title: Pre-dive Whole-Body Vibration Better Reduces Decompression-Induced Vascular Gas Emboli than Oxygenation or a Combination of Both.
abstract: Purpose: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.Methods: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.Results: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 (p< 0.05), 84.1 ± 5.6% after vibration (p< 0.001), and 55.1 ± 9.6% after vibration combined with oxygen (p< 0.001). The difference between all preconditioning methods was statistically significant.Conclusions: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.
authors.affiliation: Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant - HE2BBrussels, Belgium; DAN Europe Research DivisionRoseto, Italy; DAN Europe Research DivisionBrussels, Belgium; Anatomical Research and Clinical Studies (ARCS), Vrije Universiteit BrusselBrussels, Belgium; Anatomical Research Training and Education (ARTE), Vrije Universiteit BrusselBrussels, Belgium; Motor Sciences, Université Libre de BruxellesBrussels, Belgium.
authors.forename: Costantino
authors.initials: C
authors.lastname: Balestra
authors.affiliation: Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant - HE2BBrussels, Belgium; DAN Europe Research DivisionRoseto, Italy; DAN Europe Research DivisionBrussels, Belgium.
authors.forename: Sigrid
authors.initials: S
authors.lastname: Theunissen
authors.affiliation: Dayton Lab, Department of Biomedical Engineering, University of North Carolina Chapel Hill, NC, USA.
authors.forename: Virginie
authors.initials: V
authors.lastname: Papadopoulou
authors.affiliation: Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant - HE2B Brussels, Belgium.
authors.forename: Cedric
authors.initials: C
authors.lastname: Le Mener
authors.affiliation: DAN Europe Research DivisionRoseto, Italy; DAN Europe Research DivisionBrussels, Belgium; Center for Hyperbaric Oxygen Therapy, Military Hospital "Queen Astrid"Brussels, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Germonpré
authors.affiliation: DAN Europe Research DivisionRoseto, Italy; DAN Europe Research DivisionBrussels, Belgium; ORPHY Laboratory, EA 4324, Université de Bretagne OccidentaleBrest, France.
authors.forename: François
authors.initials: F
authors.lastname: Guerrero
authors.affiliation: DAN Europe Research DivisionRoseto, Italy; DAN Europe Research DivisionBrussels, Belgium; ORPHY Laboratory, EA 4324, Université de Bretagne OccidentaleBrest, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Lafère
keywords: decompression sickness/*etiology/metabolism; diving/*adverse effects; preconditioning; risk assessment; risk factors