Intensive Care Medicine

, Volume 34, Issue 10, pp 1788–1795 | Cite as

A randomised, controlled trial of conventional versus automated weaning from mechanical ventilation using SmartCare™/PS

  • Louise RoseEmail author
  • Jeffrey J. Presneill
  • Linda Johnston
  • John F. Cade



Preliminary assessment of an automated weaning system (SmartCare™/PS) compared to usual management of weaning from mechanical ventilation performed in the absence of formal protocols.

Design and setting

A randomised, controlled pilot study in one Australian intensive care unit.


A total of 102 patients were equally divided between SmartCare/PS and Control.


The automated system titrated pressure support, conducted a spontaneous breathing trial and provided notification of success (“separation potential”).

Measurements and results

The median time from the first identified point of suitability for weaning commencement to the state of “separation potential” using SmartCare/PS was 20 h (interquartile range, IQR, 2–40) compared to 8 h (IQR 2–43) with Control (log-rank = 0.3). The median time to successful extubation was 43 h (IQR 6–169) using SmartCare/PS and 40 (14–87) with Control (log-rank P = 0.6). Unadjusted, the estimated probability of reaching “separation potential” was 21% lower (95% CI, 48% lower to 20% greater) with SmartCare/PS compared to Control. Adjusted for other covariates (age, gender, APACHE II, SOFAmax, neuromuscular blockade, corticosteroids, coma and elevated blood glucose), these estimates were 31% lower (95% CI, 56% lower to 9% greater) with SmartCare/PS. The study groups showed comparable rates of reintubation, non-invasive ventilation post-extubation, tracheostomy, sedation, neuromuscular blockade and use of corticosteroids.


Substantial reductions in weaning duration previously demonstrated were not confirmed when the SmartCare/PS system was compared to weaning managed by experienced critical care specialty nurses, using a 1:1 nurse-to-patient ratio. The effect of SmartCare/PS may be influenced by the local clinical organisational context.


28. Mechanical ventilation: weaning.


Respiration Artificial Mechanical ventilation Weaning Automated weaning Closed-loop ventilation 



The authors thank the Intensive Care Unit nursing staff and nurse education team for their assistance in the completion of this study. This study was supported by The Victor Hurley Medical Research Fund, The Royal Melbourne Hospital and Australian College of Critical Care Nurses’ (ACCCN) Nursing Research Fund.

Conflict of interest statement

The authors have no potentially conflicting financial interests to be declared, but report that SmartCare/PS software, and associated technical upgrades for two ventilators, were provided free of charge to the Intensive Care Unit of The Royal Melbourne Hospital by Dräger Medical, Australia.


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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Louise Rose
    • 1
    • 4
    Email author
  • Jeffrey J. Presneill
    • 2
    • 5
  • Linda Johnston
    • 3
  • John F. Cade
    • 2
  1. 1.The University of Melbourne and Intensive Care Unit, The Royal Melbourne HospitalVictoriaAustralia
  2. 2.Intensive Care UnitThe Royal Melbourne HospitalVictoriaAustralia
  3. 3.Neonatal Nursing Research, School of NursingThe University of Melbourne, Royal Children’s Hospital and Murdoch Children’s Research InstituteVictoriaAustralia
  4. 4.Lawrence S. Bloomberg Faculty of NursingUniversity of TorontoTorontoCanada
  5. 5.Intensive Care UnitSt Vincent’s HospitalFitzroy, VictoriaAustralia

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