Hyperbaric
oxygen administration improved hearing for patients with sudden hearing loss who
had shown no improvement with standard therapy for two weeks.
Clinical Bottom Line:
1.
Significantly more patients with sudden hearing loss had an improvement in
hearing of 10 dB or more following hyperbaric oxygen.
2.
There was apparent improvement in tinnitus, significance not tested.
Appraised
by: Mike Bennett, Dept. of Diving and
Hyperbaric Medicine, Prince of Wales Hospital
Sydney; Monday, 19 July 1999
Clinical
Scenario: A patient with a recent history
of sudden hearing loss presents for treatment. We wondered if hyperbaric oxygen
administration would improve hearing loss or tinnitus.
Three-part
Question: For patients with sudden
hearing loss, with or without tinnitus, does the addition of hyperbaric oxygen
to a standard treatment protocol, result in any improvement in hearing or
tinnitus?
Search Terms: Hyperbaric oxygen,
hearing loss, tinnitus
The
Study:
Non-blinded randomised
controlled trial with intention-to-treat.
Patients with a history of
sudden hearing loss, with or without tinnitus, and showing no improvement with a
14 day course of standard treatment including haemodilution with hydroxyethyl
starch, pentoxifylline and cortisone.
Control group (N = 10; 10
analysed): No treatment.
Experimental group (N = 10; 10
analysed): 100% oxygen at 1.5ATA for 45 minutes daily, five days each week for
two to four weeks (10-20 sessions).
The
Evidence:
|
Outcome |
Time
to Outcome |
Control
group |
HBO
group |
Relative
risk reduction |
Absolute
risk reduction |
NNT |
|
Hearing
improved by 10dB or more |
3
months |
0 |
0.30 |
INF |
0.30 |
3 |
|
95%
CI: |
|
|
|
|
0.02
to 0.58 |
2
to 63 |
|
Tinnitus
improved (subjective) |
3
months |
0.3 |
0.60 |
0.50 |
0.30 |
3 |
|
|
|
|
|
-0.39
to 100 |
-0.17
to 0.72 |
NNT=9
to INF NNH=1
to INF |
Non-Event Outcomes Time to outcome
Untreated group
HBO group
P-value
Mean
hearing change
(dB)
3 months
-0.7
7.5
not given
Tinnitus
rating
3 months
5.6
2.7
not given
Comments:
1. Small, unblinded study.
2. No statistical analysis of
results made.
3. The proportion of patients
with tinnitus is not known. No details given on the nature of the subjective
tinnitus scale, therefore the importance or otherwise of this finding is
unknown.
Expiry
date:
July 2002
References:
1. Hoffmann G, Bohmer D,
Desloovere C. Hyperbaric oxygenation as a treatment for sudden deafness and
acute tinnitus. In: Wen-ren Li, pres. Proceedings of the Eleventh International
Congress on Hyperbaric Medicine, Fuzhou, China. Best Publishing, Flagstaff,
Arizona 1993:146-152.
