外源性呼气末正压对气道压力的影响

目的探讨外源性呼气末正压（PEEP）对气过压力影响的规律。方法通过模拟肺（静态顺应性为28ml／cmH2O,气道阻力为0．8cmH2O·L－1·S-1）试验，设置不同的PEEP，观察气道压力（修压、平均压、平台压）的变化。结果外源性PEEP从0增加至3cmH2O时，气过压力增幅最大，平均每增加1cmH2OPEEP，气道峰压、平台压增加3．5～4．1cmH2O,当PEEP增加至12cmH2O时，气道峰压和平台压增加了20cmH2O以上。结论外源性PEEP对气造压力的影响，可产生一种“扩大”效应，这种“扩大”效应在低水平的PEEP时尤为显著。在使用人工机械通气时，如需设置外源性PEEP时，必须严密监测气道压力的变化，以防止肺损伤。

The effects of positive end- expiratory pressure in airway pressure with a lung model

Objective To study the effects of positive ent -expiratory pressure (PEEP) in airway pressure with a lung model .Methods The chagnes of ariway pressure which included peak pressure (PpK), mean pressure (Pme ), plateau pressure (Ppl) were recorded while veriable PEEPs were set with a lung model (compliance : 28 ml/cmH2O, resistance : 0.8 ml/cmH2O. L-1. S-1 ). Results There was a biggest increment in ariway pressure while PEEP from zero to 3 cmH2O per raise one cmH2Oof PEEP. When PEEP raised to 12 cmH2O Ppk and Ppl increased more than 20 cmH2O. Conclusion Amplifier efeect might occur in airway pressure when PEEP wae applied ,and this amplifier effect was obvious in olw lwvel of PEEP. In order to prevent lung injury ,the change of airway pressure must be put under close monitor as PEEP was set in a mechanical ventilation .