Delirium

Delirium is a serious and sudden change in mental abilities that can develop within hours or days, causing confusion, disorientation, and changes in behavior. While it is more common in older adults, especially those in hospitals, it can affect anyone at any age and requires immediate medical attention.

Table of contents

• What is delirium
• Types of delirium
• Symptoms and signs
• Causes and risk factors
• Who is at risk
• Complications
• How doctors diagnose delirium
• Treatment approaches
• Behavioral strategies and prevention
• How to help someone with delirium
• Outlook and long-term effects

What is delirium

Delirium is a serious change in mental abilities that develops quickly, usually within hours or a few days^[1]. It affects a person’s thinking, memory, awareness, and ability to focus. When someone has delirium, they may act very differently than they typically would, showing confused thinking and reduced awareness of their surroundings^[1].

By definition, delirium is caused by an underlying medical condition and is not better explained by another pre-existing brain disorder^[3]. The syndrome (a group of symptoms that occur together) is characterized by an alteration of attention, consciousness, and thinking ability, with reduced capacity to focus, sustain, or shift attention^[3].

Delirium is a temporary condition that can often be reversed if the cause is identified and treated quickly^[2]. However, it is a dangerous condition that can lead to long-term or even lasting problems, especially if not treated promptly^[2]. This makes prevention and early detection extremely important.

Types of delirium

Healthcare providers have identified three main types of delirium based on a person’s level of activity and alertness^[2][4]:

• Hyperactive delirium is the most easily recognized form. People with this type feel stressed, excited, restless, and very alert. They may show agitation, rapid mood changes, or experience hallucinations^[2][6].
• Hypoactive delirium is less obvious and often goes unrecognized. People with this type have low energy, are sleepy, move less than normal, and aren’t fully aware of what is going on^[2][6]. This “quiet” form happens in up to 75 percent of people with delirium^[4]. Healthcare providers may mistakenly assume this is depression rather than delirium^[4].
• Mixed delirium occurs when people switch back and forth between hyperactive and hypoactive forms^[2]. Sometimes a person may switch between having low energy and being excitable within a single day^[4].

Symptoms and signs

Symptoms of delirium usually begin over a few hours or a few days^[1]. They typically come and go during the day, with periods where there may be no symptoms at all. The symptoms tend to be worse at night when it’s dark and things look less familiar, and in unfamiliar settings such as hospitals^[1][2].

The main symptoms include reduced awareness of surroundings, poor thinking skills, and behavior and emotional changes^[1].

Reduced awareness of surroundings may result in trouble focusing on a topic or changing topics, getting stuck on an idea rather than responding to questions, being easily distracted, and being withdrawn with little activity or response^[1]. People may not know where they are, what time of day it is, or may not recognize familiar people^[2][7].

Poor thinking skills can appear as memory problems, such as forgetting recent events or not remembering where they are or who they are^[1]. People may have trouble with speech, recalling words, rambling or nonsense speech, trouble understanding what others say, difficulty reading or writing, and disorganized thinking with trouble concentrating^[1][2].

Behavior and emotional changes include anxiety, fear, distress, agitation, anger, depression, and irritability^[1][2]. Some people may see or hear things that aren’t really there, which are called hallucinations. They may also believe things that aren’t proven to be true, called delusions^[2].

Additional symptoms can include changes in sleep patterns, such as being awake at night and feeling tired during the day, feeling restless or having slowed activity, and problems remembering facts, events, or people^[2].

Causes and risk factors

Delirium happens when the body or brain is under too much stress and has a hard time coping^[2]. The underlying cause can vary widely and involve anything that stresses the baseline health of a vulnerable person^[3].

