Magnan A, Philip-Joet F, Rey M, Reynaud M, Porri F, Arnaud A
Service de Pneumologie, CHU Nord, Marseilles, France.
Chest. 1993 Jan;103(1):129-31. doi: 10.1378/chest.103.1.129.
The diagnosis of sleep apnea syndrome (SAS) requires expensive and complex instrumentation. The purpose of the present study was to determine the value of end-tidal CO2 (EtCO2) in screening for sleep apneas. Thirty-nine patients referred to our sleep laboratory because of suspected SAS and ten normal subjects were studied. The EtCO2 was measured using an infrared spectrometer (POET) designed for simultaneous measurement of CO2 and pulse oximetry. In 29 subjects, expired gas was sampled with a nasobuccal mask (Respiron) with lateral orifices. In the other 20 subjects, sampling was done with nasobuccal prongs (Criticare) comprising a four-channel plastic tube to the mouth and the nostrils. Data from an 8-h night were transferred the following day to a microcomputer (Apple Macintosh) for processing. Apnea was defined as an absence of detection of CO2 for more than 10 s. Conventional polysomnography was performed (Respisomnographe). The number of apneas in 8 h and the apnea index (number of apneas in 1 h) were calculated after visual analysis on the screen of the polysomnograph and also with EtCO2 analysis. For recordings made with a nasobuccal mask, the regression curve between the apnea indices computed with EtCO2 and polysomnography was an order 2 polynomial curve (r = 0.76; p < 0.001), with an inflection point at 39 apneas per hour. For recordings with nasobuccal prongs, the correlation was very significant (r = 0.95; p < 0.0001), and the regression curve was linear. The EtCO2 with nasobuccal prongs appears to be a simple and reliable method for screening for SAS.
睡眠呼吸暂停综合征（SAS）的诊断需要昂贵且复杂的仪器设备。本研究的目的是确定呼气末二氧化碳（EtCO2）在筛查睡眠呼吸暂停中的价值。对39名因疑似SAS转诊至我们睡眠实验室的患者和10名正常受试者进行了研究。使用设计用于同时测量二氧化碳和脉搏血氧饱和度的红外光谱仪（POET）测量EtCO2。在29名受试者中，使用带有侧孔的口鼻面罩（Respiron）采集呼出气体。在另外20名受试者中，使用由一根通向口腔和鼻孔的四通道塑料管组成的口鼻插管（Criticare）进行采样。8小时夜间的数据于次日传输至微型计算机（苹果麦金塔电脑）进行处理。呼吸暂停定义为二氧化碳检测缺失超过10秒。进行了传统的多导睡眠图检查（Respisomnographe）。在多导睡眠图屏幕上进行视觉分析后，计算8小时内的呼吸暂停次数和呼吸暂停指数（每小时呼吸暂停次数），同时也通过EtCO2分析进行计算。对于使用口鼻面罩进行的记录，通过EtCO2和多导睡眠图计算出的呼吸暂停指数之间的回归曲线为二次多项式曲线（r = 0.76；p < 0.001），拐点为每小时39次呼吸暂停。对于使用口鼻插管进行的记录，相关性非常显著（r = 0.95；p < 0.0001），回归曲线为线性。使用口鼻插管的EtCO2似乎是一种简单可靠的SAS筛查方法。
