Bench study of auto-CPAP devices using a collapsible upper airway model with upstream resistance.

ABSTRACT

The aim of this study was to investigate the response of auto-CPAP devices to respiratory events (apnea, hypopnea, flow-limitation and snoring) on the same condition using a physiological upper airway model. The hypothesis of this study is that collapsibility of the flow-limiting collapsible segment of the airway is influenced by the upstream airway resistance. Five auto-CPAP devices, AutoSet T, AutoSet Spirit, Goodnight 420E, PV10i and REMstar Auto were evaluated. Apnea all the devices increased the auto-CPAP level, while AutoSet T and AutoSet Spirit did not respond to apnea for 30s. Hypopnea all the devices except the AutoSet T and Goodnight 420E increased pressure. Flow-limitation: all the devices except the PV10i and REMstar Auto increased pressure. Snoring the snoring sounds disappeared when REMstar Auto and PV10i were used, and the Goodnight 420E lowered the level of snoring. In conclusion, the response of auto-CPAP devices to respiratory events differed. Collapsible upper airway model with upstream resistance is useful for the first-step assessment of auto-CPAP devices.