The topical nasal decongestant,
oxymetazoline, did not reduce the rate of middle-ear barotrauma in patients
having hyperbaric oxygen therapy.
Clinical
Bottom Line:
1.
No evidence that topical decongestants reduce middle ear barotrauma.
Appraised by:
Mike Bennett, Dept of Diving and Hyperbaric Medicine, Prince of Wales Hospital
Sydney;
Thursday, 04 February, 1999
Clinical Scenario:
A patient presents for hyperbaric oxygen therapy. We wondered if topical
nasal decongestants would decrease the incidence of aural barotrauma.
Three-part Question:
In patients undergoing hyperbaric oxygen therapy, does the pre-hyperbaric use of
topical nasal decongestant compared to no specific pre-treatment, result in less
middle ear barotrauma?
Search Terms:
ear, middle, barotrauma, nasal decongestants
The Study:
Double-blinded
concealed randomised controlled trial with intention-to-treat.
Adults
requiring hyperbaric therapy for acute carbon monoxide poisoning and able to
make informed consent.
Control
group (N = 30; 30 analysed): Two sprays of sterile water into each nostril at
least 15 minutes prior to hyperbaric exposure at 2.4 ATA.
Experimental
group (N = 30; 30 analysed): Two sprays of oxymetazoline hydrochloride into each
nostril at least 15 minutes prior to hyperbaric exposure at 2.4 ATA.
The Evidence:
|
Outcome |
Water
group rate |
Oxymet
group rate |
Relative
risk increase |
Absolute
risk increase |
NNH |
|
Teed
score > zero after treatment |
0.4 |
0.467 |
17% |
0.067 |
15 |
|
95%
CI: |
|
|
-46% to 79% |
-0.183to 0.317 |
NNH = 3 to INF NNT = 5to INF |
|
Ear
pain on compression |
0.2 |
0.300 |
50% |
0.100 |
10 |
|
95%
CI: |
|
|
-59% to 100% |
-0.118 to 0.318 |
NNH = 3 to INF NNT = 8 to INF |
|
Asymptomatic
compression |
0.333 |
0.367 |
10% |
-0.034 |
29 |
|
95%
CI: |
|
|
-62% to 83% |
-0.207 to 0.275 |
NNH = 4 to INF NNT = 5 to INF |
Comments:
1.
Well-designed study with 80% power to detect 50% reduction in the incidence of
barotrauma.
2.
All CO poisoned patients, probably treated in a monoplace chamber.
3.
Most patients experienced some discomfort in the ears.
4.
Compression rate not specified.
Expiry date: July 2002
References: 1.
Carlson S, Jones J, Brown M, Hess C. Prevention of hyperbaric-associated middle
ear barotrauma. Annals of Emergency Medicine 1992; 21:1468-1471.
