Granowitz
Both hyperbaric oxygen and pressure reduced stimulated lymphocyte production of interferon-gamma
| Clinical bottom line 1. Immune function suppression but no clinical implication is clear. 2. Pressure alone also reduced interferon level on stimulus |
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 2005Email: [| m.bennett@unsw.edu.au] Kill or Update By: December 2006
