What is Exhalation Relief like C-Flex, A-Flex, EPR, and SmartFlex?
Exhalation relief is the ability of a CPAP machine or BiPAP machine to reduce the inspiratory pressure during exhale, making it easier to breathe out against the pressure. Manufacturers have different names for exhalation relief, but they mostly work the same way. Pressure can be adjusted up to 3cm for comfort.
Respironics calls their pressure relief C-Flex, A-Flex, or C-Flex+. C-Flex lowers the pressure on exhale and quickly ramps back up to the prescribed pressure. A-Flex, available on Auto CPAP machines only, lowers the pressure on exhale and gradually increases the pressure during inhale. This allows for a more fluid breath.
ResMed uses EPR for pressure relief. Pressures are decreased up to 3cm during exhale and quickly increased back to prescribed pressure when inhale is detected.
DeVilbiss SmartFlex is similar to Respironics C-Flex and ResMed EPR.