title: Venous gas emboli are involved in post-dive macro, but not microvascular dysfunction.
abstract: OBJECTIVE
  Previous studies have shown vascular dysfunction of main conductance arteries and microvessels after diving. We aim to evaluate the impact of bubble formation on vascular function and haemostasis. To achieve this, we used a vibration preconditioning to influence bubble levels without changing any other parameters linked to the dive.
  
  
  METHODS
  Twentty-six divers were randomly assigned to one of three groups: (1) the "vibrations-dive" group (VD; n = 9) was exposed to a whole-body vibration session 30 min prior the dive; (2) the "diving" group (D; n = 9) served as a control for the effect of the diving protocol; (3) The "vibration" protocol (V; n = 8) allowed us to assess the effect of vibrations without diving. Macro- and microvascular function was assessed for each subject before and after the dive, subsequently. Bubble grades were monitored with Doppler according to the Spencer grading system. Blood was taken before and after the protocol to assess any change of platelets or endothelial function.
  
  
  RESULTS
  Bubble formation was lower in the VD than the diving group. The other measured parameters remained unchanged after the "vibration" protocol alone. Diving alone induced macrovascular dysfunction, and increased PMP and thrombin generation. Those parameters were no longer changed in the VD group. Conversely, a microvascular dysfunction persists despite a significant decrease of circulating bubbles.
  
  
  CONCLUSIONS
  Finally, the results of this study suggest that macro- but not microvascular impairment results at least partly from bubbles, possibly related to platelet activation and generation of pro-coagulant microparticles.
authors.affiliation: ORPHY Laboratory, UBO, 6 avenue Le Gorgeu, 29200, Brest, France.|IRBA-ERRSO, Armed Forces Biomedical Research Institute-Resident Operational Subaquatic Research Team, Toulon, BP 610, 83800, Toulon, France.
authors.forename: Kate
authors.initials: K
authors.lastname: Lambrechts
authors.affiliation: Environmental and Occupational Physiology Laboratory (ISEK), Haute Ecole Bruxelles-Brabant (HE2B), 1160, Brussels, Belgium.
authors.forename: Costantino
authors.initials: C
authors.lastname: Balestra
authors.affiliation: ORPHY Laboratory, UBO, 6 avenue Le Gorgeu, 29200, Brest, France.
authors.forename: Michaël
authors.initials: M
authors.lastname: Theron
authors.affiliation: Hyperbaric Medicine Unit, CHRU Cavale Blanche, 29200, Brest, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Henckes
authors.affiliation: Hematology Laboratory, CHRU Cavale Blanche, 29200, Brest, France.
authors.forename: Hubert
authors.initials: H
authors.lastname: Galinat
authors.affiliation: Hematology Laboratory, CHRU Cavale Blanche, 29200, Brest, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Mignant
authors.affiliation: ORPHY Laboratory, UBO, 6 avenue Le Gorgeu, 29200, Brest, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Belhomme
authors.affiliation: Hyperbaric Medicine and Diving Expertise Department, Military Teaching Hospital, HIA Sainte Anne, BP 610, 83000, Toulon, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Pontier
authors.affiliation: ORPHY Laboratory, UBO, 6 avenue Le Gorgeu, 29200, Brest, France. francois.guerrero@univ-brest.fr.
authors.forename: François
authors.identifier: http://orcid.org/0000-0002-0283-3503
authors.initials: F
authors.lastname: Guerrero
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000502:physiology; D055252:Cell-Derived Microparticles / Q000502:physiology; D003665:Decompression Sickness / Q000503:physiopathology*; D004242:Diving / Q000502:physiology; D004618:Embolism, Air / Q000097:blood*; D006801:Humans; D008297:Male; D055806:Microvessels / Q000503:physiopathology*; D008875:Middle Aged; D015539:Platelet Activation
keywords: Brachial artery; Cutaneous microcirculation; Decompression; Platelets; SCUBA; Vibration preconditionning