Delirium, defined as an acute state of confusion, is a common and devastating neurocognitive disorder that disproportionately affects older adults. This condition is characterized by a sudden-onset, fluctuating course of inattention and either hyperactive or hypoactive levels of consciousness.1 Although the prevalence of delirium is as low as 5% in hospitalized adults younger than 50, more than one-third of hospitalized adults older than 80 have this condition, with higher incidence rates in critical, postoperative, and palliative care units.2-4 Among hospitalized older adults, approximately half are admitted to the hospital with delirium, whereas the other half develop delirium during their hospital stay.4,5
The consequences of delirium can be calamitous and can include falls, physical deconditioning, and persistent cognitive impairment. Moreover, delirium prolongs hospitalization, increases healthcare costs, and increases the risk of postdischarge institutionalization, and it also is an independent predictor of mortality in hospitalized older adults. Despite a wide variety of detection instruments, a growing body of high-quality evidence, and a number of established best-practice guidelines, delirium often remains undetected and undertreated in the hospital setting.4 The purpose of this article is to inform NPs in the hospital setting to recognize, prevent, and manage delirium in hospitalized older adults.
Delirium risk factors and diagnosis
Risk factors. A defining feature of delirium is that it can usually be attributed to one or more underlying medical conditions or medications, and it generally resolves when the underlying medical conditions are treated (see Predisposing and precipitating factors for delirium and Medications that can precipitate delirium).6-8 In general, the risk of delirium increases as the number of precipitating factors increases.
The presence of additional baseline patient characteristics, called predisposing factors, further increases the likelihood that the precipitating factors listed above will cause delirium. These include advanced age, preexisting dementia, a history of neurologic disease (for example, stroke), sensory impairment, multiple comorbidities, functional impairment, a history of alcohol use disorder, high illness severity, and malnutrition.9 A patient with several of these predisposing factors (high baseline frailty) will develop delirium when only a small number of precipitating factors is present, whereas a patient with fewer predisposing factors (low baseline frailty) will develop delirium only when several precipitating factors are present.
Clinical presentation. Given the wide variety of physiologic derangements that are linked to delirium, it is not surprising that delirium has a variety of clinical presentations. While some patients present with the hyperactive form of delirium, almost three times as many present with the hypoactive form; still others present with a mix of both.1,4 These behaviors can be quite frightening to family members and to the patients themselves.10
Diagnosis. A systematic approach should be used when making the delirium diagnosis. Not only must the NP correctly identify when delirium is present, but the NP also must seek out and eliminate precipitating factors. Delirium has a very broad differential, particularly in older adults. It should be noted that patients with preexisting dementia will have impaired cognitive status at baseline. Delirium in these patients will present as sudden further behavioral disturbances and/or sudden further deterioration in attentiveness and/or language; any such symptom will be worse than the patients' usual day-to-day status.11
Assessment tools. A full neurocognitive exam takes a long time to complete, so a more efficient strategy to assess for delirium at the bedside is to use a standardized delirium assessment tool. In a recent systematic review of 30 delirium assessment instruments developed for the non-ICU setting, Helfand and colleagues identified four assessment tools with good psychometric properties.12 These were the Confusion Assessment Method (CAM), which requires 10-15 minutes to complete; the Delirium Rating Scale-Revised-98 (DRS-R-98), which requires 1 to 1.5 hours; the Memorial Delirium Assessment Scale (MDAS), which requires 25-45 minutes; and the Delirium Observation Screening Scale (DOSS), which requires fewer than 5 minutes.
