Snapshot A 69-year-old man is brought to the ED by his daughter for an acute change in his mental status. According to the daughter, the patient was at his baseline mental status 3 days ago but significantly altered when she visited him today. She describes him as being barely responsive and garbling nonsense whenever he did speak. On physical exam, the patient is obtunded and non-responsive to verbal stimuli, though he remains responsive to painful stimuli. The patient has a temperature of 101.3°F (38.5°C) and is found to have dry mucous membranes. He is started on IV fluids and undergoes blood draws for laboratory work-up. Introduction Overview delirium is characterized by a transient change of consciousness with waxing and waning confusion Epidemiology Prevalence affects up to 10-30% of hospitalized adults up to 80% of mechanically ventilated patients in the intensive care unit Demographics ↑ prevalence in patients with older age, cognitive decline, and severe medical illness extremely common among nursing home residents ETIOLOGY Pathophysiology possible causes certain medications (e.g., benzodiazepines) or drug toxicity (e.g., lithium) alcohol/substance intoxication or withdrawal severe illness malnutrition or dehydration pain sleep deprivation or severe emotional distress anesthesia from surgery Presentation Symptoms fluctuating consciousness disorientation hallucinations (often visual) illusions disorganized thinking disturbance in sleep-wake cycle cognitive dysfunction dysphasia dysarthria tremor Differential Major neurocognitive disorder key distinguishing factor acute onset of altered mental status Schizophrenia key distinguishing factor hallucinations are typically visual, with fluctuating level of consciousness Major depressive disorder key distinguishing factor fluctuating level of consciousness, which is not seen in depression Treatment Lifestyle supportive therapy reorientation and memory cues (e.g., calendar, clocks, and family photos) ensuring a well-lit, quiet environment, preferably near a window for daytime/nighttime orientation constant observation (e.g., sitter) may help avoid use of physical restraints Medical treating the underlying cause stop potentially causative medications multivitamins (especially thiamine) for patients with alcohol toxicity or withdrawal antipsychotics (e.g., haloperidol and risperidone) indication treatment of choice for psychotic symptoms of delirium benzodiazepines indication treatment for alcohol and benzodiazepine withdrawal-induced delirium Complications Malnutrition Falls Long-term cognitive impairment Prognosis Mortality rate among older patients in the hospital with delirium ranges from 20-75% Some patients recover completely with adequate diagnosis and treatment