Mobilisation in the EveNing to prevent and TreAt deLirium (MENTAL): a mixed-methods, randomised controlled feasibility trial

BACKGROUND: Delirium is common in critically ill patients and associated with longer hospital stays, increased morbidity and higher healthcare costs. Non-pharmacological interventions have been advocated for delirium management, however there is little evidence evaluating feasibility and acceptability of physical interventions administered in the evening. The aim of this study was to conduct a feasibility trial of evening mobilisation to prevent and treat delirium in patients admitted to intensive care. METHODS: In this mixed-methods, randomised controlled feasibility trial we recruited participants from intensive care units at two university hospitals in the United Kingdom. Eligible participants who were able to respond to verbal stimulus (Richmond agitation and sedation scale ≥3) and expected to stay in intensive care for at least 24 h were randomly assigned (1:1) to receive usual care or usual care plus evening mobilisation. The evening mobilisation was delivered between 19:00 and 21:00, for up to seven consecutive evenings or ICU discharge, whichever was sooner. All outcome assessments were completed by a team member blinded to randomisation and group allocation. Primary objective was to assess feasibility and acceptability of evening mobilisation. Primary feasibility outcomes were recruitment, consent and retention rates, and intervention fidelity. Intervention acceptability was evaluated through semi-structured interviews of participants and staff. Secondary outcomes included prevalence in incidence and duration of delirium, measured using the Confusion Assessment Method for ICU. This trial is registered at ClinicalTrials.gov, NCT05401461. FINDINGS: Between July 16th, 2022, and October 31st, 2022, 58 eligible patients (29 usual care; 29 usual care plus evening mobilisation) were enrolled. We demonstrated the feasibility and acceptability of both the trial design and evening mobilisation intervention. Consent and retention rates over three months were 88% (58/66) and 90% (52/58) respectively, with qualitative analysis demonstrating good acceptability reported by both participants and staff. Secondary outcomes for the evening intervention group compared with the control group were: delirium incidence 5/26 (19%; 95% CI: 6–39%) vs 8/28 (29%; 95% CI: 13–49%) and mean delirium duration 2 days (SD 0.7) vs 4.25 days (SD 2.0). INTERPRETATION: Results of this trial will inform the development of a definitive full-scale randomised controlled trial investigating the effects of evening mobilisation to treat delirium and improve health-related outcomes. FUNDING: None.