[Effect of hypoxia on pulmonary gas exchange and hemodynamics]

To test the influence of hypoxia upon the pulmonary gaseous exchange and the hemodynamics of the pulmonary circulation 12 healthy test-persons at the age from 33 to 47 years (mean = 36.7 years) were submitted to a pulmonary and cardiocirculatory basis-investigation with determination of VK, VE, VO2, VCO2, Hb, PO2A/a, PCO2A/a, pH, BE, HR, ECG, PVd, PAp, SV, HZV, RL. These investigations were followed by stress examination by means of the bicycle-ergometry in four rectangular steps under conditions of normoxia from 95.5 to 97.3 kPa, x = 96.5 kPa (716 to 730 torr, mean = 723.6 torr) and of hypobarohypoxia in a low-pressure chambre at 66.5 kPa (500 torr) each of 6 min duration. Under the influence of hypoxia a PO2a-decrease in the sense of partial insufficiency could be already observed at rest under conditions of a decreased alveolar oxygen-partial-pressure. At this simultaneously increases the CO2-exhalation. At the same time was found a significant increase of the systolic peripheric and the diastolic pulmonary-arterial pressure. At the increasing step-by-step ergometric employment under conditions of the hypoxia stress were growing significance evidence of different reactions of the pulmonary and cardiocirculatory parameters occurred.