title: Rationale and study design of ViPS - variable pressure support for weaning from mechanical ventilation: study protocol for an international multicenter randomized controlled open trial.
abstract: BACKGROUND
  In pressure support ventilation (PSV), a non-variable level of pressure support is delivered by the ventilator when triggered by the patient. In contrast, variable PSV delivers a level of pressure support that varies in a random fashion, introducing more physiological variability to the respiratory pattern. Experimental studies show that variable PSV improves gas exchange, reduces lung inflammation and the mean pressure support, compared to non-variable PSV. Thus, it can theoretically shorten weaning from the mechanical ventilator.
  
  
  METHODS
  The ViPS (variable pressure support) trial is an international investigator-initiated multicenter randomized controlled open trial comparing variable vs. non-variable PSV. Adult patients on controlled mechanical ventilation for more than 24 hours who are ready to be weaned are eligible for the study. The randomization sequence is blocked per center and performed using a web-based platform. Patients are randomly assigned to one of the two groups: variable PSV or non-variable PSV. In non-variable PSV, breath-by-breath pressure support is kept constant and targeted to achieve a tidal volume of 6 to 8 ml/kg. In variable PSV, the mean pressure support level over a specific time period is targeted at the same mean tidal volume as non-variable PSV, but individual levels vary randomly breath-by-breath. The primary endpoint of the trial is the time to successful weaning, defined as the time from randomization to successful extubation.
  
  
  CONCLUSIONS
  ViPS is the first randomized controlled trial investigating whether variable, compared to non-variable PSV, shortens the duration of weaning from mechanical ventilation in a mixed population of critically ill patients. This trial aims to determine the role of variable PSV in the intensive care unit.
  
  
  BACKGROUND
  clinicaltrials.gov NCT01769053.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kiss
authors.forename: Andreas
authors.initials: A
authors.lastname: Güldner
authors.forename: Thomas
authors.initials: T
authors.lastname: Bluth
authors.forename: Christopher
authors.initials: C
authors.lastname: Uhlig
authors.forename: Peter Markus
authors.initials: PM
authors.lastname: Spieth
authors.forename: Klaus
authors.initials: K
authors.lastname: Markstaller
authors.forename: Roman
authors.initials: R
authors.lastname: Ullrich
authors.forename: Samir
authors.initials: S
authors.lastname: Jaber
authors.forename: Jose Alberto
authors.initials: JA
authors.lastname: Santos
authors.forename: Jordi
authors.initials: J
authors.lastname: Mancebo
authors.forename: Luigi
authors.initials: L
authors.lastname: Camporota
authors.forename: Richard
authors.initials: R
authors.lastname: Beale
authors.forename: Guilherme
authors.initials: G
authors.lastname: Schettino
authors.forename: Felipe
authors.initials: F
authors.lastname: Saddy
authors.forename: Immaculada
authors.initials: I
authors.lastname: Vallverdú
authors.forename: Bärbel
authors.initials: B
authors.lastname: Wiedemann
authors.forename: Thea
authors.initials: T
authors.lastname: Koch
authors.forename: Marcus Josephus
authors.initials: MJ
authors.lastname: Schultz
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Dresden, Technische Universität Dresden, Dresden, Germany. mgabreu@uniklinikum-dresden.de.
authors.forename: Marcelo Gama
authors.initials: MG
authors.lastname: de Abreu
mesh_terms: D002985:Clinical Protocols; D006801:Humans; D007362:Intensive Care Units; D008168:Lung / Q000503:physiopathology*; D011312:Pressure; D020127:Recovery of Function; D012107:Research Design; D012121:Respiration, Artificial; D013997:Time Factors; D016896:Treatment Outcome; D015300:Ventilator Weaning / Q000379:methods*