一氧化氮吸入复合呼气末正压治疗羊感染性急性呼吸窘迫综合征

Effect of the combination of inhaled nitric oxide and positive end expiratory pressure ventilation on sheep endotoxin-induced acute respiratory distress syndrome

目的 观察一氧化氮 (NO)吸入复合呼气末正压 (PEEP)通气对羊感染性急性呼吸窘迫综合征 (ARDS)血流动力学、肺气体交换和机械力学的影响。方法 静脉注入小剂量内毒素诱导的羊感染性ARDS模型 12只 ,随机均分为两组 ,NO组 :吸入 40ppmNO ;复合组 :PEEP(6cmH2 O)通气复合吸入 40ppmNO。通过肺动脉导管和动脉血气分析 ,测定基础、ARDS和治疗 3 0min后肺气体交换和血流动力学参数 ,记录相应时点的气道峰压 (PIP)、平均气道压 (Pm)。结果 NO组和复合组治疗期间平均肺动脉压较ARDS时显著降低 (P <0 0 1) ,动脉血压和心输出量则无明显变化 ;治疗 3 0min后 ,两组ARDS的PaO2 均明显升高 (P <0 0 1) ,肺泡动脉氧分压差 (P(A -a)O2 )和肺内分流 (Qs/Qt)显著减少 (P <0 0 1) ,复合组比NO组更为显著 (P<0 0 5 ) ;NO组各监测时点PIP、Pm均无明显变化 ,复合组的PIP、Pm较治疗前明显增高 (P <0 0 5 )。结论 吸入NO复合PEEP通气协同改善ARDS肺氧合 。

Objective To observe the effect of the combination of inhaled nitric oxide (NO) and positive end expiratory pressure (PEEP) ventilation on lung gas exchange and hemodynamics in sheep endotoxin-induced acute respiratory distress syndrome (ARDS). Methods ARDS sheep model was induced by intravenously infusion low dose endotoxin, then animals were randomly divided into two groups. ①NO group (n=6) inhaled 40 ppm NO.②Combination group(n=6) received mechanical ventilation with PEEP(6 cmH 2O) and inhaled 40 ppm NO. The parameters of lung gas exchange and hemodynamics were measured at baseline, ARDS and 30 minutes after treatment. Results The combination of PEEP and 40ppm NO inhalation rapidly reduced mean pulmonary arterial pressure (MPAP) of ARDS (P<0.01), increased PaO 2(P<0.01), decreased P (A-a) O 2 and Qs/Qt (P<0.01) without causing significant change on systemic hemodynamics, and it was more effective method for avoiding hypoxemia than inhaled nitric oxide alone. The airway pressure of the model remained unchangable in NO group, but PEEP plus inhaled NO resulted in increase of peak inspiratory pressure(PIP) and mean airway pressure(Pm). Conclusion The combination of PEEP and inhaled NO had an additive effect on lung gas exchange in sheep endotoxin-induced acute respiratory distress syndrome.