School of Veterinary Medicine, Murdoch University, Perth, Australia.
Systems and Computer Engineering, Carleton University, Ottawa, Canada.
J Vet Intern Med. 2021 Jul;35(4):2035-2044. doi: 10.1111/jvim.16152. Epub 2021 May 11.
Electrical impedance tomography (EIT) generates images of the lungs based on impedance change and was able to detect changes in airflow after histamine challenge in horses.
To confirm that EIT can detect histamine-provoked changes in airflow and subsequent drug-induced bronchodilatation. Novel EIT flow variables were developed and examined for changes in airflow.
Bronchoconstriction was induced using stepwise histamine bronchoprovocation in 17 healthy sedated horses. The EIT variables were recorded at baseline, after saline nebulization (control), at the histamine concentration causing bronchoconstriction (C ) and 2 and 10 minutes after albuterol (salbutamol) administration. Peak global inspiratory (PIF ) and peak expiratory EIT (PEF ) flow, slope of the global expiratory flow-volume curve (FV ), steepest FV over all pixels in the lung field, total impedance change (surrogate for tidal volume; VT ) and intercept on the expiratory FV curve normalized to VT (FV /VT ) were indexed to baseline and analyzed for a difference from the control, at C , 2 and 10 minutes after albuterol. Multiple linear regression explored the explanation of the variance of Δflow, a validated variable to evaluate bronchoconstriction using all EIT variables.
At C , PIF , PEF , and FV significantly increased whereas FV /VT decreased. All variables returned to baseline 10 minutes after albuterol. The VT did not change. Multivariable investigation suggested 51% of Δflow variance was explained by a combination of PIF and PEF .
Changes in airflow during histamine challenge and subsequent albuterol administration could be detected by various EIT flow volume variables.
电阻抗断层成像（EIT）基于阻抗变化生成肺部图像，能够检测马组胺激发后气流的变化。
确认 EIT 可以检测到气流的组胺诱发变化以及随后的药物诱导支气管扩张。开发了新的 EIT 流量变量，并检查了气流变化。
在 17 头镇静马中，使用逐步组胺支气管激发来诱导支气管收缩。在基线、盐水雾化后（对照）、引起支气管收缩的组胺浓度（C ）以及沙丁胺醇（沙丁胺醇）给药后 2 分钟和 10 分钟记录 EIT 变量。吸气末全局峰流量（PIF ）和呼气末 EIT 峰流量（PEF ）、全局呼气流量-容积曲线的斜率（FV ）、肺场中所有像素的最陡 FV 、总阻抗变化（替代潮气量；VT ）和呼气 FV 曲线中归一化到 VT 的截距（FV /VT ）与基线相比进行索引，并分析与对照、C 、沙丁胺醇给药后 2 分钟和 10 分钟的差异。多元线性回归探索了使用所有 EIT 变量评估支气管收缩的验证变量Δflow 的方差解释。
在 C 时，PIF 、PEF 和 FV 显著增加，而 FV /VT 降低。沙丁胺醇给药后 10 分钟，所有变量均恢复至基线。VT 没有变化。多变量研究表明，Δflow 的方差有 51%可以用 PIF 和 PEF 的组合来解释。
组胺激发期间和随后沙丁胺醇给药后的气流变化可以通过各种 EIT 流量体积变量来检测。
