ANALYSIS

The diver subsequently flew back to Australia and then across to the west coast without a return of symptoms. He was returning to work in a remote area without recompression facilities so he closely liaised with DAN AP in case any symptoms developed.

He was advised to undergo a follow-up diving medical assessment as, in light of his symptoms (i.e., vestibular), it was suspected that he may well have a patent foramen ovale (PFO), a type of heart defect. The examining doctor agreed, and a subsequent test confirmed this suspicion. After discussions with diving medical professionals and his cardiologist, the diver has decided to have the PFO repaired.

At least one quarter of the population has a PFO, and the presence of a large PFO (or one that allows blood and bubbles to pass through without provocation) can significantly increase the chances of DCI. Yet again, this case details a diver with an unknown PFO who suffered DCI after a repetitive series that included a deep dive (48 metres) followed by a relatively short (two-hour) surface interval, then another dive (27 metres). This is a common scenario and one that sometimes leads to DCI.

To reduce the chances of a decompression incident, divers are advised to set their dive computers to a conservative mode and stay well within these reduced limits. Surface intervals should be extended as far as possible and if this is not practical, the repetitive dive(s) should be shortened to stay even further within computer limits.