Alveolar stability under different combinations of positive end-expiratory pressure and tidal volume： alveolar microscopy in isolated injured rat lungs

作     者：LIU Hui Claudius A. Stahl Knut Moeller Matthias Schneider Steven Ganzert ZHAO Zhan-qi TONG Xiao-wen Josef Guttmann 

作者机构：Department of Breast Surgery Tongji Hospital Tongji University School of Medicine Shanghai 200065 China Department of Anesthesiology and Critical Care Medicine University Medical Center Freiburg 79106 Germany Biomedical Engineering Furtwangen University VS-Schwenningen 78056 Germany Woman Health Care Center of Tongji University Shanghai 200065 China 

出 版 物：《Chinese Medical Journal》 (中华医学杂志（英文版）)

年 卷 期：2010年第123卷第4期

页      面：406-411页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 1002[医学-临床医学] 07[理学] 08[工学] 09[农学] 0903[农学-农业资源与环境] 0803[工学-光学工程] 0713[理学-生态学] 

基　　金：the Deutsche Forschungsgemeinschaft (DFG)(GU 561/6-1) 

主　　题：alveolar microscopy alveolar mechanics tidal volume positive end-expiratory pressure 

摘      要：Background High positive end-expiratory pressure （PEEP） and low tidal volume （VT） ventilation is thought to be a protective ventilation strategy. It is hypothesized that the stabilization of collapsible alveoli during expiration contributes to lung protection. However, this hypothesis came from analysis of indirect indices like the analysis of the pressure-volume curve of the lung. The purpose of this study was to investigate isolated healthy and injured rat lungs by means of alveolar microscopy, in which combination of PEEP and VT is beneficial with respect to alveolar stability （I-E%）. Methods Alveolar stability was investigated in isolated, non-perfused mechanically ventilated rat lungs. Injured lungs were compared with normal lungs. For both groups three PEEP settings （5, 10, 20 cmH20） were combined with three VT settings （6, 10, 15 ml/kg） resulting in nine PEEP-VT combinations per group. Analysis was performed by alveolar microscopy. Results In normal lungs alveolar stability persisted in all PEEP-VT combinations （I-E% （3.2±11.0）%）. There was no significant difference using different settings （P 〉0.01）. In contrast, alveoli in injured lungs were extremely instable at PEEP levels of 5 cmH20 （mean I-E% 100%） and 10 cmH2O （mean I-E% （30.7±16.8）%）; only at a PEEP of 20 cmH20 were alveoli stabilized （mean I-E% of （0.2±9.3）%）. Conclusions In isolated healthy lungs alveolar stability is almost unaffected by different settings of PEEP and VT. In isolated injured lungs only a high PEEP level of 20 cmH2O resulted in stabilized alveoli whereas lower PEEP levels are associated with alveolar instability.