Mask pressure effects on the nasal Bridge during noninvasive Ventilation: impact of mask design, Ventilator Settings and body position
Background: Masks for noninvasive ventilation (NIV) must provide a good seal but can exert high pressure on the face, particularly over the nasal bridge (NB) which can limit treatment tolerability. We assessed the effects of different mask models, ventilator settings and body position on NB skin pressure. Methods: The pressure exerted by the NIV mask on the NB was measured with an I Scan system in 20 healthy volunteers in a seated position with 4 different commercially available masks. Each mask was measured in a seated position with the NIV ventilator set at IPAP/EPAP: 15/5 cmH 2 0, 20/5 cmH 2 0 and 25/5 cmH 2 0 in a random order. Additionally NB pressure was measured in the supine position at 20/5 cmH 2 0. Air leak was kept Results: The 4 different masks resulted in very variable NB pressures between median 37 mmHg (IQR: 23 59) in an oronasal dual wall cushion mask and 94 mmHg (IQR: 53 129) in a gel cushioned mask. There was no significant change in NB pressure with the different IPAP levels. NB pressure was similar (3 masks) or significantly lower in the supine position (1 mask) Subjective discomfort was correlated with both, IPAP level and NB pressure. Conclusion: Mask choice does not have to be adapted to the IPAP level. Mask fitting in the supine position can be considered in the clinical routine. A range of different masks should be available within an NIV service to reduce pressure effects over the nasal bridge.