Some Causes of Agitation or Confusion in Critical Care Patients

Underlying disorder

Head injury

Shock

Toxin ingestion

Electrolyte abnormalities (eg, hypercalcemia, hypocalcemia, hypomagnesemia, hypernatremia, hyponatremia, hypophosphatemia)

Pain and discomfort (eg, caused by injuries, surgical procedures, endotracheal intubation, IVs, blood drawing, or nasogastric tube)

Complications

Hypoxia

Hypotension

Sepsis

Organ failure (eg, hepatic encephalopathy)

Pulmonary embolism

Medications or substances

Sedatives and other drugs active in the central nervous system, particularly opioids, benzodiazepines, H2 blockers, and antihistamines

Withdrawal from alcohol, illicit drugs, or both

Intensive care unit (ICU) environment*

Sleep deprivation (eg, due to noise, bright lights, or round-the-clock medical interventions)

Fear of death

Anxiety about unpleasant medical procedures