|
1. Immune function suppression but no clinical
implication is clear. |
Citation:
1. Granowitz EV, Skulsky EJ, Benson RM, Wright J, Garb JL, Cohen ER, Smithline
EC, Brown RB. Exposure to increased pressure or hyperbaric oxygen suppresses
interferon-gamma secretion in whole blood cultures of healthy humans. Undersea
and Hyperbaric Medicine 2002; 29(3):216-225.
Three-part Clinical Question: In human subjects, does the application
of hyperbaric oxygen result in a change in immune function?
Search Terms: cytokine; interferon; pressure
The Study:
Double-blinded (to gas mix) and single-blinded (to pressure) randomised
crossover trial (four arms) with intention-to-treat.
The Study Patients: Healthy adult male volunteers.
Control group (N = ; 5 analysed): A single exposure for 90 minutes on air
and 100% oxygen at 1ATA, and on 10.5% oxygen at 2 ATA. Standard protocol to sham
therapy for subjects.
Experimental group (N = ; 5 analysed): 90 minutes breathing 100% oxygen
at 2 ATA
The Evidence:
|
Measure |
Controls |
HBO |
Difference
(% change) |
95% CI |
||
|
Mean |
SD |
Mean |
SD |
|||
|
Stimulated release of interferon from lymphocytes |
100 |
20.6 |
49 |
26 |
51 |
16.8 to 85.2 |
|
Non-Event Outcomes |
Time to outcome/s |
Control group |
|
White cell counts, haematocrit and platelet count |
24 hours |
no significant differences detected between groups |
Comments:
1. Small study with low power
2. No clinical significance at this stage
3. Change persisted for at least 24 hours
Appraised by: Mike Bennett Prince of Wales Hospital ; Friday, 2 December 2005
Email: m.bennett@unsw.edu.au
Kill or Update By: December 2006