Department of Critical Care Medicine, Zhejiang Hospital, 12 Lingyin Road, Xihu District, Hangzhou, 310013, Zhejiang, China.
Department of Cardiovascular Medicine, Xinchang People's Hospital, No. 117, Gushan Road, Nanming St, Xinchang, 312500, China.
BMC Pulm Med. 2022 Sep 7;22(1):337. doi: 10.1186/s12890-022-02133-5.
The optimum timing to wean is crucial to avoid negative outcomes for mechanically ventilated patients. The rapid shallow breathing index (RSBI), a widely used weaning index, has limitations in predicting weaning outcomes. By replacing the tidal volume of the RSBI with diaphragmatic excursion (DE) and diaphragm thickening fraction (DTF) assessed by ultrasonography, we calculated two weaning indices, the diaphragmatic excursion rapid shallow breathing index (DE-RSBI, respiratory rate [RR]/DE) and the diaphragm thickening fraction rapid shallow breathing index (DTF-RSBI, RR/DTF). The aim of this study was to evaluate the predictive values of DTF-RSBI, DE-RSBI and traditional RSBI in weaning failure.
This prospective observational study included patients undergoing mechanical ventilation (MV) for > 48 h and who were readied for weaning. During a pressure support ventilation (PSV) spontaneous breathing trial (SBT), right hemidiaphragmatic excursion and DTF were measured by bedside ultrasonography as well as RSBI. Weaning failure was defined as: (1) failing the SBT and (2) SBT success but inability to maintain spontaneous breathing for more than 48 h without noninvasive or invasive ventilation. A receiver operator characteristic (ROC) curve was used for analyzing the diagnostic accuracy of RSBI, DE-RSBI, and DTF-RSBI.
Of the 110 patients studied, 37 patients (33.6%) failed weaning. The area under the ROC (AUROC) curves for RSBI, DE-RSBI, and DTF-RSBI for predicting failed weaning were 0.639, 0.813, and 0.859, respectively. The AUROC curves for DE-RSBI and DTF-RSBI were significantly higher than for RSBI (P = 0.004 and P < 0.001, respectively). The best cut-off values for predicting failed weaning were RSBI > 51.2 breaths/min/L, DE-RSBI > 1.38 breaths/min/mm, and DTF-RSBI > 78.1 breaths/min/%.
In this study, two weaning indices determined by bedside ultrasonography, the DE-RSBI (RR/DE) and DTF-RSBI (RR/DTF), were shown to be more accurate than the traditional RSBI (RR/VT) in predicting weaning outcome during a PSV SBT.
机械通气患者的最佳撤机时机对于避免不良结局至关重要。快速浅呼吸指数（RSBI）是一种广泛应用的撤机指数，但它在预测撤机结局方面存在局限性。通过用超声评估的膈肌位移（DE）和膈肌增厚分数（DTF）替代 RSBI 的潮气量，我们计算了两个撤机指数，即膈肌位移快速浅呼吸指数（DE-RSBI，呼吸频率[RR]/DE）和膈肌增厚分数快速浅呼吸指数（DTF-RSBI，RR/DTF）。本研究旨在评估 DTF-RSBI、DE-RSBI 和传统 RSBI 在撤机失败中的预测价值。
这是一项前瞻性观察研究，纳入了接受机械通气（MV）超过 48 小时且准备撤机的患者。在压力支持通气（PSV）自主呼吸试验（SBT）期间，通过床旁超声测量右膈肌位移和 DTF 以及 RSBI。撤机失败定义为：（1）SBT 失败，（2）SBT 成功但不能在没有无创或有创通气的情况下维持自主呼吸超过 48 小时。使用受试者工作特征（ROC）曲线分析 RSBI、DE-RSBI 和 DTF-RSBI 的诊断准确性。
在 110 例研究患者中，37 例（33.6%）撤机失败。RSBI、DE-RSBI 和 DTF-RSBI 预测撤机失败的 ROC 曲线下面积（AUROC）分别为 0.639、0.813 和 0.859。DE-RSBI 和 DTF-RSBI 的 AUROC 曲线显著高于 RSBI（P=0.004 和 P<0.001）。预测撤机失败的最佳截断值分别为 RSBI>51.2 次/分钟/L、DE-RSBI>1.38 次/分钟/mm 和 DTF-RSBI>78.1 次/分钟/%。
在这项研究中，两种通过床旁超声确定的撤机指数，即 DE-RSBI（RR/DE）和 DTF-RSBI（RR/DTF），在预测 PSV SBT 中的撤机结局方面比传统的 RSBI（RR/VT）更准确。
