Abstract:

The pathogenesis of obstructive sleep apnea (OSA) has been explained from both anatomic and non-anatomic perspectives. Previous studies have indicated that OSA is most closely associated with anatomic factors related to upper airway obstruction, but its association with non-anatomic factors for upper airway obstruction has been increasingly understood and valued. The non-anatomic parameters for evaluating therapeutic effect include pharyngeal critical closing pressure, arousal threshold, loop gain and dilator muscle dysfunction, namely PALM. Monitoring and analyzing the weight of these four factors in the pathogenesis of OSA may contribute to the guidance of individualized treatment. Loop gain is a method for measuring the gain or sensitivity of negative feedback loop of respiratory control system to estimate the ventilation volume obtained by increasing the driving force of respiration to some extent. Higher loop gain may lead to hypocapnia and inhibition of upper airway respiratory drive, thereby aggravating the severity of OSA. We detailed a method for measuring loop gain and its clinical significance in patients with OSA.

Key words: Sleep apnea, obstructive, Apnea, Continuous positive airway pressure, Loop gain

摘要：

阻塞性睡眠呼吸暂停（OSA）的发病由解剖学因素与非解剖学因素共同参与，以往认为OSA与上气道解剖学相关的阻塞关系最为密切，近年来，非解剖学因素的作用越来越受到研究者重视。OSA治疗效果的非解剖学因素包括咽部临界压、低觉醒阈值、高环路增益（LG）和上气道扩张肌功能异常4个方面，即著名的PALM理论。通过监测分析PALM各项因素在发病中的权重有利于指导个体化治疗。LG即PALM中的"L"，是一种测量呼吸控制系统负反馈回路的增益或灵敏度的方法，旨在计算增加一定的呼吸驱动力能带来多大通气量。高LG可诱发低碳酸血症和抑制上气道呼吸驱动力，从而加重OSA的严重程度。本文详细介绍了OSA中LG的测量方法及其临床意义。

关键词: 睡眠呼吸暂停，阻塞性, 呼吸暂停, 连续气道正压通气, 环路增益