呼气末期正压(PEEP)常用以治疗急性呼吸衰竭,PEEP及吸入氧的张力是影响病人动脉氧张力的两个因素,而PEEP更有效。因大多数急性呼吸疾病为肺容量减低或小的气道及肺泡塌陷,结果为肺内分流。而这一部分未饱和的.血掺合至氧合血中,使全身血氧分压有很大的降低,而致低氧血症。用P丑EP增加肺容量可使塌陷的肺再膨张,因此使灌注的血能良好的进行气体交换,并改进通气与灌注的分 End-expiratory pressure (PEEP) commonly used to treat acute respiratory failure, PEEP and inhaled oxygen tension is the two factors that affect the patient’s arterial oxygen tension, and PEEP more effective. Because most acute respiratory diseases have reduced lung capacity or small airway and alveolar collapse, the result is shunting of the lungs. And this part of the unsaturated blood mixed with oxygenated blood, the partial pressure of systemic oxygen has greatly reduced, resulting in hypoxemia. Increased lung capacity with P-UEP can reshape the collapsed lungs, thus allowing perfusion of blood to perform good gas exchange and improve ventilation and perfusion scores