBO may promote BBB integrity, reduce
• cerebral edema and hyperemia, which in
• turns lower elevated ICP

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Conclusions

• 3.The author asserts that shorter, more frequent
  sessions(30 min Q8H) in a pressurized chamber may
  optimize HBO treatment

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Conclusions

• 4. This is the first study demonstrating that
• HBO therapy exerts a persistent effect on
• CBF and cerebral metabolism in severely
• injured patients

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ANY QUESTIONS OR COMMENTS?
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Thanks For Your Attention!!!