模拟肺容量控制通气辅用自动变流呼吸力学变化研究

The changes of respiratory mechanical parameters of volume controlled ventilation assisted with autoflow on model lung

目的观察容量控制通气辅用自动变流前后输送潮气量、气道峰压、平均压的变化,探讨容量控制通气辅用自动变流后影响气道压力、吸气流速的相关因素。方法观察模拟肺在不同的顺应性、阻力下,采用不同吸气流速容量控制通气辅用自动变流前后输送潮气量、气道峰压、平均压的变化。并探讨辅用自动变流后气道峰压、平均压、吸气峰值流速和平均流速分别与系统阻力、顺应性的相关性。结果不同流速、阻力、顺应性辅用自动变流后输送潮气量不变(均P>0.05),而气道峰压、气道平均压下降(均P<0.05),气道峰压、平均压及吸气峰值流速、平均流速均与系统阻力、顺应性相关(均P<0.05)。结论在需要保证潮气量,又希望尽可能控制气道压力、吸气流速以适合患者顺应性和阻力变化时,容量控制通气辅用自动变流是一种较好的方法。

Objective To demonstrate the significance of volume controlled ventilation assisted with autoflow on model lung. Methods Compare the variables of delivery tidal volume, peak airway pressure (PAP) and mean airway pressure(MAP)in volume controlled ventilation before and after assisted with autoflow under different pre-set flow velocity, compliance and resistance simulated on model lung. The correlated factor of PAP, MAP, peak inspiratory flow velocity (Pflow) and mean inspiratory flow velocity (Mflow) after being assisted with autoflow also be discussed. Results No changes of tidal volume were found(P>0.05)after assisted with autoflow, whereas peak airway pressure and mean airway pressure was descended, despite the different levels of flow velocity, resistance and compliance (P<0.05). After assisted with autoflow, PAP and MAP had positive correlations with resistance respectively (r = 0.746, P<0.05; r = 0.789, P<0.05), but negative correlations with compliance respectively (r = -0.533, P<0.05; r = -0.377, P<0.05). Pflow and Mflow had negative correlations with resistance (r = -0.830, P<0.05; r = -0.694, P<0.05) and compliance respectively (r =-0.306, P<0.05; r=-0.285, P<0.05). Conclusion Volume controlled ventilation assisted with autoflow may be helpful in the patients whose airway pressure should be kept in a lower level and the patient-ventilator synchrony should be improved while constant tidal volume is needed.