Hyperbaric
oxygen administration did not improve functional or disability scores in chronic
stable multiple sclerosis.
Clinical Bottom Line:
1.
No evidence that hyperbaric oxygen results in improvement in disability score
or functional score in chronic multiple sclerosis.
Appraised
by: Mike Bennett, Dept of Diving and
Hyperbaric Medicine, Prince of Wales Hospital
Sydney; Monday, 1 March 1999
Clinical
Scenario: A patient with chronic stable
multiple sclerosis asked if the administration of hyperbaric oxygen would
improve her condition.
Three-part
Question: In patients with chronic stable
multiple sclerosis, does the administration of hyperbaric oxygen compared to
normal air breathing result in any improvement in the signs of multiple
sclerosis?
Search
Terms: Hyperbaric oxygenation,
multiple sclerosis
The
Study:
Double-blinded concealed
randomised controlled trial with intention-to-treat.
Patients were admitted to the
study with clinically definite MS, a disability score of 3 to 7.5 and no
contra-indications to compression.
Control group (N = 41; 35
analysed): Sham hyperbaric exposures daily for 20 days, then 2 sessions 1 month
later and 5 sessions monthly thereafter. Breathed 12.5% oxygen at 1.75ATA to
mimic air breathing for 90 minutes each session.
Experimental group (N = 41; 37
analysed): Schedule as above, but 100% oxygen at 1.75ATA.
The
Evidence:
|
Outcome |
Time
to Outcome |
Air
group |
HBO
group |
Relative
risk reduction |
Absolute
risk reduction |
NNT |
|
Improved
disability score |
6
months |
0.057 |
0.054 |
5% |
0.003 |
333 |
|
95%
CI: |
|
|
|
-100%
to 100% |
-0.103
to 0.109 |
NNT=9
to INF NNH=10 to
INF |
|
Improved
functional assessment |
6
months |
0.314 |
0.324 |
-3% |
-0.010 |
-100 |
|
95%
CI: |
|
|
|
-72%
to 65% |
-0.225
to 0.205 |
NNT=5
to INF NNH=4 to
INF |
|
Exacerbation
of MS |
6
months |
0.114 |
0.081 |
29% |
0.033 |
30 |
|
95%
CI: |
|
|
|
-91%
to 100% |
-0.104
to 0.170 |
NNT=6
to INF NNH=10 to
INF |
Comments:
1. High level of methodological
rigor, with good blinding and sham treatment.
2. Matched pair design analysed
appropriately.
3. Most patients reported
(blind) that they felt they received air treatment due to lack of improvement.
4. Random samples of trial
patients did not show a difference in MRI appearance or evoked potentials.
5. Some non-significant
improvement in bladder symptoms.
Expiry
date:
January 2005
References:
