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38 Hyperbaric Oxygenation Therapy KCE Reports 74
Short summary of the evidence: low quality evidence from one small RCT for no beneficial effect of
HBOT.
Thesis: The Evidence Basis of Diving and Hyperbaric Medicine,
chapter 19 1
Cochrane review 2005: Hyperbaric oxygenation for tumour
sensitisation to radiotherapy. 29
Oxigenoterapia Hiperbárica: Utilidad Diagnóstica e Indicaciones
(IECS 2006) 38
Tumour sensitisation to
radiotherapy
Uses of Hyperbaric Oxygen Therapy (AHRQ 2006) 14
Short summary of the evidence: very low quality evidence from nineteen trials (n=2286) with major
methodological flaws for an improved local tumour control and mortality for cancers of the head
and neck, and local tumour recurrence of cancers of head, neck and uterine cervix. Little evidence
is available for other anatomical sites.
3.5 GENERAL CONCLUSIONS
Over the years HBOT has been proposed for a myriad of indications but only a limited
number of those have been endorsed by the two major scientific hyperbaric societies. In
this chapter we focussed on the evidence for those ‘accepted’ indications.
For various reasons the quality of evidence for the efficacy of HBOT is low to very low
for most of the indications. It has become accepted standard therapy in a few life
threatening conditions i.e. decompression illness and gas embolism, mainly based on
historical empirical evidence. For these indications it is unlikely that evidence from
RCTs will become available because such RCTs are considered unethical. For other
indications, the use of HBOT is mainly based on theoretical reasoning and animal
models, while clinical evidence is often only based on case series comparing outcomes
in centres with and without hyperbaric facilities or with historical controls. These
analyses are, obviously, hugely prone to bias.
For these indications, where RCTs are in theory feasible, there appears to be a general
reluctance to conduct or to fund them, as illustrated for example with the trials that
originated from the COST B14 collaboration on HBOT, that were designed and started
but still not reported. Moreover, these trials especially when involving sham therapy to
maintain double-blinding, are complex and technically not feasible in every hyperbaric
facility. As a result, RCTs are few and the available RCTs are small, possibly leading to a
publication bias towards positive results. It is unlikely that better evidence will become
available in the near future for many of the indications.
Given the paucity of evidence there is a large level of uncertainty about the role and
need of HBOT in daily medical practice in Belgium and abroad, and we have graded the
available evidence according to GRADE taskforce principles. 71
With available evidence we conclude that:
1. There is empirical evidence for the effectiveness of recompression therapy
with or without adjuvant oxygen, and there is wide consensus, but no major
RCTs are available or being conducted, for the clinical efficacy of HBOT in
the treatment of:
• decompression accidents (DCS) (evidence level: high)
• severe gas embolism (evidence level: low)
2. There is low quality evidence from small RCTs on the clinical efficacy of
HBOT, but future larger and well conducted RCTs could enhance our
knowledge base for:
• adjuvant HBOT in patients with diabetic ulcers may help avoid major
amputations in the medium term compared to standard therapy
without HBOT
• in acute deafness presenting early a slightly better recovery was
observed with adjuvant HBOT but the clinical relevance is uncertain
• improved healing in selected cases of radiation induced tissue injury