brain, spinal cord, and nerve disorders
Delirium
Causes of Delirium
Development or worsening of many disorders can cause delirium. Any person can become delirious when extremely ill or taking medications or drugs that affect brain function (psychoactive medications or drugs). Overall, themost common causesof delirium are the following: Drugs or medications (particularly Anticholinergic: What Does It Mean? or psychoactive effects) and Dehydration None Infections, such as Overview of Pneumonia , a bloodstream infection ( Overview of Kidney Failure , Other causes include hospitalization, surgery, withdrawal of a drug that has been taken for a long time, certain disorders, and poisons. Delirium often develops during hospitalization in people who have dementia. Delirium can result from less severe conditions in older people and in people who have had a stroke or who have Dementia , Minor illnesses (such as a urinary tract infection) Severe Constipation in Adults None Pain Use of a bladder catheter (a thin tube used to drain urine from the bladder) Dehydration None Prolonged sleep deprivation Sensory deprivation (including being socially isolated and not having access to needed eyeglasses or hearing aids) In some people, no cause can be identified. Being in unfamiliar surroundings such as a Confusion and Mental Decline Due to Hospitalization , 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 Seizure Disorders 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 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 Use 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: Opioids (including Misuse of Antianxiety Medications and Sedatives (including benzodiazepines and sleep aids) Antipsychotic drugs None Medications for depression None Many other drugs can also cause delirium. The following are some examples: Benefits and Risks of Prescription Drugs , including many over-the-counter (OTC) antihistamines Amphetamines and Cimetidine Medications that lower blood pressure (antihypertensive drugs, including beta-blockers) Corticosteroids Digoxinand certain other medications used to treat heart disorders Levodopa Muscle relaxants 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 Withdrawal symptoms ) and in people who have heroin use disorder and who suddenly stop using heroin. Abnormal blood levels of Overview of Electrolytes , 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 ) commonly cause delirium. An underactive thyroid gland ( Hypothyroidism ) causes delirium with sluggishness (lethargy). An overactive thyroid gland ( If Liver Failure or Inyounger people(once drugs and alcohol are excluded), the cause of delirium is usually A condition that directly affects the brain—for example, a brain infection, such as Introduction to Meningitis or Inolder people,the cause is often A common infection, such as a Overview of Urinary Tract Infections (UTIs) , Such infections can indirectly affect the brain. Wernicke Encephalopathy , 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 Overview of Stroke , 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. Delirium is more common among older people. It is a common reason that family members of older people seek help from a doctor or at a hospital. About 15 to 50% of older people experience delirium at some time during a hospital stay. Causes In older people, delirium can result from any condition that causes delirium in younger people. But it can also result from less severe conditions, such as the following: Dehydration None A disorder that normally does not affect thinking, such as a Overview of Urinary Tract Infections (UTIs) , Pain Urinary Retention or severe Sensory deprivation, as may occur when people are socially isolated or are not wearing their glasses or hearing aid Sleep deprivation Stress (any type) Use of a bladder catheter (a thin tube used to drain urine from the bladder) Certain age-related changes make older people more susceptible to developing delirium. These changes include An increased sensitivity to medications or drugs Changes in the brain The presence of conditions that increase the risk of delirium Older people are much more sensitive to many medications and drugs. In older people, drugs that affect the way the brain functions, such as sedatives, are the most common cause of delirium. However, drugs that do not normally affect brain function, including many over-the-counter medications (especially antihistamines), can also cause it. Older people are more sensitive to the Benefits and Risks of Prescription Drugs that many of these medications have. One of these effects is confusion. Age-related changes in the brain:Delirium occurs more often in older people partly because some age-related changes in the brain make them more susceptible. For example, older people tend to have fewer brain cells and lower levels of acetylcholine—a substance that enables brain cells to communicate with each other. Any stress (due to a drug, disorder, or situation) that causes the level of acetylcholine to further decrease can make it harder for the brain to function. Thus, in older people, such stresses are particularly likely to cause delirium. Other conditions:Older people are also more likely to have other conditions that make them more susceptible to delirium, such as the following: Stroke Dementia Parkinson disease Other disorders that cause nerve degeneration Use of three or more medications Dehydration Undernutrition Immobility Delirium is often the first sign of another, sometimes serious disorder. For example, the first symptom in older people with COVID-19 may be delirium, sometimes with no other symptoms of COVID-19. Symptoms Delirium tends to last longer in older people. Confusion, the most obvious symptom, may be harder to recognize in older people. Younger people with delirium may be agitated, but very old people tend to become quiet and withdrawn. In such cases, recognizing delirium is even harder. Having delirium also increases the risk that older people with COVID-19 will have to stay in an intensive care unit (ICU), go to a rehabilitation facility after being discharged from the hospital, and/or die. If psychotic behavior develops in older people, it usually indicates delirium or dementia. Psychosis due to a psychiatric disorder rarely begins during old age. Older people are more likely to have dementia, which makes delirium harder to identify. Both cause confusion. Doctors try to distinguish the two by determining how quickly the confusion developed and what the person’s previous mental function was. Doctors also ask the person a series of questions that test various aspects of thinking ( Mental Status ). Doctors usually treat people whose mental function suddenly worsens—even if they have dementia—as if they have delirium until proved otherwise. Having dementia increases the risk of developing delirium, and some people have both. Treatment Delirium and the hospitalization it usually requires can cause many other problems, such as Undernutrition , Prevention To help prevent delirium in an older person during a hospital stay, family members can ask hospital staff members to help—by doing the following: Encouraging the person to move around regularly Placing a clock and calendar in the room Minimizing the interruptions and noises during the night Making sure the person eats and drinks enough Family members can visit and talk with the person and thus help keep the person oriented. People with delirium may be frightened, and the familiar voice of a family member can have a calming effect. 