脑损伤气管切开术后误吸的上气道压力重塑及其生物流体力学机制研究

The high incidence of aspiration among acquired brain damage patients after tracheostomy resulted in a number of issues, such as difficult decannulation,swollowing disorder,aspiration pneumonia and even death. However, mechanisms and measures to prevent this complication are still in exploration. A preliminary study carried out by our team showed that patients wearing a Passy-Muir Speaking Valve (PMV) swallowed more fluently and the incidence of aspiration was reduced. It is assumed that the change in fluid dynamics in the upper airway after tracheostomy will exert a direct impact on the pressure distribution in the pharyngeal cavity during swallowing. Based on previous results, a biological fluid mechanism in the upper airways of patients after tracheostomy and its relationship with the incidence of aspiration will be investigated through experimental and numerical approaches. The high-resolution manometry will be used to experimentally gauge the swallowing function and the change in pressure in the pharyngeal cavity, without and with wearing a PMV. Moreover, based on the 320-row dynamic volume CT data, 3-d models ofthe upper airway and the region from pharyngeal cavity to upper esophageal sphincter (UES) during swallowing will be constructed to investigate numerically the changes in fluid dynamics using computational fluid dynamics (CFD) techniques, without and with wearing a PMV. The objective of this project is to investigate the effect of the pressure restoration of the upper air system with a PMV on the swallowing function in the region from pharyngeal cavity to upper esophageal sphincter (UES) in the view of the biological fluid mechanism. The long benefit of this project will provide theoretical bases for further exploring the coordination mechanism between respiratory and swallowing.

气管切开术后误吸发生率高，是导致拔管困难、吞咽障碍、吸入性肺炎及死亡的主要原因，其防治方法和机制仍在探索中。我们的前期研究发现佩戴吞咽说话瓣膜可以改善吞咽协调性，减少误吸。我们假设气切术后上气道生物流体力学的变化可能参与并直接影响吞咽时咽-食管段咽腔压力。在此基础上本项目将采用高分辨率咽腔压力测定技术，检测吞咽说话瓣膜干预前后，咽-食管段压力值的动态变化；通过320 排CT动态容积扫描技术，在上气道与咽-食管段3D解剖结构重建的基础上，利用计算流体动力学分析，基于咽-食管段压力实测值与数值模拟值的比较，分析脑损伤气管切开患者上气道流体动力学的变化特征，及其与误吸的相关性。本研究旨在从生物流体力学的角度，探讨脑损伤气管切开手术后患者，吞咽说话瓣膜重塑上气道压力对咽-食管段吞咽功能的影响及其干预机制，为进一步研究吞咽障碍患者完整的呼吸与吞咽协调机制奠定理论基础。

吞咽障碍是临床常见症状，涉及多个学科。我们创新性地采用Passy-Muir吞咽说话瓣膜治疗脑损伤后气管切开引起的吞咽障碍，疗效确切，在临床已广泛推广应用。但其机制尚不清楚。.本研究以脑损伤气管切开术后伴有吞咽障碍的患者为研究对象，采用咽腔测压检查、吞咽造影检查、上气道计算流体力学方法，探讨Passy-Muir吞咽说话瓣膜（Passy-Muir speaking valve，PMV）干预对脑损伤气管切开患者吞咽功能和上气道流体力学特征的影响，初步探索吞咽和呼吸的关系。.结果表明，脑损伤气管切开患者上气道狭窄/阻塞发生率约为67%。与健康受试者相比，脑损伤气管切开术后患者咽部收缩压力峰值、UES松弛后压力峰值、UES静息压降低，UES松弛残余压增高，UES开放持续时间缩短，舌骨向前位移减小，UES开放幅度减小。PMV干预两周后咽部收缩压力峰值、UES松弛后压力峰值明显增高，UES松弛残余压明显降低，UES开放持续时间明显延长。在吞咽过程中，健康受试者声门下压力约98Pa，气切患者声门下压力约18Pa。.该研究表明，PMV干预能够有效改善获得性脑损伤气管切开术后患者的咽部收缩压力峰值、UES松弛后压力峰值、UES松弛残余压、UES开放持续时间。初步探索了吞咽和呼吸之间的关系，为Passy-Muir吞咽说话瓣膜这一治疗方法的临床应用提供了有力的循证医学证据。