Delirium: A Marker of Vulnerability in Older People

Delirium is an acute neuropsychiatric syndrome and one of the most common presenting symptoms of acute medical illnesses in older people. Delirium can be triggered by a single cause, but in most cases, it is multifactorial as it depends on the interaction between predisposing and precipitating factors. Delirium is highly prevalent in older patients across various settings of care and correlates with an increased risk of adverse clinical outcomes. Several pathophysiological mechanisms may contribute to its onset, including neurotransmitter imbalance, neuroinflammation, altered brain metabolism, and impaired neuronal network connectivity. Several screening and diagnostic tools for delirium exist, but they are unfortunately underutilized. Additionally, the diagnosis of delirium superimposed on dementia poses a formidable challenge – especially if dementia is severe. Non-pharmacological approaches for the prevention and multidomain interventions for the treatment of delirium are recommended, given that there is currently no robust evidence of drugs that can prevent or resolve delirium. This article aims to review the current understanding about delirium in older people. To achieve this goal, we will describe the epidemiology and outcomes of the syndrome, the pathophysiological mechanisms that are supposed to be involved, the most commonly used tools for screening and diagnosis, and prevention strategies and treatments recommended. This review is intended as a brief guide for clinicians in hospital wards to improve their knowledge and practice. At the end of the article, we propose an approach to improve the quality of care provided to older patients throughout a systematic detection of delirium.

Association Between Preoperative Malnutrition and Postoperative Delirium After Hip Fracture Surgery in Older Adults

OBJECTIVES

To determine whether poor nutritional status can predict postoperative delirium in elderly adults undergoing hip fracture surgery.

DESIGN

Prospective observational cohort study.

SETTING

Italian orthogeriatric unit.

PARTICIPANTS

Individuals aged 70 and older (mean age 84.0 ± 6.6, 74.5% female) consecutively admitted for surgical repair of a proximal femur fracture between September 2012 and April 2016 (N = 415).

MEASUREMENTS

Participants underwent a comprehensive geriatric assessment including nutritional status, which was evaluated using the Mini Nutritional Assessment Short Form (MNA-SF). The MNA-SF-based three-class stratification was tested using multivariable logistic regression to assess its role in predicting postoperative delirium (outcome).

RESULTS

Seventy-eight malnourished individuals (MNA-SF score 0-7), 185 at risk of malnutrition (MNA-SF score 8-11), and 152 who were well nourished (MNA-SF score 12-14) were compared. On average, individuals with poor nutritional status were more disabled and more cognitively impaired than those who were well nourished and those at risk of malnutrition. Moreover, those who were malnourished were more likely to have postoperative delirium. Multivariate regression analysis adjusted for age, sex, comorbidity, functional impairment, preoperative cognitive status, and American Society of Anesthesiologists score showed that those who were at risk of malnutrition (odds ratio (OR) = 2.42, 95% confidence interval (CI) = 1.29-4.53) and those who were overtly malnourished (OR = 2.98, 95% CI = 1.43-6.19) were more likely to develop postoperative delirium.

CONCLUSION

This is the first study in a Western population showing that risk of malnutrition and overt malnutrition, as assessed using the MNA-SF, are independent predictors of postoperative delirium. Accordingly, nutritional status should be assessed in individuals with hip fracture before surgery to determine risk of developing delirium.