The Science Journal of the American Association for Respiratory Care

2009 OPEN FORUM Abstracts


Faera L. Byerly2, Kathy Short1, Haithcock A. John1, Alvis Page3, Phillip Boysen3, Bruce A. Cairns2; 1Respiratory Care, UNC Hospitals, Chapel Hill, NC; 2Department of Surgery, UNC Hospitals, Chapel Hill, NC; 3Department of Anesthesia, UNC Hospitals, Chapel Hill, NC

Background: The VDR-4® high frequency percussive ventilator (HFPV) has been shown to be beneficial in the management of inhalation injury by improving secretion clearance while maintaining oxygenation and ventilation using lung protective strategies. Airway Pressure Release Ventilation (APRV) has been used with acute respiratory distress syndrome, with lower mean airway pressures (MAP) and fewer adverse hemodynamic effects when compared to conventional ventilation, yet secretion clearance for patients with inhalation injury could be problematic. We hypothesized that the HFPV could mimic the airway mechanics of APRV as determined by generating a similar MAP and total positive end expiratory pressure (PEEP) for a given inspiratory (I) time. Methods: An Ingmar Medical (Pittsburg, PA) dual adult test with Pneu View software was used to compare the HFPV to APRV at I times of 2, 3, 4, and 5 seconds at varying lung compliance and resistance (Rp20). Pressure control inverse ratio ventilation (PC-IRV) served as a control. Total PEEP and MAP were measured while controlling peak inspiratory pressure (PIP), PEEP, I time, and expiratory (E) time. Data was analyzed using ANOVA with significance p< 0.05. Results: Airway mechanics of HFPV compare favorably with APRV and seem quite similar at increasing I times. HFPV resulted in a lower MAP than APRV and PC-IRV at all I times (p< 0.05). While total PEEP in HFPV increased with increasing I times (p< 0.05), this effect was not observed in APRV and PC-IRV, but differences were not significant. These data suggest that HFPV and APRV can be quite similar other than the high frequency percussive breaths delivered by HFPV. For a given I time and peak inspiratory pressure, total PEEP and MAP delivered by these two modes of ventilation were similar at different lung compliance levels. Sponsored Research - None