The pressure effects of facemasks during noninvasive ventilation: a volunteer study.

Noninvasive ventilation by facemask is commonly used for patients with respiratory failure. We evaluated the pressure exerted by two types of facemask on the faces of 12 healthy volunteers while they were being given different levels of continuous or bi-level positive airway pressure ventilation. The mean (SD) pressure recorded on the bridge of the nose was much higher than that on the cheek (nose: 65.8 (21.2) vs cheek 15.4 (7.2) mmHg, p < 0.0001). Progressive tightening of the harness and increasing of the volume of air in the facemask cushions increased the pressure on the bridge of the nose, and the effect of these two factors was additive. Some commercially available facemasks can produce substantial pressure on the bridge of the nose and this explains why pressure complications on the bridge of the nose are common during noninvasive ventilation.