Venous gas bubbles while flying with cabin altitudes of airliners or general aviation aircraft 3 hours after diving.

Decompression venous gas bubbles were detected with the precordial Doppler utrasound technique in humans at simulated altitudes of 1,000-3,000 m 3 h after no-stage decompression dives to 15 or 39 m. Bubbles were detected at 3,000 m in a total of 60% of the subjects: in 90% after the 100-min shallow dives to 15 m with some bubbles present in the first minutes (mean onset 12 min), and in only 30% after the 10-min deeper dives to 39 m with later appearances of bubbles (mean onset 28 min). At both 2,000 and 1,000 m bubbles could also be detected, sometimes in the first minutes. The risk of decompression sickness must be considered high with the amount of gas bubbles found, even though only uncertain symptoms appeared in this study. Thus, a safe interval between ordinary SCUBA-diving and flying in airliners or general aviation aircraft seems to be more than 3 h.