WHAT IS DELIRIUM? BASIC FACTS AND INFORMATION

We all have minor problems with memory and understanding as we get older.  We forget names or take more time to figure out directions.  These problems are a normal part of aging for everyone. But some older adults develop extreme problems with remembering, understanding, or thinking. For example, they can get lost walking to the bathroom, become confused by simple tasks, forget the names of loved ones, and have trouble speaking in a logical way. These problems can be very difficult to cope with, not only for the person affected, but also for their family, friends, and other caregivers.

Delirium, which is a term meaning “sudden confusion”, refers to an abrupt, rapid change in mental function that goes well beyond the typical forgetfulness of aging.  This syndrome has also been called acute confusional state, toxic psychosis, metabolic encephalopathy, or acute organic brain syndrome.  Delirium is a result of abnormal functioning of the brain.

Many of the characteristics of delirium are the same as those for dementia.  The differences between these two conditions are described more fully later in this chapter. People with dementia are also at high risk of developing delirium, and the two conditions often occur together. Whenever the behavior or thinking of a person with dementia suddenly gets much worse, particularly if the person is sick or in hospital, the cause is likely to be delirium.

A sudden change in mental function in an older person is a serious situation that requires the attention of a healthcare professional.

TYPES OF DELIRIUM 

Delirium usually occurs in two forms: 

• A hyperactive form, in which patients are agitated or very vigilant, or
• A hypoactive form in which patients are lethargic, move less than usual, and have little awareness of their surroundings.

Often, doctors and nurses in hospital are not aware that an older patient is suffering from delirium because the patient becomes less active (hypoactive), rather than more restless (hyperactive). Sometimes, the hyperactive and hypoactive forms switch fairly quickly, so that a delirious person cycles between lethargy and agitation within a single day.

HOW COMMON IS DELIRIUM?

Delirium occurs frequently especially in older people.  Hospital records show that one-third of older adults arriving at emergency departments are delirious.  For older people living at home, the risk increases with age.

For older adults in hospital, delirium is one of the most common complications of medical illness or recovery from surgery.  Approximately one-third of patients over age 70 who are admitted to the hospital experience delirium, and about two-thirds of older people experience delirium after surgery.

Delirium is present in half of hospital patients transferred to a nursing home, and about two-thirds of patients who are residents of nursing homes. About 80% of people suffer from delirium at the end of life.

CAUSES & SYMPTOMS

Healthcare professionals still don't completely understand what makes a person delirious, but many factors are probably involved, and some causes are now known.  Generally, people who become delirious already have some type of illness, and are exposed to some additional injury or environmental trigger. For example, if a patient already has dementia, then a relatively minor injury or upset—such as a single dose of a new medication or a change in residence—may bring on delirium.

In fact, dementia is the most common risk factor for delirium, and two-thirds of cases of delirium occur in patients who already have dementia. In other patients who aren’t as vulnerable, delirium may develop only after several factors have occurred together, such as general anesthesia, major surgery, and psychiatric medications.

Addressing just one contributing factor is unlikely to resolve delirium in an older person; they should all be addressed when possible. A key goal for the healthcare professional is to find as many causes as he or she can identify and correct those that are reversible.

Reversible causes of delirium are outlined by the following acronym (DELIRIUM): 

• Drugs, including any new medications, increased dosages, drug interactions, over-the-counter drugs, alcohol, etc. 

• Electrolyte disturbances, especially dehydration, and thyroid problems. 

• Lack of drugs, such as when long-term sedatives (including alcohol and sleeping pills) are stopped, or when pain drugs are not being given adequately. 

• Infection, especially urinary or respiratory tract infection. 

• Reduced sensory input, which happens when vision or hearing are poor. 

• Intracranial (referring to processes within the skull) such as a brain infection, hemorrhage, stroke, or tumor (rare). 

• Urinary problems or intestinal problems, such as constipation. 

• Myocardial (heart) and lungs, eg heart attack, problems with heart rhythm (arrhythmia), worsening of heart failure or chronic obstructive lung disease.

