Delirium

Being in unfamiliar surroundings such as a hospital Confusion and Mental Decline Due to Hospitalization Being ill, particularly when it involves taking medications for pain or anxiety, can make anyone confused. The hospital environment adds to the problem. There, people give up their personal... read more , particularly in an intensive care unit (ICU), can contribute to or trigger delirium.

In ICUs, people are isolated in a room that typically has no windows or clocks. Thus, people are deprived of normal sensory stimulation and can become disoriented. Sleep is disturbed by staff members who awaken people during the night to monitor and treat them and by loud beeping monitors, intercoms, voices in the hallway, and alarms. Furthermore, most people in ICUs have serious disorders and may be treated with medications that can trigger delirium.

People in ICUs may have seizures Seizure Disorders In seizure disorders, the brain's electrical activity is periodically disturbed, resulting in some degree of temporary brain dysfunction. Many people have unusual sensations just before a seizure... read more that do not cause convulsions (called nonconvulsive seizures). These seizures can cause delirium, but the seizures may not be recognized because they do not cause convulsions or other typical symptoms of seizures. If the seizures are not recognized, they may not be treated appropriately and promptly.

Delirium is also very common after surgery, probably because of the stress of surgery, the anesthetics used during surgery, and the pain relievers (analgesics) used after surgery.

Delirium may also develop when people who are about to have surgery do not have access to a substance they have been using, such as a recreational drug, alcohol, or tobacco. When people stop using such substances, they may have withdrawal Withdrawal Substance use disorders generally involve behavior patterns in which people continue to use a substance (for example, a recreational drug) despite having problems caused by its use. The substances... read more symptoms, including delirium.

The most common reversible cause of delirium is use of medications and recreational drugs. In younger people, using recreational drugs and acute intoxication with alcohol Alcohol Use Alcohol (ethanol) is a depressant (it slows down brain and nervous system functioning). Consuming large amounts rapidly or regularly can cause health problems, including organ damage, coma,... read more are common causes. In older people, prescription medications are usually the cause.

Psychoactive drugs directly affect nerve cells in the brain, sometimes causing delirium. They include the following:

Many other drugs can also cause delirium. The following are some examples:

Delirium can also result from suddenly stopping a medication or drug that has been taken for a long time—for example, a sedative (such as a benzodiazepine or barbiturate) or an opioid pain reliever.

Delirium commonly occurs in people who have alcohol use disorder and who suddenly stop drinking alcohol (called delirium tremens Withdrawal symptoms ) and in people who have heroin use disorder and who suddenly stop using heroin.

Abnormal blood levels of electrolytes Overview of Electrolytes More than half of a person's body weight is water. Doctors think about water in the body as being restricted to various spaces, called fluid compartments. The three main compartments are Fluid... read more , such as calcium, sodium, or magnesium, can interfere with the metabolic activity of nerve cells and lead to delirium. Abnormal electrolyte levels may result from use of a diuretic, dehydration, or disorders such as kidney failure and widespread cancer.

Blood sugar levels that are extremely high (hyperglycemia) or low (hypoglycemia Hypoglycemia Hypoglycemia is abnormally low levels of sugar (glucose) in the blood. Hypoglycemia is most often caused by medications taken to control diabetes. Much less common causes of hypoglycemia include... read more ) commonly cause delirium.

An underactive thyroid gland (hypothyroidism Hypothyroidism Hypothyroidism is underactivity of the thyroid gland that leads to inadequate production of thyroid hormones and a slowing of vital body functions. Facial expressions become dull, the voice... read more ) causes delirium with sluggishness (lethargy). An overactive thyroid gland (hyperthyroidism Hyperthyroidism Hyperthyroidism is overactivity of the thyroid gland that leads to high levels of thyroid hormones and speeding up of vital body functions. Graves disease is the most common cause of hyperthyroidism... read more ) causes delirium with hyperactivity.

