A proof-of-concept trial of HELIOX with different fractions of helium in a human study modeling upper airway obstruction

Background Helium in oxygen (HELIOX) can relieve airway obstruction and lower the work of breathing because it increases the threshold at which turbulent gas flow is induced. Less turbulent and more laminar flow lowers the work of breathing. According to guidelines, the fraction of Helium in HELIOX should be maximized (e.g. to 79%). Here, we investigate whether HELIOX with less than 60% of Helium is able to relieve the sensation of dyspnea in healthy volunteers.