Long-Term Oxygen Therapy: In a Perfect World This issue of RESPIRATORY CARE contains 2 papers of

interest that deal with long-term oxygen therapy (LTOT). In the first, Martí et al investigated the efficacy of 2 ox-ygen-conserving devices in correcting exercise-induced hy-poxemia in subjects with either COPD or interstitial lung disease (ILD). Of the 59 subjects who completed the study, 28 were diagnosed with COPD and 31 were diagnosed with ILD. A pulse-demand oxygen delivery system and a pendant reservoir cannula were compared to conventional continuous-flow oxygen therapy. All 3 systems were pow-ered by small compressed oxygen cylinders. In a manner of speaking, the researchers “chased after ” a satisfactory SpO2 during exercise in these 2 groups of subjects with lung disease who had first demonstrated exercise-induced hypoxemia. The threshold to qualify for this was an aver-age SpO2 88 % during a 6-min walk test (6MWT) with-out supplemental oxygen. The procedure monitored heart rate, breathing frequency, SpO2, dyspnea (using a modified Borg scale), and distance walked. The researchers found that, despite their best efforts in manipulating the settings of all 3 delivery systems, some 20 % of the severe COPD subjects could not achieve a satisfactory SpO2 during ex-ercise (defined as an average SpO2 90%), regardless of the delivery system. In the subjects with ILD the pulse-demand system fell far short of being effective: almost 40 % did not achieve a satisfactory SpO2. Interestingly, in both the COPD and the ILD groups the pendant reservoir cannula had the best results in correcting exercise-induced hypoxemia, but the pulse-demand system was the pre-ferred system when given a choice. As the authors noted, the subjects apparently made their choice of device based more on esthetics and comfort than other factors.