title: [Risk of barotrauma when using non-reinhalation Waters valves: a comparative study on bench test].
abstract: OBJECTIVE
  Manual ventilation is delivered in the operating room or the intensive care unit to intubated or non-intubated patients, using non-rebreathing systems such as the Waters valve. New generation Waters valves are progressively replacing the historic Waters valve. The aim of this study was to evaluate maximal pressure delivered by these 2 valves.
  
  
  METHODS
  Bench test.
  
  
  METHODS
  Thirty-two different conditions were tested, according to 2 oxygen flow rates (10 and 20L/min), without (static condition) or with manual insufflations (dynamic condition) and 4 valve expiratory opening pressures. The primary endpoint was maximal pressure measured at the exit of the valve, connected to a model lung and a bench test.
  
  
  RESULTS
  Measured pressures were different for most evaluated conditions. Increasing oxygen flow from 10 to 20L/min increased maximal pressure for both valves. Increasing valve expiratory opening pressure induced a significant increase in maximal pressure for the new generation valve (from 4 to 61cmH2O in static conditions and from 18 to 68cmH2O in dynamic conditions). For the historic valve, maximal pressure increased significantly but remained below 15cmH2O in both static and dynamic conditions.
  
  
  CONCLUSIONS
  Use of new generation Waters valves should be different from historic Waters valves. Indeed, barotrauma could be caused by badly adapted valve expiratory opening pressure settings.
authors.affiliation: Département d'anesthésie-réanimation St-Éloi, CHU de Montpellier, 80, avenue Augustin-Fliche, 34295 Montpellier cedex 5, France; Inserm U1046, université Montpellier 1, 34000 Montpellier, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Coisel
authors.forename: F
authors.initials: F
authors.lastname: Galia
authors.forename: M
authors.initials: M
authors.lastname: Conseil
authors.forename: B
authors.initials: B
authors.lastname: Jung
authors.forename: G
authors.initials: G
authors.lastname: Chanques
authors.forename: S
authors.initials: S
authors.lastname: Jaber
mesh_terms: D000399:Air Pressure; D001469:Barotrauma / Q000453:epidemiology*; D023381:Endpoint Determination; D004867:Equipment Design; D006801:Humans; D007327:Insufflation / Q000009:adverse effects; D010100:Oxygen / Q000008:administration & dosage / Q000032:analysis; D011175:Positive-Pressure Respiration / Q000295:instrumentation; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000295:instrumentation*; D018570:Risk Assessment
chemical_list: D010100:Oxygen
keywords: Barotrauma; Barotraumatisme; Manual ventilation; Non-rebreathing expiratory valve; Valve expiratoire de non-réinhalation; Ventilation manuelle