Predisposing and Precipitating Risk Factors for Delirium in Elderly Patients Admitted to a Cardiology Ward: An Observational Cohort Study in 1,042 Patients.

Carl Moritz Zipser,Florian Freimut Hildenbrand,Roland Von Känel,Maria Schubert,Katja-Daniela Jordan,Jutta Ernst,Soenke Boettger,Jeremy Deuel,Bernhard Haubner,Heidi Petry

doi:10.3389/fcvm.2021.686665

Abstract

Aim: Although the risk factors for delirium in general medicine are well-established, their significance in cardiac diseases remains to be determined. Therefore, we evaluated the predisposing and precipitating risk factors in patients hospitalized with acute and chronic heart disease.Methods and Results: In this observational cohort study, 1,042 elderly patients (≥65 years) admitted to cardiology wards, 167 with and 875 without delirium, were included. The relevant sociodemographic and cardiac- and medical-related clusters were assessed by simple and multiple regression analyses and prediction models evaluating their association with delirium. The prevalence of delirium was 16.0%. The delirious patients were older (mean 80 vs. 76 years; p < 0.001) and more often institutionalized prior to admission (3.6 vs. 1.4%, p = 0.05), hospitalized twice as long (12 ± 10 days vs. 7 ± 7 days; p < 0.001), and discharged more often to nursing homes (4.8 vs. 0.6%, p < 0.001) or deceased (OR, 2.99; 95% CI, 1.53–5.85; p = 0.003). The most relevant risk factor was dementia (OR, 18.11; 95% CI, 5.77–56.83; p < 0.001), followed by history of stroke (OR, 6.61; 95% CI 1.35–32.44; p = 0.020), and pressure ulcers (OR, 3.62; 95% CI, 1.06–12.35; p = 0.040). The predicted probability for developing delirium was highest in patients with reduced mobility and institutionalization prior to admission (PP = 31.2%, p = 0.001). Of the cardiac diseases, only valvular heart disease (OR, 1.57; 95% CI, 1.01–2.44; p = 0.044) significantly predicted delirium. The patients undergoing cardiac interventions did not have higher rates of delirium (OR, 1.39; 95% CI 0.91–2.12; p = 0.124).Conclusion: In patients admitted to a cardiology ward, age-related functional and cognitive impairment, history of stroke, and pressure ulcers were the most relevant risk factors for delirium. With regards to specific cardiological factors, only valvular heart disease was associated with risk for delirium. Knowing these factors can help cardiologists to facilitate the early detection and management of delirium.

Highlights

Delirium is the most prevalent acute neuropsychiatric syndrome in elder general hospital populations, with a relevant shortand long-term impact on individual health and health care costs [1,2,3]
The association with delirium that we found here supports the need for skin examination in patients at risk for pressure ulcers
The novelty of this study was the systematic assessment of predisposing and precipitating factors for delirium in a large sample of patients admitted to the cardiology ward

Summary

Introduction

Delirium is the most prevalent acute neuropsychiatric syndrome in elder general hospital populations, with a relevant shortand long-term impact on individual health and health care costs [1,2,3]. It is characterized by an abrupt onset and fluctuating course of disturbances in attention, awareness, and disturbance in cognition due to an underlying precipitant or, more commonly, several precipitants [4, 5]. In patients admitted to internal medicine services, advanced age, frailty, and cognitive impairment are the most relevant predisposing risk factors, while infection, electrolyte disturbance, and acute renal failure may precipitate delirium among many other factors [3, 15]. The interrelation remains incompletely understood, epidemiology indicates that delirium may accelerate cognitive decline and dementia and that patients with dementia likely develop delirium [17, 18]

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