Positive Airway Pressure Units, Expiratory
Definition : Devices designed to apply positive airway pressure only during expiration; sub-atmospheric pressures are generated on inspiration. Expiratory positive airway pressure (EPAP) units typically consist of a pressurized circuit including a one-way valve that allows gas to enter the airway on inspiration and directs exhaled gas through a threshold resistor, such as underwater seals or weighted balls. A threshold resistor is a device that exerts a predictable, quantifiable, and constant force at the expiratory limb, creating a threshold pressure (typically of 5 to 20 cm of H20) that must be exceeded to allow flow thorough the valve. EPAP units do not require a high-flow gas source. These units are intended to provide noninvasive positive pressure breathing assistance therapy through a mask (either nasal or oronasal), a mouthpiece; they are used to treat central sleep or obstructive apnea disorders. They are not intended for continuous breathing support.
Entry Terms : "EPAP Units" , "Expiratory Positive Airway Pressure (EPAP) Units"
UMDC code : 20744