Rockswold SB et al. Effects of hyperbaric
oxygenation therapy on cerebral metabolism and intracranial pressure
in severely brain injured patients. J Neurosurg 2001
Please note that HDOT has been substituted for
HBO in this summary of the summary.
A prospective randomized trial has already
shown that hyperbaric oxygenation therapy (HDOT) reduces the
mortality of severely brain-injured patients by 50%. In this study
the effects of HDOT on cerebral blood flow (CBF), cerebral
metabolism, and intracranial pressure (ICP), have been measured in
an attempt to determine the optimum frequency of treatment. 100% at
1.5 atm absolute was delivered to 37 patients for 60 minutes every
24 hours (maximum of seven treatments/patient). The increased
cerebral metabolic rate of oxygen (CMRO2) and decreased
cerebrospinal fluid (CSF) lactate levels after treatment indicate
that HDOT may improve aerobic metabolism in severely brain-injured
patients. This is the first study to demonstrate a prolonged effect
of HDOT treatment on CBF and cerebral metabolism. On the basis of
their data the authors suggest that shorter, more frequent exposure
to HDOT may be better.
- The authors have not acknowledged that Sukoff and Ragatz
actually showed this nearly 20 years ago. Ref: Sukoff MH and
Ragatz RE Hyperbaric oxygenation for the treatment of Acute
cerebral edema. Neurosurgery 1982;10: 29-38).
- One hour of a higher dosage of oxygen in 24 hours is not
enough. A total of at least 16 hours in 24 has been given at 2 atm
abs in the resuscitation of a patient after cardiac surgery. Ref.
Yacoub MH, Zeitlin GL. Hyperbaric oxygen in the treatment of the
Postoperative low-cardiac-output syndrome. Lancet 1965; i: 581-83.
- Giving more oxygen (HDOT) in the presence of a lack of
oxygen is likely to improve the CMRO2, that is the brain's use of
oxygen. Ref. No reference is needed here ...........
- The presence of lactate indicates that there is not enough
oxygen for (normal) aerobic (air related) metabolism and giving
some more (HDOT) allows more normal (aerobic) metabolism. Ref. No
reference is needed here either...
Dr P.B. James MB ChB DIH PhD
Wolfson Hyperbaric Medicine Unit