Shono Atsuko, Kotani Toru
1Department of Anesthesiology, Shimane University, 89-1 Enya-cho, Izumo City, Shimane 693-8501 Japan.
2Department of Intensive Care Medicine, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8666 Japan.
J Intensive Care. 2019 Jan 18;7:4. doi: 10.1186/s40560-019-0358-4. eCollection 2019.
Mechanical ventilation can initiate ventilator-associated lung injury (VALI) and contribute to the development of multiple organ dysfunction. Although a lung protective strategy limiting both tidal volume and plateau pressure reduces VALI, uneven intrapulmonary gas distribution is still capable of increasing regional stress and strain, especially in non-homogeneous lungs, such as during acute respiratory distress syndrome. Real-time monitoring of regional ventilation may prevent inhomogeneous ventilation, leading to a reduction in VALI. Electrical impedance tomography (EIT) is a technique performed at the patient's bedside. It is noninvasive and radiation-free and provides dynamic tidal images of gas distribution. Studies have reported that EIT provides useful information both in animal and clinical studies during mechanical ventilation. EIT has been shown to be useful during lung recruitment, titration of positive end-expiratory pressure, lung volume estimation, and evaluation of homogeneity of gas distribution in a single EIT measure or in combination with multiple EIT measures. EIT-guided mechanical ventilation preserved the alveolar architecture and maintained oxygenation and lung mechanics better than low-tidal volume ventilation in animal models. However, careful assessment is required for data analysis owing to the limited understanding of the results of EIT interpretation. Previous studies indicate monitoring regional ventilation by EIT is feasible in the intensive care setting and has potential to lead to lung protective ventilation. Further clinical studies are warranted to evaluate whether monitoring of regional ventilation using EIT can shorten the duration of ventilation or improve mortality in patients with acute respiratory distress syndrome.
机械通气可引发呼吸机相关性肺损伤（VALI），并促使多器官功能障碍的发生。尽管限制潮气量和平台压的肺保护策略可减少VALI，但肺内气体分布不均仍可增加局部应力和应变，尤其是在非均质肺中，如急性呼吸窘迫综合征期间。区域通气的实时监测可能预防通气不均，从而减少VALI。电阻抗断层成像（EIT）是一种在患者床边进行的技术。它无创且无辐射，可提供气体分布的动态潮气量图像。研究报告称，EIT在机械通气期间的动物和临床研究中均能提供有用信息。EIT已被证明在肺复张、呼气末正压滴定、肺容积估计以及通过单次EIT测量或与多次EIT测量相结合来评估气体分布均匀性方面很有用。在动物模型中，EIT引导的机械通气比低潮气量通气能更好地保留肺泡结构，并维持氧合和肺力学。然而，由于对EIT解释结果的理解有限，数据分析需要仔细评估。先前的研究表明，在重症监护环境中通过EIT监测区域通气是可行的，并且有可能实现肺保护性通气。有必要进行进一步的临床研究，以评估使用EIT监测区域通气是否能缩短急性呼吸窘迫综合征患者的通气时间或改善其死亡率。
