Decompression venous gas formation intensity scale

Relevance. Severe decompression sickness is the most common diving disorder; therefore, its diagnosis and prevention is considered important aspects of hyperbaric physiology and diving medicine. Diver’s susceptibility to gas bubble formation under decompression is most critical for decompression sickness prevention. Doppler bubble detection is the most common procedure to identify divers who are most susceptible to gas bubble formation under decompression; nevertheless, a more comprehensive examination including pulse pressure and 2D visualization of gas bubbles provide valuable advantages.

The objective is to provide justify the implementation of the decompression risk and venous gas bubble formation scale.

Methods. The study enrolled 42 divers who were examined for tolerance to gas bubble formation under decompression; gas bubbles were visualized using Doppler ultrasound. Next, the developed decompression risk and venous gas bubble formation scale was used to verify its efficiency and practical value.

Results and discussion. After hyperbaric exposure, 2D gas bubble visualization data were analyzed showing that 6 subjects (14.3 %) had no decompression-caused gas bubble formation (0 points); 9 subjects (21.4 %) scored up to 5 points, showing a small amount of gas bubbles during exercise; 22 subjects (52.4 %) scored between 6 and 15; whereas the remaining 5 subjects presented with gas bubbles at rest and a sharp increase in bubble formation during mild exercise. The obtained data suggest that the examined diver cohort included 13 subjects (31 %) with very high tolerance to gas bubble formation, 21 divers (50 %) showing average tolerance and 8 highly susceptible subjects (19 %).

Conclusion. During decompression, venous gas bubble formation scale has significant diagnostic value providing a tool to measure individual diver’s susceptibility to gas bubble formation. The scale allows to reduce the hyperbaric load by decreasing exposure on the ground at threshold pressure (0.4 MPa) and thus reduce the decompression time, based on sufficient evidence regarding individual susceptibility to gas bubble formation under decompression

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