COPD病人压力支持通气时呼吸力学线性和非线性分析拟合效率的比较

Comparison of Fitting Efficiency between Linear and Non-linear Analysis of Respiratory Mechanics in COPD Patients with Pressure Support Ventilation

目的:探讨慢性阻塞性肺疾病(chronic obstructive pulmonary diseases,COPD)病人压力支持通气(pressure support ventilation,PSV)时呼吸力学线性分析和非线性分析拟合效率的比较。方法:以本院英东重症医学监护中心于2004年1月至2005年1月收治的14例COPD患者为研究对象,将PSV水平调到大于或等于20cmH2O,通气15min,使病人达到"接近放松"状态。分别以呼吸力学线性和非线性模型分析此状态下的压力(P)、流量(V′)和容量(V)数据,比较二者的拟合效率指标决定系数(R2)和根均方差(root mean squaredifference,RMSD)。结果:非线性分析所得RMSD值(1.95±0.93)cmH2O小于线性分析所得RMSD值(3.29±1.31)cmH2O,非线性分析所得R2值(0.96±0.03)大于线性分析所得R2值(0.84±0.05),差异均有统计学意义(P<0.05)。结论:呼吸力学的非线性模型比线性模型更加适合COPD病人压力支持通气呼吸力学分析。

Objective：To compare the fitting efficiency between linear and non-linear analysis of respiratory mechanics in COPD patients with pressure support ventilation.Methods：Fourteen COPD patients mechanically ventilated were ventilated at a PSV level of no less than 20 cmH2O in a period of 15 minutes to attain so-called near-relaxation state.Data on the pressure（P）,flow（V＇）and volume（V）were analysed by linear and non-linear models of respiratory mechanics respectively.RMSD and R2 were compared between the two methods.Results：The mean values of RMSD in linear and non-linear analyses of respiratory mechanics were（3.29±1.31）and（1.95±0.93）cmH2O respectively,whereas R2 were（0.84±0.05）and（0.96±0.03）respectively（P〈0.05）.Conclusion：Non-linear model of respiratory mechanics appeared better for respiratiory mechanics study of COPD patients mechanically ventilated with PSV mode.