Positive end-expiratory pressure (PEEP) is a cornerstone treatment for critically ill patients, with beneficial effects for acute respiratory distress syndrome (ARDS). In ARDS, PEEP prevents alveolar collapse during expiration and counteracts increased surface tension due to surfactant impairment, alveolar over-deflation, and superimposed pressure. These mechanisms contribute to a reduction in intrapulmonary shunting. Furthermore, alveolar recruitment maintained through PEEP may translate into a higher end-expiratory lung volume (EELV), which often leads to better compliance of the respiratory system (CRS) and therefore a reduction in the driving pressure (DP), both of which are associated with higher survival rates [1]. Moreover, alveolar stability protects against intra-tidal recruitment/derecruitment (i.e., atelectrauma) [2] and imposed mechanical stresses and inflammation (i.e., biotrauma) [3], and it reduces ventilation heterogeneity [4]. Advantages of PEEP should be balanced against its potential disadvantages, namely, a reduction in cardiac output, an increase in pulmonary vascular resistance and alveolar dead space, and the risk of regional over-inflation [5].

中文翻译：

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我如何设置呼气末正压：基于证据和生理学！

呼气末正压 (PEEP) 是危重患者的基石治疗方法，对急性呼吸窘迫综合征 (ARDS) 具有有益效果。在 ARDS 中，PEEP 可防止呼气期间肺泡塌陷，并抵消由于表面活性剂受损、肺泡过度放气和叠加压力而增加的表面张力。这些机制有助于减少肺内分流。此外，通过 PEEP 维持的肺泡复张可能会转化为更高的呼气末肺容积 (EELV)，这通常会导致呼吸系统 (CRS) 的顺应性更好，从而降低驱动压 (DP)，两者都是与更高的存活率相关[1]。此外，肺泡稳定性可防止潮内招募/停止招募（即，外伤）[2] 并施加机械应力和炎症（即生物创伤）[3]，它减少了通气异质性 [4]。PEEP 的优点应与其潜在缺点相平衡，即心输出量减少、肺血管阻力和肺泡死腔增加以及局部过度充气的风险 [5]。