Purpose: The hypoxic challenge test (HCT) is used to evaluate safety for air travel in individuals with respiratory disease by breathing in 15% oxygen for 20 min. Our aim was to determine if a prolonged HCT, lasting 120 min, identified more individuals with neuromuscular disease at potential risk than the standard HCT lasting 20 min.
Methods: This was a cross-sectional study. All of the clinical testing took place at SickKids, Toronto, Canada. Patients were included in the study if they had a diagnosis of NMD, greater than 6 years of age, resting oxygen saturation ≥ 94%, and partial pressure of carbon dioxide (pCO2) ≤ 45 mmHg. Notable exclusion criteria were left ventricular ejection fraction < 30%, presence of a tracheostomy, and use of non-invasive ventilation for more than 12 h daily. Participants underwent a standard HCT as well as the prolonged HCT on the same day.
Results: Twenty-three patients consented to the study. One patient was withdrawn because he was unable to follow the study procedures. The 22 study participants had a mean age of 14.9 years (standard deviation (SD) of 5 years). Seventeen (77%) participants were male. Two participants were withdrawn on the day of testing due to hypercapnia. Twenty participants completed the standard and prolonged HCTs. None of the participants had a positive standard or prolonged HCT.
Conclusion: Our results suggest that performing a standard or prolonged HCT may, in fact, not be of clinical utility in individuals with less severe NMD.
Keywords: Air travel; Hypoxic challenge test; Neuromuscular disease; Non-invasive ventilation.
© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.