• delirium
• duration of hospitalization
• liaison psychiatry
• neurocognitive disordes
• psychopharmacological treatment

Delirium is a complex, multifactorial and potentially transient neuropsychiatric syndrome characterised by acute alterations in mental status with a fluctuating course. This makes it difficult to diagnose and manage in hospital. Because of the difficulty of diagnosis and therefore treatment due to the heterogeneity of its manifestations, and because of its high impact on duration of hospital stay, ward workload and clinical outcomes of patients, this condition represents a major challenge for clinicians. The aim of this retrospective observational study was to analyse the clinical characteristics, psychopharmacological treatments and duration of hospital stay of 168 patients hospitalised between May 2020 and May 2021 with a diagnosis of delirium confirmed by a psychiatric consultation, carried out at the University General Hospital of Pisa.
With a mean age of 72 years and a higher prevalence of women, the cohort was predominantly elderly. They were mainly from medical departments and to a lesser extent from surgical departments. The most common medical diagnoses included cardiovascular disease, nephro-uropathy and diabetes mellitus, showing a profile of chronic co-morbidities that are often present in patients with delirium. The most common neuropsychiatric comorbidities were anxiety, depression and dementia supporting the interaction between cognitive and psychiatric predisposition in the risk of delirium.
The average duration of stay was 13.3 days with surgical patients tending to stay longer than medical patients. This finding reflects the increased complexity of managing post-operative patients where factors such as pain, use of sedatives and surgical complications can increase the risk of delirium. Patients with traumatic injuries and nephrouropathies had the longest average duration of stay, while those with chronic infections and dementia had shorter average duration of stay, probably due to management strategies aimed at transfer to long-term care facilities or home.
First- and second-generation antipsychotics were the most commonly used pharmacological treatments followed by mood stabilisers, benzodiazepines and trazodone. Although there were not statistically significant associations between the use of particular drugs and duration of hospital stay, more complex therapeutic combinations such as benzodiazepines and mood stabilizers were associated with longer hospital stays. This finding, which reflects the severity of the clinical picture rather than direct efficacy in reducing length of stay, suggests that such combinations may be preferred in more clinically severe and resistant cases or those with complex psychiatric comorbidities.
Underdiagnosis of the hypokinetic form of delirium, which is often confused with other conditions such as depression, asthenia or cognitive impairment, has emerged as a critical element. This diagnostic gap highlights the need for greater use of standardised tools such as the Confusion Assessment Method (CAM) in routine clinical practice to improve early recognition, particularly in elderly and frail patients. In order to implement appropriate interventions that reduce the risk of duration of stay, in-hospital complications and mortality early diagnosis of delirium is crucial. Using validated tools can also help differentiate delirium from other neurocognitive conditions, such as dementia, and psychiatric disorders, such as psychosis and depression.
The study has some limitations including its retrospective nature, lack of post-discharge follow-up, and lack of detailed data on drug dosages and duration. In addition, excluding patients with unconfirmed diagnoses or who did not receive a psychiatric consultation may have limited the representativeness of the sample by reducing the generalisability of the results. In conclusion, by highlighting the challenges of early diagnosis and pharmacological management of this complex syndrome this study provides an overview of the clinical and therapeutic dynamics of delirium in hospital. Results emphasise the need for common diagnostic and therapeutic strategies complemented by multidisciplinary approaches to improve outcomes. Further prospective studies are essential to develop more effective and personalised management models and to further investigate the relationships between clinical features, treatments and outcomes. This research provides an important foundation for future initiatives to improve the quality of care and to optimise the use of health care resources in patients with delirium.