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Learning Objectives

By the end of this section, you will be able to:

  • Identify risk factors for delirium in older adults
  • Comprehend the three categories of delirium in older adults
  • Identify ways to detect delirium in an older adult
  • Discuss the nurse’s role in planning care for an older adult with delirium

Medical and psychological problems co-occur often in older persons who are hospitalized for medical, psychiatric, and surgical reasons. In a U.S. teaching hospital’s quality improvement program, prospective chart reviews of medical records revealed comorbidity of delirium in 10.1 percent of the cases (Bayer et al., 2022). Delirium can occur in any setting.

Risk Factors

Psychosis caused by medical issues is often referred to as delirium, which is a mental state in which the client becomes temporarily confused, disoriented, and not able to think or remember clearly. It usually starts suddenly and can indicate the onset of a life-threatening medical condition. Delirium resolves as the underlying condition is effectively treated.

Causative Factors of Delirium

The first step in managing delirium is to address the causative factors. There are many common causes of delirium, including the following:

  • dehydration and/or electrolyte imbalances
  • dementia
  • hospitalization, especially in intensive care
  • intoxication or withdrawal from alcohol or drugs
  • kidney or liver failure
  • medications, such as sedatives, opioids, anesthesia, antihistamines, anticholinergics, antidepressants, antipsychotics, or anticonvulsants
  • metabolic disorders, such as diabetic ketoacidosis (DKA)
  • serious infections, such as urinary tract infections, pneumonia, and influenza
  • severe pain
  • sleep deprivation

If the cause is infection, the delirium resolves as it is treated. If it is a medication, then stopping the medication should resolve the delirium. Frequently, there are multiple causative factors and some can be difficult to address. For example, Teng and Frei (2022) found that antibiotics produced a higher delirium rate in individuals sixty-five years of age and older than in younger people, and some antibiotics are included on prescribers’ reference lists as inappropriate for older persons.

A person with dementia can become delirious with a change of environment where orienting cues are not available. When the causative factor is unavoidable, such as hospital admission or postanesthesia, supportive care can help to resolve the delirium over time. The state of delirium may wax and wane, which means that the client has periods of confusion followed by periods of clarity in waves. Over time, the periods of confusion or inattentiveness become less and less until the person is back to their baseline level of cognition. Delirium superimposed on dementia appears as new onset behavior, distinct from the changes in memory and cognition that occur with the gradual progression of dementia over months or years.

Risk Factors Due to Comorbidities

There are many risk factors for older adults for delirium; comorbidities can contribute significantly and exacerbate those risk factors. Any older person with multiple medical issues, and particularly those with any level of cognitive impairment, is at risk for developing delirium. An alteration in cognition that causes a decline in memory and thinking that happens with age and many medical and inherited factors is considered cognitive impairment. Delirium is not only an issue for hospitalized people but can happen in the home or any other residential setting. There are many factors that can contribute to delirium, with many being preventable. The most preventable are those caused or contributed to by medications. Polypharmacy (the use of five or more medications simultaneously) increases this risk with each medication added. Especially high risk are anticholinergics, narcotics, and sedative-hypnotics. Some antibiotics can increase risks as well. In some people, it is not the addition of a drug that causes delirium, but the removal with withdrawal. Infection is another very common cause of acute delirium. (Health In Aging, 2023) displays the following map outlining the reversible causes of delirium using the acronym, DELIRIUM:

  • Drugs, including any new medications, increased dosages, drug interactions, over-the-counter drugs, alcohol, etc.
  • Electrolyte disturbances, especially dehydration and thyroid problems
  • Lack of drugs, such as when long-term sedatives (including alcohol and sleeping pills) are stopped, or when pain drugs are inadequate
  • Infection, commonly urinary or respiratory tract infection
  • Reduced sensory input, which happens when vision or hearing are poor
  • Intracranial (referring to processes within the skull), such as a brain infection, hemorrhage, stroke, or tumor (rare)
  • Urinary problems or intestinal problems, such as constipation or inability to urinate
  • Myocardial (heart) and lungs, such as heart attack, problems with heart rhythm (arrhythmia), worsening of heart failure, or chronic obstructive lung disease

Risk Factors Due to Psychosocial Status

Biopsychosocial status is an important factor in delirium. A low functional capacity, poor general health, or lack of social support can increase the risk of developing delirium when the body and mind are challenged by exposure to a high-risk factor. According to Ormseth et al. (2023), factors decreasing the risk of delirium are strong and consistent family involvement, frequent reorientation, and supportive environmental cues. Physical wellness, enhanced by sleep, oxygenation, and hydration, with good social support provides a higher resistance to delirium.

Categories of Delirium

Delirium is divided into three types based on the symptoms. The three types are hyperactive, hypoactive, and mixed. In older adults, hypoactive and mixed delirium are the most common. Frequently, the nurse or the family are the first to notice that a client is “not themselves” or has had a change in mental status from their baseline. Figure 24.3 provides a visual representation and summary of the two main forms of delirium.

