title: Effects of a single saturation dive on lung function and exercise performance.
abstract: We studied the effects of an experimental saturation dive to 360 and 450 m in a simulation chamber on spirometric lung function, diffusing capacity, pulmonary compliance, and exercise performance in eight professional divers (age 22-40 years). To assess intraindividual variability, all parameters were measured on 2 days before and on 2 consecutive days immediately after the dive. For the group as a whole there was a significant increase in vital capacity and alveolar volume, and a decrease in Krogh factor and specific compliance (P < 0.01). These changes were reduced on the 2nd day after the dive. All subjects showed lowered exercise performance after the dive. Arterial pressure of oxygen and ventilation during exercise increased (P < 0.01), whereas arterial pressure of carbon dioxide, oxygen uptake, and anaerobic threshold decreased (P < 0.01). Exercise parameters showed only a slight trend towards pre-dive values on the 2nd day after a dive. The individual analysis revealed that after the dive two subjects showed a marked decrease in diffusing capacity and a more than average decrease in Krogh factor (TLCO/VA). One of them had signs of mild decompression sickness and the other, signs of pre-existing obstructive airways disease. Our data are compatible with the hypothesis that the effects of a single deep saturation dive on pulmonary function and exercise performance are the results of counteracting mechanisms. We suggest that lung volumes increase due to the enhanced work of breathing during a deep saturation dive and that these changes could mask an impairment in gas exchange. Furthermore, a saturation dive can induce an apparent deterioration of pulmonary function.
authors.affiliation: Krankenhaus Grosshansdorf, Zentrum für Pneumologie und Thoraxchirurgie, LVA Freie und Hansestadt Hamburg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Lehnigk
authors.forename: R A
authors.initials: RA
authors.lastname: Jörres
authors.forename: D H
authors.initials: DH
authors.lastname: Elliott
authors.forename: J
authors.initials: J
authors.lastname: Holthaus
authors.forename: H
authors.initials: H
authors.lastname: Magnussen
mesh_terms: D000328:Adult; D004242:Diving / Q000009:adverse effects* / Q000502:physiology; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000502:physiology*; D008170:Lung Compliance; D012129:Respiratory Function Tests; D014797:Vital Capacity / Q000502:physiology