The Application Of Neurally Adjusted Ventilation Assist On Patients With Acute Exacerbation Of Chronic Obstructive Pulmonary Disease

Objective: To evaluate the clinical application of neurally adjusted ventilation assist(NAVA)on the treatment of patients with respiratory failure in the acute exacerbation of chronic obstructive pulmonary diseases(AECOPD),by comparing the difference between NAVA and conventional synchronized intermittent mandatory ventilation with pressure support ventilation(SIMV+PSV),and analyzing the clinical data such as patient-ventilator interaction,respiratory load,serum inflammatory factor levels,rate of direct weaning and total mechanical ventilation time during menchanical ventilation.Methods: A prospective,randomized controlled trial was conducted in 60 mechanically ventilated patients with respiratory failure in AECOPD who were randomly allocated to NAVA group(n=30)and SIMV+PSV group(n=30).The parameters of arterial blood gas were measured at 0,6 hours,respectively.The parameters of patient-ventilator interaction such as trigger delay time,cycling-off delay time,ineffective trigger number and ineffective trigger index were analysed with NAVA-Tracker software at 1,24,48,72 hours,respectively;and the parameters of respiratory mechanics such as peak airway pressure,peak electrical activity of diaphragm,patient’s work of breathing and ventilator’s work of breathing were measured.The total mechanical ventilation time and rate of direct weaning from mechanical ventilation were also observed.The levels of interleukin-6 and interleukin-8 in serum were detected by enzyme-linked immunosorbent assay at 0,24,48,72 hours of mechanical ventilation,respectively.Results:1.There was no statistical difference between the treatment effects of the two groups in the treatment of AECOPD complicated with respiratory failure(P > 0.05).2.The trigger delay time,cycling-off delay time and patient’s work of breathing in the NAVA group were statistically lower than those in the SIMV+PSV group at 1,24,48,72 hours(P < 0.05).No ineffective trigger was observed in NAVA group,and ineffective trigger count and ineffective trigger index were statistically different between NAVA group and SIMV + PSV group(P < 0.05).Magnitude of assist: in NAVA group,the peak airway pressure had a significant positive correlation with the peak electrical activity of diaphragm(linear correlation coefficient 0.95,P < 0.05).But there was no correlation between peak airway pressure and peak electrical activity of diaphragm in SIMV+PSV group(P > 0.05).3.Compared with SIMV+PSV group,the serum inflammatory factor levels related to ventilation-associated lung injury were lower in NAVA group: the serum interleukin-6 and interleukin-8 levels were not statistically different between two group when the patients underwent mechanical ventilation at 0 hour(P > 0.05);Within 72 hours of mechanical ventilation,the serum interleukin-6 and interleukin-8 levels revealed an overall downward trend in NAVA group,but the serum interleukin-6 level displayed a upward trend in SIMV+PSV group and its interleukin-8 level in 48 hours decreased gradually first and then increased.4.There was no significant difference in the rates of direct weaning from mechanical ventilation between the two groups(P > 0.05).But in NAVA group,the total mechanical ventilation time was statistically lower than that in SIMV+PSV group(P < 0.05).Conclusions: Compared with SIMV+PSV,NAVA could significantly improve the patient-ventilation interaction in mechanically ventilated patients with AECOPD complicated with respiratory failure,reducing respiratory load and the risk of ventilator-associated lung injury,and shortening the duration of mechanical ventilation;therefore it may improve the prognosis of patients.