The optimal strategy for positive end-expiratory pressure (PEEP) titration in the management of severe acute respiratory distress syndrome (ARDS) patients remains unclear. Current guidelines emphasize the importance of a careful risk–benefit assessment for PEEP titration in terms of cardiopulmonary function in these patients. Over the last few decades, the primary goal of PEEP usage has shifted from merely improving oxygenation to emphasizing lung protection, with a growing focus on the individual pattern of lung injury, lung and chest wall mechanics, and the hemodynamic consequences of PEEP. In moderate-to-severe ARDS patients, prone positioning (PP) is recommended as part of a lung protective ventilation strategy to reduce mortality. However, the physiologic changes in respiratory mechanics and hemodynamics during PP may require careful re-assessment of the ventilation strategy, including PEEP. For the most severe ARDS patients with refractory gas exchange impairment, where lung protective ventilation is not possible, veno-venous extracorporeal membrane oxygenation (V-V ECMO) facilitates gas exchange and allows for a “lung rest” strategy using “ultraprotective” ventilation. Consequently, the importance of lung recruitment to improve oxygenation and homogenize ventilation with adequate PEEP may differ in severe ARDS patients treated with V-V ECMO compared to those managed conservatively. This review discusses PEEP management in severe ARDS patients and the implications of management with PP or V-V ECMO with respect to respiratory mechanics and hemodynamic function.

中文翻译：

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重度 ARDS 患者的呼气末正压管理：俯卧位和体外膜肺氧合的影响


在严重急性呼吸窘迫综合征 （ARDS） 患者管理中，呼气末正压 （PEEP） 滴定的最佳策略仍不清楚。目前的指南强调在这些患者的心肺功能方面对 PEEP 滴定进行仔细的风险-获益评估的重要性。在过去的几十年里，PEEP 使用的主要目标已经从单纯改善氧合转变为强调肺保护，越来越关注肺损伤的个体模式、肺和胸壁力学以及 PEEP 的血流动力学后果。对于中度至重度 ARDS 患者，建议将俯卧位通气 （PP） 作为肺保护性通气策略的一部分，以降低死亡率。然而，PP 期间呼吸力学和血流动力学的生理变化可能需要仔细重新评估通气策略，包括 PEEP。对于最严重的难治性气体交换障碍 ARDS 患者，在无法进行肺保护性通气的情况下，静脉-静脉体外膜肺氧合 （V-V ECMO） 可促进气体交换，并允许使用“超保护性”通气的“肺休息”策略。因此，与保守治疗的患者相比，接受 V-V ECMO 治疗的重度 ARDS 患者肺复张对改善氧合和均匀通气以及足够的 PEEP 的重要性可能有所不同。本综述讨论了重度 ARDS 患者的 PEEP 管理，以及 PP 或 V-V ECMO 管理对呼吸力学和血流动力学功能的影响。