UNASSIGNED: To determine the ability and efficiency of each monitoring modality in detecting changes in lung function associated with onset of pulmonary edema.
UNASSIGNED: Twenty healthy ewes were anesthetized, positioned in sternal (prone) recumbency and instrumented. Synchronized recordings of EIT, spirometry and VCap were performed for 60 s prior to start of injection, during xylazine injection over 60 s (0-60 s) and continuously for 1 min (60-120 s) after the end of injection. After visual assessment of the recorded mean variables, statistical analysis was performed using a mixed effect model for repeated measures with Bonferroni\'s correction for multiple comparisons, to determine at which breath after start of injection the variable was significantly different from baseline. A significant change over time was defined as an adjusted p < 0.05. All statistics were performed using GraphPad Prism 0.1.0.
UNASSIGNED: Electrical impedance tomography showed significant changes from baseline in all but two variables. These changes were observed simultaneously during xylazine injection at 48 s and were consistent with development of edema in dependent lung (decreased end-expiratory lung impedance, ventilation in centro-ventral and ventral lung region) and shift of ventilation into non-dependent lung (decreased non-dependent silent spaces and increased center of ventilation ventral to dorsal and increased ventilation in centro-dorsal and dorsal lung region). All changes in lung mechanics also occurred during injection, including decreased dynamic respiratory system compliance and increased peak expiratory flow, peak inspiratory pressure and airway resistance at 48, 54 and 60 s, respectively. Changes in VCap variables were delayed with all occurring after completion of the injection.
UNASSIGNED: In this model of pulmonary edema, EIT detected significant and rapid change in all assessed variables of lung function with changes in regional ventilation indicative of pulmonary edema. Volumetric capnography complemented the EIT findings, while respiratory mechanics were not specific to lung edema. Thus, EIT offers the most comprehensive method for pulmonary edema evaluation, including the assessment of ventilation distribution, thereby enhancing diagnostic capabilities.
■确定每种监测方式在检测与肺水肿发作相关的肺功能变化方面的能力和效率。
■20只健康母羊被麻醉,位于胸骨(俯卧)卧位和仪器。EIT的同步记录,在开始注射前进行肺活量测定和VCap60s,在注射赛拉嗪期间超过60s(0-60s),并在注射结束后连续1分钟(60-120s)。在对记录的平均变量进行视觉评估后,使用混合效应模型对重复测量进行统计分析,并使用Bonferroni校正进行多重比较,为了确定在开始注射后的哪一次呼吸,变量与基线有显著差异.随时间的显著变化定义为调整后的p<0.05。使用GraphPadPrism0.1.0进行所有统计。
■电阻抗断层扫描显示,除两个变量外,其他所有变量均有较基线的显着变化。在48s注射赛拉嗪期间同时观察到这些变化,并且与依赖性肺水肿的发展一致(呼气末肺阻抗降低,中央腹侧和腹侧肺区域的通气)和通气向非依赖性肺的转移(减少非依赖性沉默空间,增加腹侧到背侧的通气中心,增加背侧和背侧肺区域的通气)。肺力学的所有变化也发生在注射过程中,包括动态呼吸系统顺应性降低和呼气流量峰值增加,在48、54和60s时的峰值吸气压力和气道阻力,分别。VCap变量的变化都在注射完成后发生延迟。
■在这个肺水肿模型中,EIT检测到所有评估的肺功能变量的显着和快速变化,以及区域通气的变化表明肺水肿。容量二氧化碳图补充了EIT的发现,而呼吸力学不是肺水肿特有的。因此,EIT为肺水肿评估提供了最全面的方法,包括通风分布的评估,提高诊断能力。