Mask leak solutions

CPAP Mask leaks are a common problem. all masks have an intentional leak or vent rate that ranges from 24 to 36 L/min depending on design or pressure. This is to prevent rebreathing of expired air. Note that leak rate is anywhere from 7 to 7 times the air volume required for respiration, generally 5 to 10 L/min depending on the individual. In addition, some CPAP machines like Philips report total leaks, while Resmed reports only the excess leak. So when we talk about an acceptable leak rate, we allow for the designed mask leak and add about 25 L/min for unintentional leak before we reach the large (excessive) leak rate. That may be as high as 55-60 L/min of total leak depending on variables of mask type and pressure. What really matters is whether the CPAP can maintain control of the airway at any given leak rate. When we see detected respiratory flow rates drop and a lack of definition in the detection of breathing, that is a good indication that leak is really excessive. Finally, if leaks are disruptive to sleep they need to be reduced so we can sleep well.

For a more comprehensive discussion on mask leaks and how to fit a mask see the Mask Primer wiki. In addition, the Leak Rate Graph wiki provides a more concise discussion of what is a large leak.

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