If liver failure Liver Failure Liver failure is severe deterioration in liver function. Liver failure is caused by a disorder or substance that damages the liver. Most people have jaundice (yellow skin and eyes), feel tired... read more or kidney failure Overview of Kidney Failure Kidney failure is the inability of the kidneys to adequately filter metabolic waste products from the blood. Kidney failure has many possible causes. Some lead to a rapid decline in kidney function... read more develops and is not diagnosed, a medication that a person has been taking for a long time can cause delirium, even though it previously caused no problems. In these disorders, the liver or kidneys do not process and eliminate medications normally. As a result, medications may accumulate in the blood and reach the brain, causing delirium.

In younger people (once drugs and alcohol are excluded), the cause of delirium is usually

In older people, the cause is often

Such infections can indirectly affect the brain.

Wernicke encephalopathy Wernicke Encephalopathy Wernicke encephalopathy is a brain disorder that causes confusion, eye problems, and loss of balance and results from thiamin deficiency. Wernicke encephalopathy is caused by a severe deficiency... read more , which results from by a severe deficiency of the B vitamin thiamin, can cause confusion and delirium. If untreated, Wernicke encephalopathy can cause severe brain damage, coma, or death.

Some disorders (such as strokes Overview of Stroke A stroke occurs when an artery to the brain becomes blocked or ruptures, resulting in death of an area of brain tissue due to loss of its blood supply (cerebral infarction). Symptoms occur suddenly... read more , brain tumors Overview of Brain Tumors A brain tumor can be a noncancerous (benign) or cancerous (malignant) growth in the brain. It may originate in the brain or have spread (metastasized) to the brain from another part of the body... read more , or brain abscesses Abscess of the Brain A brain abscess is a pocket of pus in the brain. An abscess may form in the brain when bacteria from an infection elsewhere in the head or in the bloodstream or from a wound enter the brain... read more ) cause symptoms of delirium by directly damaging the brain.

Delirium may be the first symptom in older people with a viral disease, such as COVID-19.

In younger people, ingestion of poisons, such as rubbing alcohol or antifreeze, is a common cause of delirium.

Friends, family members, or other observers are asked for information because people with delirium are usually unable to answer. Questions include the following:

Information may also come from medical records, the police, emergency medical personnel, or evidence such as pill bottles and certain documents. Documents such as a checkbook, recent letters, or notification of unpaid bills or missed appointments can indicate a change in mental function.

If delirium is accompanied by agitation and hallucinations, delusions, or paranoia, it must be distinguished from a psychosis due to a psychiatric disorder, such as manic-depressive illness Bipolar Disorder In bipolar disorder (formerly called manic-depressive disorder), episodes of depression alternate with episodes of mania (or a less severe form of mania called hypomania). Mania is characterized... read more or schizophrenia Schizophrenia Schizophrenia is a mental disorder characterized by loss of contact with reality (psychosis), hallucinations (usually, hearing voices), firmly held false beliefs (delusions), abnormal thinking... read more . Typically, people with a psychosis due to a psychiatric disorder do not have confusion or memory loss, and the level of consciousness does not change. Psychotic behavior that begins during old age usually indicates delirium or dementia.

During the physical examination, doctors check for signs of disorders that can cause delirium, such as infections and dehydration. A neurologic examination Neurologic Examination When a neurologic disorder is suspected, doctors usually evaluate all of the body systems during the physical examination, but they focus on the different parts of the nervous system. Examination... read more is also done.

People who may have delirium are given a mental status test Mental Status When a neurologic disorder is suspected, doctors usually evaluate all of the body systems during the physical examination, but they focus on the different parts of the nervous system. Examination... read more . First, they are asked questions to determine whether the main problem is being unable to pay attention. For example, they are read a short list and asked to repeat it. Doctors must determine whether people take in (register) what is read to them. People with delirium cannot. The mental status test also includes other questions and tasks, such as testing short-term and long-term memory, naming objects, writing sentences, and copying shapes. People with delirium may be too confused, agitated, or withdrawn to respond to this test.

Samples of blood and urine are usually taken and analyzed to check for disorders that doctors think may be causing delirium. For example, abnormalities in electrolyte and blood sugar levels and liver and kidney disorders are common causes of delirium. So doctors usually do blood tests to measure electrolyte and blood sugar levels and to evaluate how well the liver and kidneys are functioning. If doctors suspect a thyroid disorder, tests may be done to evaluate how well the thyroid gland is functioning. Or if doctors suspect that certain medications may be the cause, they may do tests to measure medication levels in the blood. These tests can help determine whether the levels are high enough to have harmful effects and whether a person took an overdose.

