engleski

A no-decompression air dive and ultrasound lung comets

Increased accumulation of extravascular lung water after repetitive deep trimix dives was recently reported. This effect was evident 40 min post-dive, but in subsequent studies most signs of this lung congestion were not evident 2-3 h post-dive, indicating no major negative effects on respiratory gas exchange following deep dives. Whether this response is unique for trimix dives or also occurs in more frequent air dives is presently unknown. Methods: A single no-decompression fi eld dive to 33 m with 20 min bottom time was performed by 12 male divers. Multiple ultrasound lung comets (ULC), bubble grade (BG), and single-breath lung diffusing capacity (DLCO) measurements were made before and up to 120 min after the dive. Results: Median BG was rather high with maximal values observed at 40 min post-dive [median 4 (4 – 4)]. Arterialization of bubbles from the venous side was observed only in one diver lasting up to 60 min post-dive. Despite high BG, no DCS symptoms were noted. DLCO and ULC were unchanged after the dive at any time point (DLCO corr was 33.6 6 1.9 ml z min 2 1 z mmHg 2 1 pre-dive, 32.7 6 3.8 ml z min 2 1 z mmHg 2 1 at 60 min post-dive, and 33.2 6 5.3 ml z min 2 1 z mmHg 2 1 at 120 min post-dive ; ULC count was 4.1 6 1.9 pre-dive, 4.9 6 3.3 at 20 min post-dive, and 3.3 6 1.9 at 60 min post-dive. Discussion: These preliminary fi ndings show no evidence of increased accumulation of extravascular lung water in male divers after a single no-decompression air dive at the limits of accepted Norwegian diving tables.

ultrasound lung comets; gas bubbles; air dives; diffusing lung

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