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目的:通过建立比格犬急性呼吸窘迫综合征（acute respiratory distress syndrome，ARDS）动物模型，施加不同水平机械通气，探讨ARDS机械通气时呼吸力学与右心功能变化关系，为ARDS右心保护通气策略提供理论依据。方法:以比格犬为实验对象（n n=6），麻醉成功后置入肺动脉漂浮导管、食管测压管及股动脉导管。压力控制模式下固定驱动压，调整呼气末正压（PEEP）由2 cmHn 2O逐步上升至14 cmHn 2O，观察在此过程中呼吸力学、血流动力学和右心功能指标的变化。通过中心静脉注射油酸建立比格犬ARDS模型，成功造模后均予以相同参数的机械通气。以自身为对照，分析造模前后实验犬的呼吸力学、血流动力学和右心功能指标的变化。造模前后不同PEEP各项指标比较采用方差分析，事后Student-Newman-Keuls比较，组间n t检验比较，以n P<0.05为差异有统计学意义。n 结果:造模前在PEEP递增时气道峰压（Pn peak）、平台压（Pn plat）增大（n F值分别为232.733、196.33），吸气末跨肺压（Pn trans-I）、呼气末跨肺压（Pn trans-E）、肺静态顺应性（Cn stat）、潮气量（Vt）变小（n F值分别为4.524、6.499、64.803、2.31），右心室变化面积（FAC）变小（n F值为3.09）；每搏输出量（SV）先增大后减小（n F值为3.24），中心静脉压（CVP）、平均肺动脉压（MPAP）变大（n F值分别为19.07、14.81），差异有统计学意义（n P0.05）。造模后在PEEP递增时Pn peak、Pn plat、Pn ES-I、Pn ES-E增加（n F值分别为24.829、41.95、9.78、87.86），Vt、Pn trans-I、Pn trans-E、Cn stat先增大后减小（n F值分别为2.91、4.29、5.84、48.890），TAPSE、SV先增大后减小（n F值分别为6.22、6.54），CVP、MPAP递增（n F值分别为5.23、19.24），MAP先变大后变小（n F值为5.02），SpOn 2变大（n F值为2.77），差异有统计学意义（n P0.05）。n 结论:跨肺压及肺顺应性更好体现ARDS肺复张有效性，具有良好协同性；PEEP增加，右心收缩功能TAPSE最早受影响，SV代偿性增大，但PEEP继续增大会致TAPSE及SV变小；肺内血流分布在改善肺泡氧合方面更重要。ARDS治疗应实时监测跨肺压、TAPSE及肺内血流指标。“,”Objective:To explore the relationship between respiratory mechanics and right heart function during ARDS mechanical ventilation through the establishment of Beagle dogs acute respiratory distress syndrome (ARDS) animal model and the application of different levels of mechanical ventilation, which will provide theoretical basis for right heart protective ventilation strategy of ARDS.Methods:Beagle dogs were anesthetized successfully and then pulmonary artery floating catheter, esophageal manometric catheter and femoral artery catheter were inserted. Under the pressure control mode, the driving pressure was fixed. After adjustment, PEEP gradually increased from 2 cmHn 2O to 14 cmHn 2O. The changes of respiratory mechanics, hemodynamics and right heart function were observed. ARDS model was established by injecting oleic acid into central vein, and mechanical ventilation with the same parameters was given after the model was established successfully. In contrast to itself, the changes of respiratory mechanics, hemodynamics and right heart function indexes of experimental dogs before and after modeling were analyzed. In the group, the indexes of different PEEP were compared by ANOVA, and then compared by Student-Newman-Keuls. The difference was statistically significant at a n P value <0.05.n Results:Before modeling, the peak airway pressure (Pn peak) and plateau pressure (Pn plat) increased with the increase of PEEP (n F=232.733,196.33, n P<0.05). However, Pn trans-I, Pn trans-E, Cn stat and Vt decreased significantly (n F=4.524, 6.499, 64.803, 2.31, n P<0.05). The area of change of right ventricle (FAC) became smaller (n F=3.09, n P<0.05); SV first increased and then decreased (n F=3.24, n P<0.05), and CVP and MPAP increased (n F=19.07,14.81, n P0.05). After modeling, as PEEP increased, Pn peak, Pn plat, Pn ES-I and Pn ES-E increased significantly (n F=24.829, 41.95, 9.78, 87.86, n P<0.05). Vt, Pn trans-I, Pn trans-E, Cn stat and Vt first increased and then decreased (n F=2.91, 4.29, 5.84, 48.890, n P<0.05). TAPSE and SV first increased and then decreased (n F=6.22,6.54, n P<0.05). CVP and MPAP increased (n F=5.23, 19.24, n P<0.05). MAP increased first and then decreased (n F=5.02, n P<0.05). SpOn 2 increased (n F=2.77, n P0.05).n Conclusions:Trans pulmonary pressure and lung compliance can reflect the effectiveness of ARDS lung recruitment, and have good synergy; with the increase of PEEP, the right ventricular systolic function TAPSE is first affected, and SV compensatory increase, but with the increase of PEEP, TAPSE and SV decrease; pulmonary blood flow distribution is more important in improving alveolar oxygenation. Therefore, real-time monitoring of trans pulmonary pressure, TAPSE and intrapulmonary blood flow should be performed in ARDS treatment.