title: Use of a Structured Mirrors Intervention Does Not Reduce Delirium Incidence But May Improve Factual Memory Encoding in Cardiac Surgical ICU Patients Aged Over 70 Years: A Pilot Time-Cluster Randomized Controlled Trial.
abstract: Introduction:Post-operative delirium remains a significant problem, particularly in the older surgical patient. Previous evidence suggests that the provision of supplementary visual feedback about ones environment via the use of a mirror may positively impact on mental status and attention (core delirium diagnostic domains). We aimed to explore whether use of an evidence-based mirrors intervention could be effective in reducing delirium and improving post-operative outcomes such as factual memory encoding of the Intensive Care Unit (ICU) environment in older cardiac surgical patients.Methods:This was a pilot time-cluster randomized controlled trial at a 32-bed ICU, enrolling 223 patients aged 70 years and over, admitted to ICU after elective or urgent cardiac surgery from October 29, 2012 to June 23, 2013. The Mirrors Group received a structured mirrors intervention at set times (e.g., following change in mental status). The Usual Care Group received the standard care without mirrors. Primary outcome was ICU delirium incidence; secondary outcomes were ICU delirium days, ICU days with altered mental status or inattention, total length of ICU stay, physical mobilization (balance confidence) at ICU discharge, recall of factual and delusional ICU memories at 12 weeks, Health-Related Quality of Life at 12 weeks, and acceptability of the intervention.Results:The intervention was not associated with a significant reduction in ICU delirium incidence [Mirrors: 20/115 (17%); Usual Care: 17/108 (16%)] or duration [Mirrors: 1 (1-3); Usual Care: 2 (1-8)]. Use of the intervention on ICU was predictive of significantly higher recall of factual (but not delusional) items at 12 weeks after surgery (p= 0.003) and acceptability was high, with clinicians using mirrors at 86% of all recorded hourly observations. The intervention did not significantly impact on other secondary outcomes.Conclusion:Use of a structured mirrors intervention on the post-operative ICU does not reduce delirium, but may result in improved factual memory encoding in older cardiac surgical patients. This effect may occur via mechanisms unrelated to delirium, altered mental status, or inattention. The intervention may provide a new means of improving outcomes in patients at risk of post-ICU anxiety and/or Post-Traumatic Stress Disorder.Trial Registration:Clinicaltrials.gov identifier NCT01599689.
authors.affiliation: Cognitive Research Unit, Research & Development Department, Papworth Hospital NHS Foundation Trust Cambridge, UK.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Giraud
authors.affiliation: Critical Care Unit, Papworth Hospital NHS Foundation Trust Cambridge, UK.
authors.forename: Megan
authors.initials: M
authors.lastname: Pontin
authors.affiliation: Leeds Institute of Clinical Trials Research, Faculty of Medicine and Health, University of Leeds Leeds, UK.
authors.forename: Linda D
authors.initials: LD
authors.lastname: Sharples
authors.affiliation: Department of Psychiatry, School of Clinical Medicine, University of Cambridge Cambridge, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Fletcher
authors.affiliation: Cognition, Emotion, and Mental Health Programme, Medical Research Council Cognition and Brain Sciences Unit Cambridge, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Dalgleish
authors.affiliation: Physiotherapy Department, Papworth Hospital NHS Foundation Trust Cambridge, UK.
authors.forename: Allaina
authors.initials: A
authors.lastname: Eden
authors.affiliation: Cardiac Services, Papworth Hospital NHS Foundation Trust Cambridge, UK.
authors.forename: David P
authors.initials: DP
authors.lastname: Jenkins
authors.affiliation: Department of Cardiothoracic Anaesthesia & Intensive Care, Papworth Hospital NHS Foundation Trust Cambridge, UK.
authors.forename: Alain
authors.initials: A
authors.lastname: Vuylsteke
keywords: cardiac surgery; delirium; delusional memories; factual memories; intensive care unit (ICU); mirror; post-operative; post-traumatic stress disorder (PTSD)