Baedorf Kassis Elias, Loring Stephen H, Talmor Daniel
Division of Pulmonary and Critical Care, Beth Israel Deaconess Medical Center and Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
Ann Transl Med. 2018 Oct;6(19):390. doi: 10.21037/atm.2018.06.35.
Ventilator management of patients with acute respiratory distress syndrome (ARDS) has been characterized by implementation of basic physiology principles by minimizing harmful distending pressures and preventing lung derecruitment. Such strategies have led to significant improvements in outcomes. Positive end expiratory pressure (PEEP) is an important part of a lung protective strategy but there is no standardized method to set PEEP level. With widely varying types of lung injury, body habitus and pulmonary mechanics, the use of esophageal manometry has become important for personalization and optimization of mechanical ventilation in patients with ARDS. Esophageal manometry estimates pleural pressures, and can be used to differentiate the chest wall and lung (transpulmonary) contributions to the total respiratory system mechanics. Elevated pleural pressures may result in negative transpulmonary pressures at end expiration, leading to lung collapse. Measuring the esophageal pressures and adjusting PEEP to make transpulmonary pressures positive can decrease atelectasis, derecruitment of lung, and cyclical opening and closing of airways and alveoli, thus optimizing lung mechanics and oxygenation. Although there is some spatial and positional artifact, esophageal pressures in numerous animal and human studies in healthy, obese and critically ill patients appear to be a good estimate for the "effective" pleural pressure. Multiple studies have illustrated the benefit of using esophageal pressures to titrate PEEP in patients with obesity and with ARDS. Esophageal pressure monitoring provides a window into the unique physiology of a patient and helps improve clinical decision making at the bedside.
急性呼吸窘迫综合征(ARDS)患者的呼吸机管理一直以实施基本生理原则为特征,即尽量减少有害的扩张压力并防止肺萎陷。这些策略已使治疗结果有了显著改善。呼气末正压(PEEP)是肺保护策略的重要组成部分,但尚无标准化的方法来设定PEEP水平。由于肺损伤类型、体型和肺力学差异很大,食管测压对于ARDS患者机械通气的个性化和优化变得很重要。食管测压可估算胸膜压力,并可用于区分胸壁和肺(跨肺)对整个呼吸系统力学的影响。胸膜压力升高可能导致呼气末跨肺压力为负,从而导致肺塌陷。测量食管压力并调整PEEP以使跨肺压力为正,可以减少肺不张、肺萎陷以及气道和肺泡的周期性开闭,从而优化肺力学和氧合。尽管存在一些空间和位置伪影,但在健康、肥胖和重症患者中进行的大量动物和人体研究表明,食管压力似乎是对“有效”胸膜压力的良好估计。多项研究表明,在肥胖患者和ARDS患者中使用食管压力来滴定PEEP有益。食管压力监测为了解患者独特的生理学提供了一个窗口,并有助于改善床边的临床决策。