Prevalence and characteristics of lung function changes in recreational scuba divers

Aims: To investigate the hypothesis that a salt water SCUBA dive may cause bronchoconstriction in some individuals. Methods: 100 experienced recreational SCUBA divers acted as their own controls. Spirometry measures were taken with Easyone (TM) spirometers before and after a dive. Measures recorded included FEV1/FVC ratio and forced mid-expiratory flow (FEF25-75%). Results: 60 participants (68% male, 32% female) aged between 19-68 years (mean 47 years) produced data meeting ATS/ERS international standards. Of these, 23% exhibited pre-dive FEV1/FVC ratio values less than 75%. Statistics on paired samples of pre- and post-parameters showed a significant decrease in FVC post-dive but did not show significanct reductions in FEV1 or FEV1/FVC. Six (10%) were current smokers and 13 (21%) were former smokers. Conclusions: 25% of participants had reduced FEV1/FVC ratio regardless of undertaking a dive. Consideration of the clinical implications requires further investigation. (C) 2011 Primary Care Respiratory Society UK. All rights reserved. Q Zhang et al. Prim Care Respir J 2011; 20(1): 97-101 doi:10.4104/pcrj.2010.00061