58. CONCEPTUALIZING TERMINAL DELIRIUM SUPERIMPOSED ON DEMENTIA: A SCOPING REVIEW

Abstract

Introduction

Terminal delirium is defined in the literature as persistent and intractable delirium present in the days, weeks, or months preceding death. This behavioral phenomenon is commonly recognized in palliative and hospice settings, with estimates that it affects between 25-85% of actively dying patients. Patients with delirium superimposed on dementia experience higher rates of mortality, longer hospital stays, increased risk of institutionalization, and accelerated cognitive and functional decline compared to patients with either condition alone. To the best of our knowledge (based on non-systematic literature reviews), terminal delirium is most often studied in cancer patients in palliative care settings. We hypothesize that less is known about terminal delirium in the context of dementia and other end-of-life conditions. The objective of our scoping review is to summarize the existing body of literature on terminal delirium superimposed on dementia and propose future directions for research.

Methods

Two health sciences librarians developed the search strategies and searched multiple databases (PsycInfo, Ovid Medline, Embase, CINAHL) in November 2024. The searches were based on a combination of keyword terms and controlled vocabulary related to Terminal Delirium or Terminal Restlessness. The searches were limited to 2013-present and English language. The librarians peer-reviewed each other’s searches and combined them into one search strategy per database. Duplicate articles between databases were removed using Covidence software (Veritas Health Innovation, 2022). Titles and abstracts were each independently reviewed by two researchers and discrepancies were resolved by a third researcher. Full texts were then independently reviewed by two researchers. Our review followed Preferred Reporting Items for Systematic Review and Meta-Analysis scoping review guidelines. Thematic analysis of studies that met inclusion criteria was performed.

Results

The initial search by two health sciences librarians identified 2174 results across four databases. After removing duplicates, 1389 abstracts were screened for eligibility, with 309 studies remaining for full-text screening. Overall, 137 met inclusion criteria and were included in the final review. Studies included randomized controlled trials, observational studies with longitudinal or cross-sectional designs, review articles, and practice guidelines.

Conclusions

Thematic analysis revealed (1) Behavioral symptoms of terminal delirium superimposed on dementia (DSD) is linked to distress in patients, caregivers, and healthcare staff (2) Recognizing and diagnosing DSD is complex due to overlapping symptomatology and lack of validated screening tools (3) Balancing symptom management with minimizing psychotropic burden is an important but challenging aspect of treating DSD. Our review underscores knowledge gaps in risk factors, diagnostic tools, management strategies, and clinical outcomes in patients with terminal DSD. Future research directions may include qualitative interdisciplinary studies, expert consensus studies, or innovative prospective study design.