Underutilization of echocardiography for patent foramen ovale in divers with serious decompression sickness

The presence of a patent foramen ovale (PFO) in compressed gas diving has been considered a risk factor for serious decompression illness (DCS) for more than 20 years. We conducted a ten year retrospective chart review aimed at determining if physicians treating DCS in a university medical center setting used echocardiography to assess PFO in patients with severe DCS, and if so whether PFO is over-represented in that population. Over the ten-year period, 113 divers underwent recompression therapy for decompression sickness. Of these patients, 48 had serious DCS defined by at least one objective neurological finding. We reviewed medical records for the presence of agitated saline contrast echocardiogram testing and whether or not PFO was present. Only 12 of 48 patients with serious DCS underwent transthoracic agitated saline contrast echocardiogram testing. Of these 12 patients, 6 (50%) had a resting PFO. Binomial proportion testing yielded 95% confidence limits of 21% and 79%. Given 27% PFO prevalence in the general population, PFO may be over-represented in our group of most seriously injured DCS patients yet 75% of patients with objective neurological signs did not undergo echocardiography.