There
was no improvement in memory, behaviour or psychometric testing with hyperbaric
oxygen therapy in patients with cognitive impairment of the elderly.
Clinical Bottom Line:
1.
No evidence of a benefit from hyperbaric oxygen therapy in memory function or
psychometric performance in cognitive impairment of the elderly.
Appraised
by: Mike Bennett, Dept of Diving and
Hyperbaric Medicine, Prince of Wales Hospital
Sydney; Tuesday, 9 March 1999
Clinical
Scenario: A 75 year old patient with
cognitive impairment related to age.
Three-part
Question: In patients with a diagnosis of
cognitive impairment of the elderly, does the application of hyperbaric oxygen
compared to normobaric oxygen or air, result in any demonstrable improvement in
intellectual ability or memory?
Search
Terms: Hyperbaric oxygenation,
dementia
The
Study:
Double-blind randomised
controlled trial without intention-to-treat.
Ambulatory patients aged 60 to
85 years who tested to a minimum on an age-related adult intelligence scale
vocabulary sub-test (to allow completion of outcome measures) and had a
demonstrated deficit of 1 standard deviation or more on 3 out of 5 sub-tests of
memory.
Control group (N = 22; 20
analysed): 10% oxygen at 2.3ATA for 90 minutes twice daily for 15 days.
Experimental group (N = 27; 20
analysed): 100% oxygen at 2.5ATA for 90 minutes twice daily for 15 days.
The
Evidence:
Non-Event
Outcomes
Time to outcome
Air group HBO group
P-value
Recall
of faces
(?
scale)
two
weeks
3.29
3.93
NS
Social
activity
(0-4
scale)
two weeks
1.60
1.92
NS
Mean
memory quotient
(0-100)
two weeks
78
73
NS
Comments:
1. Complex outcome measures not
presented with clarity.
2. This study also tested
normobaric oxygen against placebo in a further two arms (not reported here).
3. There were eight significant
differences in 101 F tests across the four groups.
4. There was an 'acclimatisation
period' of seven days, during which 38 patients were withdrawn and replaced by
others. It is not clear what effect this may have had on the outcome.
5. Authors mention repeated
assessment up to 8 weeks but have not given supporting results in this paper.
Expiry
date:
March 2004
References:
1. Raskin A, Gershon S, Crook T,
Sathananthan G, Ferris S. The effects of hyperbaric and normobaric oxygen on
cognitive impairment in the elderly. Archives of General Psychiatry 1978;
35:50-56.
