神经电活动辅助通气模式和压力支持通气模式对急性呼吸窘迫综合征患者肺内气体分布影响的比较

摘要

目的：比较神经电活动辅助通气(NAVA)模式和压力支持通气(PSV)模式对急性呼吸窘迫综合征(ARDS)患者肺内气体分布的影响。方法本研究纳入18例符合标准的 ARDS 机械通气患者,男11例,女7例,采用单盲随机自对照的研究方法,同一患者以随机先后顺序应用 NAVA和 PSV 模式分别通气30 min,在通气0、30 min 时观察气体交换、血流动力学指标,对呼吸参数、人机同步性以及电阻抗断层摄影监测的肺气体分布均进行持续监测分析。结果与 PSV 比较,两种模式下 HR、MAP、PIP 及 PEEP 差异无统计学意义；NAVA 模式改善 ARDS 患者氧合指数(P <0.05),减少人机不同步事件的发生(P <0.05),增加重力依赖区 ROI 3、4区通气,减少非重力依赖区ROI 1、2区通气(P <0.05)。结论与 PSV 比较,NAVA 可以改善 ARDS 患者气体交换和人机同步性,改善肺内气体分布不均一性。%Objective To compare the effect of neurally adjusted ventilatory assist (NAVA) and pressure support ventilation (PSV)on the regional ventilation distribution in mechanically venti-lated patients with acute respiratory distress syndrome (ARDS).Methods Eighteen patients with ARDS were enrolled in this single centre,randomized cross over study.Patients were mechanically ventilated with NAVA or PSV for half-hour respectively,gas exchange,hemodynamics,respiratory mechanics,patient-ventilator synchrony and distribution of ventilation by electrical impedance tomo-graphy(EIT)were obtained.Results Hemodynamics and respiratory mechanics did not differ signifi-cantly between NAVA and PSV.Oxygenation index (PaO 2/FiO 2 )was improved in the NAVA group compare with PSV groups (P < 0.05 ).Number of asynchrony events was reduced in NAVA compared to PSV (P <0.05).Distribution of ventilation was increased in the dependent lung region (ROI 3 and 4)during NAVA,and decreased significantly in the nondependent (ROI 1 and 2)(P <0.05).Conclusion NAVA ventilation had a beneficial effect on patient-ventilator synchrony and gas exchange,compared to PSV,NAVA was associated with better improved the inhomogeneity distri-bution of ventilation.