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

Abstract

Objective: 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.

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

Interventions: 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 P = 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.

Conclusions: 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.

Descriptor: 28. Mechanical ventilation: weaning.