Clinical evaluation of portable oxygen concentrators: impact of pulse oxygen delivery on exercise

Introduction: In order to increase the autonomy of portable oxygen concentrators, pulse oxygen therapy (POT) have been developed. These devices are now widely used in clinical practice. However, little is known on their impact on exercise capacity. The aim of this study was to assess the exercise capacity using POT when compared to continuous oxygen delivery. Methods: French prospective multi-centric (n=19) randomized cross-over trial promoted by the ANTADIR. Eight different portable oxygen concentrators were evaluated. For each concentrator, a minimum of 25 patients underwent two 6 minutes walking tests in random order with the device set in continuous mode or in pulse mode. We recorded the walked distance, the saturation at the end of each test and the dyspnea (Borg scale). ANOVA test with correction for multiple comparison were used. Results: Study participants had a mean age of 65 years [60 to 71] and a body mass index of 24 kg/m2 [20 – 28]. A total of 234 tests were performed. The median distance walked using the continuous mode was 320m [226 - 415] and 320m [226 – 426] using POT (ns). There was no significant difference between the 8 different portable oxygen concentrators. End of test dyspnea was similar between groups: 4 [3 – 6] out of 10 (ns) as well as the end of test: 89% [85 – 91] in the continuous group and 89% [86 – 92] in the POT group (ns). The 8 concentrators did not differ significantly. Conclusion: Our results suggest that the use of POT is not associated to an impaired exercise capacity and achieved similar control of the oxygenation during exertion than continuous oxygen delivery. The performance of all tested devices were comparable.