Common causes include^[1][2][5]:

• Serious or chronic medical illness and infections, such as pneumonia, bloodstream infections, or urinary tract infections
• An imbalance in the body, such as low sodium, kidney failure, liver failure, or low oxygen levels
• Certain medicines or taking too many medicines at once, especially those with effects on the brain
• Substance intoxication or withdrawal from alcohol or drugs
• Surgery or hospital stays
• Severe injury like broken bones or serious burns
• New or sudden pain
• Not getting enough sleep or not moving around enough
• Being in a room without windows or sunlight for a long time
• Medical equipment that keeps someone in bed, like IVs or catheters
• Trouble seeing or hearing without glasses or hearing aids
• Dehydration or malnutrition

In older adults, even less severe conditions can trigger delirium, including minor illnesses such as a urinary tract infection, severe constipation, prolonged sleep deprivation, and sensory deprivation including being socially isolated and not having access to needed eyeglasses or hearing aids^[5].

Who is at risk

While delirium can occur at any age, it is more common among older adults^[2][3]. Delirium happens often among older adults, with this risk increasing with age^[4].

People may be more at risk for delirium if they^[2][4]:

• Are above age 65 (though it can affect anyone at any age)
• Experience frailty
• Had delirium before
• Have a chronic health condition like heart or lung disease
• Have a mood disorder or substance use disorder
• Have memory issues like dementia or pre-existing cognitive impairment
• Have trouble seeing or hearing
• Have had a stroke or have Parkinson disease or brain damage due to another condition

Certain settings also increase the risk. Up to half of people having high-risk surgery, such as repairing a broken hip, develop delirium^[4]. One-third of those age 70 and older who are in the hospital experience delirium^[4]. Up to 15 percent of people entering a skilled nursing home have delirium, and up to 85 percent of people have delirium when they are dying^[4].

Delirium may affect 15 to 50 percent of people sometime during hospitalization and is also common among residents of nursing homes^[5].

Complications

Delirium is associated with significant negative outcomes. It can lead to prolonged hospital stay, need for institutional care, poor functionality, and high treatment costs^[3]. It has also been shown to be associated with high short-term and long-term mortality^[3].

Complications may include^[2]:

• Aspiration pneumonia (lung infection from breathing in food or liquid)
• Bedsores (pressure ulcers)
• Weakness, leading to loss of mobility
• Falls and injuries like fractures
• Combative behavior
• Malnutrition and dehydration
• Cognitive impairment
• Loss of independence
• Dementia (new or worsening)

These complications may be short-term with treatment, or they can be serious and even life-threatening, especially for people who are already sick^[2]. In older persons, delirium increases the risk of functional decline, institutionalization, and death^[13].

Earlier it was thought that delirium is not associated with any long-term consequences, but now it is increasingly recognized that in the long run, delirium is associated with cognitive decline and development of dementia^[10].

How doctors diagnose delirium

Healthcare providers can diagnose delirium based on medical history and tests of mental status^[9]. The provider also will consider factors that may have caused the disorder. Providers may rely on input from a family member or caregiver to diagnose the disorder, as healthcare professionals don’t recognize delirium in up to half of people who have it^[1][4].

The diagnosis is often missed, especially the hypoactive type, due to its subtle clinical presentation^[3]. Delirium may be difficult to diagnose without first establishing a person’s usual mental function or cognitive baseline^[8].

A provider will make a diagnosis after^[2][9]:

• A physical exam
• A neurological exam
• Observing the person’s behavior
• Learning more about symptoms
• Reviewing medical history
• Lab testing

There is no single test that shows delirium^[2]. The provider may order blood, urine, and other tests, and brain-imaging tests may be used when a diagnosis can’t be made with other information^[9].

Because delirium is a temporary condition, determining how many people have it is difficult^[5]. Assessment for and prevention of delirium should occur at admission to the hospital and throughout the stay^[13].

Treatment approaches

The first goal of delirium treatment is to address any causes or triggers^[9]. The first and most important step in managing delirium is identifying its underlying cause and treating this precipitant directly^[12]. That may include stopping certain medicines, treating an infection, or treating an imbalance in the body^[9].

There is no treatment for delirium itself. The goal is to treat the cause of delirium and keep the person as comfortable as possible^[20]. Finding the cause usually means doing some tests and asking about any recent changes in health. The cause of delirium may never be known^[20].

