Selasa, 17 Juni 2014

Hyperbaric Oxygen Therapy for Non-Healing Ulcers in Diabetes Mellitus ,--An Evidence-Based Analysis

Executive Summary
To examine the effectiveness and cost-effectiveness of hyperbaric oxygen therapy (HBOT) to treat people
with diabetes mellitus (DM) and non-healing ulcers. This policy appraisal systematically reviews the
published literature in the above patient population, and applies the results and conclusions of the review
to current health care practices in Ontario, Canada.
Although HBOT is an insured service in Ontario, the costs for the technical provision of this technology
are not covered publicly outside the hospital setting. Moreover, access to this treatment is limited, because
many hospitals do not offer it, or are not expanding capacity to meet the demand.

Clinical Need
Diabetes mellitus is a chronic disease characterized by an increase in blood sugar that can lead to many
severe conditions such as vision, cardiac, and vascular disorders. The prevalence of DM is difficult to
estimate, because some people who have the condition are undiagnosed or may not be captured through
data that reflect access to the health care system. The Canadian Diabetic Association estimates there are
about 2 million people in Canada with diabetes (almost 7% of the population). According to recent data,
the prevalence of DM increased from 4.72% of the population aged 20 years and over in 1995, to 6.19%
of the population aged 20 years and over in 1999, or about 680,900 people in 1999. Prevalence estimates
expanded to 700,000 in 2003.
About 10% to 15% of people with DM develop a foot wound in their lifetimes because of underlying
peripheral neuropathy and peripheral vascular disease. This equals between 70,000 and 105,000 people in
Ontario, based on the DM prevalence estimate of 700,000 people. Without early treatment, a foot ulcer
may fester until it becomes infected and chronic. Chronic wounds are difficult to heal, despite medical
and nursing care, and may lead to impaired quality of life and functioning, amputation, or even death.

The Technology
Hyperbaric oxygen therapy has been in use for about 40 years. It is thought to aid wound healing by
supplying oxygen to the wound. According to the Hyperbaric Oxygen Therapy Association, HBOT acts
as a bactericidal, stops toxin production, and promotes tissue growth to heal difficult wounds.
During the procedure, a patient is placed in a compression chamber with increased pressure between 2.0
and 2.5 atmospheres absolute for 60 to 120 minutes, once or twice daily. In the chamber, the patient
inhales 100% oxygen. Treatment usually runs for 15 to 20 sessions.
Noted complications are rare but may include claustrophobia; ear, sinus, or lung damage due to pressure;
temporary worsening of short sightedness; and oxygen poisoning. Careful monitoring during the
treatment sessions and follow-up by a trained health care provider is recommended.


The aim of this health tecnology policy appraisal were to asses the effectiveness,safety and cost  effectiveness of HBOT,either alloneor as an adjunct, compared with the standart treatments for non healing foot or leg ulcers in patients with DM. the following questions were asked:
 Alone or as an adjunct therapy, is HBOT more effective than other therapies for non-healing foot or
leg ulcers in patients with DM?
 If HBOT is effective, what is the incremental benefit over and above currently used strategies?
 When is the best time in a wound treatment strategy to use HBOT?
 What is the best treatment algorithm with HBOT?

The Medical Advisory Secretariat searched for health technology assessments in the published and grey
literature. The search yielded 4 reports, which were published from 2000 to 2005. The most recent from
the Cochrane Collaboration had a literature review and analysis of randomized control trials to 2003.

As an update to this review, as per the standard Medical Advisory Secretariat systematic review strategy,
the abstracts of peer-reviewed publications were identified using Ovid MEDLINE, EMBASE, MEDLINE
in-process and not-yet-indexed citations, Cochrane Database of Systematic Reviews, Cochrane
CENTRAL, and INAHTA using key words and searching from January 1, 2003 to 2004.

The criteria for inclusion were as follows:

 Patients with diabetes
 Live human study
 English-language study
 HBOT as adjunctive therapy or alone
 Randomized control trial

The number of excluded studies included the following:

 2 animal studies
 13 focus on condition other than DM
 8 review/protocol for HBOT use
 3 HBOT not focus of report
 2 health technology assessments (2)
 1 non-RCT

Outcomes of interest were wound healing and prevention of amputation.
The search yielded 29 articles published between 2003 and 2004. All 29 of these were excluded, as shown
beside the exclusion criteria above. Therefore, this health technology policy assessment focused
exclusively on the most recently published health technology assessments and systematic reviews.

Summary of Findings

Four health technology assessments and reviews were found. Cochrane Collaboration researchers
published the most recent review in 2005. They included only randomized controlled trials and conducted
a meta-analysis to examine wound healing and amputation outcomes. They found that, based on findings
from 118 patients in 3 studies, HBOT may help to prevent major amputation (relative risk, 0.31; 95%
confidence interval [CI], 0.13–0.71) with a number needed to treat (NNT) of 4 (95% CI, 3–11). They
noted, however, that the point estimates derived from trials were not well reported, and had varying
populations with respect to wound severity, HBOT regimens, and outcome measures. These noted
limitations rendered the comparison of results from the trials difficult. Further, they suggested that the
evidence was not strong enough to suggest a benefit for wound healing in general or for prevention of
minor amputations.
The Medical Advisory Secretariat also evaluated the studies that the Cochrane Collaboration used in their
analysis, and agreed with their evaluation that the quality of the evidence was low for major and minor amputation, but low to moderate for wound healing, suggesting that  for results from new and well conducted
studies would likely change the estimates calculated by cochrane and others.


In 2003, the Ontario Health Technology Advisory Committee recommended a more coordinated strategy
for wound care in Ontario to the Ministry of Health and Long-term Care. This strategy has begun at the
community care and long-term care institution levels, but is pending in other areas of the health care
There are about 700,000 people in Ontario with diabetes; of these, 10% to 15% may have a foot ulcer
sometime in their lifetimes. Foot ulcers are treatable, however, when they are identified, diagnosed and
treated early according to best practice guidelines. Routine follow-up for people with diabetes who may
be at risk for neuropathy and/or peripheral vascular disease may prevent subsequent foot ulcers. There are
4 chambers that provide HBOT in Ontario. Fewer than 20 people with DM received HBOT in 2003.

The quality of the evidence assessing the effectiveness of HBOT as an adjunct to standard therapy for
people with non-healing diabetic foot ulcers is low, and the results are inconsistent. The results of a recen
meta-analysis that found benefit of HBOT to prevent amputation are therefore uncertain. Future well
conducted studies may change the currently published estimates of effectiveness for wound healing and
prevention of amputation using HBOT in the treatment of non-healing diabetic foot ulcers.

Although HBOT is an insured service in Ontario, a well conducted, randomized controlled trial that has
wound healing and amputation as the primary end-points is needed before this technology is used widely
among patients with foot wounds due to diabetes.