Unestablished indications are conditions in which systematic clinical use of hyperbaric
oxygen treatment (HBOT) is not supported by adequate proof of benefit. HBOT is vulnerable to use in many such conditions for various reasons, perhaps the most important being that a placebo or participation effect may create an impression of efficacy. The systematic use of HBOT in unestablished indications raises ethical concerns about provision of misleading information, giving false hope, and taking payment for
therapy of doubtful benefit. Any practice perceived as unethical or unscientific has the potential to draw the wider field into disrepute. Of substantial contemporary relevance is the use of HBOT in treatment of various forms of
chronic brain injury; in particular,
cerebral palsy in children and the sequelae of
mild traumatic brain injury in adults. There are now multiple, randomised, blinded,
sham-controlled trials of HBOT in both indications. None of these studies showed benefit of HBOT when compared to
sham control, though the
sham and HBOT groups often both improved, indicating that a placebo or participation effect influenced outcomes. These results almost certainly explain those of open-label trials (lacking
sham controls) in which HBOT frequently seems beneficial. Advocates for HBOT in
chronic brain injury claim that the
sham treatments (usually 1.3 ATA pressure exposure whilst air breathing) in the blinded trials are actually active treatments; however, the same dose of
oxygen can be achieved at 1 ATA breathing 27%
oxygen. To counter this argument, advocates also claim that the extra 0.3 ATA of pressure is somehow independently beneficial, but this notion has limited
biological plausibility and there is little supporting evidence.
Chronic brain injuries remain unestablished indications at this time and, in our opinion, should not be systematically treated with HBOT.