Preparation phase:
Eighteen asthma patients were selected based on physical and medical characteristics. During the year of preparation, several time points of evaluation were planned: evaluation at baseline, maximal exercise test in hypoxia (FiO2: 11%), 24hour stay at cold air environment.
At baseline, medical history was evaluated and clinical examination, ECG, lung function, Fraction of exhaled NO measurement and histamine provocation were performed.
During a second visit, patients stayed for approximately one hour in a chamber to simulate high altitude (FiO2:11%) and performed a maximal exercise test after 30 minutes of rest. Oxygen saturation, ECG and oxygen consumption were continuously monitored. Lung function and fraction of exhaled NO were assessed before and after the test. Also, peripheral blood was drawn before and after the test. This test allowed us to identify whether patients may develop acute mountain sickness later on during expedition.
During a third visit, patients stayed for 24 hours in a indoor ski centre to practice climbing techniques, building up a tent and working with the specialized materials. Temperature at the ski piste varies between -5°C and -10°C. Lung function, fraction of exhaled NO and induced sputum was assessed before and after the stay at the ski centre.
During the expedition, clinical status, heart rate and oxygen saturation were measured daily. Also, lung function and fraction of exhaled NO were regularly measured. A screening for acute mountain sickness was performed daily. Asthmatics patients were supported by two pulmonologist. Before and after expedition, spirometry, histamine provocation and induced sputum were performed.
