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Patient-ventilator asynchrony in preterm infants on nasal intermittent positive pressure ventilation
  1. Cornelia G de Waal1,
  2. Ruud W van Leuteren1,
  3. Frans H de Jongh1,
  4. Anton H van Kaam1,2,
  5. Gerard J Hutten1
  1. 1 Department of Neonatology, Emma Children’s Hospital, Academic Medical Center, Amsterdam, The Netherlands
  2. 2 Department of Neonatology, VU University Medical Center, Amsterdam, The Netherlands
  1. Correspondence to Cornelia G de Waal, Department of Neonatology, Emma Children’s Hospital, Academic Medical Center, Amsterdam 1100 DD, The Netherlands; c.g.dewaal{at}


Objective To describe the incidence of patient-ventilator asynchrony and different types of asynchrony in preterm infants treated with non-synchronised nasal intermittent positive pressure ventilation (nIPPV).

Design An observational study was conducted including preterm infants born with a gestational age (GA) less than 32 weeks treated with non-synchronised nIPPV. During 1 hour, spontaneous breathing was measured with transcutaneous electromyography of the diaphragm simultaneous with ventilator inflations. An asynchrony index (AI), a percentage of asynchronous breaths, was calculated and the incidence of different types of inspiratory and expiratory asynchrony were reported.

Results Twenty-one preterm infants with a mean GA of 26.0±1.2 weeks were included in the study. The mean inspiratory AI was 68.3%±4.7% and the mean expiratory AI was 67.1%±7.3%. Out of 5044 comparisons of spontaneous inspirations and mechanical inflations, 45.3% of the mechanical inflations occurred late, 23.3% of the mechanical inflations were early and 31.4% of the mechanical inflation were synchronous. 40.3% of 5127 expiratory comparisons showed an early termination of ventilator inflations, 26.7% of the mechanical inflations terminated late and 33.0% mechanical inflations terminated in synchrony with a spontaneous expiration. In addition, 1380 spontaneous breaths were unsupported and 611 extra mechanical inflations were delivered.

Conclusion Non-synchronised nIPPV results in high patient-ventilator asynchrony in preterm infants during both the inspiratory and expiratory phase of the breathing cycle. New synchronisation techniques are urgently needed and should address both inspiratory and expiratory asynchrony.

  • neonatology
  • respiratory
  • technology
  • intensive care
  • monitoring

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  • Contributors CGdeW, FHdJ, AHvK, GJH contributed to the conception and study design. All authors contributed to the collection, analysis and interpretation of data; drafting the manuscript for important intellectual content and decision to submit the paper for publication.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent Not required.

  • Ethics approval Medical Ethics Committee AMC Amsterdam.

  • Provenance and peer review Not commissioned; externally peer reviewed.