What is Delirium?

Image courtesy Grant Cochrane @ http://www.freedigitalphotos.comAcute confusional state, or delirium, is a syndrome or group of symptoms often seen during times of acute illness, such as when a person is admitted to the hospital.  The most commonly seen symptoms are increased confusion and disorientation, which typically develops suddenly and shows rapid fluctuations.  This differs from dementia, where similar symptoms are seen to progress slowly over time, and be relatively constant.  The main characteristics of delirium include a disturbance of consciousness (decreased awareness of the environment, as well as reduced ability to focus, shift, or maintain attention), changes in cognition (for example, problem solving or memory) or perceptual disturbances (hallucinations), onset ranging from hours to days with a tendency to fluctuate in severity, overactive or underactive behavior with changes in sleep patterns, and slow or muddled thinking with a preservation of complexity of thought.  A person who is delirious may also show disorganized thinking, poor memory, emotional lability, and delusions.

Delirium affects probably 10-20% of all hospitalized adults, and is estimated to be the most common acute medical problem affecting adults in hospitals.  Especially affected are the elderly, with 30-40% developing symptoms of delirium, and 80% of those in intensive care units.  It has been reported that persons in the ICU, or who have other medical conditions requiring critical care, and who develop signs of delirium, show a greatly increased risk of mortality within 12 months of discharge from the hospital.

There are a number of medical conditions which can cause a person to become delirious.  These can include various disease processes (urinary tract infections or pneumonia, for example) or reactions to medications.  There must be a definite organic process at work in the body, which can be identified through physical, functional, or chemical means.  Changes in behavior or cognitive functioning related to existing psychiatric diseases cannot be considered a true delirium.  (However, it should be noted that persons with a chronic condition such as schizophrenia or dementia may develop signs of delirium related to another, newly-developed, condition such as a reaction to anesthesia.)

Individuals who already have compromised health, or who are in generally weakened condition, are at a higher risk for developing delirium.  Some factors that can predispose a person to develop delirium include older age, pre-existing cognitive impairment or dementia, physical disease (heart failure, cancer, etc.), pre-existing psychiatric illness (depression, etc.), sensory impairment (vision or hearing), requiring assistance for self-care and mobility, dehydration and/or malnutrition, and abuse of drugs or alcohol.

In addition to factors which might predispose a person to develop delirium, there are a number of events that can immediately precipitate that development — or set the process in action.  Some of these include metabolic deficiencies (malnutrition, hypoxia, anemia, hypoglycemia, endocrine disorders, etc.), infections (especially respiratory and urinary tract infections), some medications (anticholinergics, dopaminergics, opioids, steroids, or any recent change in medication), poisoning, surgery, vascular incidents (TIA/stroke, heart attack, physical/psychological stress — including pain or a fall/traumatic event), or intoxication/withdrawal from alcohol or recreational drugs.

There is increasing evidence that older individuals who enter the hospital with delirium, or who develop it while a patient there, stand at a significantly greater risk of having poor outcomes upon discharge.  One meta-analysis of 12 studies showed that older persons experiencing delirium while in the hospital are twice as likely to die as those who did not.  It has also been shown that those who develop delirium are twice as likely to be institutionalized after discharge, and are three times as likely to have increased functional dependence on other persons.

There are reports that persons who develop delirium are significantly more likely to be diagnosed as having dementia, however there is some discussion as to how this can be so.  One theory is that there may be a mild cognitive impairment, or a mild undiagnosed dementia, which only became apparent when the symptoms of dementia were added to the mix.  Other studies show that older adults who are hospitalized for any reason show increased risk of developing dementia.  Authorities agree, however, that those who have a previous diagnosis of dementia will often show increased cognitive and functional symptoms.

To fully and accurately diagnose delirium, it is important to collect a thorough medical history.  This should include information as to baseline cognitive functioning, or what the person was like before the onset of the most recent illness or injury.  Other tests should be conducted as well, in an effort to learn more about the medical condition(s) that precipitated the delirious state.  These can include blood work, x-rays, CT scans, MRI, urinalysis, and others.

One of the best ways to treat delirium is to prevent it from developing in the first place.  One way to do this is to identify those who are at risk for such,  to closely observe them for the first signs of illness, and then to deal with any precipitating factors that may emerge before a full-blown delirium can develop.  (One estimate is that 30-40% of all cases of delirium could be prevented in this way.)

Treatment for delirium consists largely of treating the underlying cause for the changes that are occurring.  In some cases, this might mean administering antibiotics to treat a urinary tract infection.  Other interventions might be utilized as well, such as providing comfort to a person who has been intubated due to severe pneumonia.  At the same time, treatment needs to provide an optimal circumstance for the patient’s brain to return to as close to their baseline function as possible.

It is almost always preferable to use non-pharmacological methods for treating the behavioral aspects of delirium, unless the person is in serious danger of harming himself or others.  Some strategies that are helpful include avoiding unnecessary movements, having family members participate in care when possible, and using external compensatory mechanisms to aid in orientation.  A calm approach is always best.  A good little mnemonic device to remember is “T-A-Da,” or “Tolerate, anticipate, don’t agitate.”  Remove unnecessary attachments, such as catheters, that might be interpreted as a restraint.  As long as the individual’s behavior is not causing any serious problems, it may be best not to try and change it.  (This does necessitate that the person be closely supervised for the sake of safety.)  Careful care planning can anticipate possible problems that might occur.  Physical (or chemical) restraints should be used only as a last resort.



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