利用压力-容积曲线选择呼气末正压治疗急性呼吸窘迫综合征

目的探讨利用压力-容积曲线选择呼气末正压(PEEP)对急性呼吸窘迫综合征(ARDS)患者肺力学、血流动力学及动脉血气参数的影响,并选择最佳PEEP范围.方法选择16例确诊为ARDS患者,根据压力-容积曲线,设下拐点压力为PLIP,设上拐点压力为PUIP.分别选择PEEP为0、PLIP/2、PLIP、(PLIP+PUIP)/2和PUIP,测量肺力学、血流动力学及动脉血气参数的变化.结果当PEEP为PLIP/2时,动脉血氧分压与吸入氧浓度比(PaO2/FiO2)及Cst虽然较未加用PEEP时有改善(P<0.05及P<0.01),但尚未达到正常水平;当PEEP为PLIP时,PaO2/FiO2及Cst较PLIP/2时有显著提高(P<0.01),接近正常范围;当PEEP为PUIP时,PaO2/FiO2较(PLIP+PUIP)/2时显著增高(P<0.01),但Cst较PLIP时反而有所降低(P<0.01),MAP下降(P<0.01),CVP升高(P<0.01),同时Pip增高(P<0.01).结论ARDS患者行呼吸机治疗时,在PLIP～PUIP之间可有效纠正低氧血症,而对血流动力学影响较小,可获得满意疗效.

Treatment of acute respiratory distress syndrome by PEER using the pressure-volume curve

Objective:To discuss the effect of variant positive end expiratory pressure(PEEP) on compliance of lung(Cst),peak inspiratory pressure(Pip),hemodynamic,artery blood gas paremeters by using the Pressure Volume curve(P V curve) in patient with Acute Respiratory Distress Syndrome(ARDS) and to choose the favorate PEEP range.Methods:The pressure at lower inflexion point was set as P LIP and the upper inflexion point as P LIP . We studied 16 ARDS patients with mechanical ventilation under different PEEP(0,P LIP /2,P LIP ,(P LIP P UIP )/2,P UIP by using the Pressure Volume curve.Results:Although PaO 2/FiO 2 and Cst increased significantly when PEEP was at P LIP /2 compaired with PEEP at 0(P<0.05 and P<0.01),they didn't reach normal level yet. They increasead significantly when PEEP was at P LIP , and PaO 2/FiO 2 almost reached norml level and it had no obivous side effect on hemodynamic,compared with PEEP at P LIP /2(P<0.01). When PEEP was at P UIP , although PaO 2/FiO 2 and Pip increased significantly(P<0.01) in contrast to PEEP at (P LIP P UIP )/2. Cst decreased(P<0.01),MAP decreased(P<0.05),and CVP increased(P<0.01).Conclusion:We can control hypoxaemia and gain the least side effect when PEEP ranges from P LIP to P UIP .