No
significant improvement in hearing with the addition of hyperbaric oxygen to a
pharmacological regime for the treatment of sudden idiopathic sensorineural
hearing loss.
Clinical Bottom Line:
1.
No significant improvement in the proportion of patients gaining over 50%
hearing return was demonstrated.
2.
Similarly, there was no significant proportion of patients obtaining 25%
improvement or better.
Appraised
by: Mike Bennett, Dept of Diving and
Hyperbaric Medicine, Prince of Wales Hospital, Sydney, Monday, 23 November, 1998
Clinical
Scenario: A patient with sudden onset of
sensorineural hearing loss of unknown origin.
Three-part
Question: In adult patients with sudden
idiopathic sensorineural hearing loss, does the addition of hyperbaric oxygen
therapy to a standard treatment regime result in any additional benefit?
Search
Terms: Hyperbaric oxygenation,
deafness, hearing loss, noise
induced.
The
Study:
Non-blinded randomised
controlled trial with intention-to-treat.
Adults with sudden sensorineural
hearing loss where no cause was known.
Control group (N = 30; 30
analysed): Multiple drug therapy consisting of heparin, betamethasone, nicotinic
acid, flunarizine, citidinephosphocoline, dextran, vitamins, neurotropic and
antiviral drugs- doses not given.
Experimental group (N = 34; 34
analysed): Pharmacotherapy as for control group plus oxygen at 2.5ATA for 60
minutes daily for 15 sessions over 3 weeks.
The
Evidence:
|
Outcome |
Time to
Outcome |
Control |
HBO |
Relative
benefit increase |
Absolute
benefit increase |
NNT |
|
Return of
hearing greater than 50% |
3 weeks |
0.43 |
0.53 |
22% |
0.096 |
10 |
|
95% CI |
|
|
|
-34% to 79% |
-0.15 to 0.34 |
NNT=7 to INF
NNH=3 to INF |
|
Return of
hearing greater than 25% |
3 weeks |
0.57 |
0.74 |
30% |
0.168 |
6 |
|
95% CI |
|
|
|
-11% to 70% |
-0.06 to 0.40 |
NNT=16 to NF NNH=3 to INF |
Comments:
1. No details given on
randomisation, blinding or exclusions from analysis.
2. Small study with no power,
significance levels or confidence intervals given.
3. Trends apparent for some
improvement with the addition of hyperbaric oxygen, but do not reach statistical
significance.
4. No details given on outcome
measures.
Expiry
date: July 2002
References:
1.
Cavallazzi G, Pignataro L, Capaccio P. Italian experience in hyperbaric oxygen
therapy for idiopathic sudden sensorineural hearing loss. In Proceedings of the
International Joint Meeting on Hyperbaric and Underwater Medicine. Marroni A,
Oriani G, Wattel F, eds. Grafica Victoria, Bologna 1996:647-649.
