Air travel and cystic fibrosis: An algorithm to assess the risk of In-Flight Hypoxemia

Abstract

Background: Air travel may cause significant hypoxemia in patients with cystic fibrosis (CF). A pre-flight algorithm has previously been validated for patients with chronic obstructive pulmonary disease (COPD). No such tools are available for CF patients. The aim of this study was to evaluate if the pre-flight algorithm for COPD patients can be used by CF patients.

Methods: In this prospective cross-sectional study, oxygen saturation at sea level (SpO_{2 SL}) and during exercise (SpO_{2 6MWT}) were used to evaluate whether CF patients a) are fit for flight without further assessment, b) require in-flight supplemental oxygen, or c) need further evaluation with hypoxia-altitude simulation test (HAST). HAST was used as reference method, and SpO_{2 HAST} ≤85 % was the criterion for recommending in-flight supplemental oxygen.

Results: 79 CF patients (41 men), age 38.0 ± 13.4 years, with FEV₁ of 71±23 % of predicted underwent HAST (SpO_{2 HAST} 89.2 ± 4.0 %). Categories for SpO_{2 SL} were >95 % (N = 53), 92-95 % (N = 25), and <92 %, (N = 1), and the cut-off value for SpO_{2 6MWT} was <84 %. HAST showed that CF patients with SpO_{2 SL} >95 % combined with SpO_{2 6MWT} ≥84 % can travel by air without further assessment. Supplemental oxygen is recommended if SpO_{2 SL} is 92-95 % combined with SpO_{2 6MWT} <84 %, or if SpO_{2 SL}<92 %. Otherwise, HAST should be performed. Only 21 patients (27 %) would have needed referral to HAST. The algorithm correctly identified those who needed and those did not need in-flight supplemental oxygen.

Conclusions: The algorithm for COPD patients may be used in the pre-flight evaluation of adult CF patients.

Clinicaltrials: gov (NCT03843723).

Keywords: Air travel; Cystic fibrosis; Hypoxaemia; Pre-flight algorithm.