肺通气的垂直轴动态不均匀性可能预测撤机失败，而与膈肌功能障碍无关。

Dynamic inhomogeneity of aeration along the vertical axis of the lung may predict weaning failure regardless of diaphragm dysfunction.

机构信息

Department of Pulmonology and Critical Care Medicine, Chosun Universitiy Hospital, Gwangju, Republic of Korea.

Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.

出版信息

J Crit Care. 2021 Oct;65:186-191. doi: 10.1016/j.jcrc.2021.06.010. Epub 2021 Jun 28.

DOI:10.1016/j.jcrc.2021.06.010

PMID:34198210

Abstract

PURPOSE

This study aimed to investigate dynamic changes of lung aeration during a spontaneous breathing trial (SBT) in patients with diaphragm dysfunction (DD) and to predict weaning failure using electrical impedance tomography (EIT).

MATERIALS AND METHODS

We enrolled 40 adult patients who received mechanical ventilation over 48 h and were eligible for SBT with a T-piece. All patients were screened for DD using ultrasonography before SBT. EIT data, including global inhomogeneity index (an off-site parameter), and temporal skew of aeration (TSA) (an on-site parameter) were collected.

RESULTS

Sixteen (40%) patients had DD. During SBT, the tidal impedance variation decreased by 32% from baseline in patients with DD and by 14% in those without DD (p = 0.001). The global inhomogeneity index in the SBT failure group (n = 9) was 0.92 (median), and that of the SBT success group was 0.65 (p = 0.004). The TSA along the vertical axis of the lung was 12.0% and 2.0%, respectively (p = 0.001). With a vertical TSA cutoff of ≥4.35%, SBT failure was predicted with a sensitivity of 88.9% and specificity of 96.9% (area under the curve: 0.955).

CONCLUSION

Dynamic inhomogeneity of aeration along the vertical axis of the lung as assessed using TSA predicts SBT failure regardless of DD.

TRIAL REGISTRATION

This trial was retrospectively registered at cris.nih.go.kr (identifier: KCT003567; release date February 27, 2019).

摘要

目的

本研究旨在通过电阻抗断层成像（EIT）研究膈肌功能障碍（DD）患者在自主呼吸试验（SBT）期间肺通气的动态变化，并预测撤机失败。

材料和方法

我们纳入了 40 名接受机械通气超过 48 小时且符合 T 型管 SBT 条件的成年患者。所有患者在 SBT 前均通过超声检查筛查 DD。收集 EIT 数据，包括全局不均匀指数（场外参数）和通气时间偏斜（TSA）（场内参数）。

结果

16 名（40%）患者存在 DD。在 SBT 期间，DD 患者的潮气量阻抗变化较基线下降 32%，而无 DD 患者则下降 14%（p = 0.001）。SBT 失败组（n = 9）的全局不均匀指数为 0.92（中位数），SBT 成功组为 0.65（p = 0.004）。沿肺垂直轴的 TSA 分别为 12.0%和 2.0%（p = 0.001）。垂直 TSA 截距≥4.35%时，SBT 失败的预测敏感性为 88.9%，特异性为 96.9%（曲线下面积：0.955）。