Exertional oxygen of limited benefit in patients with chronic obstructive pulmonary disease and mild hypoxemia.

Abstract

It is unclear whether short-term benefits from supplemental oxygen translate into improved quality of life in patients with severe COPD. In a 12 wk double-blind randomized crossover study, we assessed the effects of supplemental air and oxygen on exercise performance (step tests and 6 min walking distance [6MWD]) initially and after two 6 wk periods at home using exertional cylinder air or oxygen. We measured quality of life at baseline and after the two 6 wk domiciliary periods. The 26 patients (24 males) had a mean age of 73 +/- 6 yr; mean FEV1, 0.9 +/- 0.4 L; mean DLCO, 10.6 +/- 2.4 ml/min/mm Hg; mean resting PO2, 69 +/- 8.5 (range 58 to 82) mm Hg; mean PCO2, 41 +/- 3.3 mm Hg; and mean resting SaO2, 94 +/- 2.1 (mean +/- SD). Laboratory tests were performed breathing intranasal air or oxygen at 4 L/min, and measurements were made of SaO2 and Borg dysnea scores. Supplemental oxygen increased 6MWD and steps by small, statistically significant increments acutely at baseline and after 6 and 12 wk, without corresponding falls in Borg score. Degree of desaturation at baseline did not correlate with increase in 6MWD or steps achieved at baseline or at 6 or 12 wk, nor with the domiciliary gas used. There was no difference in 6MWD or steps achieved while breathing supplemental oxygen after 6 wk of domiciliary oxygen compared with domiciliary air. Small improvements in quality of life indices were found after domiciliary oxygen, and mastery also improved after domiciliary air. There were no differences in quality of life, however, when domiciliary oxygen was compared with domiciliary air. Although oxygen supplementation induced small acute increments in laboratory exercise performance, such improvements had little impact on the patients' daily lives.

Time to Desaturation Less Than One Minute Predicts the Need for Long-Term Home Oxygen Therapy

“…Some studies have found that, in patients who have only mild or nocturnal hypoxemia, oxygen therapy does not improve survival, 3,15 quality of life, 16 or activities of daily living. 17 By contrast, Eaton et al, who studied patients with COPD and exercise desaturation, found improved quality of life in their patients. 18 Fujimoto et al, who studied 75 patients with mild to severe COPD and mild hypoxemia, found that their desaturator patients walked farther in the 6-min walk test and had improved pulmonary pressure after administration of oxygen during exercise.…”

Nonpharmacological treatment and relief of symptoms in COPD

“…Oxygen therapy during exercise in patients normoxaemic at rest improves exercise endurance and dyspnoea [45][46][47][48], but may not have a direct enduring effect on exercise capacity. Despite previous studies of COPD patients trained while using supplemental oxygen failing to demonstrate benefits [49][50][51], supplemental oxygen during exercise training may enable individuals with COPD to tolerate higher levels of exercise activity with fewer exertional symptoms, ultimately improving their QoL, although larger studies are required in order to establish its effect on functional outcomes [52]. A randomised study failed to find an advantage in QoL of ambulatory oxygen over placebo in COPD patients who did not meet the criteria for mortality reduction with LTOT, thus not supporting the general off-label application of this treatment in patients not meeting recognised criteria for LTOT [53].…”

Ambulatory Home Oxygen: What Is the Evidence for Benefit, and Who Does It Help?

“…51 In an additional crossover randomized trial comparing portable oxygen versus air in 9 patients with a resting P aO 2 Ͻ 60 mm Hg, no differences in 6-min walk distances were found. 52 In a single blind trial in 20 patients, no significant differences in 6-min walk distance were found after 8 weeks of treadmill exercise training using either supplemental oxygen or compressed air.…”