Background: Nocturnal oxygen desaturations (NOD), especially during REM sleep, have been described in patients with COPD. However, the role of NOD in the evolution of COPD to chronic respiratory failure has not been well studied. Objective: The aim of our study was to evaluate whether NOD is a risk factor for the development of chronic respiratory failure in COPD patients. Methods: We studied 34 consecutive COPD patients with a stable daytime PaO2gt; 60 mm Hg over a period of 42 months. We classified patients as desaturators (NOD) when episodic desaturations were found mainly during REM sleep, independently of baseline SaO2 values. Results: At enrolment 19 patients (55.8%) had NOD. Over the follow-up period, 10 patients (29.4%) were included in a long-term oxygen therapy (LTOT) programme (9 were desaturators). The LTOT was initiated a median time of 22 ± 6.8 months after enrolment. Patients who were subsequently prescribed LTOT had lower values of FEV1 at enrolment, with a higher degree of NOD and PaCO2. Stable respiratory failure developed earlier in patients with NOD: the two enrolment curves for LTOT differed significantly (log-rank test 2.56, p =0.005). PaCO2, NOD and FEV1 were statistically significantly associated, both in univariate and multivariate Cox proportional hazards analyses, with an increased risk of entering a LTOT programme. Conclusions: We conclude that NOD may represent an independent risk factor for the development of chronic respiratory failure in COPD patients with daytime PaO2> 60 mm Hg. A larger study is needed to confirm the role of NOD in the natural history of COPD and subsequently to identify the most appropriate therapeutic approach.
- Pulmonary function
- Respiratory failure
- Sleep-related hypoxaemia
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine