肺超声评分评估油酸致山羊急性肺损伤的实验研究

Experimental study of lung ultrasound score for the evaluation of acutelung injury induced by oleic acid in goats

目的 探讨肺超声评分(LUS)对油酸致山羊急性肺损伤(ALI)的诊断价值。方法 将16只山羊随机分为轻伤组和重伤组,每组各8只,通过耳缘静脉分别注射不同剂量油酸(轻伤组0.05 ml/kg,重伤组0.10 ml/kg),建立相应ALI模型。以山羊双侧胸壁第5肋为界分为左上、左下、右上及右下4个肺区,于致伤前和致伤后1 h、3 h、6 h动态观察两组山羊全肺及各肺区超声表现,比较两组LUS的差异;绘制受试者工作特征(ROC)曲线分析致伤后1 h、3 h、6 h全肺及各肺区LUS预测山羊ALI严重程度的诊断价值。通过血气分析和炎症因子检测分别获得各时间点动脉血气指标[氧分压(PaO_(2))、氧饱和度(SaO_(2))、氧合指数(PaO_(2)/FiO_(2))]和肿瘤坏死因子-α(TNF-α),比较两组上述指标的差异。然后处死山羊,观察肺大体损伤情况,取肺组织行病理组织学检查并进行病理损伤评分,计算肺湿干比,分析全肺及各肺区LUS与肺湿干比、病理损伤评分的相关性。结果 轻伤组1只山羊于致伤后5 h死亡,余山羊均成功建立油酸诱导ALI模型。(1)各ALI模型致伤后全肺LUS随着时间增加呈逐渐上升趋势,重伤组致伤后1 h、3 h、6 h全肺LUS均高于轻伤组,差异均有统计学意义(均P<0.05)。两组致伤后1 h、3 h、6 h右下肺LUS比较差异均有统计学意义(均P<0.05),其余肺区LUS比较差异均无统计学意义;重伤组致伤后6 h左下肺LUS高于左上肺,致伤后3 h、6 h右下肺LUS均高于右上肺,差异均有统计学意义(均P<0.05);轻伤组致伤后同一时间点各肺区LUS比较差异均无统计学意义。(2)ROC曲线分析显示,致伤后各时间点全肺LUS预测山羊ALI严重程度的曲线下面积(AUC)均>0.8;各时间点右下肺LUS预测山羊ALI严重程度的AUC均>0.9,其中致伤后1 h右下肺LUS的预测效能最高(AUC=0.938)。(3)重伤组致伤后3 h、6 h PaO_(2)、SaO_(2)、PaO_(2)/FiO_(2)均低于轻伤组,差异均有统计学意义(均P<0.05)。轻、重伤组致伤后TNF-α随着时间增加均呈逐渐上升趋势,但与致伤前比较差异均无统计学意义。(4)重伤组肺湿干比和全肺病理损伤评分均高于轻伤组[7.36±0.97 vs. 5.86±0.50,(17.63±3.15)分vs.(13.86±4.07)分],差异均有统计学意义(均P<0.05);重伤组左下肺病理损伤评分高于左上肺,右下肺病理损伤评分高于右上肺,差异均有统计学意义(均P<0.05);轻伤组右下肺病理损伤评分高于右上肺,差异有统计学意义(P<0.05)。(5)相关性分析显示,致伤后6 h全肺、左下肺、右上肺及右下肺LUS均与肺湿干比呈正相关(均P<0.05),尤以右下肺LUS的相关性最高;致伤后6 h全肺、左下肺及右下肺LUS均与病理损伤评分呈正相关(均P<0.05),尤以右下肺LUS的相关性最高。结论 应用LUS可准确评估山羊ALI早期严重程度和变化,具有一定的诊断价值;不同肺区LUS存在差异,其中右下肺LUS与其严重程度的相关性最高。

