What is delirium?
Delirium is a state of acute confusion. In contrast to dementia, delirium does not develop gradually and continuously, but suddenly within hours or days. It is one of the organic-psychological disorders. Those affected suffer suddenly from various symptoms that can affect the brain as well as the body. Examples include disorders of consciousness, thinking, memory, orientation, attention and perception. This can be accompanied by sweating, restlessness or a rapid pulse. Delirium can even turn into a life-threatening condition, which is why treatment in an intensive care unit may be necessary.
Medical professionals can often recognize delirium from the symptoms. There are also effective tests that can be used to determine the level of confusion and its severity.
The treatment always depends on the cause. Doctors therefore first look for the cause and treat it. The delirium then often improves again. Equally important in the treatment of delirium are non-drug measures. These include a calm atmosphere, involvement of relatives, early mobilization after an operation, stimulation of mental activities or reorientation (e.g. clock, calendar, no change of room) for use. These help with both treatment and prevention. Otherwise, medication for symptomatic treatment, such as neuroleptics and benzodiazepines, can help.
Delirium – frequency and age
Delirium is not a rare clinical picture and occurs more frequently today than in the past. The reason is that people are getting older today and they are undergoing more intensive treatments. It can also be assumed that the diagnosis of delirium is better known today and therefore more frequent than in the past. In principle, acute confusion can occur at any age. However, delirium is most common in elderly people who suffer from several chronic illnesses.
In general, the frequency of delirium increases with age. Doctors estimate that around 10 percent of the population over the age of 85 develop delirium. Dementia is an important risk factor. And many elderly people suffer from this – in Switzerland too. Some figures:
- Around 22 percent of elderly dementia patients living at home show symptoms of delirium.
- When admitted to hospital, eleven to 25 percent of over 65-year-olds have delirium. An additional 30 percent develop a state of acute confusion during treatment.
- Up to 80 percent of patients who are treated in an intensive care unit suffer from delirium.
Delirium: causes and risk factors
Delirium can have many different causes. The following causes and risk factors can be responsible for acute confusion:
Risk factors:
- old age
- Diseases of the central nervous system, e.g. dementia (e.g. Alzheimer’s disease), Parkinson’s disease, stroke, cerebral hemorrhage, brain tumor, epilepsy, brain and meningitis, craniocerebral trauma
- Poor hearing and eyesight
- certain environmental factors, e.g. transfer to another room, lack of clock and calendar in the room, hardly any visits from relatives or friends
- Mental and physical stress, e.g. stress, pain, disturbed sleep-wake rhythm
- Malnutrition, vitamin deficiency
- Medication, especially if many different medications are taken
Causes:
- Infections, e.g. pneumonia, urinary tract infections, blood poisoning (sepsis), brain (skin) inflammation
- Surgery – delirium can develop, especially in the recovery phase (so-called transit syndrome)
- Disorders of the electrolyte balance, e.g. sodium deficiency
- Dehydration and dehydration (exsiccosis), such as diarrhea, in which the body loses a lot of fluid and electrolytes
- Oxygen deficiency (hypoxia)
- Metabolic diseases, e.g. diabetes (hyper- or hypoglycemia), hyperthyroidism or hypothyroidism
- Various drugs – including alcohol
- Alcohol withdrawal when a person is addicted to alcohol
- Withdrawal from benzodiazepines in case of addiction
- Medication, especially if many different medications are taken, there are often interactions and side effects
- Starting and stopping painkillers
Symptoms: Delirium begins abruptly
People with delirium are acutely confused. Unlike dementia, the state of confusion sets in suddenly within a few hours or days. The severity of the symptoms also varies. Doctors refer to this as fluctuating symptoms. Symptoms often worsen in the late afternoon and evening (“sundowning”). They usually subside after a few days. In some people, however, delirium can last longer than a month. The symptoms of delirium affect the brain, but also the body.
The following signs may indicate delirium:
- Disorders of consciousness, thinking, memory, orientation (e.g. time, place, situation, own person), attention, perception and emotionality
- Pathological restlessness (agitation) and increased state of excitement (hyperactive delirium): senseless, stereotypical movements, urge to be busy, fiddling around. There is also delirium with reduced activity (hypoactive delirium) – in the majority of cases, however, both forms are mixed. Hypoactive delirium is dangerous because it is often overlooked and therefore not adequately treated.
- Increased irritability
- Hallucinations, fears
- Trembling (tremor)
- High blood pressure (hypertension)
- Accelerated heartbeat, palpitations (tachycardia)
- Fever
- heavy sweating
Delirium can become life-threatening and treatment must begin as quickly as possible. Depending on the severity of the delirium, treatment in the intensive care unit may be necessary.
Delirium: Diagnosis by the doctor
The diagnosis of delirium is not easy, as the symptoms are very varied and can easily be confused with dementia. The fact that many people with dementia develop delirium often makes diagnosis difficult. Hypoactive delirium in particular is often overlooked in older people. Differentiation from Parkinson’s disease, which can also present with delirium-like conditions, also requires some specialist knowledge.
