Figure 5.

Maximum exhaled air dispersion distances during the application of NPPV to the HPS via different face masks. In the study of the ResMed Ultra Mirage mask,⁸ tidal volume was set at 500 mL, and a respiratory rate of 14 breaths/min was used to represent a patient with very mild lung injury. For the study of Respironics masks, tidal volume was set as 300 mL, and a respiratory rate of 25 breaths/min was used to represent a patient with mild lung injury.13, 14 EPAP was maintained at 4 cm H₂O throughout the studies.