Forced expiration and inspiration under hyperbaric conditions.

Assessment in 37 healthy volunteers (aged 23 to 53 years) provided evidence that in a hyperbaric environment (0.4 MPa) a significant decline of expiratory and inspiratory dynamic indicators of pulmonary ventilation occurs, as compared with normobaric conditions (0.1 MPa). This phenomenon has a physical basis and it should be a contraindication for subjects with bronchopulmonary obstruction to dwell in a hyperbaric environment.