title: Seven Ventilators Challenged With Leaks During Neonatal Nasal CPAP: An Experimental Pilot Study.
abstract: BACKGROUND
  Nasal CPAP is the most common respiratory support for neonates. Several factors are considered important for effective treatment, including leaks at the patient interface and the delivery of pressure-stable CPAP. Investigations of pressure stability during leaks should include both the change in the mean delivered CPAP and the pressure variation during each breath. The aim of this study was to examine the response of ventilators delivering nasal CPAP when challenged with leaks at the patient interface.
  
  
  METHODS
  Seven ventilators providing nasal CPAP at 4 cm H2O were challenged with leaks during simulated neonatal breathing. Leak was applied for 15 consecutive breaths at a constant level (1-4 L/min).
  
  
  RESULTS
  The 2 aspects of pressure stability were evaluated by measuring the mean delivered CPAP and the amplitude of pressure swings before, during, and after leaks. The ability to maintain the delivered CPAP and the amplitude of pressure swings varied greatly among the 7 ventilators before, during, and after leaks. Four of the ventilators tested have built-in leak compensation.
  
  
  CONCLUSIONS
  There was no simple relationship between maintaining delivered CPAP during leaks and providing CPAP with low pressure swing amplitude. Maintaining the delivered CPAP and providing this without pressure swings are 2 separate aspects of pressure stability, and investigations concerning the clinical importance of pressure stability should address both aspects. This study also shows that compensation for leaks does not necessarily provide pressure-stable CPAP.
authors.affiliation: Department of Women's and Children's Health, Karolinska Institutet, Stockholm Department of Anaesthesiology, Östersund Hospital, Östersund thomas.drevhammar@regionjh.se.
authors.forename: Thomas
authors.initials: T
authors.lastname: Drevhammar
authors.affiliation: Ventinvent AB, Östersund.
authors.forename: Kjell
authors.initials: K
authors.lastname: Nilsson
authors.affiliation: Department of Surgical Sciences, Anaesthesiology and Critical Care Medicine, Uppsala, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterström
authors.affiliation: Department of Women's and Children's Health, Karolinska Institutet, Stockholm.
authors.forename: Baldvin
authors.initials: B
authors.lastname: Jonsson
mesh_terms: D045422:Continuous Positive Airway Pressure / Q000295:instrumentation* / Q000592:standards; D004867:Equipment Design; D004868:Equipment Failure; D006801:Humans; D007231:Infant, Newborn; D009666:Nose; D010865:Pilot Projects; D012122:Ventilators, Mechanical / Q000706:statistics & numerical data*
keywords: continuous positive airway pressure; equipment design; infant newborn; intensive care; mechanical; neonatal; ventilators; work of breathing