Purpose: Delirium is a frequent and critical condition in long-term care (LTC) settings. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) states that delirium requires three key elements: acute onset, fluctuating course, and disturbances in attention and awareness. As the Hydra, a mythological monster with multiple heads that doubles when cut down, delirium is multifactorial in nature. Understanding the multicomponents of delirium is decisive for effective prevention, early detection, and management.
Method: This paper aimed to outline etiologies of delirium in LTC settings. A comprehensive literature search was conducted using the Cochrane Database and MEDLINE to identify relevant studies on the etiology and diagnosis of delirium, particularly in LTC settings. Two geriatricians selected papers based on five criteria and one researcher extracted data. A narrative review was conducted to produce this article.
Results: The results were organized and compared to known literature. The three Ps model of delirium was elaborated, consisting of predisposing, precipitating and perpetuating factors. A multicomponent model of delirium in LTC was developed, likened to the mythological multiheaded Hydra. Predisposing factors identified comprise dementia, mild cognitive impairment, and depressive symptoms. Precipitating factors include infections (urinary, cellulitis, respiratory), medication (antipsychotics, anticholinergics, benzodiazepines), pain, sensory loss or deprivation, environmental stressors, malnutrition, cardiovascular conditions (such as stroke and myocardial infarction), and dehydration.
Conclusion: This work allowed the conceptualization of a model for delirium in LTC settings. More studies, as well as more comprehensive systematic reviews, might help to further develop and validate this model.
Keywords: Delirium; Etiology; Geriatrics; Long-term care; Multifactorial.
© 2025. The Author(s), under exclusive licence to European Geriatric Medicine Society.