Franc ¸ois Lellouche Pierre-Alexandre Bouchard Serge Simard Erwan L’Her Marc Wysocki Evaluation of fully automated ventilation: a randomized controlled study in post-cardiac surgery patients Received: 26 July 2012 Accepted: 14 November 2012 Published online: 22 January 2013 Ó Springer-Verlag Berlin Heidelberg and ESICM 2013 Trial registration number: NCT01090258. Electronic supplementary material The online version of this article (doi:10.1007/s00134-012-2799-2) contains supplementary material, which is available to authorized users. F. Lellouche ( ) ) Á P.-A. Bouchard Á S. Simard Centre de recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Que ´bec, Universite ´ Laval, 2725, chemin Sainte-Foy, Quebec City, QC G1V 4G5, Canada e-mail: Francois.Lellouche@criucpq. ulaval.ca Tel.: ?1-418-6568711 Fax: ?1-418-6564509 E. L’Her Ho ˆtel Dieu de Le ´vis, Quebec City, Canada E. L’Her Centre Hospitalier Universitaire La Cavale Blanche, Brest, France M. Wysocki GE Healthcare, Life Care Solution Europe, Buc, France e-mail: marc.wysocki@ge.com Abstract Purpose: Discrepancies between the demand and availability of clinicians to care for mechanically ventilated patients can be anticipated due to an aging population and to increasing severity of illness. The use of closed-loop ventilation provides a potential solution. The aim of the study was to evaluate the safety of a fully automated ventilator. Methods: We conducted a random- ized controlled trial comparing automated ventilation (AV) and pro- tocolized ventilation (PV) in 60 ICU patients after cardiac surgery. In the PV group, tidal volume, respiratory rate, FiO 2 and positive end-expiratory pressure (PEEP) were set according to the local hospital protocol based on currently available guidelines. In the AV group, only sex, patient height and a maximum PEEP level of 10 cmH 2 O were set. The primary end- point was the duration of ventilation within a ‘‘not acceptable’’ range of tidal volume. Zones of optimal, acceptable and not acceptable venti- lation were based on several respiratory parameters and defined a priori. Results: The patients were assigned equally to each group, 30 to PV and 30 to AV. The percentage of time within the predefined zones of optimal, acceptable and not accept- able ventilation were 12 %, 81 %, and 7 % respectively with PV, and 89.5 %, 10 % and 0.5 % with AV (P \ 0.001). There were 148 inter- ventions required during PV compared to only 5 interventions with AV (P \ 0.001). Conclusion: Fully AV was safe in hemodynamically stable patients immediately following cardiac surgery. In addition to a reduction in the number of interven- tions, the AV system maintained patients within a predefined target range of optimal ventilation. Keywords Positive-pressure respiration Á Randomized trial Á Closed-loop Á Thoracic surgery Á Cardiac surgery Á Mechanical ventilation Introduction Discrepancies between demand (the number of patients requiring mechanical ventilation) and supply (the number of skilled clinicians available to manage these patients) are anticipated to become more frequent due to an aging population and to increasing severity of illness in patients [1, 2]. Costs related to ICU patients represent a major burden for healthcare systems [3] and they are largely driven by costs pertaining to mechanically ventilated Intensive Care Med (2013) 39:463–471 DOI 10.1007/s00134-012-2799-2 ORIGINAL