The mechanism of lung volume change during mechanical ventilation
The mechanism of lung volume change during mechanical ventilation
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DOI：
10.1164/ajrccm.160.5.9812031
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发表时间：
1999-11-01
影响因子：
24.7
通讯作者：
Nieman, GF
中科院分区：
文献类型：
--
作者：
Carney, DE;Bredenberg, CE;Nieman, GF
为了了解正压通气时呼吸机诱导的肺损伤（VILI），必须首先建立正常肺泡力学的机制。各向同性的“气球样”肺泡容积（V-A）变化被认为是正常肺容积（V-L）变化的主要机制。我们假设V-L的变化主要是由肺泡复张-去复张（R/D）引起的。麻醉15只杂种犬，用气管分隔器插管。通过胸廓切开术切口，进行胸膜下肺泡的体内显微镜检查，因为脱气的肺膨胀至80%TLC，然后放气至残余体积（RV）。评价静态显微照片，以确定V-L的变化是否是由于肺泡VA或R/D的变化。当V-L增加到80%TLC时，我们注意到肺泡复张的稳定、显著增加（p < 0.05）。而V-A则显著增加，但仅在20% TLC时（p < 0.05）。一旦恢复，肺泡没有表现出任何进一步的体积变化，而肺作为一个整体保持正常的压力/体积关系。在我们的模型中，V-L的变化主要由R/D引起。
To understand ventilator-induced lung injury (VILI) during positive pressure ventilation, mechanisms of normal alveolar mechanics must first be established. Isotropic "baIloonlike" alveolar volume (V-A) change has been viewed as the prevailing mechanism of normal lung volume (V-L) changes. We hypothesized that change in V-L is predominantly caused by alveolar recruitment-derecruitment (R/D). Fifteen mongrel dogs were anesthetized and intubated with a tracheal divider. Through a thoracotomy incision, in vivo microscopy of subpleural alveoli was performed as the degassed lung was inflated to 80% TLC, and then deflated to residual volume (RV). Still photomicrographs were evaluated to determine if change in V-L is due to change in VA or R/D Of alveoli. We noted a steady, significant increase in alveolar recruitment as V-L increased to 80% TLC (p < 0.05). However, V-A increased significantly, but only to 20% TLC (p < 0.05). Once recruited, alveoli did not demonstrate any further volume change, whereas the lung as a whole maintained a normal pressure/volume relationship. In our model, changes in V-L predominantly are caused by R/D.