Relationships between plasma lipids, proteins, surface tension and post-dive bubbles.
Summary
This study found no link between blood surfactants and venous gas emboli (VGE) in divers, challenging the classic surfactant hypothesis for decompression sickness (DCS). Further research is needed to understand bubble formation and stabilization.
Area of Science:
- Diving Medicine
- Physiology
- Biochemistry
Background:
- Decompression sickness (DCS) in divers results from inert gas bubbles, primarily venous gas emboli (VGE).
- VGE are hypothesized to be stabilized by surfactants that reduce plasma-air surface tension (γ).
Purpose of the Study:
- To investigate the interrelations between blood surfactants, plasma-air surface tension (γ), and VGE.
- To examine the influence of dietary fat intake on these parameters during simulated dives.
Main Methods:
- 63 dry dive simulations (21 msw/40 min) were conducted on 52 divers.
- VGE were measured using precordial Doppler, and blood parameters (albumin, total protein, triglycerides, cholesterol, fatty acids) were analyzed pre- and post-dive.
- Subjects consumed either fat-rich or fat-poor breakfasts to alter blood plasma composition.
Main Results:
- No significant correlations were found between VGE scores and albumin, total protein, or total cholesterol.
- Correlations were also absent for triglycerides and fatty acids, despite substantial variations.
- No correlation was observed between surface tension (γ) and VGE.
Conclusions:
- The study challenges the classical surfactant hypothesis regarding bubble stabilization in DCS.
- Findings suggest proteins may play a more significant role in lowering surface tension than lipids.
- Reconsideration of current hypotheses on DCS pathophysiology is warranted.
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