低潮气量和呼气末正压在肝肺综合征患者肝移植期的临床应用

Low tidal volume and end-expiratory positive pressure in liver transplantation for patients with hepato-pulmonary syndrome

目的:终末期肝硬化患者肝病晚期常合并肝肺综合征,伴随低氧血症出现,在肝移植期间进行针对性的通气治疗和管理,对于降低肝移植期的肺部并发症,甚至降低死亡率具有重要的临床意义。文章综合分析低潮气量和低呼期末正压通气对肝移植期间呼吸治疗的作用及其愈后。资料来源:应用计算机检索1970-01/2007-07MEDLINE及万方数据库有关肝移植期间呼吸治疗方面的文献。中文检索词包括"肝移植,肝肺综合征,潮气量,正压呼吸";英文检索词有"liver transplantation,hepato-pulmonary zsyndrome,Tidal ventilation,end-expiratory positive pressure mechanical ventilation"。包括临床研究(不限观察对象的年龄、性别、种族)和基础研究,不限体内或体外研究。资料选择:共收集到1310篇文献,阅读全部文章的文题和大部分文章的摘要,选择肝肺综合征病理改变和通气治疗方面的文献。排除重复性研究和Meta分析类文章。资料提炼:共得到符合纳入条件的文献159篇,排除1141篇。选择其中27篇英文文献及4篇中文文献进行分析。资料综合:①肝肺综合征发病机制错综复杂,术中血流动力学变化及新肝期内毒素、炎性介质、内环境改变等均易发生顽固性低氧血症,甚至出现通透性肺水肿,导致呼吸和心功能衰竭。这些变化是多因素共同作用的结果,在众多发病机制中,肺不张、门肺分流、通气减少或灌流增加均可使通气/灌流比值降低,是导致低氧血症的重要原因。②目前关于肝肺综合征主要是药物处理文献较多,但呼吸治疗报道尚未见到。③根据临床表现术前动脉血氧分压<60mmHg(1mmHg=0.133kPa),动脉二氧化碳分压在正常范围,以及新肝期供肝炎性介质释放,类似于急性呼吸窘迫综合征,因此临床处理均采用呼吸治疗,小潮气量和呼气末正压治疗效果及预后较好。结论:肝肺综合征患者肝移值围手术期应用小潮气量和呼气末正压机械治疗,可降低术后肺部并发症和重症监护时间。

OBJECTIVE： Patients with terminal stage cirrhosis are always combined with hepato-pulmonary syndrome and hypoxemia. Venting treatment and management in liver transplantation is significant for decreasing lung complication, even death rate. This article is aimed to analyze the effects of a low tidal volume and PEEP on respiratory therapy in liver transplantation and its prognosis. DATA SOURCES： The Medline and Wanfang Database were searched for relevant articles on respiratory therapy of liver transplantation published from January 1970 to July 2007 with the key words of ＂liver transplantation,hepato-pulmonary syndrome,Tidal ventilation,end-expiratory positive pressure mechanical ventilation＂ in English and Chinese, including clinical research （no matter age, sex or race） and basis research, no matter in vitro or ex vivo. STUDY SELECTION： Totally 1 310 articles were selected. Headline and most abstracts of articles were checked. Articles on pathological changes of hepato-pulmonary syndrome and tidal ventilation were collected, and articles of repetitive research and Meta analysis were excluded. DATA EXTRACTION： Totally 159 articles met the criteria were included and 1 141 were excluded. Twenty-seven English and four Chinese articles were collected. DATA SYNTHESIS： ① Pathogenesy of hepato-pulmonary syndrome is complicated. Change of intraoperative hemodynamics, endotoxin, inflammatory mediator and change of internal environment after neohepatic period can result in refractoriness hypoxemia, even permeability lung edema, which will lead to respiratory and heart function failure. The course of the disease is typically progressive. Pulmonary atelectasis, pulmonary shunt, decreased venting or increased perfusion will reduce the ratio of venting to perfusion, which is the key reason of hypoxemia. ②At present, there are many literatures on drug treatment for hepato-pulmonary syndrome, but no reports on respiratory therapy appear.③ Preoperative pressure of oxygen in arterial blood （PaO2） was below 60 mm Hg（1 mm Hg=0.133 kPa）, partial pressure of carbon dioxide in artery was normal, as well as release of inflammatory mediator after neohepatic period. These are similar to those of acute respiratory distress syndrome （ARDS）. Thus, respirator therapy was performed in clinic. Therapeutic efficacy of a low tidal volume and end-expiratory positive pressure（PEEP）and prognosis were well. CONCLUSION： A low tidal volume and PEEP for liver transplantation during the peri-operative period can decrease the postoperative lung complication and timing of intensive care in patients with hepato-pulmonary syndrome.