Early Diagnosis of Delirium in Palliative Care Patients Decreases Mortality and Necessity of Palliative Sedation: Results of a Prospective Observational Study

Introduction: Delirium in end-of-life patients is reported to be between 13% and 42% and up to 80% in the terminal phase. It is a serious clinical situation, often a cause of death due to the frequent ineffectiveness of treatments. This study aimed to assess whether and how much precocity of diagnosis, hitherto little considered, could affect the outcomes and prognosis of delirium in palliative care settings. Methods: Patients consecutively admitted to a palliative care unit (PCU) between October 2018 and December 2019, cared for both in hospice and home programs, were analyzed. All patients were subjected to a careful procedure aimed at recognizing the onset of delirium. The first step was the detection of prodromal "sentinel" symptoms related to incoming delirium. PCU staff and family members/caregivers were trained to observe the patients and immediately identify the appearance of even one symptom. The final diagnosis was performed with the 4AT (4 A's test). Patients were then included in the categories of "early" or "slow" diagnosis (cut-off: four hours) depending on the time between sentinel symptom observation and the final diagnosis of delirium. Results: Among 503 admitted patients, 95 developed delirium. Confusion was the most frequent sentinel symptom (49.5%). The early diagnosis was more frequent in hospice than in home care (p-value<0.0001). Delirium was positively resolved in 43 patients, of which 25 with an early diagnosis (p-value=0.038). Time to resolution was shorter in the case of early diagnosis (7.1 vs. 13.7 hours in hospice patients; p-value=0.018). Palliative sedation was performed on 25 patients, but only 8 of them had an early diagnosis. Conclusion: Time of diagnosis was important in determining the clinical outcomes of patients in charge of PCU who experienced delirium. The early diagnosis reduced both mortality and the necessity of palliative sedation.