机械通气小型猪张力性气胸实验模型的建立

Construction of an experimental tension pneumothorax model during mechanical ventilation in swines

目的 探讨呼吸回路与胸膜腔间使用单向气流旁路来建立机械通气张力性气胸模型的可行性.方法 6头小型猪麻醉后气管插管行机械通气,呼吸回路与胸膜腔间连接单向气流旁路,在呼气末胸膜腔内压为5、10、15 mmHg（1 mmHg=0.133 kPa）时测定循环、呼吸指标等,心输出量（CO）下降超70％时,床旁X线片纵膈定位.每头小型猪行2次模型建立.结果 6头小型猪顺利实施12次模型建立,从旁路通气至CO下降至基础值的30％,需时（18±4）min,第五肋间纵隔移位≥1/4胸廓横径者12例.结论 在呼吸回路与胸膜腔之间通过单向气流旁路的连接,建立机械通气小型猪张力性气胸模型,简单有效、重复性好.

Objective To explore the feasibility of constructing an experimental tension pneumothorax model during mechanical ventilation by one way flow bypass used between the breathing circuit and pleural cavity.Methods Six swines were intubated followed by ventilation after anesthesia.One way flow bypass was connected between the breathing circuit and pleural cavity.The parameters of hemodynamics and respiration were determined when the intrapleural pressure was 5,10,15 mmHg （1 mmHg =0.133 kPa）.Whe cardiac output （CO） was decreased by above 70% of basic value,mediastinal location was done by bedside X-ray.The model was constructed in one animal twice.Results Twelve models were implemented successfully for six swines.The timre from openning of the airway bypass to CO decreasing to 30% of the basic value was （18 ±4） min.Mediastinal shift exceeded 1/4 horizontal length of the chest at fifth intercostal space for 12 cases.Conclusion One way flow bypass is used between the breathing circuit and pleural cavity,and it was simple,effective and reproducible to construct an experimental tension pneumothorax model during mechanical ventilation in swines.