Abstract
Background: Prevalence of significant nocturnal desaturation(NOD) in non-apnoeic patients with Chronic Obstructive Pulmonary Disease (COPD)varies widely from 27 to70% with limited information on its predictors and impacts.
Aims: To determine the prevalence and predictors of NOD in non-apnoeic COPD and evaluate its impacts.
Methods: Sixty patients with COPD with daytime oxygen saturation (SaO2) > 90% were categorized as “desaturators” and “non-desaturators” after overnight pulse oximetry, with desaturation defined as SaO2 < 90% occurring for > 30% of total recording time with a nadir< 85%. Investigations included a 6-minute walk test, lung function study, high resolution computed tomography (HRCT Chest), and measurement of Pittsburgh Sleep Quality Index and health-related quality of life. Sleep apnoea was ruled out using Epworth Sleepiness Score and Apnea-Hypopnea Index (AHI) on sleep screening.
Results: The prevalence of NOD was 25%. These patients had greater dyspnea, higher GOLD severity, lower FEV1 and diffusion capacity, higher BODE index, greater frequency of exercise desaturation,and a poorer quality of sleep and health-related quality of life but were similar to non-desaturators for age, gender distribution, AHI and frequency of emphysema on HRCT. Multiple regression analysis identified exercise desaturation and lower daytime PaO2 as significant predictors of NOD.
Conclusions: NOD is common in non-apnoeic COPD, is associated with disease severity and adversely impacts sleep quality and health-related quality of life. Exercise desaturation and low daytime PaO2 predict its occurrence.
- Copyright ©ERS 2015
