The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts


Andrew D. Marchese1, Demet Sulemanji1, Joseph Krathovil1, Jesús Villar2, Robert M. Kacmarek1; 1Respiratory Care, Massachusetts General Hospital, Boston, MA; 2Multidisciplinary Organ Dysfunction Evaluation Research Network, Research Unit, Hospital Universitario Dr. Negrin, Las Palmas de Gran Canaria, Spain

Background: A number of new transport ventilators have recently entered the market none of which have been evaluated. Patients are increasingly being ventilated with spontaneous breathing modes. The ability of the Uni-Vent 731 (Impact), PB540 (Covidien), HT70 (Newport), Oxylog 3000 (Drager) and Trilogy O2 (Philips) to provide pressure support (PS) was evaluated using the IngMar ASL 5000 lung simulator. Methods: Simulator settings: respiratory rate 20 breaths/min, inspiration time 0.8 seconds, active inspiration 3.5% of breath cycle time (BCT), a hold at maximum muscle effort of 0.5% BCT, and return of pressure to baseline 22.7% BCT, maximum muscle effort (Pmus) 5 and 10 cmH2O. Three combinations of compliance (C) and resistance (R): C 60 mL/H2O/R10 cmH2O/L/sec (C60/R10); C60/R5; and C30/R10 were evaluated. PS was set 15cm H2O above PEEP levels of 5 and 15 cmH2O. Manufacturers default settings and optimal setting of trigger sensitivity, rise time and termination criteria were compared. The following variables are reported: Time to Trigger (TT): The time, in milliseconds, from start of the breath to ventilator triggering. Pressure to Trigger (PT): The magnitude of pressure difference, measured in cmH2O, between initial airway pressure at start of breath and the negative deflection in airway pressure needed to trigger. Time to Baseline (TB): The time, in milliseconds, from ventilator triggering to the point when airway pressure reestablishes and maintains baseline pressure (PEEP), Inspiratory T90 (T90). Results: Optimal setting outperformed default setting. Optimal setting results are listed in table below. Conclusion: Considerable performance variability exists across these ventilators and is affected by Pmus and optimal settings. Some perform equivalent to ICU ventilators. Sponsored Research - None Indicates difference between low and high Pmus setting. * Indicates difference among ventilators.