Hatam N, Goetzenich A, Rossaint R, Karfis I, Bickenbach J, Autschbach R, Marx G, Bruells C S
Clinic for Cardiac, Thoracic and Vascular Surgery, Aachen University hospital RWTH Aachen.
Department of Anesthesiology, Aachen University hospital RWTH Aachen.
Ultraschall Med. 2014 Dec;35(6):540-6. doi: 10.1055/s-0034-1366090. Epub 2014 Mar 19.
Noninvasive pressure support ventilation is intended to relieve the load on respiratory muscles and to prevent exhaustion. This includes continuous positive airway pressure (CPAP) as well as pressure support ventilation (PSV). Speckle tracking echocardiography (STE) allows quantification of tissue deformation by tracing characteristic grayscale patterns, independent of the acquisition angle. The aim of the present study was to assess the applicability of using STE as a way to investigate diaphragm movement using deformation analysis as a parameter for respiratory workload.
Healthy male subjects (n = 13, 27 ± 7 years) were treated while in a seated supine position with the following respirator settings: regular breathing, 5 mbar CPAP, CPAP + 5 / + 10 / + 15 mbar PSV. A 2 - 4 MhZ M5S phased array sector transducer was used on a Vivid E 9 (GE, Horton, Norway) to visualize the diaphragm. The inspiratory peak transverse strain was measured as a parameter of maximal inspiratory muscle workload and compared to the M-mode-based fractional thickening (FT).
Both the FT and the transverse strain increased significantly under CPAP and PSV. The transverse strain correlated well with the FT (r = 0.753; p < 0.001).
The results measured by STE were comparable to the M-mode-based measurements. The capturing of a larger diaphragmatic sample area and movement tracking possibly lead to higher precision compared to one-dimensional M-mode. The use of STE in patients might provide a reproducible, bedside method to analyze the respiratory workload. Due to the larger sampling area, it might prove superior to mere M-mode acquisition.
无创压力支持通气旨在减轻呼吸肌负荷并防止疲劳。这包括持续气道正压通气（CPAP）以及压力支持通气（PSV）。斑点追踪超声心动图（STE）可通过追踪特征性灰度模式来量化组织变形，而不受采集角度的影响。本研究的目的是评估使用STE通过变形分析作为呼吸负荷参数来研究膈肌运动的适用性。
健康男性受试者（n = 13，27±7岁）在仰卧位时接受以下呼吸机设置治疗：正常呼吸、5 mbar CPAP、CPAP + 5 / + 10 / + 15 mbar PSV。在Vivid E 9（GE，霍顿，挪威）上使用2 - 4 MhZ M5S相控阵扇形换能器来可视化膈肌。测量吸气峰值横向应变作为最大吸气肌负荷的参数，并与基于M型的增厚分数（FT）进行比较。
在CPAP和PSV下，FT和横向应变均显著增加。横向应变与FT相关性良好（r = 0.753；p < 0.001）。
STE测量结果与基于M型的测量结果具有可比性。与一维M型相比，捕获更大的膈肌样本区域和运动追踪可能导致更高的精度。在患者中使用STE可能提供一种可重复的床边方法来分析呼吸负荷。由于采样区域更大，它可能比单纯的M型采集更具优势。
