A randomized trial of nocturnal oxygen therapy in chronic obstructive pulmonary disease patients

Abstract

The beneficial effects of nocturnal oxygen therapy (NOT) in chronic obstructive pulmonary disease (COPD) patients with mild-to-moderate daytime hypoxaemia (arterial oxygen tension (Pa,O 2 ) in the range 7.4±9.2 kPa (56±69 mmHg)) and exhibiting sleep-related oxygen desaturation remains controversial. The effectiveness of NOT in that category of COPD patients was studied. The end points included pulmonary haemodynamic effects after 2 yrs of follow-up, survival and requirement for long-term oxygen therapy (LTOT).Seventy-six patients could be randomized, 41 were allocated to NOT and 35 to no NOT (control). The goal of NOT was to achieve an arterial oxygen saturation of >90% throughout the night. All these patients underwent polysomnography to exclude an associated obstructive sleep apnoea syndrome. The two groups exhibited an identical meanSD daytime Pa,O 2 of 8.40.4 kPa (633 mmHg) at baseline.Twenty-two patients (12 in the NOT group and 10 in the control group, p=0.98) required LTOT during the whole follow-up (3514 months). Sixteen patients died, nine in the NOT group and seven in the control group (p=0.84). Forty-six patients were able to undergo pulmonary haemodynamic re-evaluation after 2 yrs, 24 in the NOT and 22 in the control group. In the control group, mean resting pulmonary artery pressure increased from 19.85.6 to 20.56.5 mmHg, which was not different from the change in mean pulmonary artery pressure in the NOT group, from 18.34.7 to 19.55.3 mmHg (p= 0.79).Nocturnal oxygen therapy did not modify the evolution of pulmonary haemodynamics and did not allow delay in the prescription of long-term oxygen therapy. No effect of NOT on survival was observed, but the small number of deaths precluded any firm conclusion. These results suggest that the prescription of nocturnal oxygen therapy in isolation is probably not justified in chronic obstructive pulmonary disease patients. Eur Respir J 1999; 14: 1002±1008. The beneficial effects of long-term oxygen therapy (LTOT) have been demonstrated in chronic obstructive pulmonary disease (COPD) patients with marked daytime hypoxaemia, i.e. in patients with an arterial oxygen tension (Pa,O 2 ) measured in the stable state of the disease, of <7.3 kPa (<55 mmHg) or in the range 7.4±7.8 kPa (56±59 mmHg), and exhibiting "cor pulmonale" or polycythaemia [1, 2]. These beneficial effects include improved survival [1, 2], but also an amelioration of pulmonary haemodynamics [3,4]. The beneficial effects of LTOT on survival have not been observed in COPD patients with moderate hypoxaemia (Pa,O 2 in the range 7.4±8.6 kPa (56±65 mmHg)), as indicated by a very recent Polish study [5].The worsening of hypoxaemia during sleep, and particularly during rapid eye movement sleep, has been well established in patients with advanced COPD [6±10]. It must be underlined, however, that most of these studies have included patients with severe COPD, exhibiting marked daytime hypoxaemia. Conventional LTOT, given for >15±18 h . day -1 , compulsorily includes sleep time and, accordingly, sle...

Supplemental Oxygen Needs During Sleep. Who Benefits?

“…A second, similar study showed no difference in mortality and no difference in pulmonary hemodynamics. 115 These results are consistent with those of Gorecka and colleagues, who studied long-term oxygen therapy in patients with more mild hypoxemia (P a O 2 56 -65 mm Hg). 116 Although not measured, their study participants likely had NOD, and there was no survival advantage to supplemental oxygen after 3 years.…”

Long-term Oxygen Treatment in Chronic Obstructive Pulmonary Disease: Recommendations for Future Research

“…In contrast to the NOTT and MRC studies, trials reported by Gó recka and colleagues and Chaouat and colleagues found no effect of LTOT on survival (28,29). The important difference in these studies appears to be the inclusion of subjects with moderate, rather than severe, resting hypoxemia (typically meaning a resting arterial oxygen concentration between 56-60 and 65-69 mm Hg).…”

Respiratory medications and sleep

“…However, nocturnal oxygen therapy has not been shown to have the same mortality benefits as continuous oxygen therapy [39]. There have been conflicting reports on the effect of nocturnal oxygen on sleep.…”