Treatment focuses on creating the best setting for healing the body and calming the brain^[9]. Supportive care aims to prevent complications and includes protecting the airway, providing fluids and nutrition, assisting with movement, treating pain, addressing lack of bladder control, and avoiding the use of physical restraints and bladder tubes when possible^[9].

While behavioral interventions and psychotropic medications may target specific symptoms associated with delirium, pharmacological treatment should be used in a time-limited manner and in the lowest possible dose for the management of highly stressful symptoms or high-risk behavior^[14]. Pharmacologic interventions should be reserved for patients who are a threat to their own safety or the safety of others, and those patients nearing death^[13].

Delirium can also happen in the last days and hours of life. The focus at the end of life is to keep the person comfortable^[20]. Delirium is possible during the end stages of life, especially for people receiving palliative care or hospice care^[2].

Behavioral strategies and prevention

Behavioral interventions are key in both the management and prevention of delirium^[12]. The goal of these measures is to maintain safety, reinforce an appropriate sleep-wake cycle, and reorient the patient to their environment^[12].

It is not always possible to prevent delirium. However, if someone is at risk of delirium, there are some things that can be done to reduce the risk and help recovery^[7]. Preventive interventions such as frequent reorientation, early and recurrent mobilization, pain management, adequate nutrition and hydration, reducing sensory impairments, and ensuring proper sleep patterns have all been shown to reduce the incidence of delirium, regardless of the care environment^[13].

Practical steps include^[12][20]:

• Keeping the person’s room free of clutter or unnecessary equipment
• Removing extraneous leads, IV lines, or other monitoring equipment to decrease overstimulation
• Encouraging early mobilization and physical activity
• Keeping the room well-lit during the day with room lights on and window blinds or curtains open to allow natural light
• Keeping the room free of unnecessary stimuli at night by silencing non-essential alarms, turning off lights and TV, and minimizing noise and light from the hallway
• Avoiding interruptions in sleep by consolidating care and retiming blood draws and vital signs checks so they are not collected overnight, if avoidable
• Frequently reorienting the person and reassuring them that they are in a safe place with people who are caring for them
• Using a clock and calendar to help them remember the time and date
• Making sure the person wears their aids like glasses, hearing aids, or dentures
• Playing their favorite music quietly
• Leaving the radio or TV off, as added voices and images may add to confusion

How to help someone with delirium

Family members and caregivers have an important role in managing delirium, whether in hospital or at home^[7]. If a loved one develops signs of delirium, family should let their healthcare provider know right away^[18]. Family members and carers are often the first to notice small changes^[7].

Practical ways to help include^[20][22]:

• Speaking clearly, softly, and using fewer words, allowing time for the person to respond
• Not arguing with or correcting them
• Reassuring them, as they may be confused and frightened
• Keeping the area around them calm and soothing
• Visiting often but keeping the visits short in the early days
• Taking turns so no one gets too tired
• Visiting at mealtimes to help ensure they eat and drink enough
• Bringing in items they know and may find comforting
• Offering light and nourishing meals at home
• Making sure they drink enough fluids
• Helping them move around or get some light exercise
• Making sure someone is with them at all times at home
• Removing anything that could be a safety risk

Physicians should train nursing staff, home health aides, and family members or caregivers on recognizing and treating delirium^[13].

Outlook and long-term effects

Delirium could go away if the doctor finds and treats the cause^[2]. If the cause of delirium is identified and corrected quickly, delirium can usually be cured^[5]. Symptoms may last for hours or weeks^[6].

However, delirium may lead to ongoing issues with thinking or memory^[2]. Delirium can be serious and lead to life-threatening complications in certain cases^[2]. Each case is different^[2].

Delirium can be very upsetting for family members to watch^[18]. Not everyone remembers delirium, but those that do may find the memories distressing^[7]. Delirium has been shown to be associated with significant distress to the patient and the family^[10].

Because delirium is a serious complication with significant consequences, efforts should focus on prevention, early detection, and treatment of the underlying cause^[3]. People who have delirium need immediate medical attention^[5].