The influence of an innovative inspiratory pressure relief accessory on continuous positive airway pressure profiles in a laboratory bench setting.

Study objectives: Despite its efficacy, long-term adherence to continuous positive airway pressure (CPAP) hovers around 50%. The V-com (SleepRes, Murfreesboro, TN), an inspiratory pressure relief (IPR) accessory, claims to improve comfort by decreasing inspiratory pressures. We aim to independently assess its impact on fixed CPAP settings in a laboratory bench model.

Methods: An ASL-5000 Breathing simulator (IngMar Medical, Pittsburgh, PA) with normal lung settings was employed. A ResMed AirSense 11 device was connected to ASL-5000 through a React Health Rio II exhalation vent and an elbow adapter. Mean inspiratory and expiratory pressures were measured at fixed CPAP settings (4, 6, 8, 10, 12, 14, 16, 18, and 20 cmH2O) at baseline, one IPR unit, and two IPR units in series, without and with expiratory pressure relief (EPR). Generalized linear models were applied to evaluate changes in pressure across CPAP settings.

Results: With one IPR, mean inspiratory pressures decreased significantly from the baseline pressures (p<0.001), with only a marginal reduction of mean expiratory pressures (p=0.239). The inspiratory pressure reduction was consistently greater than the expiratory pressure drop across all settings (P<0.001). Higher CPAP settings resulted in larger reductions in inspiratory and expiratory pressures (p<0.001). Two IPR units in series led to a greater decrease in both pressures (p=0.001). When EPR 3 was combined with IPR, a larger drop in pressure was noted. (P<0.001).

Conclusions: This IPR accessory decreases inspiratory pressures but only marginally reduces expiratory pressures in this laboratory bench model. Two IPR units further decrease both inspiratory and expiratory pressures.