Respiratory Institute, Cleveland Clinic, Cleveland, Ohio.
Enterprise Respiratory Therapy, Cleveland Clinic Health System, Cleveland, Ohio.
Respir Care. 2023 Jun;68(6):767-772. doi: 10.4187/respcare.10642.
Analysis of observational data suggests that both a T-piece and zero pressure support ventilation (PSV) and zero PEEP impose work of breathing (WOB) during a spontaneous breathing trial (SBT) similar to what a patient experiences after extubation. The aim of our study was to compare the WOB imposed by the T-piece with zero PSV and zero PEEP. We also compared the difference in WOB when using zero PSV and zero PEEP on 3 different ventilators.
This study was conducted by using a breathing simulator that simulated 3 lung models (ie, normal, moderate ARDS, and COPD). Three ventilators were used and set to zero PSV and zero PEEP. The outcome variable was WOB expressed as mJ/L of tidal volume.
An analysis of variance showed that WOB was statistically different between the T-piece and zero PSV and zero PEEP on all the ventilators (Servo-i, Servo-u, and Carescape R860). The absolute difference was lowest for the Carescape R860, which increased WOB by 5-6%, whereas the highest for Servo-u, which reduced the WOB by 15-21%.
Work may be imposed or reduced during spontaneous breathing on zero PSV and zero PEEP when compared to T-piece. The unpredictable nature of how zero PSV and zero PEEP behaves on different ventilators makes it an imprecise SBT modality in the context of assessing extubation readiness.
分析观察数据表明，在自主呼吸试验（SBT）中，T 型管和零压力支持通气（PSV）以及零呼气末正压（PEEP）都会对呼吸功（WOB）产生影响，这与患者拔管后所经历的情况相似。我们的研究目的是比较 T 型管与零 PSV 和零 PEEP 所产生的 WOB。我们还比较了在 3 种不同呼吸机上使用零 PSV 和零 PEEP 时 WOB 的差异。
本研究使用呼吸模拟器模拟了 3 种肺模型（即正常、中度 ARDS 和 COPD）。使用了 3 种呼吸机，并设置为零 PSV 和零 PEEP。结果变量为以每潮气量毫焦耳（mJ/L）表示的 WOB。
方差分析表明，在所有呼吸机上（Servo-i、Servo-u 和 Carescape R860），T 型管与零 PSV 和零 PEEP 之间的 WOB 存在统计学差异。Carescape R860 的绝对差异最小，增加了 5-6%的 WOB，而 Servo-u 的绝对差异最大，降低了 15-21%的 WOB。
与 T 型管相比，在零 PSV 和零 PEEP 下进行自主呼吸时，可能会产生或减少呼吸功。不同呼吸机上零 PSV 和零 PEEP 的行为方式不可预测，这使得它在评估拔管准备情况方面成为一种不精确的 SBT 方式。
