双腔管肺通气时判定选择性单肺通气的声学监测方法

气管内插管最常见的并发症是置入一侧支气管（单肺插管）（OLI）。对此，目前尚无有效的早期监测方法。在本研究中我们探讨使用声学分析的方法来判定单肺插管。11例需要使用双腔气管导管的胸外科手术患者纳入研究。麻醉诱导后及确认双腔气管导管位置正确后，于手术前记录每侧肺的通气数据。使用3个压电扩音器来记录肺呼吸音，其中每侧胸壁各一个，第3个置于右前臂用于记录背景噪音。采集到的声音经过滤后，计算信号的能量包，并将呼吸及其间歇分为小片段。根据单肺能量信号的比率，呼吸被分成以下三类：双侧通气、选择性的右肺通气以及选择性的左肺通气。右肺通气时11例患者中有10例可以通过此项技术确认，在左肺通气时确认率达到100％。研究提示声学监测能有效地监测选择性单肺通气，并可用于早期诊断OLI。

One-lung intubation （OLI） is among the most common complications of endotracheal intubation. None of the monitoring tools now available has proved effective for its early detection. In this study we investigated the efficacy of acoustic analysis for the detection of OLI. We collected lung sounds from 11 patients undergoing thoracic surgery requiring the placement of a double-lumen tube. Recordings of separate lung ventilation were performed after induction and confirmation of adequate tube positioning, before surgery. Samples of lung sounds were collected by three piezoelectric microphones, one on each side of the chest and one on the right forearm, for background noise sampling. The samples were filtered, the signals＇ energy envelopes were calculated, and segmentation to breath and rest periods was performed. Each respiration was classified into one of the three categories： bilateral ventilation, selective right-lung ventilation, or selective left-lung ventilation, on the basis of the ratio between the energy signals of each lung. OLI was accurately identified in 10 of the 11 patients during right OLI and in all 11 patients during left OLI. This study suggests that acoustic monitoring is effective for the detection of selective lung ventilation and may be useful for early diagnosis of OLI.