HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Physiology of repeated mixed gas 100-m wreck dives using a closed-circuit rebreather: a field bubble study

Abstract : Purpose: Data regarding decompression stress after deep closed-circuit rebreather (CCR) dives are scarce. This study aimed to monitor technical divers during a wreck diving expedition and provide an insight in venous gas emboli (VGE) dynamics. Methods: Diving practices of ten technical divers were observed. They performed a series of three consecutive daily dives around 100 m. VGE counts were measured 30 and 60 min after surfacing by both cardiac echography and subclavian Doppler graded according to categorical scores (Eftedal–Brubakk and Spencer scale, respectively) that were converted to simplified bubble grading system (BGS) for the purpose of analysis. Total body weight and fluids shift using bioimpedancemetry were also collected pre- and post-dive. Results: Depth-time profiles of the 30 recorded man-dives were 97.3 ± 26.4 msw [range: 54–136] with a runtime of 160 ± 65 min [range: 59–270]. No clinical decompression sickness (DCS) was detected. The echographic frame-based bubble count par cardiac cycle was 14 ± 13 at 30 min and 13 ± 13 at 60 min. There is no statistical difference neither between dives, nor between time of measurements (P = 0.07). However, regardless of the level of conservatism used, a high incidence of high-grade VGE was detected. Doppler recordings with the O’dive were highly correlated with echographic recordings (Spearman r of 0.81, P = 0.008). Conclusion: Although preliminary, the present observation related to real CCR deep dives questions the precedence of decompression algorithm over individual risk factors and pleads for an individual approach of decompression.
Document type :
Journal articles
Complete list of metadata

https://hal.univ-brest.fr/hal-03655061
Contributor : Patricia Calloch Connect in order to contact the contributor
Submitted on : Friday, April 29, 2022 - 11:19:54 AM
Last modification on : Monday, May 2, 2022 - 2:51:33 PM

File

Balestra2022_Article_Physiolog...
Publication funded by an institution

Identifiers

Collections

Citation

Costantino Balestra, François Guerrero, Sigrid Theunissen, Peter Germonpré, Pierre Lafère. Physiology of repeated mixed gas 100-m wreck dives using a closed-circuit rebreather: a field bubble study. European Journal of Applied Physiology, Springer Verlag, 2021, 122 (2), pp.515-522. ⟨10.1007/s00421-021-04856-5⟩. ⟨hal-03655061⟩

Share

Metrics

Record views

1

Files downloads

0