Einfluss einer Flugsimulation auf die motorische Ausdauerleistung und Atempumpleistung bei COPD Patienten mit und ohne chronisch ventilatorischer Insuffzienz

At least until the beginning of the Sars-CoV-2 pandemic there was an increase of air travel by 6.4 % in 2018 compared to 2017. The prevalence of COPD is also increasing. Due to the decreased cabin pressure during air travel, the oxygen saturation in all passengers drops. In this situation especially passengers with preexisting pulmonary diseases develop symptoms. The increase in air travel is the reason for growing airports, which causes longer walking distances at airports. Patients suffering from COPD already have a decreased endurance performance. Air travel followed by longer walking distances at the destination airport can cause very strong symptoms like severe dyspnea in patients suffering from pulmonary diseases. There are inconsistencies both in the data situation and in suggestions to evaluate the fitness to fly of passengers who suffer from a respiratory disease. The possibility to obtain supplementary oxygen during air travel is not always given and often involves high costs. The object of this thesis was to investigate the impact of hypobaric flight simulation lasting three hours on exercise endurance of COPD patients, measured by a six-minute walking test. The hypothesis that air travel causes hypercapnia and hypoxia in patients with preexisting pulmonary diseases by increasing exhaustion of the respiratory pump was to be examined. Furthermore, the correlation between parameters collected prior to the flight simulation and the lowest oxygen saturation during the flight simulation was examined. This can be really important to patients because it could facilitate the evaluation of fitness to flight in patients suffering from COPD or other pulmonary diseases. To date, measurements in a hypobaric chamber are the gold standard to evaluation the fitness to flight. Furthermore, there is an easier test – the hypoxia altitude simulation test – which causes a normobaric hypoxia by breathing a lower oxygen fraction. In this study, a three-hour lasting exposition in a hypobaric chamber was chosen to simulate an air travel. This study found that there was a statistically significant reduction of the six-minute walking distance when comparing the distances before and after the flight simulation. The previously defined clinical significance was not reached. The decrease of the six- minute walking distance in patients with manifest pulmonary insufficiency and established non-invasive ventilation was not bigger than in patients without pulmonary insufficiency and consequently without non-invasive ventilation. The oxygen saturation and the diffusion capacity for carbon monoxide measured prior to flight simulation correlated with the lowest oxygen saturation during the flight simulation. Moreover, a model to predict the lowest oxygen saturation during flight simulation by using the diffusion capacity for carbon monoxide could be developed by means of regression analysis. Looking at the study results, the actual reduction of the exercise endurance of patients suffering from COPD after air travelling seems questionable. However, the basic requirement during the six-minute walking test was easier due to the lack of luggage and a flat, straight track without any stairs or inclinations. Thus, the real reduction of the six-minute walking distance could have been underestimated. Hypobaric hypoxia caused by flight simulation was very well tolerated by the participants despite partially huge decreases of oxygen saturation. According to existing directives, most patients would have been called fit for flight only with supplemental oxygen during air travel. But acute dyspnea only caused two participants the termination of the running flight simulation. Finally, it seems to be necessary to reevaluate and adjust existing directives by conducting bigger studies.