Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Avenue Schaller, 91, 1160, Brussels, Belgium.
Physical Activity Teaching Unit, Motor Sciences Department, Université Libre de Bruxelles (U.L.B.), Brussels, Belgium.
Eur J Appl Physiol. 2022 Feb;122(2):515-522. doi: 10.1007/s00421-021-04856-5. Epub 2021 Nov 28.
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.
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.
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).
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.
关于深闭式循环呼吸器（CCR）潜水后的减压应激的数据很少。本研究旨在监测沉船潜水探险期间的技术潜水员，并深入了解静脉气体栓塞（VGE）的动力学。
观察了 10 名技术潜水员的潜水实践。他们在 100 米左右进行了一系列连续三天的潜水。潜水后 30 和 60 分钟通过心脏超声和锁骨下多普勒测量 VGE 计数，并根据分类评分（分别为 Eftedal-Brubakk 和 Spencer 量表）进行分级，然后转换为简化的气泡分级系统（BGS）进行分析。潜水前后还使用生物电阻抗法测量了总体体重和体液转移。
30 次记录的男子潜水深度-时间曲线为 97.3±26.4 msw[范围：54-136]，运行时间为 160±65 min[范围：59-270]。未发现临床减压病（DCS）。心脏周期的超声帧基气泡计数为 30 分钟时为 14±13，60 分钟时为 13±13。潜水之间和测量时间之间均无统计学差异（P=0.07）。然而，无论使用何种程度的保守主义，均检测到高等级 VGE 的高发生率。O'dive 的多普勒记录与超声记录高度相关（Spearman r 为 0.81，P=0.008）。
尽管初步，但与真实 CCR 深潜相关的本次观察结果质疑了减压算法对个体危险因素的优先性，并呼吁采用个体化的减压方法。
