Bian Weishuai, Chen Wei, ChaO Yangong, Wang Lan, Li Liming, Guan Jian, Zhen Jie
Department of Critical Care Medicine, Beijing Shijitan Hospital, Affiliated to Capital Medical University Beijing 100038, China.
Department of Critical Care Medicine, The First Affiliated Hospital, Tsinghua University Beijing 100016, China.
Int J Clin Exp Med. 2015 Aug 15;8(8):13954-61. eCollection 2015.
The aim of the present study was to explore a novel insight to determine the positive end expiratory pressure (PEEP) for sustained ventilation after lung recruitment in an acute respiratory distress syndrome (ARDS) model. Continuous infusion of oleic acid was performed to establish a ARDS model. Pressure control ventilation (PCV) was applied for lung recruitment with PEEP of 20 cm H2O. After lung recruitment, maneuver was changed to volume-controlled ventilation and PEEP titration were performed by decreasing PEEP gradually starting from the level of 20 cm H2O. The optimal level of PEEP for sustained ventilation was set as the lowest PEEP until oxygen partial pressure (PaO2) plus carbon dioxide partial pressure (PaCO2) ≥400 mmHg. Hemodynamic and respiratory parameters at basal level, ARDS state and different levels of PEEP around the optimal PEEP were recorded. The defined optimal PEEP was 13.14 ± 1.35 cm H2O. Respiratory parameters including intrapulmonary shunt (Qs/Qt) and arterial oxygen saturation (SaO2) were significantly improved by various levels of PEEP for sustained ventilation after lung recruitment (P<0.05). Static compliance (Cst) and dynamic compliance (Cdyn) were also significantly increased after application of different levels of PEEP ventilation after lung recruitment (P<0.05). There was no significant statistic difference on most hemodynamic parameters (P>0.05) between various levels of PEEP. The application of different PEEP levels around the defined optimal PEEP had an obvious improvement on respiratory mechanics and gas exchange for collapsed lung tissue without influencing the hemodynamics.
本研究的目的是探索一种新的方法，以确定急性呼吸窘迫综合征（ARDS）模型中肺复张后持续通气的呼气末正压（PEEP）。通过持续输注油酸建立ARDS模型。采用压力控制通气（PCV）进行肺复张，PEEP为20 cm H2O。肺复张后，通气模式改为容量控制通气，并从20 cm H2O开始逐渐降低PEEP进行PEEP滴定。将持续通气的最佳PEEP水平设定为氧分压（PaO2）加二氧化碳分压（PaCO2）≥400 mmHg时的最低PEEP。记录基础水平、ARDS状态以及最佳PEEP附近不同PEEP水平时的血流动力学和呼吸参数。确定的最佳PEEP为13.14±1.35 cm H2O。肺复张后持续通气的不同PEEP水平可显著改善包括肺内分流（Qs/Qt）和动脉血氧饱和度（SaO2）在内的呼吸参数（P<0.05）。肺复张后应用不同水平的PEEP通气后，静态顺应性（Cst）和动态顺应性（Cdyn）也显著增加（P<0.05）。不同PEEP水平之间的大多数血流动力学参数无显著统计学差异（P>0.05）。在定义的最佳PEEP附近应用不同的PEEP水平对塌陷肺组织的呼吸力学和气体交换有明显改善，且不影响血流动力学。
