An international phase iii randomised trial on the efficacy of helium/oxygen during spontaneous breathing and intermittent non-invasive ventilation for severe exacerbations of chronic obstructive pulmonary disease (the E.C.H.O.ICUtrial)

Due to its reduced density, Helium/Oxygen (He/O2) reduces the work of breathing, intrinsic PEEP and hypercapnia more than Air/O2 during non-invasive ventilation (NIV) in COPD exacerbations [1, 2]. Two prospective, randomized multicenter trials were inconclusive in showing a benefit of He/O2 NIV on outcome (intubation, mortality, length of stay (LOS) in ICU) but were potentially underpowered [3, 4].