Risk of neurological decompression sickness in the diver with a right-to-left shunt: literature review and meta-analysis.
OBJECTIVE
Literature review and meta-analysis to review the evidence of relationship between the presence of right-to-left shunts (RLSs) and the occurrence of neurological decompression sickness (DCS) in divers.


METHODS
MEDLINE, Google Scholar, and Health Technology Assessment databases.


METHODS
Five case-control studies in which the prevalence of a RLS in a group of divers with neurological DCS was compared with that of a group of divers with no history of DCS, 3 cross-transversal studies in which the prevalence of RLS was measured in divers with neurological DCS, and 4 cross-transversal studies in which the prevalence of RLS was measured in divers with no history of DCS were reviewed.


METHODS
Only case-control studies were retained for meta-analysis.


RESULTS
This meta-analysis gathers 5 studies and 654 divers. The combined odds ratio of neurological DCS in divers with RLS was 4.23 (3.05-5.87). The meta-analysis including only large RLS found a combined odds ratio of 6.49 (4.34-9.71).


CONCLUSIONS
Because of a low incidence of neurological DCS, increase in absolute risk of neurological DCS due to RLS is probably small. Thus, in recreational diving, the systematic screening of RLS seems unnecessary. In professional divers, because of a chronic exposition and unknown consequences of cerebral asymptomatic lesions, these results raise again the benefit of the transcranial Doppler in the screening and quantification of the RLS, independently of their location.
Lairez
Olivier
O
Department of Cardiology, CHU Rangueil, Toulouse, France. lairez@gmail.com
Cournot
Maxime
M
Minville
Vincent
V
Roncalli
Jérôme
J
Austruy
Julien
J
Elbaz
Meyer
M
Galinier
Michel
M
Carrié
Didier
D
D001265:Athletic Injuries / Q000453:epidemiology*; D015897:Comorbidity; D003665:Decompression Sickness / Q000453:epidemiology*; D004242:Diving / Q000293:injuries*; D006343:Heart Septal Defects / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D012306:Risk