摘要
目的：比较不同潮气量水平通气对重症患者心脏舒张功能的影响。方法统计重庆市北部新区第一人民医院重症医学科2008～2013年进行机械通气的患者208例，在双水平正压通气（BIPA P ）模式下，调整吸气压使潮气量（VT）分别维持于6、8、10、15 mL／kg水平，其他呼吸机支持条件不变，以上各种条件维持30 min后测量中心静脉压（CVP）及血流动力学，心脏彩超监测左室射血分数（LEVF）。根据心脏指数（CI）分为心功能正常组（CI≥2．2 L·min-1·m -2）和心功能低下组（CI＜2．2 L·min-1·m-2），通气过程中若出现心率、血压明显下降或者恶性心律失常，则立即调整呼吸机参数。为排除 PEEP （呼气末正压）的影响，各组 PEEP均设定在5 cm H2 O 水平。结果在相同呼吸模式条件下，CI、胸内血容量指数（ITBVI）、舒张早期频谱幅度／舒张末期频谱幅度（E／A ）比值随着潮气量水平的升高而减小，平均气道压（Pmean），体循环血管阻力指数（SVRI）随着潮气量水平升高而升高，差异有统计学意义（P＜0．05）。而心率（HR）、LEVF在各组潮气量水平间无明显变化。心功能正常组在相同呼吸模式、相同呼吸支持条件下的CI、ITBVI、Pmean均无明显差异。心功能低下组患者中，8 mL／kg潮气量水平组CI较高，而在6、10、15 mL／kg潮气量水平组，CI较低，差异有统计学意义（P＜0．05）。结论在机械通气过程中应设置潮气量于6～8 mL／kg ，对血流动力学无明显影响，适用于心功能正常和心功能低下患者。
Objective To compare the effects of different tidal volume ventilation on cardiac diastolic function in severe cases .Methods A total of 208 cases ,receiving mechanical ventilation from 2008 to 2013 in Intensive Care Unit of the First People′s Hospital of Northern New District of Chongqing ,were enrolled .In the bi-level positive airway pressure (BIPAP) mode ,inspiratory pressure was adjusted to makes the tidal volume (VT) was maintained at 6 ,8 ,10 ,15 mL/kg .Central venous pressure (CVP) and hemodynamic indexes were detected ,and left ventricular ejec-tion fraction (LVEF) was monitored after the maintenance of condition ,mentioned above ,for 30 min ,when the other supportive conditions of respirator were kept as the same .According to the cardiac index (CI) ,patients were divided into normal heart function group (CI≥2 .2 L · min-1 · m -2 ) and poor cardiac function group (CI<2 .2 L · min-1 · m -2 ) .According to LEVF value ,patients were divided into systolic heart failure (LEVF<40% ) and diastolic heart failure (≥40% ) .Mechanical ventilation parameters were immediately adjusted ,when patient was with significant de-creasing of heart rate (HR) or blood pressure ,or malignant arrhythmia .To avoid the influence of positive end expira-tory pressure (PEEP) ,PEEP value was set at 5 cmH2 O in each group .Results At the same breath mode condition , CI ,intrathoracic blood volume index (ITBVI) ,early diastolic spectrum amplitude(peak E)/diastolic spectrum ampli-tude(peak A) ratio (E/A) decreased with the increasing of VT ,but mean airway pressure (Pmean) and systemic vascular resistance index (SVRI) increased ,all of which were with significant difference (P<0 .05) .While HR and LEVF were without significant difference between different groups (P> 0 .05) .Under the same breath mode and supportive conditions of respirator ,CI ,ITBVI and Pmean in patients with normal heart function were without signifi-cant difference between different group (P> 0 .05) .Among patients with poor cardiac function ,CI value was t
出处
《检验医学与临床》
CAS
2014年第7期886-888,共3页
Laboratory Medicine and Clinic