A chart detailing the types of delirium (Hyperactive delirium Mixed delirium, and Hypoactive delirium), causes, and adverse affects.
Figure 24.3 Delirium can be identified by applying these descriptions and classifications to avoid these adverse outcomes. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)


Hyperactive delirium will usually entail restlessness, anxiety, and sometimes aggressiveness, as well as potential hallucinations. Mood swings are also common. This is the easiest type to recognize because the clients frequently resist care.


Hypoactive delirium is often overlooked as delirium because the client is quiet and withdrawn. Hypoactive delirium is characterized by symptoms of drowsiness and inactivity. The clients may seem to be in a daze and not interact with family or others. It is more difficult to recognize and is associated with poorer outcomes than hyperactive delirium.


Mixed delirium is a combination of hyperactive and hypoactive delirium and may fluctuate between the two.

Identifying Delirium

One of the most frequent tools used to identify delirium is the Confusion Assessment Method (CAM). The CAM is a bedside screening tool used to determine if a client is showing signs of delirium. The CAM-ICU is also available for ICU clients and can be used for clients who are unable to speak due to being on a ventilator or other reason.

The CAM is a questionnaire that prompts assessment answers of yes/no or entering a descriptive term, such as alert or lethargic. The tool includes assessment data, such as onset, thought process, distractibility, level of consciousness, orientation, and agitation. The scoring alerts to the need for follow-up care.

Onset, Presentation, Signs, Symptoms, and Nursing Interventions

The symptoms of delirium usually start suddenly, over a few hours or a few days, and they often come and go. The most common symptoms are as follows:

  • changes in alertness (usually more alert in the morning, less at night)
  • changing levels of consciousness
  • confusion
  • disorganized thinking or talking in a way that doesn’t make sense
  • disrupted sleep patterns or sleepiness
  • emotional changes: anger, agitation, depression, irritability, or overexcitement
  • hallucinations and delusions
  • incontinence
  • trouble concentrating

Table 24.5 indicates the most frequent signs of delirium along with proposed nursing interventions.

Signs and Symptoms of Delirium Nursing Interventions
Changes in alertness (usually more alert in the morning, less at night) Making sure the room is quiet and well-lit with blinds or curtains open for exposure to daylight; getting clients up and out of bed when possible
Changing levels of consciousness Having clocks and calendars within view
Confusion Inviting family members to spend time in the room
Disorganized thinking or talking in a way that doesn’t make sense Ensuring hearing aids and glasses are worn
Disrupted sleep patterns or sleepiness Allowing for uninterrupted sleep when possible
Emotional changes: anger, agitation, depression, irritability, or overexcitement Calm approach, inform before touching or moving; administering prescribed medications to distressed clients at risk to themselves or to others to calm and settle them (administer medications with caution because oversedation can worsen delirium)
Hallucinations and delusions Controlling pain with pain relievers (unless the pain medication is causing the psychosis)
Incontinence Avoiding the use of restraints
Memory problems, especially with short-term memory Prompt with environmental and verbal cues
Trouble concentrating Speak clearly, repeat as necessary
Table 24.5 Signs and Symptoms of Delirium

Identifying Delirium in a Person with Dementia

A person with dementia, no matter the type of dementia, is automatically at very high risk of developing delirium. To make it more complicated, delirium can be difficult to recognize. A person with dementia may already exhibit behaviors that are consistent with delirium. The most notable difference is inattention. A person with dementia can be disoriented at baseline, but they are attentive. A change in mental status of a person with dementia at times can be the first indication of an acute illness and delirium. The most difficult factor in dementia with superimposed delirium can be figuring out the precipitating factors. When there was a recent medication or treatment addition, it can be easy, but when it is a possible infection, pain, sleep issue, or other seemingly small factor, it can be difficult to recognize.

Care Partner Engagement for Older Adults with Delirium

To improve care, clients, their families, and health-care professionals must actively participate at all levels of the health-care system. This is known as care partner (client and family) engagement and can be applied to collaborative care of the older adult with delirium.

Engagement of care partners at the level of direct care can take several forms, from consultation and participation in decision-making to the delivery of direct care. It can also take place at the corporate and societal levels when developing health-care policy through shared leadership. With this model, both the quality of care and the quality of life are improved because of care partners’ active involvement in decision-making and care management.

The characteristics of the individual client, the preparedness of the care partner, including their knowledge and skills, and the capacity and preparedness of the care team all have an impact on the implementation of care partnerships in the delivery of care to delirium clients. A five-step engaged caring approach is used to operationalize care partnerships. It consists of negotiation and risk assessment, awareness and information support, a joint monitoring plan, shared decision-making and early intervention, and making adjustments (Hill et al., 2014).

Clinical Judgment Measurement Model

Evaluate Outcomes: Intervening on Delirium

The client is resting in the bedside chair watching a church service on television. The client answers to their name. The family states the client is better than yesterday. Nursing knowledge is required to recognize improvements in prior problems of agitation, distractibility, disorientation, and family’s report of client behaviors unlike baseline. The nursing action is to continue providing orienting cues and comfort measures to the client, monitor hydration status and laboratory test values, and encourage family involvement. The nurse will reassess as needed and continue care to the next identified problem.


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