正压机械通气的优点是没有疑问的。但由此引起的,特别在严重弥漫性肺损伤的病人容易发生的严重合并症值得注意。在肺顺应性降低时需要使用高的吸气压力,而严重缺氧时又常常要用呼气终末正压通气(PEEP),漏气和心排血量降低是最常见的并发症。此外,压力异常可使呼吸道内透明膜形成而加速肺损伤。这些很难通过试验来证明, The advantages of positive pressure mechanical ventilation are beyond doubt. However, the serious comorbidities that are likely to occur especially in patients with severe diffuse lung injury are noteworthy. A high suction pressure is required when lung compliance decreases, while PEEP is often used in times of severe hypoxia, and the most common complication is reduced leak and cardiac output. In addition, abnormal pressure can cause the formation of transparent membranes in the respiratory tract to accelerate lung injury. These are hard to prove through experiments,