静态肺压力-容积曲线确定最佳呼气末正压的比较性试验研究

To determine best positive end-expiratory pressure by static pressure-volume curve

目的 通过静态肺压力 -容积曲线 (P -Vcurve)法和最大氧分压 (PEEPtrail)法确定不同PEEP对急性肺损伤家兔模型肺机械力学、氧代谢、血流动力学及病理学方面的影响 ,探讨最佳PEEP(BestPEEP)的确定方法。方法 采用内毒素诱导的家兔急性肺损伤 (ALI)模型 ,根据P -V曲线低位转折点 (Pinf)和PEEPtrail法确定PEEP水平 :Pinf- 2cmH2 O、Pinf、Pinf+2cmH2 O以及Ptrail,观察不同水平PEEP对ALI家兔肺机械力学、氧代谢、血流动力学及病理学的影响。结果 Ptrail和Pinf分别为 (15 8± 2 5 )cmH2 O和 (10 2± 2 1)cmH2 O差异显著 (P >0 0 5 )。虽然Ptrail组PaO2 显著高于Pinf组和Pinf+2cmH2 O组 ,但是Ptrail组心脏指数及氧输送指数均显著低于Pinf组和Pinf+2cmH2 O组 (P <0 0 5 )。Pinf组及Pinf+2cmH2 O组肺静态顺应性显著高于Ptrail组和Pinf- 2cmH2 O组 ,且Pinf组及Pinf+2cmH2 O组肺损伤指数显著低于Ptrail组和Pinf - 2cmH2 O组 (P <0 0 1)。结论 根据P -V曲线法确定PEEP是选择最佳PEEP的理想方法。Pinf或Pinf+2cmH2 O为最佳PEEP ,可获得最大肺顺应性和最大氧输送 ,而肺损伤最小。

Objective To determine the best PEEP by static pressure-volume(P-V)curve and PEEP trail method.Methods ALI rabbit model was induced by intravenously infusing 3μg/kg LPS,PEEP levels were determined by lower inflection point(Pinf)of P-V curve and PEEP trail:Pinf-2cmH 2O,Pinf,Pinf+2cmH 2O,Ptrail. Parameters of pulmonary mechanics,oxygen metabolism and hemodynamics were measured at different PEEP levels.Results Ptrail was(15 8±2 5)cmH 2O,and Pinf was(10.2±2.1)cmH 2O. Ptrail was significantly different from Pinf(P>0 05).Although PaO 2 of Ptrail team was higher than that of Pinf team and Pinf+2 cmH 2O team,the CI and DO 2I of Ptrail team were lower significantly than those of Pinf team and Pinf+2cmH 2O team (P<0 05).The Cst of Pinf team and Pinf+2 cmH 2O team were higher significantly than those of Ptrail team and Pinf-2 cmH 2O team,and the lung injury score of Pinf team and Pinf+2cmH 2O team were lower significantly than that of Ptrail team and Pinf-2cmH 2O team (P<0 01) Conclusion To determine PEEP by P-Vcurve was optimistical method for selecting best PEEP. Pinf or Pinf+2cmH 2O might yield the best PEEP and show maximum Cst,maximum oxygen delivery and minimal lung injury.