Pre-dive Whole-Body Vibration Better Reduces Decompression-Induced Vascular Gas Emboli than Oxygenation or a Combination of Both

• Published in: Frontiers in physiology 2016-11, Vol.7, p.586-586
• Main Authors: Balestra, Costantino, Theunissen, Sigrid, Papadopoulou, Virginie, Le Mener, Cedric, Germonpré, Peter, Guerrero, François, Lafère, Pierre
• Format: Article
• Language: English
• Subjects: Decompression Sickness/etiology/metabolism; Diving/adverse effects; Human health and pathology; Life Sciences; Physiology; preconditioning; Risk Assessment; Risk factors; Tissues and Organs
• ISSN: 1664-042X; 1664-042X
• DOI: 10.3389/fphys.2016.00586

Since non-provocative dive profiles are no guarantor of protection against decompression sickness, novel means including pre-dive "preconditioning" interventions, are proposed for its prevention. This study investigated and compared the effect of pre-dive oxygenation, pre-dive whole body vibration or a combination of both on post-dive bubble formation. Six healthy volunteers performed 6 no-decompression dives each, to a depth of 33 mfw for 20 min (3 control dives without preconditioning and 1 of each preconditioning protocol) with a minimum interval of 1 week between each dive. Post-dive bubbles were counted in the precordium by two-dimensional echocardiography, 30 and 90 min after the dive, with and without knee flexing. Each diver served as his own control. Vascular gas emboli (VGE) were systematically observed before and after knee flexing at each post-dive measurement. Compared to the control dives, we observed a decrease in VGE count of 23.8 ± 7.4% after oxygen breathing ( < 0.05), 84.1 ± 5.6% after vibration ( < 0.001), and 55.1 ± 9.6% after vibration combined with oxygen ( < 0.001). The difference between all preconditioning methods was statistically significant. The precise mechanism that induces the decrease in post-dive VGE and thus makes the diver more resistant to decompression stress is still not known. However, it seems that a pre-dive mechanical reduction of existing gas nuclei might best explain the beneficial effects of this strategy. The apparent non-synergic effect of oxygen and vibration has probably to be understood because of different mechanisms involved.