论文部分内容阅读
目的:研究脉搏指示连续心排血量（PiCCO）监测下肺保护性通气策略对百草枯（PQ）诱导急性呼吸窘迫综合征（ARDS）家猪血管外肺水的影响。方法:于2020年6月，采用PQ诱导家猪ARDS模型，造模成功后所有家猪均接受机械通气并按照吸入潮气量（Vn T）分为小Vn T组（6 ml/kg）、中Vn T组（10 ml/kg）和大Vn T组（15 ml/kg），每组各5只，设置呼气末正压（PEEP）为10 cmHn 2O。分别于造模前（基础值）、造模成功时（tn 0）及机械通气后2 h（tn 2）、4 h（tn 4）和6 h（tn 6）时进行动脉血气分析，计算氧合指数（OI），并测量血管外肺水指数（ELWI）和肺血管通透性指数（PVPI）等指标；同时采用苏木精-伊红（HE）染色法分别在造模前、tn 0和tn 6时观察肺组织病理学变化。n 结果:造模成功后，各组tn 0时心率（HR）、平均动脉压（MAP）和二氧化碳分压（PaCOn 2）水平高于基础值，而pH值、氧分压（PaOn 2）及OI水平低于基础值（n P<0.05）；接受机械通气后，各组tn 2、tn 4、tn 6时HR和MAP水平低于tn 0时，tn 4、tn 6时PaCOn 2水平高于tn 0时，差异均有统计学意义（n P<0.05）；而各组PaOn 2和OI水平在通气后呈先上升后下降的趋势；中、大Vn T组tn 2、tn 4、tn 6时MAP、PaOn 2、PaCOn 2及OI水平低于同期小Vn T组（n P<0.05）。各组家猪tn 0时ELWI和PVPI均高于基础值（n P<0.05）；小Vn T组ELWI在tn 6时低于同组tn 0时以及中、大Vn T组tn 6时（n P<0.05）。HE染色发现，造模成功后家猪肺泡组织充血水肿、毛细血管肿胀，红细胞渗出，肺泡间隔增宽，tn 6时各组肺组织可见肺泡融合、肺泡间隔进一步增宽，部分可见肺泡间隔断裂，小Vn T组损伤程度最轻。n 结论:肺保护性通气策略可减少PQ中毒家猪血管外肺水，减轻ARDS，改善氧合状况。“,”Objective:To study the effects on extravascular lung water of lung protective ventilation strategy applying on piglets with acute respiratory distress syndrome (ARDS) induced by paraquat (PQ) under pulse indicating continuous cardiac output (PiCCO) monitoring.Methods:The piglets models with ARDS induced by PQ were established in June 2020 and all of them were received mechanical ventilation and divided into three groups according to tidal volume (Vn T) : small Vn T group (6 ml/kg) , middle Vn T group (10 ml/kg) and large Vn T group (15 ml/kg) , there were 5 piglets in each group. The positive end expiratory pressure (PEEP) were all setup on 10 cmHn 2O. The indexes such as arterial blood gas analysis, oxygenation index (OI) , extravascular lung water index (ELWI) and pulmonary vascular permeability index (PVPI) were monitored at time of before the model was established (baseline) , time of the model was established (tn 0) and 2 h (tn 2) , 4 h (tn 4) , 6 h (tn 6) after mechanical ventilation. Lung tissue were punctured at time of baseline, tn 0 and tn 6 to be stained by Hematoxylin-eosin (HE) staining and pulmonary pathology were observed under light microscopy.n Results:The heart rate (HR) , mean arterial pressure (MAP) and partial pressure of carbon dioxide (PaCOn 2) of all groups were higher than the base value while the pH values, partial pressure of oxygen (PaOn 2) and OI were lower than the base value when the models were established (n P<0.05) . After mechanical ventilation, the HR and MAP values of all groups at tn 2, tn 4 and tn 6 were lower than tn 0 while the PaCOn 2 of tn 4 and tn 6 were all higher than tn 0, the differences were statistically significant (n P<0.05) . The PaOn 2 and OI of all groups showed a trend of rising at first and then decreasing after mechanical ventilation. The MAP, PaOn 2, PaCOn 2 and OI of the middle Vn T group and large Vn T group were apparently lower than that of the small Vn T group at tn 2, tn 4 and tn 6 (n P<0.05) . The ELWI and PVPI at tn 0 of all groups were higher than that of baseline (n P<0.05) . The ELWI of the small Vn T group at tn 6 were lower than tn 0 of the same group and tn 6 of the middle Vn T group and large Vn T group (n P<0.05) . HE staining showed congestion and edema of alveolar tissue, swelling of capillaries, exudation of red blood cells and widening of alveolar septum in piglets after successful modeling. And further widening of alveolar septum and rupture of alveolar septum could be seen in the lung tissues of each group at tn 6, and the injury was the slightest in the small Vn T group.n Conclusion:The lung protective ventilation strategy can alleviate the extravascular lung water and ARDS induced by PQ and improve oxygenation.