Extended biological explanation of delirium:

Drugs

Side effects of familiar medications or sudden withdrawal from drugs are the most common and most treatable causes of delirium. Since many older people take multiple medications which may interact in harmful ways, you must be sure that the appropriate healthcare professionals are told about every prescription and non-prescription drug in use.

Alcohol

Alcohol abuse is frequently overlooked as a cause of delirium in older adults. Either overuse (intoxication) or a sudden withdrawal from alcohol can cause delirium. Delirium caused by withdrawal of alcohol appears to be as common in older adults with alcoholism as in their younger counterparts, although the death rate after withdrawal is higher in older alcoholics.

Medical Conditions

Virtually any physical illness or condition can bring on delirium, especially when more than one illness is present. Sometimes, delirium is also the first sign of a serious, life-threatening illness such as a heart attack. In hospital, the most common causes are sudden blood loss, dehydration, low blood pressure, fluid retention, infections, low levels of oxygen (hypoxia), kidney or liver failure, high blood sugar (hyperglycemia) or low blood sugar (hypoglycemia) in the blood, intestinal blockage (impaction), sleep deprivation, or inability to urinate. Delirium caused by a sudden change in the nervous system, such as a stroke, brain tumor, or brain infection, is less common.  Immobility, sleep deprivation or fragmented sleep, and pain can all contribute to bringing on delirium.

Environmental Conditions

Delirium can also result from too little stimulation of the senses, especially in people who already have some degree of mental impairment, or who are confined to a featureless hospital or nursing home room. In one study, delirium after an operation occurred twice as often in patients in intensive care units without windows as in patients in similar units with windows. In addition, a form of delirium that occurs in the evening (known as “sundowning”) may be partly due to sensory deprivation. Vision and hearing loss may also make it more difficult for the person to perceive reality and increases the likelihood of delusions or hallucinations.

Delirium after Surgery

Delirium may be the most common complication after surgery in older adults, and leads to longer hospital stays, a higher death rate, and a greater need for nursing-home care afterwards. It may also signal that there will be complications after surgery.

The chance that a patient will become delirious after an operation increases if a patient is an older adult, already has dementia or a physical disability, abuses alcohol, or has very abnormal blood tests. Also, certain types of operations are more frequently associated with delirium. For example, delirium is much more common after hip surgery and heart surgery.

SYMPTOMS AND WARNING SIGNS

Delirium is recognized by the presence of a number of specific symptoms, but these may change quickly, for example, from lethargy to agitation and then back again. The symptoms also vary quite a bit from one person to the next. Delirium may also come and go within a 24-hour period.

Typical Symptoms of Delirium include: 

• Sudden onset over hours to days 

• Slurred speech and language difficulties: talking that doesn’t make sense 

• Changes in feeling (sensation) and perception 

• Easily distracted, decreased attention, concentration, and environmental awareness; usually more alert in the morning than at night; in and out of consciousness 

• Changes in movement (for example, may be slow moving or very restless) 

• Changes in sleep patterns, such as reversed sleep-wake cycles 

• Confusion and disorientation: not aware of correct time or place 

• Memory loss, including decreased short-term memory and recall 

• Disorganized thinking 

• Emotional or personality changes, with frequent changes in moods, including anger, agitation, anxiety, apathy, depression, fear, euphoria, irritability, suspicion 

• Incontinence 

• Hallucinations (visual, but not auditory) 

• Signs of medical illness (such as fever, chills, pain, etc) or drug side effects

DIAGNOSIS & TESTS 

Healthcare professionals pay special attention to changes from the usual mental state, while taking into consideration any physical problems. For example, when speaking to the patient, they may notice that the patient’s attention wanders, that he or she is restless, distracted easily and unable to follow directions, or that the patient’s speech is disorganized and does not make sense.

A diagnosis of delirium is made on the basis of careful observation and, if necessary, testing. To evaluate thinking, doctors may use a simple set of tests and standardized questions similar to those used to diagnose dementia.

The following tests are typical: 

• Perform a simple math calculation 

• Spell a short word backward 

• Repeat a series of four or five numbers, in order and then in reverse order 

• Name the days of the week backward.

