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Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise
Published on: February 20, 2017
Pre-dive exercise and post-dive evolution of venous gas emboli
Mikael Gennser1, Karen M Jurd, S Lesley Blogg
1Department of Environmental Physiology, School of Technology and Health, Royal Institute of Technology, Solna, Sweden.
Aviation, Space, and Environmental Medicine
|January 26, 2012
Summary
Pre-dive exercise did not reduce circulating venous gas emboli (VGE) or decompression sickness risk. Exercise performed 2 or 24 hours before diving showed no benefit compared to no exercise, contrary to some studies.
Area of Science:
- Hyperbaric Medicine
- Physiology
- Diving Science
Background:
- Exercise before diving may reduce decompression sickness (DCS) risk.
- Optimal timing for pre-dive exercise remains unclear.
Purpose of the Study:
- To determine the most effective time delay between exercise and diving.
- To investigate the impact of pre-dive exercise timing on venous gas emboli (VGE) formation.
Main Methods:
- Ten male subjects underwent simulated dives in a hyperbaric chamber.
- Exercise (40 min cycling) was performed 2h and 24h before dives.
- Venous gas emboli (VGE) were quantified using Doppler ultrasound and the Kisman Masurel (KM) scale.
Main Results:
- Exercise 2h or 24h prior to diving did not reduce VGE compared to control dives.
- Bubbles cleared slower after exercise dives than control dives.
- Time to zero VGE was longer for both exercise groups (225 min for 2h, 165 min for 24h) versus control (120 min).
Conclusions:
- Cycling exercise before diving did not reduce VGE.
- Findings contrast with some previous studies, possibly due to exercise type, experience, or measurement differences.
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