Older trauma patients are at high risk of delirium, especially those with underlying dementia or baseline frailty

BACKGROUND: Given the increasing numbers of older patients presenting with trauma, and the potential influence of delirium on outcomes, we sought to investigate the proportion of such patients who were diagnosed with delirium during their stay—and patient factors associated therewith—and the potential associations between delirium and hospital length of stay (LOS). We hypothesized that delirium would be common, associated with certain patient characteristics, and associated with long hospital LOS (highest quartile). METHODS: We conducted a retrospective observational cohort study of all trauma patients aged ≥65 years presenting in September to October 2019, interrogating medical records and the institutional trauma database. The primary outcome measure was occurrence of delirium. RESULTS: Among 99 eligible patients, delirium was common, documented in 23% (23 of 99). On multivariable analysis, adjusting for age, frailty and history of dementia, frailty (OR 4.09, 95% CI 1.08 to 15.53, p=0.04) and dementia (OR 5.23, 95% CI 1.38 to 19.90, p=0.02) were independently associated with likelihood of delirium. Standardized assessment tools were underused, with only 34% (34 of 99) screened within 4 hours of arrival. On univariate logistic regression analysis, having an episode of delirium was associated with long LOS (highest quartile), OR of 5.29 (95% CI 1.92 to 14.56, p<0.001). In the final multivariable model, adjusting for any (non-delirium) in-hospital complication, delirium was independently associated with long LOS (≥16 days; OR 4.81, p=0.005). DISCUSSION: In this study, delirium was common. History of dementia and baseline frailty were associated with increased risk. Delirium was independently associated with long LOS. However, many patients did not undergo standardized screening at admission. Early identification and targeted management of older patients at risk of delirium may reduce incidence and improve care of this vulnerable cohort. These data are hypothesis generating, but support the need for initiatives which improve delirium care, acknowledging the complex interplay between frailty and other geriatric syndromes in the older trauma patients. LEVEL OF EVIDENCE: III.