Effect of conservative dive profiles on the occurrence of venous and arterial bubbles in divers with a patent foramen ovale: A pilot study
Abstract
Patent foramen ovale (PFO) is a risk factor for decompression sickness (DCS) in divers due to paradoxical embolization of nitrogen bubbles formed in peripheral blood during decrease of ambient pressure [1]. In our previous study we have demonstrated that catheter-based PFO closure prevented right-to-left shunting of bubbles and might prevent DCS recurrence [2].
However, the question of PFO closure is still debatable [3]. Also, randomized clinical data are lacking in this field.
Therefore, the majority of divers are currently not referred for PFO closure, and various conservative dive profiles (CDP) are recommended to prevent unprovoked DCS (i.e., without violation of decompression regimen) [4]. Unfortunately, to date, the safety of these CDP has not been tested in divers with PFO.
The aim of this study was to test the effect of dive time and ascent rate restrictions on the occurrence of venous and arterial bubbles in divers with PFO after simulated dives. We compared a standardly recommended no-decompression dive [5] and a stricter regimen with slower ascent to the same control dive, which was previously used to test the efficacy of catheter-based PFO closure [2].