title: Comparison of nasal continuous positive airway pressure delivered by seven ventilators using simulated neonatal breathing.
abstract: OBJECTIVE
  Nasal continuous positive airway pressure (NCPAP) is an established treatment for respiratory distress in neonates. Most modern ventilators are able to provide NCPAP. There have been no large studies examining the properties of NCPAP delivered by ventilators. The aim of this study was to compare pressure stability and imposed work of breathing (iWOB) for NCPAP delivered by ventilators using simulated neonatal breathing.
  
  
  METHODS
  Experimental in vitro study.
  
  
  METHODS
  Research laboratory in Sweden.
  
  
  METHODS
  None.
  
  
  RESULTS
  Neonatal breathing was simulated using a mechanical lung simulator. Seven ventilators were tested at different CPAP levels using two breath profiles. Pressure stability and iWOB were determined. Results from three ventilators revealed that they provided a slight pressure support. For these ventilators, iWOB could not be calculated. There were large differences in pressure stability and iWOB between the tested ventilators. For simulations using the 3.4-kg breath profile, the pressure swings around the mean pressure were more than five times greater, and iWOB more than four times higher, for the system with the highest measured values compared with the system with the lowest. Overall, the Fabian ventilator was the most pressure stable system. Evita XL and SERVO-i were found more pressure stable than Fabian in some simulations. The results for iWOB were in accordance with pressure stability for systems that allowed determination of this variable.
  
  
  CONCLUSIONS
  Some of the tested ventilators unexpectedly provided a minor degree of pressure support. In terms of pressure stability, we have not found any advantages of ventilators as a group compared with Bubble CPAP, Neopuff, and variable flow generators that were tested in our previous study. The variation between individual systems is great within both categories. The clinical importance of these findings needs further investigation.
authors: Department of Woman and Child Health, Karolinska Institutet, Stockholm, Sweden. thomas.drevhammar@jll.se
authors: Thomas
authors: T
authors: Drevhammar
authors: Kjell
authors: K
authors: Nilsson
authors: Henrik
authors: H
authors: Zetterström
authors: Baldvin
authors: B
authors: Jonsson
mesh_terms: D045422:Continuous Positive Airway Pressure / Q000295:instrumentation*; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000502:physiology; D008954:Models, Biological; D011312:Pressure; D012122:Ventilators, Mechanical; D014939:Work of Breathing