外源性呼气末正压对肺不张病人动脉血气及血液动力学的影响

Effect of Extrinsic positive end expiratory pressure on arterial blood gas and Hemodynamics in patients with atelectasis

目的探讨外源性呼气末正压(PEEPe)对肺不张病人动脉血气及血液动力学的影响。方法对20例行机械通气的肺不张病人先后给PEEPe 0、4和8 cmH2O,记录并比较每次机械通气后30 min的气道峰压(Ppeak)、气道平均压(Pmean)、呼吸系统静态顺应性(Cst.rs)、气道阻力(RI)的大小,同时比较给予三种不同数值的PEEPe时对氧合指数(PaO2/FiO2)、二氧化碳分压(PaCO2)、PH值及平均动脉压(MBP)、中心静脉压(CVP)、左室射血分数(CI)的影响。结果 PEEPe为8 cmH2O时Ppeak、Pmean及CVP值较0、4 cmH2O时明显增高(P<0.05),而Cst.rs、PaO2/FiO2、CI、MBP及RI则明显降低(P<0.05);PEEPe为0 cmH2O时与4 cmH2O时比较,在Ppeak、Pmean、CVP、PaO2/FiO2、CI及MBP方面无显著差异(P>0.05);三种数值的PEEPe时的PH值及PaCO2无显著性差异(P>0.05)。结论在正压机械通气的肺不张病人,低PEEPe的应用对患者动脉血气及血液动力学无明显影响,而较高的PEEPe可产生明显不利的影响。

Objective To study the Effect of Extrinsic positive end expiratory pressure on arterial blood gas and Hemodynamics in patients with atelectasis during continuous positive pressure mechanical ventilation.Mothods Twenty patients with atelectasis were included in this study.Patients were received continuous positive pressure mechanical ventilation with 0 cmH2O,4 cmH2O and 8 cmH2O PEEPe subsequently.Respiratory mechanics,arterial blood gas,and hemodynamics at 30 min after receiving continuous positive pressure mechanical ventilation with different PEEPe were recorded and compared.Results Comparing with 8 cmH2O PEEPe（P〈0.05）,0 cmH2O PEEPe and 4 cmH2O PEEPe created significantly lower Ppeak,Pmean and CVP and higher Cst.rs,PaO2/FiO2,CI,MBP and RI.0 cmH2O PEEPe and 4 cmH2O PEEPe created no significant difference in Ppeak、Pmean、CVP、PaO2、CI and MBP（P〉0.05）;Three kind of PEEPe had no significant difference in PH and PaCO2（P〉0.05）.Conclusions In patients with atelectasis during continuous positive pressure mechanical ventilation,the use of the lower PEEPe have no obviously effect on arterial blood gas and Hemodynamics,while evidently disadvantageous effect can be found in course of the use of the higher PEEPe.