Delirium is a complex medical problem affecting many elderly patients admitted to the emergency
department (ED). Many descriptions and terms were proposed in the literature, including acute confusional state,
septic encephalopathy, acute brain failure, and intensive care unit psychosis. It remains poorly recognized because
of its heterogeneous and polymorphic presentation: a study showed that 60% of patients presenting to the ED with
delirium were under-diagnosed [1].
Delirium is often the first symptom for many diseases whose underlying cause can be multifactorial. Despite medical
progress, it remains a major challenge for health care workers with the increasing burden of an aging population [2].
In this mini review, we address the issues of diagnosis and the forms of confusion among the elderly, summarizing the
pathophysiology and diagnosis approach for the emergency physician.