Other tests to assess cognitive health include the Mini–Mental State Examination (MMSE), the Confusion Assessment Method (CAM), and other similar tests. Since many subtle or hypoactive cases of delirium are missed, healthcare professionals need to check the cognitive health of every older hospitalized patient. If you think that delirium may be present in a family member or someone close to you, you must alert a healthcare professional and have the person evaluated.

When the causes of delirium are not clear, the healthcare professional must take a complete history and physical exam. The history will include a review of all drugs being taken, including over-the-counter medications and herbal remedies. Blood tests and other studies may also be appropriate (see below).

The following tests may be used by healthcare professionals to diagnose delirium: 

• Neurological exam, including tests of feeling (sensation), thinking (cognitive function), and motor function 

• Neuropsychological studies 

• Cognitive testing (such as the Mini-Mental State Examination) 

• Blood tests (such as a comprehensive metabolic panel or toxicology screen).

Other tests may include:

• Chest xray
• Cerebrospinal fluid test
• Electroencephalogram (EEG)
• CT or MRI scans of the head
• Urine analysis.

  

DIFFERENTIATING DELIRIUM FROM LOOK-ALIKE 

DEMENTIA	DELIRIUM
Slow onset over months to years; remains a long-term condition	Sudden onset over hours to days; lasts a shorter length of time
Normal speech	Slurred speech
Conscious and attentive until late stages; status relatively stable	In and out of consciousness; inattentive, easily distracted; decreased attention and environmental awareness; symptoms variable, disappearing and reappearing rapidly
Hallucinations possible	Hallucinations common (usually visual)
Listless or apathetic mood most common; agitation possible	Can be anxious, fearful, suspicious, agitated, apathetic, disoriented, disorganized thinking, listless, unaware
Often no other sign of physical or medical illness	Other signs of illness are common (fever, chills, pain) or drug side effects

Delirium can be mistaken for dementia or for psychiatric diseases such as schizophrenia. Certain rare forms of epilepsy can also closely resemble delirium. However, in epilepsy there is usually a history of seizures before the episode of sudden confusion.

Delirium and dementia share several characteristics that often make it hard to tell them apart. For example, both syndromes involve memory loss and language difficulties. Also, since dementia greatly increases the risk of delirium, they commonly occur at the same time.

Different Characteristics of Dementia and Delirium:

Delirium occurs very often in older people suffering from dementia, but it is a distinct syndrome requiring medical attention.

Differences between Delirium and Psychiatric Conditions

The best way to differentiate delirium from psychiatric problems is by considering age and how suddenly the symptoms appeared. If an older person's behavior changes suddenly, you should consider delirium as a possibility. Other features that may help separate psychiatric disease from delirium are the types of hallucinations that the person experiences. Psychotic patients typically hear voices or sounds, while people with delirium usually have visual hallucinations, seeing things that aren’t really there. Certain physical characteristics – for example, hand-flapping and EEG changes – are typical of delirium. Sudden underlying medical illness is also unusual in psychiatric disorders.

LIFESTYLE & MANAGEMENT

Delirium is traditionally viewed as a short-term, temporary problem. However, evidence is growing that it may persist for weeks to months in many people, especially in older people. In hospitalized patients, delirium is linked to poor outcomes, such as higher risk of death, complications, long hospital stays, and nursing home care. Poor outcomes are particularly common among older adults whose delirium continues for a long time.

Nevertheless, family members need to understand that, Usually—delirium goes away eventually, although it may take weeks or months. Slow recovery is more common if delirium is severe or if the person already has dementia or is 85 years old or older. Careful supportive care and monitoring of mental status during this period are crucial to recovery.

CAREGIVER AND FAMILY ASSISTANCE

Family members can play an important role by providing appropriate orientation, support, and assistance. More and more, hospitals are allowing family members to sleep overnight with relatives who are already delirious or at high risk of becoming so. If you are a caregiver, get medical help right away if the patient's mental status worsens suddenly.

You can join Caregiver Support Groups.  Members of these groups obtain support by talking about their experiences, sharing strategies for coping, and informing each other about community resources.

(Source:  Healthinaging.org)