Low-volume ventilation causes peripheral airway injury and increased airway resistance in normal rabbits
Low-volume ventilation causes peripheral airway injury and increased airway resistance in normal rabbits
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DOI：
10.1152/japplphysiol.00776.2001
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发表时间：
2002-03-01
影响因子：
3.3
通讯作者：
Milic-Emili, J
中科院分区：
文献类型：
--
作者：
D'Angelo, E;Pecchiari, M;Milic-Emili, J
对10只正常开胸家兔（A组）在生理潮气量（8-12 ml/kg）、零呼气末压（ZEEP）下机械通气（MV）3-4 h，与5只家兔（B组）在2.3 cmH（2）O的PEEP下机械通气3 - 4 h后的肺力学和形态计量学进行了比较。相对于PEEP的初始MV，ZEEP的MV引起准静态弹性（+36%）和气道（Rint; +71%）和粘弹性阻力（+29%）的逐渐增加，粘弹性时间常数没有变化。PEEP恢复后，准静态弹性和粘弹性阻力恢复到对照水平，而Rint保持升高（+22%）。PEEP时，MV对肺力学无影响。A组和B组PEEP气体交换量相同，肺湿干比正常。两组肺泡形态均正常，而只有A组呼吸性和膜性细支气管受损。总之，ZEEP上的MV延长诱导外周气道损伤的组织学证据，同时增加Rint，其在恢复正常呼气末容积后持续存在。这可能是由于ZEEP上外周气道的周期性打开和关闭。
Lung mechanics and morphometry of 10 normal open-chest rabbits (group A), mechanically ventilated (MV) with physiological tidal volumes (8-12 ml/kg), at zero end-expiratory pressure (ZEEP) for 3-4 h, were compared with those of five rabbits (group B) after 3-4 h of MV with a positive end-expiratory pressure (PEEP) of 2.3 cmH(2)O. Relative to initial MV on PEEP, MV on ZEEP caused a progressive increase in quasi-static elastance (+36%) and airway (Rint; +71%) and viscoelastic resistance (+29%), with no change in the viscoelastic time constant. After restoration of PEEP, quasi-static elastance and viscoelastic resistance returned to control levels, whereas Rint remained elevated (+22%). On PEEP, MV had no effect on lung mechanics. Gas exchange on PEEP was equally preserved in groups A and B, and the lung wet-to-dry ratios were normal. Both groups had normal alveolar morphology, whereas only group A had injured respiratory and membranous bronchioles. In conclusion, prolonged MV on ZEEP induces histological evidence of peripheral airway injury with a concurrent increase in Rint, which persists after restoration of normal end-expiratory volumes. This is probably due to cyclic opening and closing of peripheral airways on ZEEP.