AccuO2 Oximetry-Driven Oxygen-Conserving Device Versus Fixed-Dose Oxygen Devices in Stable COPD Patients

BACKGROUND: Because standard home oxygen (O 2) systems deliver O2 at fixed rates, these systems are not designed to ensure optimal oxygen delivery based on physiologic need. We tested the ability of the AccuO 2 (OptiSat Medical, Minneapolis, Minnesota), a portable, closed-loop, oximetrydriven, O 2-conserving device to maintain SpO2 at > 90%, compared to continuous-flow oxygen and a standard O 2-conserving device (CR-50, Puritan-Bennett, Pleasanton, California). METHODS: We randomly assigned 28 patients who were on continuous home O 2 for COPD to use each of 3 O2 delivery systems (continuous-flow O2, CR-50, and AccuO2) for 8 hours a day, for 2 consecutive days, at home, at their current O 2 prescription. We recorded SpO2 and calculated the conservation ratio (duration of a given O 2 supply with an O2-conserving device compared to continuous-flow O2). RESULTS: Twenty-two patients completed all 3 study arms; 2 additional patients completed the AccuO 2 arm and the continuous-flow O2 arm. The mean SD SpO2 was 92 4% with continuousflow O 2 ,9 2 4% with the CR-50, and 91 2% with AccuO2 (P .006 for the AccuO2 vs continuous-flow O 2, P .03 for the AccuO2 vs the CR-50). SpO2 variability was less with the AccuO 2 (P < .001 vs continuous-flow O2 and vs the CR-50). The conservation ratios were 9.9 7.3 for the AccuO 2 and 2.6 1.0 for the CR-50 (P < .001). CONCLUSIONS: Compared to continuous-flow O 2 or the CR-50, the AccuO2 maintained SpO2 closer to the target, and AccuO2 had a higher conservation ratio than CR-50. Key words: COPD; long-term oxygen therapy; oxygenconserving device; pulse oximetry. [Respir Care 2011;56(12):1901–1905]