The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts


Thomas Blakeman1, Dario Rodriquez2, Dennis Hanseman1, Branson Richard1; 1Department of Surgery, University of Cincinnati, Cincinnati, OH; 2Center for Sustainment of Trauma and Readiness Skills (CSTARS), Cincinnait, OH

Introduction: Portable ventilators (PV) continue to decrease in physical size while increasing in performance. We studied seven PV in the laboratory evaluating three important characteristics; triggering, battery life, and accuracy of volume (VT) delivery. Methods: Triggering was tested using a modified dual chamber test lung to simulate spontaneous breathing at weak, normal, and aggressive effort. Battery life was determined by fully charging the battery and operating the ventilator (500 ml x 20 bpm and 5 of PEEP) until breath delivery ceased. Accuracy of VT delivery and VT measurement was tested using pediatric (50 ml and 100 ml x 50 bpm with an inspiratory time of 0.3 secs and 5 of PEEP) and adult scenarios (400 ml x 30 bpm with an inspiratory time of 0.5 secs and 5 of PEEP). A pneumotachograph was placed at the proximal airway and airway pressure, volume, and flow signals were recorded to a PC for later analysis. Results: At the adult settings, measured VT ranged from 360 ml – 426 ml. The measured VT range on the pediatric settings of 50 bpm x 50 ml and 50 bpm x 100 ml were 51 ml – 182 ml and 90 ml – 141 ml respectively. The VT delivered by the Vela at both the 50 ml and 100 ml, and the HT 50 at the 100 ml settings exceeded the ASTM standards for tidal volume accuracy. Additionally, the HT 50 was unable to deliver a VT of 50 ml. Triggering response and battery duration varied widely among ventilators. Data below shows the negative pressure generated from baseline using an aggressive setting of 600 ml VT and inspiratory flow of 1.3 L/s and battery duration with each ventilator. Conclusions: Manufacturers continue to improve the performance of portable ventilators. Wide variability still exists between ventilator models with regard to battery life and triggering sensitivity. The majority of the ventilators we evaluated performed adequately in terms of VT delivery across a wide range of settings. The combination of high respiratory rate and low VT presented problems for two of the devices. Clinicians must be aware of ventilator limitations when choosing a device for their patient populations. Sponsored Research - Funding for this study was provided by GE Healthcare