Centre de Recherche, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada.
Unidad Funcional de Sueño, Hospital Universitario (Site, Hospital Santiago Apostol), Vitoria-Gasteiz, Spain.
Respiration. 2020;99(2):132-139. doi: 10.1159/000505299. Epub 2020 Jan 29.
Chronic obstructive pulmonary disease (COPD) and sleep apnea are common conditions and often coexist. The proper diagnosis of sleep apnea may affect the management and outcome of patients with COPD.
To determine the accuracy of home nocturnal oximetry to distinguish between nocturnal oxygen desaturation related to COPD alone or to sleep apnea in patients with moderate-to-severe COPD who have significant nocturnal hypoxemia with cyclical changes in saturation.
This study involved a comparison of home nocturnal oximetry and laboratory-based polysomnography (PSG) in patients with moderate-to-severe COPD considered for inclusion in a trial of nocturnal oxygen therapy. All of the patients had significant nocturnal oxygen desaturation (defined as ≥30% of the recording time with a transcutaneous arterial oxygen saturation <90%) with cyclical changes in saturation suggestive of sleep apnea.
PSG was obtained in 90 patients; 45 patients (mean age = 68 years, SD = 8; 71% men; mean forced expiratory volume in 1 s [FEV1] = 50.6% predicted value, SD = 18.6%; data from 41 patients) fulfilled the criteria for sleep apnea (mean apnea-hypopnea index = 32.6 events/h, SD = 19.9) and 45 patients (mean age = 69 years, SD = 8; 87% men; mean FEV1 predicted value 44.6%, SD = 15%) did not (mean apnea-hypopnea index = 5.5 events/h, SD = 3.8). None of the patients' characteristics (including demographic, anthropometric, and physiologic measures) predicted the diagnosis of sleep apnea according to PSG results.
The diagnosis of sleep apnea in patients with moderate to severe COPD cannot rely on nocturnal oximetry alone, even when typical cyclical changes in saturation are seen on oximetry tracing. When suspecting an overlap syndrome, a full-night, in-laboratory PSG should be obtained.
慢性阻塞性肺疾病（COPD）和睡眠呼吸暂停是常见的病症，且常同时存在。对睡眠呼吸暂停的正确诊断可能会影响 COPD 患者的管理和预后。
确定家庭夜间血氧饱和度测定在中重度 COPD 患者中用于鉴别单纯 COPD 所致夜间低氧血症与睡眠呼吸暂停所致夜间低氧血症的准确性，这些患者有明显的夜间低氧血症且伴有饱和度的周期性变化。
本研究比较了中重度 COPD 患者的家庭夜间血氧饱和度测定和实验室多导睡眠图（PSG），这些患者正在考虑进行夜间氧疗试验。所有患者均有明显的夜间低氧血症（定义为 30%以上的记录时间经皮动脉血氧饱和度＜90%），且饱和度呈周期性变化，提示睡眠呼吸暂停。
90 例患者进行了 PSG 检查；45 例患者（平均年龄 68 岁，标准差 8；71%为男性；平均 1 秒用力呼气量占预计值的百分比[FEV1]为 50.6%，标准差 18.6%；41 例患者的数据）符合睡眠呼吸暂停标准（平均呼吸暂停低通气指数[AHI]为 32.6 次/小时，标准差 19.9），45 例患者（平均年龄 69 岁，标准差 8；87%为男性；平均 FEV1 预测值 44.6%，标准差 15%）不符合（平均 AHI 为 5.5 次/小时，标准差 3.8）。PSG 结果显示，患者的特征（包括人口统计学、人体测量学和生理学指标）均不能预测睡眠呼吸暂停的诊断。
即使在血氧饱和度监测图上出现典型的饱和度周期性变化，中重度 COPD 患者的睡眠呼吸暂停诊断也不能仅依靠夜间血氧饱和度测定。当怀疑重叠综合征时，应进行整夜的实验室 PSG 检查。
