Respiratory Unit, Hospital Universitario Central de Asturias, Oviedo, Spain.
Sleep Breath. 2020 Dec;24(4):1531-1535. doi: 10.1007/s11325-020-02026-z. Epub 2020 Feb 7.
The collapsibility of the upper airway is a key factor in the pathogenesis of obstructive sleep apnea (OSA). The exact measurement of this parameter, typically performed by obtaining the critical pressure (Pcrit), has not been introduced into clinical practice. The techniques that are used to measure the upper airway resistance could provide information on its the collapsibility of the airway. The aim of this study was to associate resistance in the upper airway with the presence of OSA.
Using a cross-sectional design with a control group, consecutive cases that were seen in the Chest Diseases Sleep Unit were recruited after undergoing nocturnal polysomnography. The upper airway collapsibility was determined based on the change in its resistance from the standing position to the supine position with a flow interruption (Rint) device by measuring the angle formed between the pressure/flow lines (PF angle) between the two positions.
The PF angle was greater in the OSA group than in the controls: 7.5° (4) vs. 4° (2) (P < .001), with a positive correlation between the width of the angle and the apnea-hypopnea index (AHI) (r: 0.28, P = .03). Placing the threshold level at 10°, a sensitivity of 25% was obtained, along with a specificity of 96%, for the diagnosis of OSA.
The measurement of resistance in the upper airway using flow interruption (Rint) can predict the presence of moderate and severe OSA with high specificity but low sensitivity.
上气道的 collapsibility 是阻塞性睡眠呼吸暂停（OSA）发病机制的关键因素。该参数的精确测量（通常通过获得临界压力（Pcrit）来进行）尚未引入临床实践。用于测量上气道阻力的技术可以提供有关气道 collapsibility 的信息。本研究的目的是将上气道阻力与 OSA 的存在联系起来。
采用具有对照组的横断面设计，连续入选在胸部疾病睡眠单元接受夜间多导睡眠图检查的病例。上气道 collapsibility 是通过使用 Rint 设备测量两个位置之间的压力/流量线（PF 角）之间的角度来确定的，该设备在流量中断时测量上气道阻力的变化（Rint）。
OSA 组的 PF 角大于对照组：7.5°（4）比 4°（2）（P < .001），角的宽度与呼吸暂停低通气指数（AHI）呈正相关（r：0.28，P = .03）。将阈值水平设置为 10°，可以以 25%的灵敏度和 96%的特异性诊断 OSA。
使用流量中断（Rint）测量上气道阻力可以高度特异性但低灵敏度地预测中重度 OSA 的存在。
