不同呼气末正压设定对机械通气患者血流动力学及心功能的影响  

Study of the effects on the heart function when different positive end expiratory pressure levels were used on patients treated with mechanical ventilation

作　　者：李敏[1] 秦英智[1] 马丽君[1] 

机构地区：[1]天津市第三中心医院ICU,天津市呼吸机治疗研究中心,300170

出　　处：《中国危重病急救医学》2007年第2期86-89,共4页Chinese Critical Care Medicine

基　　金：天津市卫生局科研基金资助项目（20010171）

摘　　要：目的 探讨不同呼气末正压（PEEP）水平对机械通气患者血流动力学及心功能的影响。方法 将39例呼吸衰竭进行机械通气的危重患者根据心排血指数（CI）分为两组。应用部分CO2重复呼吸法（NICO）连续监测血流动力学，观察心功能正常组（CI≥2．0L·min^-1·m^-2,n=18）与心功能低下组（CI〈2．0L·min^-1·m^-2，n=21）在双水平气道正压通气（BIPAP）模式下0、5、7、10和13cmH2O（1cmH2O=0．133kPa）PEEP水平对血流动力学[心排血量（CO）、CI、肺毛细血管血流（PCBF）、中心静脉压（CVP）、外周血管阻力（SVR）]、肺机械参数[内源性呼气末正压（PEEPi）、气道峰压（PIP）、平均气道压（Pmean）]及脉搏血氧饱和度（SpO2）、血压（BP）、心率（HR）等的变化。结果心功能正常组随PEEP增加，CVP明显升高，CO、CI、SVR和PCBF无明显变化；心功能低下组随PEEP增加，CVP明显升高，CO、CI呈曲线变化，且明显下降，SVR下降后显著升高，PCBF明显减少；两组患者随PEEP增加，Pmean、PIP、PEEPi均相应增加，气道阻力明显下降。结论 机械通气在相对容量恒定时，在0～13cmH2O的PEEP对正常心脏无明显影响，对衰竭心脏可明显减少右心前负荷、PCBF和左心室前负荷，设定适当PEEP可改善心功能。气道压力的变化与CO、CI的变化并非一致。Objective To study the effects on the hemodynamics and the heart function when different positive end -expiratory pressure （PEEP） levels were used on patients treated with mechanical ventilation. Methods Thirty -nine critical patients with respiratory failure and treated with mechanical ventilation, and hemodynamics was monitored, were divided into two groups according to the cardiac index （CI）. Hemody- namics was measured with non -invasive cardiac output （NICO） continuously. The changes in hemodynamic parameters [including cardiac output （CO）, CI, pulmonary capillary blood flow （PCBF）, central venous pressure （CVP）, systemic vascular resistance （SVR）], lung mechanical parameters [intrinsic positive end expiratory pressure （PEEPi）, peak inspiratory pressure （PIP）, mean of airway pressure （Pmean）], pulse saturation of oxygen （SpO2）, blood pressure （BP） and heart rate （HR）] were determined with different selected PEEP levels of 0, 5, 7, 10 and 13 cm H2O （1 cm H2O=0. 133 kPa） under the bi -phasic positive airway pressure （BIPAP） mode in normal cardiac function group （CI≥2.0 L · min^-1· m^-2, n= 18） and poor cardiac function group （CI〈2.0 L · min^-1· m^- 2, n= 18）. Results In the normal cardiac function group, the increase in PEEP led to an increase of CVP, but it had no significant effects on CO, CI, PCBF and SVR; in the poor cardiac function group, the increase of PEEP led to an increase of CVP and SVR, a decrease of PCBF, CO, CI, and the latter two variables showed a curvilinear change. In both groups, PIP, Pmean, PEEPi increased and the resistance of airway （R） fell with the increase of PEEP. Conclusion Under the condition of mechanical ventilation, when the lung volume was relatively constant, change in PEEP levels （0 - 13 cm H2O） had no obvious effects on the normal cardiac function group, but can significantly decrease right ventricular preload, PCBF and left ventricular preload. Optimal PEEP may improve the cardiac function.

关 键 词：呼气末正压 血流动力学 心功能 机械通气 

分 类 号：R686[医药卫生—骨科学]