title: Patient-ventilator asynchrony during noninvasive ventilation: a bench and clinical study.
abstract: BACKGROUND
  Different kinds of ventilators are available to perform noninvasive ventilation (NIV) in ICUs. Which type allows the best patient-ventilator synchrony is unknown. The objective was to compare patient-ventilator synchrony during NIV between ICU, transport—both with and without the NIV algorithm engaged—and dedicated NIV ventilators.
  
  
  METHODS
  First, a bench model simulating spontaneous breathing efforts was used to assess the respective impact of inspiratory and expiratory leaks on cycling and triggering functions in 19 ventilators. Second, a clinical study evaluated the incidence of patient-ventilator asynchronies in 15 patients during three randomized, consecutive, 20-min periods of NIV using an ICU ventilator with and without its NIV algorithm engaged and a dedicated NIV ventilator. Patient-ventilator asynchrony was assessed using flow, airway pressure, and respiratory muscles surface electromyogram recordings.
  
  
  RESULTS
  On the bench, frequent auto-triggering and delayed cycling occurred in the presence of leaks using ICU and transport ventilators. NIV algorithms unevenly minimized these asynchronies, whereas no asynchrony was observed with the dedicated NIV ventilators in all except one. These results were reproduced during the clinical study: The asynchrony index was significantly lower with a dedicated NIV ventilator than with ICU ventilators without or with their NIV algorithm engaged (0.5% [0.4%-1.2%] vs 3.7% [1.4%-10.3%] and 2.0% [1.5%-6.6%], P < .01), especially because of less auto-triggering.
  
  
  CONCLUSIONS
  Dedicated NIV ventilators allow better patient-ventilator synchrony than ICU and transport ventilators, even with their NIV algorithm. However, the NIV algorithm improves, at least slightly and with a wide variation among ventilators, triggering and/or cycling off synchronization.
authors.affiliation: Réanimation Médicale, AP-HP, Groupe Hospitalier Albert Chenevier-Henri Mondor, Rouen, France; INSERM Unité 955 (Equipe 13), Université Paris EST, Créteil, France. Electronic address: guillaume.carteaux@yahoo.fr.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Carteaux
authors.affiliation: Réanimation Médicale, AP-HP, Groupe Hospitalier Albert Chenevier-Henri Mondor, Rouen, France; INSERM Unité 955 (Equipe 13), Université Paris EST, Créteil, France.
authors.forename: Aissam
authors.initials: A
authors.lastname: Lyazidi
authors.affiliation: Réanimation Médicale, AP-HP, Groupe Hospitalier Albert Chenevier-Henri Mondor, Rouen, France; INSERM Unité 955 (Equipe 13), Université Paris EST, Créteil, France.
authors.forename: Ana
authors.initials: A
authors.lastname: Cordoba-Izquierdo
authors.affiliation: Department of Intensive Care, Geneva University Hospital and Geneva University, Geneva.
authors.forename: Laurence
authors.initials: L
authors.lastname: Vignaux
authors.affiliation: Service de Médecine Intensive Adulte et Centre des brulés, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; Faculté de biologie et de medicine, Université de Lausanne, Lausanne, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Jolliet
authors.affiliation: Réanimation Médicale, AP-HP, Groupe Hospitalier Albert Chenevier-Henri Mondor, Rouen, France; INSERM Unité 955 (Equipe 13), Université Paris EST, Créteil, France.
authors.forename: Arnaud W
authors.initials: AW
authors.lastname: Thille
authors.affiliation: Réanimation médicale, Centre Hospitalier Universitaire Charles Nicolle, Rouen, France.
authors.forename: Jean-Christophe M
authors.initials: JM
authors.lastname: Richard
authors.affiliation: Réanimation Médicale, AP-HP, Groupe Hospitalier Albert Chenevier-Henri Mondor, Rouen, France; INSERM Unité 955 (Equipe 13), Université Paris EST, Créteil, France; Department of Intensive Care, Geneva University Hospital and Geneva University, Geneva.
authors.forename: Laurent
authors.initials: L
authors.lastname: Brochard
mesh_terms: D000368:Aged; D000465:Algorithms; D003422:Critical Care; D018592:Cross-Over Studies; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011175:Positive-Pressure Respiration / Q000295:instrumentation*; D012131:Respiratory Insufficiency / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D012132:Respiratory Muscles / Q000503:physiopathology; D014187:Transportation of Patients; D012122:Ventilators, Mechanical