Vector Engineering Clinical

Tidal Expiratory Flow Limitation (EFLT) is the inability to increase expiratory flow despite increasing effort. Especially in patients with mild to severe COPD, EFL can present challenges when receiving mechanical ventilation. To overcome EFLT expiratory positive airway pressure (EPAP) is applied; however, a single level or fixed EPAP may not overcome the airflow obstruction. The current study was undertaken to explore the variability of EFLT determined using Forced Oscillation Technique (FOT) to dynamically measure lung reactance (∆Xrs) and to evaluate the ability of automatically adjusted EPAP (PEEPopt) to over come EFLT overnight and over a two week period. In this prospective non-randomized trial, an unreleased noninvasive ventilator set in an S/T mode applied continuous oscillations (5 Hz, 1 cmH2O amplitude, 2 cmH20 peak to peak). Response to the oscillations was analyzed to calculate ∆Xrs and EPAP was adjusted automatically between 4 and 20 cmH2O. A fixed pressure support of 6 cmH2O was delivered. ∆Xrs was measured sitting and supine. Participants with evidence of EFLT (∆Xrs \> 2.8) were asked to undergo overnight polysomnography (PSG) and then a sub-group of patients used the ventilator at home for two weeks. EFLT within and between participants was analyzed. EFLT behavior during PSG, the response of the device to dynamically abolish EFLT, as well as the impact of this therapy on sleep quality was studied. Objective ventilator adherence data were used to determine usage after the 2-week in-home use. Additionally, experienced NIV participants qualitatively rated therapy comfort compared to their current treatment.