No
evidence of efficacy for hyperbaric oxygen in acute hearing loss or tinnitus of
long-standing.
Clinical Bottom Line:
1.No
evidence of improvement in hearing loss or tinnitus with the administration of
hyperbaric oxygen.
2.Pressurization was associated
with some benefit in both groups.
Appraised
by: Mike Bennett, Dept. of Diving and
Hyperbaric Medicine, Prince of Wales Hospital
Sydney; Wednesday, 28 July 1999
Clinical
Scenario: A patient with long-standing
hearing loss and tinnitus presented for treatment and we wondered if there was
any place for hyperbaric oxygen.
Three-part
Question: For patients with hearing loss
and/or tinnitus of acute onset, where the loss is of long standing (>6
months), does the application of hyperbaric oxygen, compared to placebo, result
in any improvement in hearing loss or tinnitus?
Search
Terms: Hyperbaric oxygen, deafness,
tinnitus
The
Study:
Double-blinded randomised
controlled trial with intention-to-treat.
Patients with a history of
sudden onset of inner-ear hearing loss and/or tinnitus lasting at least 6
months.
Control group (N = 22; 22
analysed): Air breathing at 1.5ATA for 45 minutes daily, five days each week for
3 weeks.
Experimental group (N = 22; 22
analysed): 100% oxygen breathing at 1.5ATA on the same schedule as controls.
The
Evidence:
|
Outcome |
Time
to Outcome |
Control
group |
HBO
group |
Relative
risk reduction |
Absolute
risk reduction |
NNT |
|
Improved
hearing |
3
weeks |
0.5 |
0.33 |
34% |
0.17 |
6 |
|
95%
CI: |
|
|
|
-23%
to 91% |
-0.12
to 0.46 |
NNT=2
to INF NNH=9 to
INF |
|
Improved
tinnitus |
3
weeks |
0.41 |
0.18 |
56% |
0.23 |
4 |
|
95%
CI: |
|
|
|
-8%
to 100% |
-0.03
to 0.49 |
NNT=2
to INF NNH=32 to
INF |
Comments:
1. Control group was pressurized
and breathed an increased PO2. Any benefit may be due to a placebo effect,
pressure effect or oxygen effect (equivalent 31.5% oxygen at 1ATA).
2. All patients received a
second course of hyperbaric oxygen at 1.5ATA immediately following the trial
course, making longer-term follow-up impossible.
3. 15 treatments may have been
insufficient in this chronic, well-established condition.
Expiry
date:
July 2002
References:
1. Hoffmann G, Bohmer D,
Desloovere C. Hyperbaric oxygen as a treatment of chronic forms of inner ear
hearing loss and tinnitus.In: Wen-ren Li. Proceedings of the Eleventh
International Congress of Hyperbaric Medicine, Fuzhou, China. Best Publishing,
Flagstaff, Arizona 1993:141-145.
