Hyperbaric
oxygen was not associated with improvement in chronic progressive multiple
sclerosis.
Clinical Bottom Line:
1.
Hyperbaric oxygen therapy was not associated with any significant improvement
in clinical outcome or visual evoked potential latency.
Appraised
by: Mike Bennett, Dept of Diving and
Hyperbaric Medicine, Prince of Wales Hospital
Sydney; Monday, 25 January, 1999
Clinical
Scenario: A patient with chronic
progressive multiple sclerosis.
Three-part
Question: In patients with multiple
sclerosis, does the addition of hyperbaric oxygen to the normal treatment regime
result in improved functional status or objective evidence of improved
myelination.
Search
Terms: Hyperbaric oxygenation,
multiple sclerosis.
The
Study:
Double-blinded randomised
controlled trial with intention-to-treat.
Patients with established
diagnoses of chronic progressive multiple sclerosis.
Control group (N = 12; 9
analysed): All usual care including physical therapy and medications, plus sham
hyperbaric treatments breathing air at 1.3ATA for 5 minutes, then slow bleed
back to the surface. Total chamber time equal to experimental group.
Experimental group (N = 12; 10
analysed): As above plus 100% oxygen at 2ATA for ninety minutes daily for twenty
days.
The
Evidence:
|
Outcome |
Time
to Outcome |
Control
rate |
HBO
rate |
Relative
risk reduction |
Absolute
risk reduction |
NNT |
|
Clinical
improvement |
1
week |
0.56 |
0.30 |
46% |
0.26 |
4 |
|
95%
CI: |
|
|
|
-32%
to 100% |
-0.18
to 0.69 |
NNT=1
to INF NNH =6to
INF |
|
Clinical
improvement |
6
months |
0.33 |
0.1 |
70% |
0.23 |
4 |
|
95%
CI: |
|
|
|
-38%
to 100% |
-0.13
to 0.59 |
NNT=2
to INF NNH =8to
INF |
Non-Event
Outcomes
Control group
HBO group
P-value
Mean
change in visual evoked
potential
(p 100 latency)
+1.8
-1.5
<0.05
Comments:
1. 5 patients withdrawn after
entry due to treatment intolerance. We have assumed equal rate of withdrawal as
these figures have not been given.
2. Small trial with low power to
detect clinically important differences.
3. Sham treatment procedure may
not have been adequate to maintain blinding of patient.
Expiry
date:
January 2005
References:
1. Nieman J, Nilsson B, Barr P, Perrins D. Hyperbaric oxygen
in chronic progressive multiple sclerosis: visual evoked potentials and clinical
effects. Journal of Neurology, Neurosurgery and Psychiatry 1985; 48:497-500.
