Yang Yingying, He Huaiwu, Long Yun, Chi Yi, Yuan Siyi, Shen Zhoutian, Frerichs Inéz, Zhao Zhanqi
State Key Laboratory of Complex Severe and Rare Disease, Department of Critical Care Medicine, Peking Union Medical College, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
Institute for Health Informatics, University of Minnesota, Minneapolis, MN, USA.
J Clin Monit Comput. 2023 Apr;37(2):629-637. doi: 10.1007/s10877-022-00935-w. Epub 2022 Nov 4.
This study aimed to evaluate the routine use of electrical impedance tomography (EIT) to diagnose pneumothorax (PTX) in mechanically ventilated patients in the intensive care unit (ICU).
A retrospective cohort study was conducted including mechanically ventilated supine patients who received EIT examinations. The EIT-based tidal variation was divided into ventral and dorsal regions of interest (ROIs): upper right (UR, ROI1), upper left (UL, ROI2) lower right (LR, ROI3), and lower left (LL, ROI4), and the ventilation defect score (DS) was calculated in each quadrant. Furthermore, horizontal ventral ventilation index (HVVI) was defined as ROI1 / ROI2 in the two ventral quadrants if ROI1 > ROI2, otherwise HVVI = ROI2 / ROI1.
A total of 203 patients were included, 25 of them with confirmed PTX. In the PTX patients, preceding cardiac surgery was the most common cause of PTX. Compared with the patients without PTX, the PTX patients had a higher DS in the ventral quadrants [median and interquartile range (IQR): 1.00 (0.00, 2.00) vs. 0.00 (0.00, 0.00), P < 0.001] respectively, but similar in the dorsal quadrants [median and IQR: 1.00 (0.00, 1.00) vs. 0.00 (0.00, 1.00), P = 0.722]. Moreover, a higher HVVI was found in the PTX group [median and IQR: 2.51 (1.58, 3.52) vs. 1.36 (1.15, 1.77), P < 0.001]. The area under the receiver operating characteristic curve of the HVVI to differentiate PTX from non-PTX was 0.88, with a sensitivity of 70% and a specificity of 90% when the cut-off value was 2.57.
The ventilation defect in the ventral regions and a high HVVI on EIT were observed in mechanically ventilated patients with PTX, which should trigger further diagnostics to confirm it.
本研究旨在评估在重症监护病房（ICU）中对机械通气患者常规使用电阻抗断层扫描（EIT）诊断气胸（PTX）的情况。
进行了一项回顾性队列研究，纳入接受EIT检查的机械通气仰卧位患者。基于EIT的潮气量变化被分为腹侧和背侧感兴趣区域（ROI）：右上（UR，ROI1）、左上（UL，ROI2）、右下（LR，ROI3）和左下（LL，ROI4），并计算每个象限的通气缺陷评分（DS）。此外，水平腹侧通气指数（HVVI）定义为如果ROI1>ROI2，则为两个腹侧象限中ROI1/ROI2，否则HVVI = ROI2/ROI1。
共纳入203例患者，其中25例确诊为PTX。在PTX患者中，心脏手术史是PTX最常见的原因。与无PTX的患者相比，PTX患者腹侧象限的DS更高[中位数和四分位间距（IQR）：1.00（0.00，2.00）对0.00（0.00，0.00），P < 0.001]，而背侧象限相似[中位数和IQR：1.00（0.00，1.00）对0.00（0.00，1.00），P = 0.722]。此外，PTX组的HVVI更高[中位数和IQR：2.51（1.58，3.52）对1.36（1.15，1.77），P < 0.001]。HVVI区分PTX与非PTX的受试者工作特征曲线下面积为0.88，当临界值为2.57时，敏感性为70%，特异性为90%。
在机械通气的PTX患者中观察到腹侧区域的通气缺陷和EIT上的高HVVI，这应引发进一步诊断以确认。
