Heliox
recompression for the treatment of DCI may result in fewer patients requiring
multiple recompressions.
Clinical Bottom Line:
1.
Fewer patients in the heliox group required more than one recompression due to
incomplete resolution and /or persistence of symptoms.
Appraised
by: Mike Bennett, Dept. of Diving and
Hyperbaric Medicine, Prince of Wales Hospital
Sydney; Monday, 23 November,
1998
Clinical
Scenario: A patient presenting with
decompression illness after air diving.
Three-part
Question: In patients suffering with
decompression illness, does the application of 50/50 heliox at 2.8 ATA, compared
to standard 100% oxygen treatment tables, result in any reduction in the
proportion with incomplete resolution and/or return of symptoms?
Search
Terms: Hyperbaric oxygenation,
decompression illness.
The
Study:
Double-blinded concealed
randomised controlled trial intention-to-treat unknown.
Recreational air divers with
diagnosis of decompression illness.
Control group (N = 31; 31
analysed): Recompression on a standard US Navy Table 6 to 2.8ATA with 100%
oxygen breathing periods.
Experimental group (N = 25; 25
analysed): Recompression to 2.8ATA, but substitution of 50% oxygen, 50%helium as
breathing mixture.
The
Evidence:
|
Outcome |
Time to
Outcome |
100% oxygen |
Heliox |
Relative
risk reduction |
Absolute
risk reduction |
Number
needed to treat |
|
Required
multiple recompression |
1 year |
0.65 |
0.36 |
44% |
0.285 |
4 |
|
95% CI |
|
|
|
5% to 83% |
0.03 to 0.54 |
2 to 31 |
Comments:
1. 18 of 88 enrolled patients
subsequently withdrawn due to protocol breach.
2. Interim report only in
abstract.
3. No results published for
absolute rate of treatment success.
Expiry
date: November 2003.
References:
1. Drewry A, Gorman DF. A
progress report on the prospective randomised double blind controlled study of
oxygen and oxygen-helium in the treatment of air-diving decompression illness.
Undersea and Hyperbaric Medicine Supplement 1994; 21:98.
