【摘要】 [目的]观察不同压力水平呼气末正压通气(PEEP)对全身氧动力学的影响,探讨改善体外循环心内直视术后急性呼吸窘迫综合征(ARDS)病人最佳PEEP使用方法。[方法]依次按PEEP为0kPa、0.4kPa、0.9kPa、1.6kPa递增的水平进行调节,用热稀释法测定4次平均后的心脏指数(CI),同时进行血气分析,以观察不同压力水平PEEP对气体交换功能和氧动力学的影响。[结果]当PEEP为0.4kPa时,PaO2开始升高,并随着PEEP的增加逐渐升高。PaCO2在PEEP增加过程中无明显变化。CI在PEEP为0.4kPa时开始下降,且PEEP压力水平越高,CI下降越明显。全身氧供给(DO2)在PEEP为1.6kPa时出现显著降低。[结论]PEEP治疗体外循环心内直视术后ARDS病人PaO2有一定提高,但高压力水平的PEEP反而会使DO2下降。所以应使用依次递增的方法,并根据病人生命体征、中心静脉压(CVP)、末梢血氧饱和度的变化选择最佳PEEP值。即在未使用血管活性药物及正性肌力药物的条件下,病人无氧分压下降时的PEEP值为最佳。更多还原

【Abstract】 Objective: To observe the influence of different pressure levels of positive end-expiratory pressure （PEEP） on oxygen kinetics of patients, to explore the best way of using PEEP to improve the condition of postoperative acute respiratory distress syndrome （ARDS） patients after underwent extracorporeal circulation open heart surgery. Method: The pressure level was regulated from 0 kPa to 0.4 kPa, 0.9 kPa and 1.6 kPa in turn. The mean cardiac index （CI） of four times measurement were detected by thermodilution method, and blood gas analysis of them had been performed in order to observe different pressure level of PEEP on gas exchange and oxygen kinetics of patients. Result: The PaO₂ started to increase at 0.4 kPa of PEEP, and increased gradually with the raising of PEEP, during the process, there was no PaCO₂ change. In contrary, the CI of patients began to decrease at the pressure of 0.4 kPa, and lowered obviously with the diverse change of PEEP pressure. And the systematic oxygen supply of patients decreased sharply at 1.6 kPa of PEEP. Conclusion: PEEP could increase PaO₂ a certain degree during the therapy of postoperative ARDS patients after underwent extracorporeal circulation open heart surgery. But high pressure of PEEP could decrease the systematic oxygen supply of patients meanwhile. Hence, the best way to decide the PEEP value is to increase the pressure gradually based on the changes of vital signs, central venous pressure, peripheral blood oxygen saturation of patients. That is, the PEEP value of patients without oxygen pressure decreasing and without the applying of vasoactive agent and positive inotropic drugs.更多还原