Comparation of neurally adjusted ventilator assist and synchronized intermittent mandatory ventilation on respiratory function in premature infants with respiratory distress syndrome

Objective To investigate the effect of neurally adjusted ventilator assist(NAVA) and synchronized intermittent mandatory ventilation(SIMV) on respiratory function in premature infants with respiratory distress syndrome. Methods A total of 54 preterm infants who were diagnosed neonatal respiratory distress syndrome after birth and needed invasion mechanical ventilation in our hospital from Oct.2014 to Dec.2016 were given SIMV for 4 hours and NAVA mode ventilation for 4 hours, with a total of 4 cycles.The peak inspiratory pressure(PIP), tidal volume(TV), Compliance, respiratory rate(RR), Edi peak, Edi min, FiO2 and mean airway pressure(MAP) were monitored every 30 minutes, and pressure of carbon dioxide(PaCO2)were monitored every 2 hours in different modes. Results The mean values of PIP[(19.5±3.1) cmH2O, 1 cmH2O=0.098 kPa], RR[(51.4±7.9)breaths/min], Edi peak[(5.1±3.2)μV], FiO2[(38.2±12.9)%], MAP[(12.0±0.8)cmH2O], PaCO2[(41.2±9.3)mmHg, 1 mmHg=0.133 kPa] and Edi min[(1.2±1.4)μV] in NAVA mode were significantly lower than those in SIMV mode[(22.9±3.4)cmH2O, (56.9±8.3)breaths/min, (7.9±4.9)μV, (39.9±14.1)%, (13.2±0.7)cmH2O, (47.1±10.4)mmHg, (2.0±1.7)μV, respectively](P<0.05). But the mean values of TV, Compliance in SIMV mode[(6.2±1.0)ml/kg, (0.25±0.33)ml/cmH2O, respectively] were significantly lower than those in the NAVA mode[(7.2±0.9)ml/kg, (0.37±0.21)ml/cmH2O, respectively](P<0.05). The downward trend of PIP, RR, Edi peak, FiO2, Edi min, MAP and upward trend of TV, Compliance were found during the first circle from NAVA mode to SIMV mode.The decrease and increase of above ventilator parameters were more obvious in NAVA mode compared with SIMV mode. Conclusion The respiratory muscle load is reduced, TV increases, and pulmonary compliance improves during NAVA ventilation.NAVA is better than SIMV in improving respiratory function of premature infants with respiratory distress syndrome.NAVA has lung protective effect. Key words: Neurally adjusted ventilator assist; Synchronized intermittent mandatory ventilation; Respiratory distress syndrome; Premature infants