Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Physiology of Deep Closed-Circuit Rebreather (CCR) Mixed Gas Diving: Gas Emboli, Spirometry and Biological Changes during a Week-Long Liveaboard Safari

Costantino Balestra
,
Clément Leveque
,
Simona Mrackic-Sposta
ORCID logo ,
Alessandra Vezzoli
ORCID logo ,
Pierre Wauthy
,
Peter Germonpré
ORCID logo ,
Frauke Tillmans
ORCID logo ,
François Guerrero
,
Pierre Lafère
*
Version 1 : Received: 30 December 2023 / Approved: 30 December 2023 / Online: 3 January 2024 (03:17:58 CET)

How to cite: Balestra, C.; Leveque, C.; Mrackic-Sposta, S.; Vezzoli, A.; Wauthy, P.; Germonpré, P.; Tillmans, F.; Guerrero, F.; Lafère, P. Physiology of Deep Closed-Circuit Rebreather (CCR) Mixed Gas Diving: Gas Emboli, Spirometry and Biological Changes during a Week-Long Liveaboard Safari. Preprints 2024, 2024010013. https://doi.org/10.20944/preprints202401.0013.v1 Balestra, C.; Leveque, C.; Mrackic-Sposta, S.; Vezzoli, A.; Wauthy, P.; Germonpré, P.; Tillmans, F.; Guerrero, F.; Lafère, P. Physiology of Deep Closed-Circuit Rebreather (CCR) Mixed Gas Diving: Gas Emboli, Spirometry and Biological Changes during a Week-Long Liveaboard Safari. Preprints 2024, 2024010013. https://doi.org/10.20944/preprints202401.0013.v1

Abstract

Diving decompression theory hypothesizes inflammatory processes as a source of micronuclei which could increase related risks. Therefore, we tested 10 healthy, male divers. They performed 6-8 dives with a maximum of two dives per day at depths ranging from 21 to 122 msw with CCR mixed gas diving. Post-dive VGE were counted by echocardiography. Saliva and urine samples were taken before and after each dive to evaluate to evaluate inflammation: ROS production, lipid peroxidation (8-iso-PGF2), DNA damage (8-OH-dG), cytokines (TNF-, IL-6, and neopterin). VGE exhibits a progressive reduction followed by an increase (p<0.0001) which parallels in-flammation responses. Indeed, ROS, 8-iso-PGF2, IL-6 and neopterin increases from 0.19 ± 0.02 to 1.13 ± 0.09 μmol.min−1 (p<0.001); 199.8 ± 55.9 to 632.7 ± 73.3 ng.mg-1 creatinine (p<0.0001); 2.35 ± 0.54 to 19.5 ± 2.96 pg.ml-1 (p<0.001); and 93.7 ± 11.2 to 299 ± 25.9 μmol·mol−1 creatinine (p=0.005), respectively. The variation after each dive was held constant around 158.3 ± 6.9% (p = 0.021); 151.4 ± 5.7% (p <0.0001); 176.3 ± 11.9% (p<0.0001); and 160.1 ± 5.6% (p<0.001), respectively. When oxy-inflammation reaches a certain level, it exceeds hormetic coping mechanisms allowing second-generation micronuclei substantiated by an increase of VGE after an initial continuous decrease consistent with a depletion of “first generation” pre-existing micronuclei.

Keywords

Decompression physiology; Venous gas emboli (VGE); Human; Reactive oxygen species (ROS); Oxidative stress; Inflammation; DCS; Hormesis; Acute Phase Reactants

Subject

Medicine and Pharmacology, Other

Copyright: This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Download PDF

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.

Leave a public comment
Send a private comment to the author(s)
* All users must log in before leaving a comment
Views 0
Downloads 0
Comments 0
Metrics 0
Get PDF Cite Share 0
Bookmark BibSonomy Mendeley Reddit Delicious
×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.