A no-decompression air dive and ultrasound lung comets

Area of Science:

• Diving Physiology
• Pulmonary Medicine
• Hyperbaric Medicine

Background:

• Previous research indicated potential lung water accumulation after deep Trimix dives.
• The effects of air dives on lung water and gas exchange were previously unknown.
• Understanding dive-related physiological responses is crucial for diver safety.

Purpose of the Study:

• To investigate extravascular lung water accumulation after a no-decompression air dive.
• To assess bubble formation and lung diffusing capacity post-air dive.
• To determine if air dives elicit similar lung responses as deep Trimix dives.

Main Methods:

• 12 male divers performed a single no-decompression air dive to 33m (20 min bottom time).
• Measurements included ultrasound lung comets (ULC), bubble grade (BG), and diffusing capacity for carbon monoxide (DLCO).
• Physiological parameters were assessed pre-dive and up to 120 minutes post-dive.

Main Results:

• High bubble grades (BG) were observed up to 40 minutes post-dive, but no decompression sickness (DCS) symptoms occurred.
• Arterialized bubbles were noted in one diver for up to 60 minutes.
• No significant changes in DLCO or ULC were detected post-dive.

Conclusions:

• Preliminary findings indicate no increased extravascular lung water after a single no-decompression air dive.
• Air dives to the limits of Norwegian diving tables did not appear to cause significant lung congestion.
• Further research is needed to fully understand the long-term effects of repetitive air dives.