Implications of the evidence for trial theory
An extensive body of research demonstrates the benefits of staff training in promoting effective delivery of novel ICU interventions [Our theory prioritised intervention ease and flexibility of use, an approach consistent with the ICU literature showing the benefits of ready integration within unit routines [Development of the theory underpinning our intervention was based on an ICU specific evidence base [The evidence largely supports our theoretical assumptions concerning how the intervention would work to encourage proactivity in weaning. Even where intervention deviations occurred, still the units were operating with a bundle of components, meaning that, even incrementally, an overall imperative towards weaning was sustained. Our evidence aligns with other work on the effectiveness of multifaceted ICU interventions [As anticipated, the intervention worked to promote inter-disciplinary collaboration. Although the challenges inherent in inter-professional working in ICU have been documented [In terms of consistency of weaning related care (both sedation and weaning management), the evidence concerning our theoretical assumptions is more ambivalent. The protocol did work to improve consistency of care. Two examples are bedside nurses’ use of lighter patient sedation, and doctors’ uptake of a more dynamic approach to lowering ventilator settings. However, the impetus to adhere to established practice also meant that bedside nurses continued to over-sedate, and doctors continued to wean ‘down’ to lower support. The challenges inherent in changing established practice within ICUs are well documented [