TIDAL VENTILATION AT LOW AIRWAY PRESSURES CAN AUGMENT LUNG INJURY
TIDAL VENTILATION AT LOW AIRWAY PRESSURES CAN AUGMENT LUNG INJURY
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DOI：
10.1164/ajrccm.149.5.8173774
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发表时间：
1994-05-01
影响因子：
24.7
通讯作者：
SLUTSKY, AS
中科院分区：
文献类型：
--
作者：
MUSCEDERE, JG;MULLEN, JBM;SLUTSKY, AS
大潮气量和高峰气道压的间歇正压通气可导致肺气压伤。在本研究中，我们检查了这样一个假设，即在非常低的肺容量下通气也会通过反复打开和关闭气道和肺泡管单位来加重肺损伤，因为通气发生在从吸气压力-容量曲线确定的感染点（P-inf）以下到感染点以上。我们通气隔离，非灌注，灌洗大鼠肺与生理潮气量（5至6毫升/公斤）在不同的呼气末压力（高于和低于P-inf），并研究了顺应性和肺损伤的影响。在低于P-inf的呼气末正压（PEEP）通气组中，通气后顺应性显著下降。无论是对照组还是PEEP高于P-inf的通气组，肺损伤的形态学评估均无变化。PEEP低于P-inf的通气组肺损伤明显更大，在这些组中，损伤的部位取决于PEEP的水平。无PEEP通气组的呼吸道损伤和细支气管膜损伤显著更大，而PEEP为4 cm H2O通气组的肺泡管损伤显著更大。总之，低于P-inf时肺容量的通气导致肺顺应性显著降低和肺损伤进展。因此，除了高气道压力外，呼气末肺容量是正压通气期间肺损伤程度和部位的重要决定因素。
Intermittent positive pressure ventilation with large tidal volumes and high peak airway pressures can result in pulmonary barotrauma. In the present study, we examined the hypothesis that ventilation at very low lung volumes can also worsen lung injury by repeated opening and closing of airway and alveolar duct units as ventilation occurs from below to above the infection point (P-inf) as determined from the inspiratory pressure-volume curve. We ventilated isolated, nonperfused, lavaged rat lungs with physiologic tidal volumes (5 to 6 ml/kg) at different end-expiratory pressures (above and below P-inf) and studied the effect on compliance and lung injury. In the groups ventilated with positive end-expiratory pressure(PEEP) below P-inf, compliance fell dramatically af ter ventilation. It did not change in either the control group or the group ventilated with PEEP above P-inf. Lung injury assessed morphologically was significantly greater in the groups ventilated with a PEEP below P-inf, and in these groups the site of injury was dependent on the level of PEEP. The group ventilated without PEEP had significantly greater respiratory and membranous injury to bronchioles, while the group ventilated with PEEP of 4 cm H2O had significantly greater alveolar duct injury. In conclusion, ventilation at lung volumes below those found at P-inf caused a significant decrease in lung compliance and progression of lung injury. Therefore, in addition to high airway pressures, end-expiratory lung volume is an important determinant of the degree and site of lung injury during positive-pressure ventilation.