Hyperbaric Oxygen Therapy - Hyperbaric Chamber Information ...

Background
Hyperbaric oxygen therapy
This evaluation was undertaken in response to an application for assessment of
adjunctive hyperbaric oxygen therapy delivered in monoplace-only facilities, which is
currently ineligible for funding under the Australian Medicare Benefits Scheme (see
Current Reimbursement Arrangement, pg 5). However, the scope of the review was
broadened to consider all indications for hyperbaric oxygen therapy identified in the
initial search, although in most cases it is used as an adjunctive treatment only.
Evidence from studies on hyperbaric oxygen therapy delivered in either monoplace or
multiplace systems was evaluated and no attempt was made to perform a comparative
assessment of the two types of delivery systems. This was done because, according to
expert clinical opinion, the therapeutic effect is the same regardless of the delivery
system. The higher pressures that multiplace chambers can deliver was not an issue in the
evaluation as the majority of treatments are administered at less than 3ATA.
No comparative studies of efficacy or safety in monoplace and multiplace systems were
found. However, there are marked regional variations in the delivery system used, which
are reflected in the literature. Australian clinical practice and expertise is primarily in the
use of multiplace chambers because the majority of the long-established hyperbaric
facilities have multiplace chambers only. In contrast, clinical practice in the United States
is primarily monoplace-based as many facilities, including those used for intensive care
patients, are equipped solely with monoplace chambers.
The procedure
Hyperbaric oxygen therapy (HBOT) involves the intermittent inhalation of 100 per cent
oxygen in chambers pressurised above one atmosphere absolute (ATA). 1,2 An ATA is
defined as the atmospheric pressure at sea level and is equivalent to 101.3 kiloPascals
(kPa) or about 14.7 pounds per square inch.
Exposure to hyperbaric oxygen (HBO) is measured by the pressures used in singletreatment
exposures to HBO and the number of treatment sessions. Tolerance to
therapy is dependent on both these parameters. In general, HBOT is well-tolerated if
pressures do not exceed three ATA (approximately 300 kPa) and lasts less than two
hours. Depending on the reason for HBOT, treatment duration can vary from 45 to 300
minutes, although most treatments are in excess of 90 minutes, for a variable number of
sessions. 1-4
Treatment with HBO is administered in two types of chambers – monoplace and
multiplace chambers. A monoplace chamber accommodates a single patient and is the
most common type of chamber in use worldwide. 3 It can be pressurised with either
100 percent oxygen or with air, in which case oxygen is delivered to the patient via a
mask, hood or endotracheal tube. The smaller size of the chamber translates to relative
portability and lower cost, but imposes limits on ready access to the patient. The risk of
fire is increased in oxygen chambers due to the pure oxygen used to fill the chamber. 4
2 Hyperbaric oxygen therapy