Objective: To access the effect on alveolar recruitment of positive endexpiratory pressure (PEEP) and to investigate lung recruited volume directing PEEPin acute respiratory distress syndrome(ARDS).

• 目的：评价呼气末正压(PEEP)对急性呼吸窘迫综合征(ARDS)肺复张容积的影响，探讨ARDS患者测定肺复张容积对选择PEEP的指导意义。