Objective To investigate the diagnostic value of lung ultrasound score(LUS)in oleic acid-induced acute lung injury(ALI)in goats.Methods Totally 16 goats were randomly divided into mild injury group and severe injury group,with 8 goats in each group.The ALI models were induced by injecting varying doses of oleic acid(0.05 ml/kg for the mild injury group and 0.10 ml/kg for the severe injury group)via the ear vein.The goat’s bilateral chest wall was divided into four lung regions with the fifth rib as the boundary:left upper,left lower,right upper,and right lower.Lung ultrasound was performed on the entire lung and each lung region before the injury and 1 h,3 h,and 6 h after the injury,the difference of LUS between two groups was compared.Receiver operating characteristic(ROC)curve was drawn to analyze the diagnostic value of LUS in the entire lung and each lung area in predicting the severity of goat ALI at 1 h,3 h,and 6 h after injury.Arterial blood gas indicators[partial pressure of oxygen(PaO_(2)),oxygen saturation(SaO_(2)),and oxygenation index(PaO_(2)/FiO_(2))]and tumor necrosis factor-α(TNF-α)were obtained by blood gas analysis and inflammatory factor detection at each time point.The differences of above indicators between the two groups were compared.Subsequently,the goats were sacrificed,and the entire lung injury was observed.Lung tissue samples were taken for pathological histological examination and pathological injury score determination,the lung wet-dry ratio was calculated.The correlation between LUS of the entire lung and each lung region and the lung wet-dry ratio,pathological injury score were analyzed.Results One goat in the mild injury group died 5 h after the injury,while the remaining goats were successfully established the oleic acid-induced goat ALI model.①The LUS of the entire lung after injury exhibited a progressive increase with the time extend,and the LUS of the entire lung in severe injury group was higher than that of the mild injury group at 1 h,3 h,and 6 h after the injury,the differences were statistically significant(all P<0.05).There were statistically significant differences in LUS of the right lower lung between the two groups at 1 h,3 h,and 6 h after the injury(all P<0.05).There were no statistically differences in the LUS of the other three lung regions.The LUS of the left lower lung in the severe injury group was higher than that in the left upper lung at 6 h after the injury(P<0.05).Additionally,the LUS of the right lower lung in the severe injury group was higher than that in the right upper lung at 3 h and 6 h after the injury(all P<0.05).There was no statistically difference in the LUS of each area in the mild injury group.②ROC curve analysis showed that the area under the curve(AUC)of LUS in predicting the severity of ALI in the entire lung at each time point after injury was all>0.8,the AUC of LUS in the right lower lung at each time point was all>0.9,the highest predictive efficacy was observed by LUS of the right lower lung at 1 h after the injury(AUC=0.938).③The PaO_(2),SaO_(2) and PaO_(2)/FiO_(2) of severe injury group were lower than those of the mild injury group at 3 h and 6 h after the injury,and the differences were statistically significant(all P<0.05).TNF-αincreased gradually with the time extend after the injury in mild injury group and severe injury group,but there was no statistical difference compared with the results before injury.④The lung wet-dry ratio and the entire lung pathological injury scores in the severe injury group were higher than those in the mild injury group[7.36±0.97 vs.5.86±0.50,(17.63±3.15)scores vs.(13.86±4.07)scores],the differences were statistically significant(both P<0.05).The lung pathological injury score of the left lower lung in the severe injury group was higher than that of the left upper lung,and lung pathological injury score of the right lower lung was higher than that of the right upper lung,the differences were statistically significant(both P<0.05).While the lung pathological injury score of the right lower lung in the mild injury group was higher than that of the right upper lung,and the difference was statistically significant(P<0.05).⑤Correlation analysis showed that LUS of the entire lung,left lower lung,right upper lung,and right lower lung at 6 h after injury were positively correlated with the lung wet-dry ratio(all P<0.05),with the right lower lung exhibiting the highest correlation coefficient among all lung regions.LUS of the entire lung,left lower lung,and right lower lung at 6 h after injury were positively correlated with the lung pathological injury score of the lung(all P<0.05),with the right lower lung exhibiting the highest correlation coefficient among all lung regions.Conclusion LUS can accurately in assessing the degree and changes of early lung injury in goats with ALI,which has certain diagnostic value.LUS varies in different lung regions,and LUS in the right lower lung has the highest correlation with the degree of acute lung injury.