Cultures Culture of Microorganisms Infectious diseases are caused by microorganisms, such as bacteria, viruses, fungi, and parasites. Doctors suspect an infection based on the person's symptoms, physical examination results,... read more may be done to look for infections. A chest x-ray may be done to determine whether pneumonia may be the cause of delirium, especially in older people who are breathing fast, whether or not they have a fever or cough.

Computed tomography (CT) or magnetic resonance imaging (MRI) of the brain is usually done.

Sometimes a test that records the brain's electrical activity (electroencephalography Electroencephalography Diagnostic procedures may be needed to confirm a diagnosis suggested by the medical history and neurologic examination. Imaging tests commonly used to diagnose nervous system (neurologic) disorders... read more , or EEG) is done to determine whether the delirium is caused by a seizure disorder.

Electrocardiography (ECG), pulse oximetry (using a sensor that measures oxygen levels in the blood), and a chest x-ray may be used to evaluate how well the heart and lungs are functioning.

In people with a fever or headache, a spinal tap Spinal Tap (lumbar puncture) may be done to obtain cerebrospinal fluid for analysis. Such analysis helps doctors rule out infection of or bleeding around the brain and spinal cord as possible causes.

Once the cause is identified, it is promptly corrected or treated. For example, doctors treat infections with antibiotics, dehydration with fluids and electrolytes given intravenously, and delirium due to stopping alcohol with benzodiazepines (as well as measures to help people not start drinking alcohol again).

Prompt treatment of the disorder causing delirium usually prevents permanent brain damage and may result in a complete recovery.

Any medications that may be making the delirium worse are stopped if possible.

General measures are also important.

The environment is kept as quiet and calm as possible. It should be well-lit to enable people to recognize what and who is in their room and where they are. Placing clocks, calendars, and family photographs in the room can help with orientation. At every opportunity, staff and family members should reassure people and remind them of the time and place. Procedures should be explained before and as they are done. People who need glasses or hearing aids should have access to them.

People who have delirium are prone to many problems, including dehydration Dehydration Dehydration is a deficiency of water in the body. Vomiting, diarrhea, excessive sweating, burns, kidney failure, and use of diuretics may cause dehydration. People feel thirsty, and as dehydration... read more , undernutrition Undernutrition Undernutrition is a deficiency of calories or of one or more essential nutrients. Undernutrition may develop because people cannot obtain or prepare food, have a disorder that makes eating or... read more , incontinence Urinary Incontinence in Adults Urinary incontinence is involuntary loss of urine. Incontinence can occur in both men and women at any age, but it is more common among women and older adults, affecting about 30% of older women... read more , falls Falls in Older Adults A fall is defined as unintentionally or accidentally dropping down to the ground or another lower level. Most falls occur when older adults with one or more physical conditions that impair mobility... read more , and pressure sores Pressure Sores Pressure sores are areas of skin damage resulting from a lack of blood flow due to prolonged pressure. Pressure sores often result from pressure combined with pulling on the skin, friction,... read more . Preventing such problems requires meticulous care. Thus, people, particularly older people, may benefit from treatment managed by an interdisciplinary team Interdisciplinary care Providing medical care to older people can be complicated. People often have many different health care practitioners at different locations. Travel and transportation issues become more difficult... read more , which includes a doctor, physical and occupational therapists, nurses, and social workers.

People who are extremely agitated or who have hallucinations may injure themselves or their caregivers. The following measures can help prevent such injuries:

However, sometimes during hospitalization, padded restraints must be used—for example, to keep the person from pulling out intravenous lines and to prevent falls. Restraints are applied carefully by a staff member trained in their use, released at frequent intervals, and stopped as soon as possible because they can upset the person and worsen agitation.

Medications are used to manage agitation only after all other measures have been ineffective. Two types of medications are usually used to control agitation, but neither is ideal:

Doctors are careful when prescribing these medications, particularly for older people. They use the lowest dose possible and stop the medication as soon as possible.