神经电活动辅助通气和压力支持通气对呼吸衰竭患者呼吸形式的影响

Effect of neurally adjusted ventilatory assist and pressure support ventilation on respiratory pattern of patients with acute respiratory failure

目的观察神经电活动辅助通气(NAVA)和压力支持通气(PSV)对急性呼吸衰竭患者呼吸形式的影响。方法以2018年1月至2019年6月入住苏北人民医院ICU的12例急性呼吸衰竭行机械通气患者为研究对象,随机选择NAVA或PSV模式进行通气,NAVA和PSV通气支持水平均从5 cmH_(2)O(1 cmH_(2)O=0.098 kPa)开始,分4步递增,每10 min增加1次。PSV压力支持水平分别为5、10、15、20 cmH_(2)O,分别记为PSV1~4组。NAVA组的支持水平每10 min增加1倍,分别为起始NAVA支持水平的1、2、3、4倍,分别记为HAVA1~4组。观察不同支持条件下(PSV1~4组及NAVA1~4组)潮气量(VT)、气道峰压(Ppeak)、呼吸机通气频率(VRR)、中枢呼吸频率(NRR)、膈肌电活动峰值(EAdipeak)、动脉血二氧化碳分压(PaCO2)、无效触发发生情况、呼吸机送气时间(T_(i-flow))、呼吸机呼气时间(T_(e-flow))、神经吸气时间(T_(i-neu))、神经呼气时间(T_(e-neu))、总体VT变异度等指标。结果(1)随着通气支持水平的增加,PSV1~4组VT、无效触发显著增加,VRR、NRR均明显减慢,组内比较差异均有统计学意义(F=13.471,F=30.521,F=13.672,F=9.357,P<0.05);PSV3~4组的VT较同时点NAVA3~4组均显著增加,PSV4组无效触发显著高于NAVA4组,差异均有统计学意义(P<0.05);NAVA1~4组组内各时点的VT比较,差异无统计学意义(P>0.05)。(2)随着通气支持水平的增加,PSV1~4组组内各时点的Ti-neu,以及NAVA1~4组组内各时点的T_(i-flow)、T_(e-flow)、Ti-neu、T_(e-neu)均无显著增加,差异无统计学意义(P>0.05);PSV1~4组T_(i-flow)、T_(e-flow)、T_(e-neu)显著增加,组内比较差异均有统计学意义(F=9.564,F=13.431,F=21.126,P<0.05);PSV4组T_(i-flow)、T_(e-flow)、T_(e-neu)分别显著高于NAVA4组,差异均有统计学意义(P均<0.05)。(3)NAVA组总体VT变异度显著高于PSV组,差异有统计学意义(P<0.05);NAVA组Ppeak和EAdi显著相关(r=0.96±0.14,P<0.05)。(4)PSV4组的PaCO2较PSV1组显著降低,差异有统计学意义(P<0.05)。结论与PSV相比,NAVA通气支持时间、通气支持水平与自身呼吸形式更加匹配,对呼吸形式影响更小,一定程度上避免通气不足和过度通气。

Objective To determine the effect of neurally adjusted ventilatory assist(NAVA)and pressure support ventilation(PSV)on respiratory pattern in patients with acute respiratory failure(ARF).Methods 12 ARF patients received mechanical ventilation admitted in Department of Critical Care Medicine of Northern Jiangsu People's Hospital from January 2018 to June 2019 were enrolled in the study.Patients were.randomly received NAVA and PSV.The ventilation support level of NAVA and PSV started from 5 cmH_(2)O and increased in four steps every 10 min.The pressure support levels in PSV group were 5,10,15 and 20 cmH_(2)O,respectively.The NAVA level were 1,2,3 and 4 times of the initial NAVA level in NAVA group.Parameters of the respiratory pattern and gas exchange were recorded at the same time at each time point of PSV and NAVA group.Results(1)As ventilation support levels increase,the tidal volume(Vt),invalid trigger increased significantly,VRR,NRR decreased significantly in PSV1-4(F=13.471,F=30.521,F=13.672,F=9.357,P<0.05);VT in PSV3-4 increased significantly compared with NAVA3-4 in concurrent point,invalid trigger in PSV4 increased significantly compared with NAVA4(P<0.05);the comparison of VT in each points in NAVA1-4 were not statistically significant(P>0.05).(2)Ti-neu at each point in PSV1-4,and T_(i-flow),T_(e-flow),Ti-neu,T_(e-neu)in the NAVA1-4 had no statistical significance(P>0.05);the in-group comparison with T_(i-flow),T_(e-flow),T_(e-neu)in PSV1-4 had significant differences(F=9.564,F=13.431,F=21.126,P<0.05);T_(i-flow),T_(e-flow),T_(e-neu)in PSV4 was significantly higher than that in NAVA4,respectively(P<0.05).(3)The Vt variability in NAVA group(21.7%±9.3%)was significantly higher than that in PSV group(10.7%±4.8%)(F=13.136,P<0.05).The peak airway pressure(Ppeak)in NAVA group was always closely related to the diaphragm electrical activity(EAdi)(r=0.96±0.14,P<0.05).(4)The arterial blood carbon dioxide(PaCO2)in PSV4 was significantly lower than that in PSV1(P<0.05).Conclusion Compared with PSV,the ventilation time and the support level in NAVA were more compatible with patient's own breathing pattern,and NAVA had less effects on the physiological breathing pattern andmight avoid insufficient or hyperinflation to some extent.