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Free fatty acids do not influence venous gas embolism in divers
1Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Aviation, Space, and Environmental Medicine
|October 21, 2014
Summary
This study found no link between dissolved fatty acids (dFFA) and decompression sickness bubble grades in divers. Even with higher dFFA levels after fatty meals, bubble formation was not affected, suggesting dFFA may not form protective surfactant layers.
Area of Science:
- Diving Medicine
- Physiology
- Biochemistry
Background:
- Decompression sickness (DCS) involves inert gas bubbles in venous circulation.
- Surfactant layers, potentially long-chain fatty acids (FFAs), may prolong bubble existence.
- Hypothesis: sufficient dissolved FFAs (dFFA) correlate with higher bubble grades (BGs).
Purpose of the Study:
- To investigate the association between dietary fat intake, dissolved FFAs, and DCS bubble formation.
- To test the hypothesis that higher dFFA levels increase bubble grades.
Main Methods:
- 52 divers consumed either fat-rich or fat-poor breakfasts.
- Divers underwent a dry dive simulation (21 msw/40 min).
- Bubble grades (BGs) were assessed post-dive using precordial Doppler and transformed to Kisman Integrated Severity Score (KISS).
Main Results:
- KISS scores were not influenced by meal fat content.
- No association was found between KISS and calculated dFFA levels, despite a 3.5-fold higher dFFA in the fat-rich group.
- Measured albumin-bound FFAs were abundant, but long-chain dFFA concentration (nM range) was likely insufficient for surfactant monolayer formation.
Conclusions:
- Bubble scores in divers are not associated with dissolved FFAs.
- Theoretically, long-chain dFFAs may not form post-dive surfactant monolayers.
- The specific substance forming bubble surfactant layers in DCS remains unidentified.
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