无创气道正压通气下呼气末测算气道阻力和肺顺应性实验研究

Calculating Airway Resistance and Lung Compliance at Expiration End under Non-invasive Positive Pressure Ventilation:An Experimental Study

目的采用呼气末压力短暂释放的方式,测算无创正压通气(non-invasive positive pressure ventilation,NPPV)条件下的气道阻力(R)和肺顺应性(C),并评估其测算精度。方法首先,将测算方法程序移植到NPPV呼吸机的控制器,设计基于主动模拟肺ASL5000的通气实验平台。然后,模拟正常成人(R=5 cmH_(2)O,C=50 mL/cmH_(2)O。1 cmH_(2)O=0.098 kPa)、急性呼吸窘迫综合征成人患者(R=10 cmH_(2)O,C=30 mL/cmH_(2)O)和慢性阻塞性肺疾病成人患者(R=20 cmH_(2)O,C=50 mL/cmH_(2)O)的R和C进行实验。结果测算所得R最大相对误差达到-12.67%,出现在对正常成人的测定;C最大相对误差达到17.37%,出现在对急性呼吸窘迫综合征成人患者的测定。采用均值配对双样本t检验法对每组测试数据进行分析,差异没有统计学意义(P>0.05)。结论实验所得R、C与在ASL5000上的设置值相一致。NPPV下呼气末R、C的测算方法具有良好的可行性,其实现与应用有助于呼吸机通气治疗的精准化和个体化。

Objective Airway resistance(R)and lung compliance(C)under non-invasive positive pressure ventilation(NPPV)conditions were measured using a brief pressure release at the end of expiration,and the measurement accuracy was also evaluated.Methods An NPPV respirator was developed by programming a method for calculating R and C.An experimental platform based on the active servo lung ASL5000 was designed.By simulating a healthy adult(R=5 cmH_(2)O and C=50 mL/cmH_(2)O,1 cmH_(2)O=0.098 kPa),an adult patient with acute respiratory distress syndrome(R=10 cmH_(2)O and C=30 mL/cmH_(2)O),and an adult patient with chronic obstructive pulmonary disease(R=20 cmH_(2)O and C=50 mL/cmH_(2)O),a series of experiments for calculating the R and C were conducted.Results The maximum relative error of R was-12.67%,which occurred in calculating the R of an average adult.The maximum relative error of C was 17.37%,which occurred when calculating the C values of patients with acute respiratory distress syndrome.Each group of data was analyzed using a paired t-test,which showed statistically significant differences(P>0.05).Conclusions The calculation method for R and C at the end of expiration during NPPV is feasible,and its realization and application will be beneficial for achieving precise and personalized respiratory ventilation.