title: Non-invasive neurally adjusted ventilatory assist in preterm infants: a randomised phase II crossover trial.
abstract: OBJECTIVE
  To compare non-invasive ventilation neurally adjusted ventilatory assist (NIV-NAVA) and non-invasive pressure support (NIV-PS) in preterm infants on patient-ventilator synchrony.
  
  
  METHODS
  A randomised phase II crossover trial.
  
  
  METHODS
  Neonatal intensive care units of two tertiary university hospitals in Korea.
  
  
  METHODS
  Preterm infants born <32 weeks.
  
  
  METHODS
  NIV-NAVA and NIV-PS were applied in random order after ventilator weaning. Data were recorded for sequential 5 min periods after 10 min applications of each mode.
  
  
  METHODS
  The electrical activity of the diaphragm (Edi), ventilator flow and pressure curves were compared to examine the trigger delay (primary outcome) and other parameters of patient-ventilator interaction (secondary outcomes) for each period.
  
  
  RESULTS
  Fifteen infants completed the protocol. Trigger delay (35.2±8.3 vs 294.6±101.9 ms, p<0.001), ventilator inspiratory time (423.3±87.1 vs 534.0±165.5 ms, p=0.009) and inspiratory time in excess (32.3±8.3% vs 294.6±101.9%, p=0.001) were lower during NIV-NAVA compared with NIV-PS. Maximum Edi (12.6±6.3 vs 16.6±8.7 μV, p=0.003), swing Edi (8.8±4.8 vs 12.2±8.7 μV, p=0.012) and peak inspiratory pressure (12.3±1.5 vs 14.7±2.7 cm H2O, p=0.003) were also lower during NIV-NAVA. The main asynchrony events during NIV-PS were ineffective efforts and autotriggering. All types of asynchronies except double triggering were reduced with NIV-NAVA. Asynchrony index was significantly lower during NIV-NAVA compared with NIV-PS (p<0.001). No significant differences in leakage, expiratory tidal volume or minute ventilation were observed, but the respiratory rate was lower during NIV-PS than during NIV-NAVA.
  
  
  CONCLUSIONS
  NAVA improved patient-ventilator synchrony and diaphragmatic unloading in preterm infants during non-invasive nasal ventilation even in the presence of large air leaks.
  
  
  BACKGROUND
  Registered with http://www.clinicaltrials.gov (NCT01877720).
authors.affiliation: Department of Paediatrics, Seoul National University Bundang Hospital, Kyeonggi, Korea.
authors.forename: Juyoung
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Paediatrics, Seoul National University Children's Hospital, Seoul, Korea.
authors.forename: Han-Suk
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Paediatrics, Seoul National University Children's Hospital, Seoul, Korea.
authors.forename: Young Hwa
authors.initials: YH
authors.lastname: Jung
authors.affiliation: Department of Paediatrics, Seoul National University Children's Hospital, Seoul, Korea.
authors.forename: Seung Han
authors.initials: SH
authors.lastname: Shin
authors.affiliation: Department of Paediatrics, Seoul National University Bundang Hospital, Kyeonggi, Korea.
authors.forename: Chang Won
authors.initials: CW
authors.lastname: Choi
authors.affiliation: Department of Paediatrics, Seoul National University Children's Hospital, Seoul, Korea.
authors.forename: Ee-Kyung
authors.initials: EK
authors.lastname: Kim
authors.affiliation: Department of Paediatrics, Seoul National University Bundang Hospital, Kyeonggi, Korea.
authors.forename: Beyong Il
authors.initials: BI
authors.lastname: Kim
authors.affiliation: Department of Paediatrics, Seoul National University Children's Hospital, Seoul, Korea.
authors.forename: Jung-Hwan
authors.initials: JH
authors.lastname: Choi
mesh_terms: D018592:Cross-Over Studies; D003964:Diaphragm / Q000502:physiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007363:Intensive Care Units, Neonatal; D059725:Interactive Ventilatory Support / Q000379:methods*; D008297:Male; D063087:Noninvasive Ventilation / Q000379:methods*; D056910:Republic of Korea; D015300:Ventilator Weaning
keywords: Intensive Care; Neonatology; Respiratory