Pre-flight evaluation of adult patients with cystic fibrosis: a cross-sectional study

Abstract

Background: Air travel may imply a health hazard for patients with cystic fibrosis (CF) due to hypobaric environment in the aircraft cabin. The objective was to identify pre-flight variables, which might predict severe hypoxaemia in adult CF patients during air travel.

Methods: Thirty adult CF-patients underwent pre-flight evaluation with spirometry, arterial oxygen tension (PaO₂), pulse oximetry (SpO₂) and cardiopulmonary exercise testing (CPET) at sea level (SL). The results were related to the PaO₂ obtained during a hypoxia-altitude simulation test (HAST) in which a cabin altitude of 2438 m (8000 ft) was simulated by breathing 15.1% oxygen.

Results: Four patients fulfilled the criteria for supplemental oxygen during air travel (PaO_{2 HAST} < 6.6 kPa). While walking slowly during HAST, another eleven patients dropped below PaO_{2 HAST} 6.6 kPa. Variables obtained during CPET (PaO_{2 CPET}, SpO_{2 CPET}, minute ventilation/carbon dioxide output, maximal oxygen uptake) showed the strongest correlation to PaO_{2 HAST}.

Conclusions: Exercise testing might be of value for predicting in-flight hypoxaemia and thus the need for supplemental oxygen during air travel in CF patients. Trial registration The study is retrospectively listed in the ClinicalTrials.gov Protocol Registration System: NCT01569880 (date; 30/3/2012).

Keywords: Blood gas response; Cardiopulmonary exercise testing; Gas exchange; Hypoxia altitude simulation test; Pulmonary function.