温德良　肖锐　熊旭明

[摘要]目的 比较监控跨肺压（PL）的肺保护通气策略（控制PL）和传统肺保护通气策略（控制Pplat）分别在机控通气和保留自主呼吸模式下对犬ARDS模型肺损伤的影响。方法 18只比格犬采用静注油酸复制ARDS模型，随机分为A组、B组、C组。肺保护通气4 h后通过全肺CT扫描，根据三组的CT值判断过度通气区、正常通气区、通气不足区和闭合区，计算各充气区的容积以及其占总肺容积的比例；胸活检取肺组织，HE染色进行病理学评分。结果 C组的过度充气区所占比例显著高于A组和B组，肺损伤总分高于A组和B组，差异有统计学意义（P<0.05）。C组的中性白细胞浸润和间质水肿评分高于A组和B组，肺不张评分低于A组和B组，差异有统计学意义（P<0.05）。结论 监控PL无论在自主呼吸还是机控呼吸状态下，均能够有效调控肺容量，减轻VILI。在保留自主呼吸时，单纯监控Pplat不能有效调控肺容量，可导致肺组织过度充气，加重肺损伤。

[关键词]急性呼吸窘迫综合征；肺保护通气策略；平台压；病理学；呼吸机相关性肺损伤

[中图分类号] R-332 [文献标识码] A [文章编号] 1674-4721（2016）07（a）-0004-05

[Abstract]Objective To compare the influence of lung protective ventilation strategy （LPVS） guided by PL and traditional LPVS on lung injury in a canine model of ARDS under the mode of controlled mechanical ventilation and spontaneous breath.Methods 18 beagle dogs were recruited to induct ARDS models by venous injection of oleic acid and were divided into group A，group B and group C.After 4 hours LPVS，CT scanning among the three groups was performed，and the regions of hyperventilation，normal ventilation，hypoventilation and closure were judged according to CT value，then the volume of each aerated region and its proportion to the total LV were calculated.Lung tissues were obtained by thoracotomy，HE staining was performed for pathological score.Results The proportion of hyperventilation region in group C was higher than that in group A and group B，the total score of lung injury in group C was higher than that in group A and group B，with significant difference （P<0.05）.The score of neutrophil infiltration and interstitial edema in group C was higher than that in group A and group B，the atelectasis score in group C were lower than those in group A and group B，with significant difference （P<0.05）.Conclusion Monitoring of PL in both autonomous breathing and respiratory control，can effectively control the lung capacity，reduce VILI.In the retention of spontaneous breathing，simply monitoring Pplat can not effectively control the lung capacity，which can lead to excessive inflation of the lung tissue and increase the lung injury.

[Key words]Acute respiratory distress syndrome；Lung protective ventilation strategy；Plateau pressure；Pathology；Ventilation-induced lung injury

随着呼吸机模式的不断改进，仅有不到20%的急性呼吸窘迫综合征（acute respiratory distress syndrome，ARDS）患者直接死于不可逆性的缺氧，ARDS的主要死因为呼吸机相关性肺损伤（ventilation-induced lung injury，VILI）及其导致的多脏器功能障碍综合征（multiple organ dysfunction syndrome，MODS），因此如何减轻VILI是临床急需解决的问题[1]。传统的肺保护通气策略（lung protective ventilation strategy，LPVS）通过控制吸气末平台压力（Pplat）来调控吸气末肺容积，以减轻VILI，但在保留自主呼吸的情况下，单纯监控Pplat并不能够调控吸气末肺容量，因此必须寻找一种新的肺保护通气手段。从呼吸力学角度看，跨肺压（PL）是最终决定肺容量的压力因素，无论是在完全机控呼吸还是保留自主呼吸情况下，调控PL均可以控制吸气末肺容量。理论上通过监控PL来控制吸气末容积更为合理[2]，研究也证实，根据PL指导呼吸机通气和肺复张，可改善肺氧合功能和肺顺应性[3-4]，但能否有效减轻VILI，未见相关报道。……