利用压力-容积曲线呼气支最大曲率拐点选择PEEP对ARDS患者氧合及血流动力学的影响

摘要

Objective To investigate the effects of positive end - expiratory pressure ( PEEP) by using the point of maximum curvature ( PMC) of the pressure - volume( P - V) curves deflation limb on oxygenation and hemodynamics in patients with acute respiratory distress syndrome ( ARDS). Methods Static lung P - V curves were analyzed and the lower inflection point ( LIP) and PMC from static P - V curves were determined in 25 patients with ARDS. To set ventilative PEEP by using PMC and LIP of P - V curves, 25 patients were randomized in two groups: PPMC group and PLIP group after recruitment maneuver ( RM). The effects of PEEP on gas exchange, homodynamic and airway pressure were observed in the two groups. Results PaO2/FiO2 and Cdyn in the two groups of patients were significantly increased shortly after RM, PaO2/FiO2 were higher in PPMC group at 1, 2, 4 h after RM than in PLIP group( P < 0. 05 ) . The Cdyn in PLIP group dropped very quickly, while the Cdyn were higher in PPMC group at 1, 2 h after RM than in PLIP group ( P < 0. 05 ) . In both two groups, MAP and CVP decreased, and HR increased during RM(P <0. 01) , HR, MAP recovered soon after RM. CVP in PPMC group increased till 2 h after RM(P <0. 05). Conclusion The PEEP by using the point of maximum curvature of the pressure - volume curves deflation limb improves oxygenation and compliance of the respiratory system and has no obvious adverse effect on hemodynamics.%目的 探讨利用压力-容积(P-V)曲线呼气支最大曲率拐点选择呼气末正压(PEEP)对急性呼吸窘迫综合征(ARDS)患者氧合及血流动力学影响.方法 选取25例ARDS患者,采用肺保护性通气,肺复张(RM)后随机分为两组:利用P-V曲线呼气支最大曲率拐点设置PEEP组(PPMC)和以P-V曲线低位拐点设置PEEP组(PLIP),观察并比较RM前后两组患者PaO2/FiO2、呼吸系统动态顺应性(Cdyn)、心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)等指标的变化.结果 RM后两组患者短时间内PaO2/FiO2和Cdyn均明显增加,PPMC组PaO2/FiO2在RM后1、2、4 h较PLIP组升高(P<0.05).PLIP组Cdyn在RM后很快降至RM前水平,PPMC组Cdyn在RM后1、2 h高于PLIP组(P<0.05).两组RM时均有MAP、CVP下降,HR升高(P<0.01);HR、MAP在RM后很快恢复,PPMC组CVP持续升高至RM后2 h(P<0.05).结论 RM后利用P-V曲线呼气支最大曲率拐点选择PEEP可以使氧合及呼吸系统顺应性改善更为明显,对血流动力学无严重的不良影响.