Breath‐dependent pressure fluctuations in various constant‐ and variable‐flow neonatal CPAP devices

In continuous positive airway pressure (CPAP) devices, pressure can be generated by two different mechanisms: either via an expiratory valve or by one or more jets. Valved CPAP devices are referred to as constant‐flow devices, and jet devices are called variable‐flow devices. Constant‐flow CPAP devices are said to reduce the imposed work of breathing due to lower breath‐dependent pressure fluctuations. The present study investigates the performance of various constant‐ and variable‐flow CPAP devices in relation to breath‐dependent pressure fluctuations.