Risk appetite-enhanced game-theoretic approach for modelling mandatory lane-changing behaviour in freeway merging areas.

Tracheostomy insertion is performed in 10–15% of patients admitted to intensive care units (ICUs) []. One indication for tracheostomy insertion is to aid weaning in patients requiring prolonged mechanical ventilation (MV). Around 15% of intubated patients require ongoing MV beyond 7 days [], with around 4% requiring MV beyond 60 days []. Tracheostomy insertion generally allows patients to be managed with less sedation, facilitating greater wakefulness, which promotes their ability to engage with the weaning process and rehabilitation, and improves their comfort and safety []. Patients requiring tracheostomies generally have a longer ICU length of stay (LOS), greater comorbidity, and higher mortality rates []. They may also experience physical, cognitive and psychological morbidity, including anxiety, depression, post-traumatic stress [], temporary or permanent loss of speech [], difficulty swallowing [], pain, increased work of breathing, tracheal trauma and bleeding, and tracheal stenosis []. Consequently, it would be expected that earlier tracheostomy removal could result in improved outcomes in patients requiring prolonged MV. However, whilst there is an extensive evidence base concerning the indications for, timing of, and techniques of tracheostomy insertion and their subsequent removal, little attention has been given to optimal management between the time of insertion in ICU and subsequent ICU discharge []. Similarly, evidence underpinning the most effective techniques that might accelerate the processes of weaning tracheostomy patients from prolonged MV is limited []. Weaning ventilatory support in tracheostomised patients generally follows a linear, stepwise process, although clinical practice varies. Generally, weaning ventilatory support starts with restoring spontaneous breathing effort, followed by a sequential reduction in inspiratory support towards continuous positive airway pressure (CPAP), then the introduction of supplemental oxygen via tracheostomy mask, prior to tracheostomy cuff deflation as a prelude to decannulation []. Delays in tracheostomy cuff deflation in the weaning process prevents vocalisation, and could impact swallow, cough effectiveness and protective laryngeal competence as a result of deconditioning []. Structured, protocolised weaning has been associated with a reduction in ICU LOS and an increase in ventilator-free days []. However, there is limited robust evidence comparing the effectiveness of different weaning approaches and techniques in patients with tracheostomies. The restoration of normal anatomical airflow, through tracheostomy cuff deflation and speaking valve use, is accepted as standard practice with tracheostomy patients. However, its role during the earlier phases of MV is less well established in both clinical practice and the literature. The safety and feasibility of cuff deflation within 24 hours of tracheostomy insertion has been demonstrated []. Despite this, there is little evidence examining the benefits on secondary outcomes such as ventilator-free days and LOS, with the limited current research reporting inconsistent results. One randomised controlled trial found early cuff deflation to be associated with reductions in the time to successful tracheostomy removal, as well as ICU and hospital LOS []. Freeman-Sanderson also reported that early cuff deflation facilitated earlier restoration of phonation without an associated increase in adverse events. However, compared with standard care, earlier cuff deflation did not result in a significant difference in time to decannulation and or liberation from mechanical ventilation []. Here, we report outcomes for patients without neurological injury who underwent tracheostomy insertion on our ICU over a two-year period and were deemed ‘challenging to wean’. The aims of this service evaluation were three-fold. Firstly, to define current practice regarding the circumstance and timing of initial cuff deflation within ‘challenging to wean’ patients. Secondly, to explore patient and clinical factors related to the timing of cuff deflation. Thirdly, to explore associations between timing of cuff deflation and physical, cognitive and psychological outcomes, to inform the design of a potential future trial exploring early cuff deflation.