• Also known as "acute toxic-metabolic encephalopathy"
  • Delirium vs. dementia vs. psych

Clinical Features

  • Main cognitive impairment is that of inattention (vs memory in dementia)
  • Generally develops over hours to days
  • Symptoms are classically described as fluctuating throughout the day (ie may appear normal in between episodes)

ED Confusion Assessment Method[1]

A patient must possess both features 1 and 2 AND either 3 or 4 to meet delirium criteria

Differential Diagnosis

Altered mental status

Diffuse brain dysfunction

Primary CNS disease or trauma


General Psychiatric


Main goal is to find the underlying cause

AMS Workup

Common Orders

Consider Based on Clinical Situation


  • Treat underlying cause
  • Antipsychotics (eg haloperidol, risperidone) may be useful for hyperactive delirium with psychotic features


  • Admission

See Also


  1. Inouye SK, van Dyck CH, Alessi CA, et al. Clarifying confusion: the confusion assessment method. A new method for detection of delirium. Ann Intern Med 1990; 113:941.