Sanatorio Anchorena San Martín, Buenos Aires, Argentina; and Hospital Carlos G Durand, Ciudad Autónoma de Buenos Aires, Argentina.
Sanatorio Anchorena San Martín, Buenos Aires, Argentina.
Respir Care. 2023 Nov;68(11):1483-1492. doi: 10.4187/respcare.10802. Epub 2023 Jul 18.
The precision of quasi-static airway driving pressure (ΔP) assessed in pressure support ventilation (PSV) as a surrogate of tidal lung stress is debatable because persistent muscular activity frequently alters the readability of end-inspiratory holds. In this study, we used strict criteria to discard excessive muscular activity during holds and assessed the accuracy of ΔP in predicting global lung stress in PSV. Additionally, we explored whether the physiological effects of high PEEP differed according to the response of respiratory system compliance (C).
Adults with ARDS undergoing PSV were enrolled. An esophageal catheter was inserted to calculate lung stress through transpulmonary driving pressure (ΔP). ΔP and ΔP were assessed in PSV at PEEP 5, 10, and 15 cm HO by end-inspiratory holds. C was calculated as tidal volume (V)/ΔP. We analyzed the effects of high PEEP on pressure-time product per minute (PTP), airway pressure at 100 ms (P), and V over PTP per breath (V/PTP) in subjects with increased versus decreased C at high PEEP.
Eighteen subjects and 162 end-inspiratory holds were analyzed; 51/162 (31.5%) of the holds had ΔP ≥ 12 cm HO. Significant association between ΔP and ΔP was found at all PEEP levels ( < .001). ΔP had excellent precision to predict ΔP, with 15 cm HO being identified as the best threshold for detecting ΔP ≥ 12 cm HO (area under the receiver operating characteristics 0.99 [95% CI 0.98-1.00]). C changes from low to high PEEP corresponded well with lung compliance changes (R 0.91, < .001) When C increased, a significant improvement of PTP and V/PTP was found, without changes in P. No benefits were observed when C decreased.
In subjects with ARDS undergoing PSV, high ΔP assessed by readable end-inspiratory holds accurately detected potentially dangerous thresholds of ΔP. Using ΔP to assess changes in C induced by PEEP during assisted ventilation may inform whether higher PEEP could be beneficial.
在压力支持通气（PSV）中，通过测量准静态气道驱动压（ΔP）来评估潮气量肺应力的精确度存在争议，因为持续的肌肉活动经常会影响吸气末暂停的可读性。在这项研究中，我们使用严格的标准来排除吸气末暂停期间的过度肌肉活动，并评估 ΔP 预测 PSV 中整体肺应力的准确性。此外，我们还探讨了高呼气末正压（PEEP）是否会根据呼吸系统顺应性（C）的反应而产生不同的生理效应。
纳入接受 PSV 的 ARDS 成人患者。插入食管导管以通过跨肺驱动压（ΔP）计算肺应力。在 PEEP 为 5、10 和 15 cmH2O 时，通过吸气末暂停评估 PSV 中的 ΔP 和 ΔP。C 计算为潮气量（V）/ΔP。我们分析了在高 PEEP 下，顺应性增加和降低的患者中，每分钟压力时间乘积（PTP）、100 ms 时的气道压力（P）和每呼吸 PTP 的通气量（V/PTP）的高 PEEP 对其的影响。
分析了 18 名患者和 162 次吸气末暂停，其中 51/162（31.5%）次暂停的 ΔP≥12 cmHO。在所有 PEEP 水平下，ΔP 与 ΔP 之间均存在显著相关性（<0.001）。ΔP 可极好地精确预测 ΔP，15 cmH2O 被确定为检测 ΔP≥12 cmHO 的最佳阈值（受试者工作特征曲线下面积 0.99[95%CI 0.98-1.00]）。当 C 从低值变为高值时，与肺顺应性的变化很好地对应（R 0.91，<0.001）。当 C 增加时，PTP 和 V/PTP 显著改善，而 P 没有变化。当 C 降低时，没有观察到益处。
在接受 PSV 的 ARDS 患者中，通过可读的吸气末暂停评估的高 ΔP 可以准确检测到潜在危险的 ΔP 阈值。在辅助通气期间，使用 ΔP 评估 PEEP 引起的 C 变化可能有助于确定是否可以从更高的 PEEP 中获益。
