Maximum exhaled air dispersion distance via different oxygen administration and ventilatory support strategies

MethodMaximum exhaled air dispersion distance
Oxygen via nasal cannula 5 L·min−1100 cm
Oxygen via oronasal mask 4 L·min−140 cm
Oxygen via Venturi mask FIO2 40%33 cm
Oxygen via non-rebreathing mask 12 L·min−1<10 cm
CPAP via oronasal mask 20 cmH2ONegligible air dispersion
CPAP via nasal pillows33 cm
HFNC 60 L·min−117 cm (62 cm sideways leakage if not tightly fixed)
NIV via full face mask: IPAP 18 cmH2O, EPAP 5 cmH2O92 cm
NIV via helmet without tight air cushion: IPAP 20 cmH2O, EPAP 10 cmH2O27 cm
NIV via helmet with tight air cushion: IPAP 20 cmH2O, EPAP 10 cmH2ONegligible air dispersion

FIO2: inspiratory oxygen fraction; CPAP: continuous positive airway pressure; HFNC: high-flow nasal canula; NIV: noninvasive ventilation; IPAP: inspiratory positive airway pressure; EPAP: expiratory positive airway pressure.