title: Prospective randomized crossover study of a new closed-loop control system versus pressure support during weaning from mechanical ventilation.
abstract: BACKGROUND
  Intellivent is a new full closed-loop controlled ventilation that automatically adjusts both ventilation and oxygenation parameters. The authors compared gas exchange and breathing pattern variability of Intellivent and pressure support ventilation (PSV).
  
  
  METHODS
  In a prospective, randomized, single-blind design crossover study, 14 patients were ventilated during the weaning phase, with Intellivent or PSV, for two periods of 24 h in a randomized order. Arterial blood gases were obtained after 1, 8, 16, and 24 h with each mode. Ventilatory parameters were recorded continuously in a breath-by-breath basis during the two study periods. The primary endpoint was oxygenation, estimated by the calculation of the difference between the PaO2/FIO2 ratio obtained after 24 h of ventilation and the PaO2/FIO2 ratio obtained at baseline in each mode. The variability in the ventilatory parameters was also evaluated by the coefficient of variation (SD to mean ratio).
  
  
  RESULTS
  There were no adverse events or safety issues requiring premature interruption of both modes. The PaO2/FIO2 (mean ± SD) ratio improved significantly from 245 ± 75 at baseline to 294 ± 123 (P = 0.03) after 24 h of Intellivent. The coefficient of variation of inspiratory pressure and positive end-expiratory pressure (median [interquartile range]) were significantly higher with Intellivent, 16 [11-21] and 15 [7-23]%, compared with 6 [5-7] and 7 [5-10]% in PSV. Inspiratory pressure, positive end-expiratory pressure, and FIO2 changes were adjusted significantly more often with Intellivent compared with PSV.
  
  
  CONCLUSIONS
  Compared with PSV, Intellivent during a 24-h period improved the PaO2/FIO2 ratio in parallel with more variability in the ventilatory support and more changes in ventilation settings.
authors.affiliation: Intensive Care Unit, Anesthesiology and Critical Care Department B, Saint Eloi Teaching Hospital, Montpellier, France.
authors.forename: Noémie
authors.initials: N
authors.lastname: Clavieras
authors.forename: Marc
authors.initials: M
authors.lastname: Wysocki
authors.forename: Yannael
authors.initials: Y
authors.lastname: Coisel
authors.forename: Fabrice
authors.initials: F
authors.lastname: Galia
authors.forename: Matthieu
authors.initials: M
authors.lastname: Conseil
authors.forename: Gerald
authors.initials: G
authors.lastname: Chanques
authors.forename: Boris
authors.initials: B
authors.lastname: Jung
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Arnal
authors.forename: Stefan
authors.initials: S
authors.lastname: Matecki
authors.forename: Nicolas
authors.initials: N
authors.lastname: Molinari
authors.forename: Samir
authors.initials: S
authors.lastname: Jaber
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D059725:Interactive Ventilatory Support / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D016037:Single-Blind Method; D015300:Ventilator Weaning