Delirium, sometimes called acute confusional state, is a common and potentially serious condition. It affects older people during illnesses (such as infections), during hospitalization, or after surgery. It may result in longer hospital stays and is associated with other complications (such as increased risk of nursing home admission).
What is delirium?
Delirium is a syndrome which temporarily affects a person's thinking. It interferes with the ability to focus, stay on track or shift attention. The symptoms often wax and wane during the day, and may disturb sleep. Confusion, forgetfulness, hallucinations (seeing things which are not real) and feeling restless are common (1;2). You may have had the experience of visiting a family member or friend after surgery, and found that they were not quite themselves. Perhaps they didn’t remember where they were or why they were in hospital. They may have appeared muddled and said strange things. These symptoms suggest delirium. [For an alternative definition from DSM-5 see text below (3).]
What causes delirium? Predisposing and precipitating factors
There are many causes of delirium, some of which are complicated. Scientific research identifies factors which make delirium more likely to occur. These important factors can be grouped into two main categories: predisposing and precipitating factors. Predisposing factors are conditions which exist in the patient before the delirium develops. Precipitating factors are conditions which are associated with the start of a delirium.
Predisposing factors include (2):
- older age
- male sex
- preexisting cognitive impairment (for example: problems with thinking and memory)
- difficulty seeing and hearing
- taking many medicines at the same time
- other medical conditions (for example, diabetes, chronic kidney disease, previous strokes, Parkinson's disease)
- certain heart problems (such as atrial fibrillation and heart failure)
- being a heavy alcohol drinker
Precipitating factors include (2):
- pneumonia and other infections
- abnormal blood results (for example, raised blood urea nitrogen or creatinine levels)
- recent anesthetic
- certain surgical operations (for example, operations on the heart or hip)
- recent blood transfusions
- drugs related to sleeping or mood (for example, benzodiazepines, certain medications for depression, drugs with anticholinergic side effects)
- not getting enough oxygen
- medical complications
- putting on restraints (which makes it hard for patients to move)
How is delirium detected?
There are two types of delirium. “Hyperactive” is usually obvious as the person is restless, confused and acting out of character. With the “hypoactive” type the person may appear quiet and peaceful. It can be hard to detect delirium, unless a clinical test is used. The most widely studied test is the Confusion Assessment Method (CAM) (4). This takes less than 5 minutes to complete, and is able to detect over 90% of people with delirium; the test is negative in nearly 90% of people without delirium. These results make it a very accurate test.
How is delirium treated?
The scientific research is not completely clear about the best way to help people with delirium to get better. Doctors generally believe that treating the precipitating problem (for example, the pneumonia or dehydration) will help the delirium to improve more quickly. There are also a number of simple things that we can do to help (5):
- Make sure there is good lighting in the room, so that signs and other things can be easily seen
- Bring in a clock and calendar and put these in a place where they can be easily recognized
- Visit often and have other friends and family do so as well
- Talk to the person, making sure that you explain where they are, what the date is, who you are (reminding them of your relationship to them). Talk about what is happening in the news. All of this helps to orientate them and remember what has happened to them (5).
When we look at the research, we have four studies that have used clocks and calendars to help orient patients. One study had clocks and calendars but also added specific talking to the patient (e.g. reorienting them to time and day and other such activities). On the basis of experience, the National Institute for Health and Clinical Excellence group emphasized the importance of family and friends in helping with patient reorientation (5). If the person is “disorientated” (they don’t know where they are or who you are) it is really important to note this; often being disoriented can mean that the person has underlying cognitive impairment or dementia.
There are some studies that look at the use of drugs to help people who get really agitated when they are experiencing delirium. The science is not very clear about this but sometimes doctors do choose to use medications to help. Without conclusive evidence, antipsychotic drugs can be used to calm down people who are delirious and are highly agitated, aggressive or at risk to themselves or others (6;7), but use of these types of drugs is not recommended. The exception to using these is where delirium is the result of alcohol withdrawal, in which case other drugs (benzodiazepines) are the preferred medications.
Can delirium be prevented?
As the causes of delirium are multiple, the most effective ways of preventing delirium involve multiple strategies. The scientific evidence is not conclusive, but shows encouraging results. One trend is the use of multi-component strategies which show moderate success in delirium prevention (8;9;10;11). The types of treatments used varied widely within the studies that evaluated the programs. This makes it difficult to determine which parts of the multi-component strategies may be effective.
One multi-component program called the Hospital Elder Life Program (HELP) has been evaluated in three studies. This program typically consists of 6 components:
- orientation (for example, talking to them and letting them know where they are and why they are in hospital),
- adequate fluids by mouth (drinking enough to get hydrated),
- vision protocols (making sure they have glasses so they can see),
- hearing protocols (making sure they have their hearing aids),
- sleep enhancement (making sure we can help them sleep), and
- early mobilization (moving around, such as walking, standing, or sitting as soon as they can).
In these 3 studies, the HELP program was shown to reduce how frequently people develop delirium in hospital by as much as 40% (12). These studies are a good start, but in future we would need more conclusive studies, (such as randomized clinical trials) to determine if this approach is best.
An approach used to prevent delirium after surgery involved asking a geriatrician (a specialist in care of older people) to visit and examine patients after their operations (for example, repair of a hip fracture). The geriatrician made targeted recommendations based on a structured protocol. In one study which used this proactive geriatric consultation, the risk of delirium after surgery was reduced (8). However, this study was not conclusive, and more air-tight studies are required to confirm these results.
Other interventions have been tried, including music therapy and educating the health care staff. For these the scientific evidence is weak, with only two studies supporting them (13).
A recent study though, with a few scientific problems, suggests a large positive effect in reducing the development of delirium in hospital. This randomized controlled trial showed that family members may reduce the risk of a person developing delirium by as much as 50% (14). This clinical trial involved the following:
- Education for the family members was provided by staff. This included information about the features and outcome of delirium. It took only 10 minutes. An educational pamphlet was also provided.
- A clock and calendar were placed in the patient's room.
- Sensory deprivation was avoided by providing eyeglasses and hearing aids where appropriate.
- Presence of familiar objects in the patient's room (e.g. photographs, cushions and radio).
- Re-orientating the patient (reminding him/her of the location, surroundings, current date, news of recent events etc.).
- Extended visiting time (5 hours daily).
The scientific evidence for all of these interventions to prevent delirium is still not conclusive. However, some of these strategies seem simple and inexpensive to implement.