Hyperbaric oxygen administration was not associated with objective benefit in multiple sclerosis.

Clinical Bottom Line:
1. No objective functional improvement was associated with administration of hyperbaric oxygen.
2. Symptomatic improvement in bladder/bowel function was associated with hyperbaric treatment but not confirmed by objective assessment.
3. Some evidence of a reduced rate of cerebellar degeneration in the hyperbaric group.

Appraised by: Mike Bennett, Dept of Diving and Hyperbaric Medicine, Prince of Wales Hospital, Sydney; Saturday, 23 January, 1999

Clinical Scenario: A patient with established, stable multiple sclerosis.
Three-part Question: In patients with multiple sclerosis, does the administration of hyperbaric oxygen in addition to all normal care, result in an improvement in clinical state or reduction in the duration and severity of relapse?
Search Terms: Hyperbaric oxygenation, multiple sclerosis.

The Study:
Double-blinded randomised controlled trial with intention-to-treat. Patients with chronic, stable multiple sclerosis.
Control group (N = 60; 56 analysed): All normal care on-going plus sham treatments breathing air in the chamber at 1ATA
Experimental group (N = 60; 60 analysed): As above but oxygen at 2ATA for 90 minutes daily for 20 days.

The Evidence:

Outcome
Time to Outcome
Placebo rate
HBO rate
Relative risk reduction
Absolute risk reduction
NNT
No objective bladder/bowel function improvement
1 year
0.893
0.833
7%
0.06
-167
95% CI:



-7% to 21%
-0.06 to 0.18
NNT=5 to INF NNH=16 to INF
Relapse
1 year
0.304
0.30
1%
.004
250
95% CI:



-54% to 56%
-0.16 to 0.17
NNT=6 to INF NNH=6 to INF
No subjective bladder/bowel function improved
20 days
0.946
0.783
17%
0.16
6
95% CI:



5% to 30%
0.04 to 0.28
4 to 23
No subjective bladder/bowel function improvement
1 year
0.976
0.833
10%
0.01
10
95% CI:



-2% to 23%
-0.02 to 0.21
NNT=5 to INF NNH=50 to INF

Comments:
1. Multiple subjective and objective assessments yielded no significant differences in outcome.
2. Subjective findings of improvement were not confirmed on objective testing, suggesting some differential placebo effect.

Expiry date: January 2015
References: 1. Barnes MP, Bates D, Cartlidge N, French J, Shaw D. Hyperbaric oxygen and multiple sclerosis: short-term results of a placebo-controlled, double-blind trial. Lancet 1985; 8425:297-300.
2. Barnes MP, Bates D, Cartlidge N, French J, Shaw D. Hyperbaric oxygen and multiple sclerosis: final results of a placebo-controlled, double-blind trial. Journal of Neurology, Neurosurgery and Psychiatry 1987; 50:1402-1406.


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