**2. The extent of the problem**

In the palliative care setting, delirium represents a frequent clinical condition. In patients with advanced cancer, for instance, research showed that its prevalence varies from 13 to 88% [4]. Despite on admission delirium prevalence ranges between 13 to 42%, the higher prevalence occurs in the last 24 to 48 hours of life (terminal delirium), when the phenomenon becomes part of the complex picture of multiorgan dysfunction [5]; in this context, delirium is particularly difficult to treat, and it is considered as the predominant symptom for starting terminal sedation [1]. Overall, the reversibility is about 30% [6] and failure to respond to treatment may become indicative of a worse prognosis already after the first week of palliative care [7].

Despite its high prevalence and clinical significance, delirium is poorly sought; of note, Rainsford et al. [8] demonstrated that the diagnosis of delirium was performed only in 30% of in-hospice patients.