The treatment team first asks the relatives (“anamnesis”) because people with delirium are usually not able to give good information. The following information is important:
- Type, intensity and duration of the symptoms, but also whether the symptoms worsen in the late afternoon and evening (so-called “sundowning”)
- Existing underlying diseases
- all medications, substances and drugs taken
- Physical stress, e.g. an operation
- Mental stress, e.g. stress
- Pre-existing condition of the patient
This is usually followed by a physical examination, during which the doctor listens to the heart, for example, and palpates the body for any abnormalities. Among other things, they get an idea of the body’s fluid supply and nutritional status.
An experienced doctor, resp. A doctor can often make an initial assessment of whether delirium is present based on the symptoms. In the current Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the main symptom of delirium is a disturbance of consciousness and attention, which may be accompanied by a thought disorder. This disorder begins acutely and progresses in a fluctuating manner, i.e. the type and intensity of the symptoms change.
Neuropsychiatric tests are helpful in making the diagnosis of “delirium”. What is difficult for the treatment team is the fact that there are various diagnostic systems and screening instruments that often provide blurred results. There are a variety of screening and assessment methods that are used, including
- Confusion Assessment Method for the ICU (CAM-ICU) – this method is considered to be very reliable. Doctors use test questions to determine the state of attention and consciousness and get to the bottom of thought disorders.
- Intensive Care Delirium Screening Checklist (ICDSC) – an alternative to the CAM-ICU, can be carried out within a few minutes. The treatment team checks the state of consciousness and attention, orientation, speech, hallucinations, agitation (pathological restlessness), sleep and symptoms (present or absent).
- Nursing Delirium Screening Scale (Nu-DESC): The focus is on the examination of orientation, behavior, communication, hallucinations and psychomotor slowdowns.
- 3D-CAM: Examination of attention, consciousness and thinking using test questions
- CAM-S – a relatively new test procedure that can also be used to determine the severity of delirium. The treatment team uses tests to examine the following parameters: progression, attention, thinking, level of consciousness, orientation, memory, psychomotor agitation, slowness and sleep.
There are also other screening methods that detect possible delirium, the extent of agitation and pain. Examples are the Numerical Rating Scale (NRS), Richmond Agitation Sedation Scale (RASS) and DOS (Delirium Observation Scale).
Further examination methods may be used, for example:
They provide further indications of delirium, but are not conclusive enough on their own. Once a diagnosis of delirium has been made, doctors must start treatment immediately.
Delirium: prevention, early detection, prognosis
There are several ways in which the treatment team can prevent delirium, for example after an operation. The most important strategies for preventing delirium are
- Early mobilization after surgery with occupational therapy and physiotherapy: maintaining muscle strength and mobility, promoting independence
- Stimulate mental activity
- Adequate oxygen, fluid and food supply
- Avoid polypharmacy (different medications for several illnesses) – Review medication continuously, discontinue medication if not urgently necessary
- Reorientation: Involve relatives and create a familiar environment, ensure good vision and hearing (use own glasses and hearing aids), hang clocks and calendars in a clearly visible place, offer the latest daily newspaper, avoid changing rooms, use care staff who are as constant as possible
- Ensure a good night’s sleep: get a good night’s sleep, reduce light at night, avoid stress
- Avoiding anxiety: adequate pain therapy, reducing noise, avoiding cold, explaining painful examinations and announcing the procedure in good time
In some studies, researchers have tried to prevent delirium with medication – but so far not with resounding results. Haloperidol, other antipsychotics and cholinesterase inhibitors did not clearly reduce the risk of delirium. The effectiveness of melatonin has also not yet been sufficiently scientifically proven and is not generally recommended. The active substance dexmedetomidine appears to be more promising. In one study, he was able to significantly reduce the incidence of delirium when doctors administered the medication before the operation. However, scientists still need to carry out further research.
Course and prognosis of delirium
The course and prognosis of delirium cannot be generally predicted. Both depend on various factors, for example existing underlying illnesses, the general state of health or a person’s age. Delirium often occurs in people who are older and suffer from illnesses such as dementia. The prognosis is less favorable if patients are admitted to hospital with delirium or if the delirium develops during an inpatient stay – the risk of mortality is then increased. This is why preventive measures are so important.
In many cases, the delirium improves again after a few days with the appropriate treatment. However, it can also persist for several weeks. It is always important that the treatment team recognizes the delirium quickly and treats the causes adequately. However, it is possible that a person may not fully recover from delirium. The risk of (further) cognitive impairment, loss of independence, placement in a nursing home and even death remains increased.
It seems to make a difference to the prognosis whether the delirium is hypoactive or hyperactive. Researchers have discovered in a study that hypoactive delirium is associated with a higher mortality rate. One reason could be that doctors and nurses overlook it more often. Regular delirium screening is therefore recommended for elderly patients in hospital at least every eight hours.
Delirium: treatment with several strategies
Delirium is potentially life-threatening and doctors often have to treat the acute state of confusion in the intensive care unit. There they monitor vital parameters such as breathing, cardiac activity(blood pressure, pulse), body temperature and state of consciousness. This complex topic is being monitored by a specialist group at the USZ.
Details of the treatments