Xu Mengru, He Huaiwu, Long Yun
State Key Laboratory of Complex Severe and Rare Diseases, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
Front Physiol. 2021 Oct 13;12:748724. doi: 10.3389/fphys.2021.748724. eCollection 2021.
As a portable, radiation-free imaging modality, electrical impedance tomography (EIT) technology has shown promise in the bedside visual assessment of lung perfusion distribution in critically ill patients. The two main methods of EIT for assessing lung perfusion are the pulsatility and conductivity contrast (saline) bolus method. Increasing attention is being paid to the saline bolus EIT method in the evaluation of regional pulmonary perfusion in clinical practice. This study seeks to provide an overview of experimental and clinical studies with the aim of clarifying the progress made in the use of the saline bolus EIT method. Animal studies revealed that the saline bolus EIT method presented good consistency with single-photon emission CT (SPECT) in the evaluation of lung regional perfusion changes in various pathological conditions. Moreover, the saline bolus EIT method has been applied to assess the lung perfusion in a pulmonary embolism and the effect of positive end-expiratory pressure (PEEP) on regional ventilation/perfusion ratio (V/Q) and acute respiratory distress syndrome (ARDS) in several clinical studies. The implementation of saline boluses, data analyses, precision, and cutoff values varied among different studies, and a consensus must be reached regarding the clinical application of the saline bolus EIT method. Further study is required to validate the impact of the described saline bolus EIT method on decision-making, therapeutic management, and outcomes in critically ill patients.
作为一种便携式、无辐射的成像方式，电阻抗断层成像（EIT）技术在危重症患者床边肺部灌注分布的可视化评估中显示出了应用前景。EIT评估肺灌注的两种主要方法是搏动性和电导率对比（盐水）团注法。在临床实践中评估局部肺灌注时，盐水团注EIT法正受到越来越多的关注。本研究旨在对实验和临床研究进行综述，以阐明盐水团注EIT法应用方面取得的进展。动物研究表明，在评估各种病理状态下肺区域灌注变化时，盐水团注EIT法与单光子发射计算机断层扫描（SPECT）具有良好的一致性。此外，在多项临床研究中，盐水团注EIT法已被用于评估肺栓塞中的肺灌注以及呼气末正压（PEEP）对局部通气/灌注比（V/Q）和急性呼吸窘迫综合征（ARDS）的影响。不同研究中盐水团注的实施、数据分析、精度和临界值各不相同，必须就盐水团注EIT法的临床应用达成共识。需要进一步研究来验证所述盐水团注EIT法对危重症患者决策、治疗管理和预后的影响。
