The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts


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

BACKGROUND: Pulsed dose oxygen conserving devices (PDOCD) are frequently prescribed with oxygen therapy for home care patients. Many different designs are available but little information exists regarding their performance. The purpose of this study was to evaluate 10 currently marketed PDOCDs. METHODS: Devices evaluated were Inovo - Bonzai, Lotus, Evolution; Cramer Decker - Solo2; DeVilbiss - BP1000; Invacare - 10C100P; Precision – EasyPulse5; Salter - O2XPRESS; Responsive Respiratory - Respond; Drive – Oxypulse. Pulse characteristics were measured with the Oxygen Conserver Test System (Hans Rudolph, Inc.). Oxygen delivery during simulated breathing was measured with a model nose, nasal cannula and ASL 5000 lung simulator (Ingmar Medical Inc., Pittsburgh, PA). The lung model was a sinusoidal flow pump; inspiratory rise was 5%, hold 0%, release 25%, frequency 15 to 30 breaths/minute, tidal volume = 500 mL. Median values were compared with Kruskal-Wallis One Way Analysis of Variance on Ranks with P values < 0.05 considered significant. RESULTS: Pulse flow results fell into two groups, those with low flows (£ 3 L/min), long pulses (0.5 – 1.25 s) and those with high flows (£ 20 L/min), short pulses (0.2 – 0.5 s). There was considerable variability in pulse time and volume among devices. Pulse volume increased as the PDOCD setting increased for all devices. The Bonsai triggered at the smallest pressure drop (-0.03 cm H2O); the Respondo2 required the highest pressure drop to trigger (-1.12 cm H2O), P < 0.001. Pulse delay was shortest for the Bonsai (28 ms) and longest for the Oxypulse (131 ms), P < 0.001. Data for oxygen delivery at setting #2 are shown in Figure. The Solo2 had the highest pulse volumes but also the second longest pulse time, so its oxygen delivery was among the lowest. The PD1000 had the best oxygen delivery overall, which might be explained by its combination of relatively high pulse volume, short pulse time and short pulse delay. None of the PDOCDs could duplicate constant flow at 2 L/min at frequency of 15 breaths/min. CONCLUSIONS: Considerable performance variation exists among pulsed dose oxygen conserving devices. Setting numbers have no consistent relation to constant flow and therefore cannot be used as equivalents for constant flow oxygen prescriptions. This study highlights the importance of titrating each device to the specific oxygen saturation specified by the physician for the patient at rest, exercise and sleep. Sponsored Research - Study was funded by all the device vendors mentioned in the abstract.