Is there a correlation between delirium and mortality?

From the Guidelines

Delirium is strongly correlated with increased mortality in adult ICU patients. This correlation is supported by numerous prospective cohort studies, including a 2013 study published in Critical Care Medicine 1, which found that delirium is associated with increased mortality, prolonged ICU and hospital length of stay, and development of post-ICU cognitive impairment. The relationship between delirium and mortality is thought to be dose-dependent, with longer duration and greater severity of delirium associated with worse outcomes. Delirium often reflects underlying physiological stress and vulnerability, serving as a marker of frailty and reduced physiological reserve. Additionally, delirium can lead to complications such as aspiration pneumonia, pressure ulcers, and falls, which further contribute to mortality risk.

• Key outcomes associated with delirium in adult ICU patients include:
  • Increased mortality
  • Prolonged ICU and hospital length of stay
  • Development of post-ICU cognitive impairment
• The correlation between delirium and mortality persists across various settings, including intensive care units, general medical wards, post-surgical units, and nursing homes, with elderly patients being particularly at risk.
• The mortality risk associated with delirium is approximately 2-4 times higher than those without delirium, highlighting the need for prompt medical attention and comprehensive management to potentially improve survival outcomes.

From the Research

Delirium and Mortality Correlation

• Delirium in elderly patients is associated with an increased risk of death, as shown in a meta-analysis published in JAMA 2.
• The study found that delirium is associated with a higher risk of mortality, institutionalization, and dementia, with an adjusted hazard ratio of 1.95 for death compared to controls.
• Another study published in the European heart journal found that delirium in elderly patients with acute cardiac diseases is associated with higher in-hospital, 30-day, and 6-month mortality rates 3.
• A prospective study of hospitalized older people found that delirium and frailty are both independently associated with increased mortality rates, with delirium having a greater impact on mortality at lower levels of frailty 4.

Key Findings

• Delirium is a common complication in elderly patients, with a significant impact on mortality and morbidity.
• The association between delirium and mortality is consistent across different studies, with delirium being a significant predictor of short and long-term mortality.
• Frailty and delirium interact to increase the risk of mortality, with delirium having a greater impact on mortality in individuals with lower levels of frailty.

Study Implications

• Early detection and management of delirium are crucial to reduce the risk of mortality and morbidity in elderly patients.
• A protocol for the early identification of delirium in the cardiac intensive care unit may be useful in reducing the incidence and impact of delirium 3.
• Further research is needed to understand the relationship between delirium, frailty, and mortality, and to develop effective strategies for preventing and managing delirium in elderly patients.