The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts


David M. Wheeler3, Thomas J. Williams2, Robert L. Chatburn1; 1Respiratory Institute, Cleveland Clinic, Cleveland, OH; 2Strategic Dynamics Inc, Scottsdale, AZ; 3Anesthesia Institute, Cleveland Clinic, Cleveland, OH

INTRODUCTION New portable oxygen concentrators (POCs) have recently become available but there is little information regarding their comparability. The purpose of this study was to evaluate the performance characteristics of 2 commercially available, light weight, POCs); LifeChoice (Inovo Labs) and XPO2 (Invacare). METHODS Oxygen purity and pulse characteristics were measured with the Oxygen Conserver Test System (Hans Rudolph Inc.). Oxygen delivery was evaluated with an ASL 5000 Lung Simulator (IngMar Medical Inc.). Breathing frequency was 15-35 breaths/min with tidal volume of 500 mL. The POC was connected to a fixture representing the nose with a standard adult nasal cannula. Mean values were calculated for 5 breaths after a stabilization period of 25-50 breaths. RESULTS The XPO2 delivered oxygen concentrations to the simulated lung in the range from approximately 22% to 30%. The LifeChoice delivered oxygen in the range of approximately 23% to 26% (see Figure). For both POCs, oxygen delivery decreased as frequency increased. For the XPO2, oxygen concentration increased as the device setting increased at all frequencies. For the LifeChoice, oxygen delivery increased as the device setting increased at a frequency of 15 breaths/minute. However, at 20 and 25 breaths/minute, oxygen delivery remained constant as the device setting increased from 2 to 3. The XPO2 had pulse flows that were 2 to 4 times higher than the LifeChoice. Furthermore, the XPO2 was able to increase pulse volume as the device setting increased by increasing both pulse flow and pulse duration. In contrast, the LifeChoice only increased pulse duration as the OCD setting increased. CONCLUSIONS There were important performance differences between these 2 POCS. The more stable and consistent oxygen delivery of the XPO2 can be explained by the higher oxygen purity and the pulse delivery profiles. The XPO2 delivers more oxygen than the LifeChoice at the most common breathing frequencies found with ambulatory patients in the home care environment. At any frequency, increasing the XPO2 setting increased the oxygen delivered. The LifeChoice does not trigger reliably above 25 breaths/min because it was not designed to do so. Furthermore, at frequencies above 15/min, increasing its setting from 2 to 3 did not increase oxygen delivery. The XPO2 delivers more oxygen at a larger range of patient breathing rates and therefore may prove more clinically versatile. Sponsored Research - The study was funded by Invacare.