Immersion, Hyperoxia, Hypercapnia: Additive Effect Upon Pulmonary Function

In a study of 6 men aged 29 to 48 we studied the effect of water body immersion during air or pure oxygen, or oxygen - 4 % CO₂ gas mixture breathing upon pulmonary volumes and respiratory biomechanics (using bodyplethysmography), the extent of lung hydration (two-frequency impedansometry), and pulmonary metabolic function (by determination of the concentration of biologically active substances in the condensate of the exhaled air). We found an additive nature of immersion/hyperoxic effects upon the respiratory and metabolic pulmonary functions manifested in an acceleration and growth of a deficit in pulmonary vital capacity, a bronchoconstriction effect, increase of a lung hydration, and decrease of serotonin catabolism. Contrary to our expectation, we did non find any potentiation of oxygen induced toxic effects upon the lungs during immersion/hyperoxia/hypercapnia exposures.