Frailty, delirium and hospital mortality of older adults admitted to intensive care: the Delirium (Deli) in ICU study

Background Clinical frailty among older adults admitted to intensive care has been proposed as an important determinant of patient outcomes. Among this group of patients, an acute episode of delirium is also common, but its relationship to frailty and increased risk of mortality has not been extensively explored. Therefore, the aim of this study was to explore the relationship between clinical frailty, delirium and hospital mortality of older adults admitted to intensive care. Methods This study is part of a Delirium in Intensive Care (Deli) Study. During the initial 6-month baseline period, clinical frailty status on admission to intensive care, among adults aged 50 years or more; acute episodes of delirium; and the outcomes of intensive care and hospital stay were explored. Results During the 6-month baseline period, 997 patients, aged 50 years or more, were included in this study. The average age was 71 years (IQR, 63-79); 55% were male (n = 537). Among these patients, 39.2% (95% CI 36.1-42.3%,n = 396) had a Clinical Frailty Score (CFS) of 5 or more, and 13.0% (n = 127) had at least one acute episode of delirium. Frail patients were at greater risk of an episode of delirium (17% versus 10%, adjusted rate ratio (adjRR) = 1.71, 95% confidence interval (CI) 1.20-2.43,p = 0.003), had a longer hospital stay (2.6 days, 95% CI 1-7 days,p = 0.009) and had a higher risk of hospital mortality (19% versus 7%,adjRR = 2.54, 95% CI 1.72-3.75,p < 0.001), when compared to non-frail patients. Patients who were frail and experienced an acute episode of delirium in the intensive care had a 35% rate of hospital mortality versus 10% among non-frail patients who also experienced delirium in the ICU. Conclusion Frailty and delirium significantly increase the risk of hospital mortality. Therefore, it is important to identify patients who are frail and institute measures to reduce the risk of adverse events in the ICU such as delirium and, importantly, to discuss these issues in an open and empathetic way with the patient and their families.