应用食道-胃囊管测压系统评估犬急性肺损伤早期生理学反应

目的 研究急性肺损伤合理的动物模型的制作及评估方法.方法 24只健康杂种犬采用油酸复制急性肺损伤动物模型,应用食道-胃囊管测压系统监测评估急性肺损伤早期生理学反应.结果 自主呼吸状态下犬油酸急性肺损伤早期:(1)呼吸力学方面:呼吸频率、分钟通气量、吸气流量峰值、平均吸气流量、吸气气道阻力均显著增高(P＜0.001),跨膈压峰值增高(P=0.0185);潮气量、动态肺顺应性显著降低(P＜0.001);吸气时间占呼吸周期比值无明显变化(P=0.163).(2)气体交换方面:酸碱度、动脉血氧分压、动脉血氧饱和度、氧合指数、呼气末二氧化碳分压均明显降低(P＜0.001);动脉血二氧化碳分压、肺泡死腔与潮气容积比值均显著增高(P＜0.001).结论 食道-胃囊管测压系统客观地评估了急性肺损伤早期各项生理学反应.

Assessment of early-stage physiological response to acute lung injury in canine models using balloon catheter system for measuring esophageal and gastric pressure

Objective To explore feasible and reliable methods for estnbolishment and of acute lung injury model in animal models.Methods Twenty-four healthy adult mongrel dogs with oleic acid-induced acute lung injury were evaluated for early-stage physiological response to acute lung injury using a balloon catheter system for measuring esophageal and gastric pressure.Results In canine models of early-stage oleic acid-induced acute lung injury that sustained spontaneous breathing,in terms of respiratory mechanics,some parameters obviously increased including the respiratory rate(RR),minute ventilation(VE),peak inspiratory volume(Vinsp,peak),mean inspiratory volume(VT/Ti),inspiratory airway resistance(Raw,insp)(P<0.001 for all the parameters),with also significantly increased peak transdiaphragmatic pressure(Pdi,peak,P=0.0185).The tidal volume(VT)and dynamic lung compliance(CL,dyn),however,were significantly decreased(P<0.001),and significant variation occurred in the ratio of inspiratory time to duration of one breath(Ti/Ttot,P=0.163).In terms of gas exchange,the pH,PaO2,SaO2,PaO2/FiO2,and end tidal partial pressure of carbon dioxide(PETCO2)all evidently declined(P<0.001),but PaCO2 and ratio of alveolar dead space to tidal volume [VD(alv)/VT] increased significantly(P<0.001).Conclusion Application of balloon catheter system for measuring esophageal and gastric pressures allows objective evaluation of the various physiological responses in early stage of acute lung injury.