COPD患者压力支持通气呼吸力学容积依赖性系数与动态内源性呼气末正压的相关性分析

Correlation Between Volume Dependence of Respiratory Mechanics and Dynamic Intrinsic Positive End-Expiratory Pressure in COPD Patients During Pressure Surpport Ventilation

目的探讨COPD患者压力支持通气(PSV)时呼吸力学非线性分析呼吸系统弹性和阻力的容积依赖性系数(Evd/Rvd)与动态内源性呼气末正压(PEEPidyn)的相关性。方法 25例COPD机械通气患者,将PSV水平调到大于或等于20 cm H2O,通气15 min,使患者达到"接近松弛"状态。以呼吸力学非线性模型分析此状态下的压力(P)、流量(V′)和容量(V)数据;以食管囊管法测定PEEPidyn,分析Evd、Rvd及Evd×Rvd与PEEPidyn的相关性。结果 Evd、Rvd及Evd×Rvd与PEEPidyn的相关系数分别为0.85、0.80和0.90。结论 Evd和Rvd,特别是Evd×Rvd与PEEPidyn之间具有良好的相关性,可用于COPD患者PSV时PEEPidyn的无创性监测。

Objective To investigate the correlation between dynamic intrinsic positive end-expiratory pressure（PEEPidyn） and volume dependence of elastance and resistance of respiratory system（Evd/Rvd） derived from nonlinear analysis of respiratory mechanics in COPD patients during pressure support ventilation（PSV）.Methods Twenty-five COPD patients mechanically ventilated using mode of PSV were ventilated at a PSV level of no less than 20 cm H2O in a period of 15 minutes to attain so-called near-relaxation state.The pressure（P）,flow（V′） and volume（V） data were analyzed by nonlinear mode of respiratory motion.PEEPidyn was determined by esophageal balloon-tipped catheter technique.The correlations between PEEPidyn and Evd,Rvd as well as Evd×Rvd were analyzed.Results The correlation coefficients between PEEPidyn and Evd,Rvd as well as Evd×Rvd were 0.85,0.80,and 0.90,respectively.Conclusions Nonlinear mode of respiratory motion is suitable to analyze respiratory mechanics of COPD patients mechanically ventilated using mode of PSV.There are good correlations between PEEPidyn and Evd,Rvd as well as Evd×Rvd which may be used to noninvasively monitor PEEPidyn in mechanically ventilated COPD patients using mode of PSV.