Delirium (ICU psychosis/sundowning)


Many patients experience an episode of delirium during their intensive care unit stay. Delirium is defined by periods of confusion, agitation, and vivid hallucinations that include both hearing and seeing things that are not real. Patients developing delirium may become suspicious and paranoid. Patients will often have increases in their activity, blood pressure, heart rate and respiratory rate.


The exact cause of delirium that occurs in ICU patients is not known. The stress of a critical illness or injury, major surgery, lack of sleep, medications, electrolyte abnormalities or infection have all been considered possibilities. The most likely explanation for a patient's delirium is usually a combination of factors.


The treatment of delirium is generally aimed at correcting reversible medical conditions and protecting the patient from being injured. The patient’s agitation is best controlled with supportive care that includes encouraging a family member to be present with the patient, allowing the patient to maximize uninterrupted sleep if possible, keeping the patient's room well lighted during the day in using a dim light at night, explaining all procedures in detail, and replacing the patient’s eyeglasses or hearing aids whenever possible to avoid loss of sensory cues. If the above measures fail to control the agitation, medications and temporary soft restraints may be required to protect the patient from harming himself or herself.


Delirium may occur in any hospitalized patient. Delirium is often referred to as ICU psychoses or sundowning. In general, delirium is a very frightening condition for a patient, patient's family or friends to endure. Fortunately, patients themselves do not remember the period of delirium. Delirium is typically worse during the early evening hours and improves in the morning hours. Delirium improves with support, time and improvement of the underlying conditions. Some patients require days to months to fully return to normal.

Related Links

National Library of Medicine
The National Library of Medicine presents information and pictures about delirium.