John was an 84 year-old man with high blood pressure and elevated cholesterol who underwent routine coronary artery bypass surgery. The surgery was successful and without complication, although the anesthesia and pain medications left John foggy, but no more than his family expected. Four days later, however, pneumonia and kidney failure set in, and John’s mental state got worse. At times John seemed coherent, but at other times he was totally disoriented, failing even to recognize family members. He fluctuated between periods of lethargy and agitation.   When agitated, he was afraid that people were trying to kill him.   He yelled for help, pulled out his intravenous lines and urinary catheter, and tried to get out of bed on his own, requiring restraints to prevent him from hurting himself. John’s family felt bewildered and scared. Prior to the surgery, John had been sharp. What happened?

If you’ve ever known someone who was hospitalized and seemed really out of it, he or she probably had delirium. Delirium occurs when serious illness or surgery makes the brain go haywire. Pneumonia and other infections, dehydration, electrolyte imbalances, out-of-control diabetes, stroke, head injury, and certain medications, narcotic pain medications and sleeping pills, being high on the list, are frequent causes of delirium. Thus, while delirium is a mental condition, it is not due to psychological problems; something physical always causes it.

The foremost manifestation of delirium is clouded, foggy thinking with reduced awareness of surroundings and difficulty paying attention. Some delirious patients, instead of seeming dazed and out of it are excessively vigilant, reacting with fear to mundane background events that people ordinarily ignore. Agitated patients often try to pull out urinary catheters or tubes needed for intravenous fluids, nutrition, or breathing. Paranoid fear may result in violent behavior. Frightening hallucinations are frequent. Common examples include seeing animals, birds, or snakes in the room, or faces in the window. The symptoms come and go, and patients may have calm periods, during which they seem lucid.

Cognitive impairment is common and often includes disorientation and short-term memory impairment. Patients may believe that they are at home or in a location that seems absurd, such as a cruise ship. They may ask repetitive questions, misleading some to think that they have Alzheimer’s disease.

Mood swings may occur, and periods of sadness, crying, or talking about death may cause delirium to be mistaken for depression. How does such misdiagnosis happen? Confusion, disorientation, bewilderment, and inattention can fly under the radar of doctors and nurses alike. Not until the patient starts to cry and talk about wanting to die does anyone take notice. It’s natural to conclude that such a person has depression over the awful circumstances that brought them into hospital.

Misdiagnosing delirium as depression can be catastrophic. Giving a delirious person antidepressant medications may make the delirium worse. And causes of delirium are often life threatening, so any delay in diagnosis can be dire.

Delirious individuals usually sleep erratically. This can lead to the use of sleeping pills, but sleeping pills, if not used cautiously, also can make delirium worse.

As occurred in John’s case, delirium usually begins abruptly.  As quickly as delirium appears it may clear up as rapidly, once the underlying cause or causes are corrected. In some cases, however, the effects can linger for weeks to months, or become chronic, leaving the patient at a lower level of mental functioning.

Delirium is the accepted medical term for this condition and the most accurate one to use. Other terms still in use include acute encephalopathy, altered mental status, and acute confusional state.

Few people know about it, even though it is both common and serious. It strikes fifteen to sixty percent of hospitalized older patients, and up to eighty percent of elderly patients in the intensive care unit. Older people, particularly those who are frail or have dementia, are highly susceptible. Even those with excellent mental health can succumb to delirium during bouts of severe illness or after major surgery. Despite the frequency with which delirium occurs, hospitals rarely take steps to prevent it. They also fail to warn people about delirium or educate them about what to expect. As you can imagine, delirium can really scare people, especially when they do not know what is happening to them.

And delirium has serious consequences. Delirium is associated with a greater chance of dying. People who become delirious remain in the hospital longer. They are much less likely to go home from the hospital, needing a stay in rehabilitation first, and often winding up in a nursing home or assisted living facility for long-term care. Among those who already have Alzheimer’s disease or a related disorder, delirium can cause faster decline.

In many cases, delirium does not seem to have a clear-cut cause. This is because delirium can arise when several minor problems, each one not too severe by itself, combine to disrupt brain function. In John’s case, treatment of pneumonia, correction of kidney failure, replacing narcotic pain medications with Tylenol, and stopping a bladder medication only helped somewhat. It was not until his doctors recognized that he also had congestive heart failure, and corrected this, he improved more rapidly.

Physicians not trained in geriatrics may fail to suspect delirium, especially when none of the contributing causes seems severe enough to cause serious trouble. And many physicians still have not been educated about medications that are prone to cause delirium in elderly patients.

Identification and correction of the underlying causes of delirium is the main focus of treatment. During this time, the presence of family visitors is usually very reassuring to delirious patients, as long as family members can be a calming influence. Reassuring reminders about where the person is and what has happened, along with explanations about delirium, stressing that it is temporary, may ease anxiety. Noise and commotion should be reduced. The television should be kept off if the delirious person finds it confusing or frightening. Leaving night-lights on may help reduce fear. Patients who are impulsive and prone to get out of bed on their own, may need to have someone sit with them continuously to ensure that they do not fall or wander off. When patients are very agitated, and pull out intravenous lines, feeding tubes, urinary catheters, or breathing tubes, or become violent, restraints may be needed.

During periods of severe agitation, especially when patients are frightened by hallucinations or delusions, it may be necessary and helpful to treat these symptoms with psychiatric medication. Prescription of psychiatric medications for delirium requires specialized expertise and great caution. Injudicious use of psychiatric medication may worsen the problem. Sedatives and sleeping pills often worsen the situation, as do narcotic pain medicines. Antidepressant medication can be another problem. As I mentioned earlier, delirious patients commonly exhibit depressive symptoms. Almost always, delirious patients who seem depressed should not receive antidepressant medications, since these do not treat delirium and may make it worse.

When agitated and psychotic symptoms are severe enough to require medication, antipsychotic medication is usually the correct choice.   John was given Haldol, a good choice for short-term treatment of symptoms of delirium; the dose was 0.25 mg three times a day. His wife and daughter were able to take turns sitting with him. He improved enough that his doctors were able to stop the Haldol after three days, and no further medication for agitation was needed. Within three weeks John returned to normal and went home.


Gary S. Moak, M.D

Updated September 2016