Of the various cognitive screening tools available, the CAM is the most widely used in hospital settings. It was originally designed to be used in medical-surgical inpatient areas, but it has been adapted and validated for use in EDs, ICUs, long-term care facilities, and palliative care settings. A checklist-based version of the CAM, called the 3D-CAM, can be completed in less than 3 minutes and has high sensitivity and specificity.13 The CAM-Severity (CAM-S) tool measures the severity of delirium with high convergent and predictive validity.14
As with any complex acute illness, the differential diagnosis of delirium requires a thorough (but efficient) history, focused physical exam, and appropriate diagnostic testing. A complete discussion of diagnostic decision-making in an older adult with delirium is provided elsewhere.8,11,15-17
Delirium prevention
Nonpharmacologic interventions. The goal for older adults who do not have delirium at the time of hospital admission is to prevent delirium from developing. Risk factors for delirium need to be avoided or eliminated whenever possible. Delirium prevention guidelines, systematic reviews, and meta-analyses emphasize the use of nonpharmacologic multicomponent interventions to minimize delirium risk in hospitalized older adults.18 These bundled interventions focus on meeting basic human needs such as hydration, sleep, comfort, accurate sensory perception, and orientation to the current time and place. Mobility, independence, and the avoidance of physical and chemical restraints are emphasized. The American Geriatrics Society CoCare(R): HELP program (formerly known as the Hospital Elder Life Program [HELP]) has been a particularly useful and effective systemwide approach to delirium prevention.19-21 Nonpharmacologic interventions for delirium prevention should be implemented upon admission to the hospital for older adults at high risk for delirium (see Nonpharmacologic multicomponent interventions for delirium prevention).
Delirium prevention interventions work best when they are implemented consistently and deliberately. This can be a considerable challenge for nursing staff, particularly when there is limited or insufficient availability of unlicensed assistive personnel and RNs.22 Although these interventions are considered "low-tech, high-touch" nursing activities, many of them require a great deal of time and reinforcement to be effective.23 For example, ambulation and feeding assistance can take several minutes to a half-hour to complete. Nurses and unlicensed assistive personnel are hard-pressed to find lengthy blocks of time during their shifts to dedicate to these activities, despite their importance. Family, friends, and hospital volunteers can provide assistance with certain activities, such as reorientation, range-of-motion exercises, and oral fluid encouragement; the feasibility and effectiveness of using volunteers for such a role has been well established.20,24,25
During the COVID-19 pandemic, hospital visitation policies became increasingly restrictive, even to the point where loved ones were prevented from visiting patients who were actively dying. As we transition from a "pandemic approach" to a more "endemic approach" to COVID-19, hospitals are faced with liberalizing restrictive hospital visitation policies. Although the future of these policies in the context of COVID-19 is unclear, unrestricted visitation policies are known to reduce the incidence of delirium by up to 60%.24
Delirium goes undetected in at least 75% of patients in the hospital setting when older adults are not routinely monitored for it.26 This is especially true for older adults with hypoactive delirium who are often labeled "pleasantly confused" or "sleepy." Hospitalized older adults should be monitored using a validated delirium detection tool to ensure that delirium is identified early and treated quickly. Because cognitive status fluctuates in patients with delirium, nurses should assess patients for delirium at least once per 8-hour shift, or whenever care of the patient is formally handed over from one nurse to another.
Pharmacologic interventions. Because medications can be particularly potent causes of delirium, providers should carefully review each medication the older adult patient is taking. Deprescribing, which is the systematic process of identifying and eliminating potentially inappropriate medications before they cause problems, has been recommended as a key strategy for delirium prevention.27 Medications considered potentially inappropriate in older adults should be tapered, discontinued, or switched to safer alternatives whenever possible.
Although opioids and other analgesics are known to precipitate delirium, so too can uncontrolled pain, especially in older adults with underlying dementia.28 Therefore, NPs need to work closely with other members of the interprofessional team to ensure safe, but effective, patient-centered pain control. One approach is to prescribe acetaminophen in the morning and at bedtime for older adults who have a known chronic pain syndrome, such as low back pain or arthritis.
There is no universal recommendation supporting the use of any kind of medication to prevent delirium. Clinicians may be tempted to use scheduled antipsychotics to prevent delirium in high-risk individuals. However, there is no evidence to support this practice except under very specific circumstances (such as routine management of schizophrenia); therefore, scheduled antipsychotics are not appropriate for delirium prevention.29 Since sleep deprivation is a substantial risk factor for delirium, patients with insomnia in the hospital setting may benefit from scheduled melatonin or ramelteon, but more sedating medications (for example, benzodiazepines and zolpidem) should be avoided.30
Delirium management
Delirium management refers to the ongoing interventions used to ensure patient and staff safety, whereas delirium treatment refers to the interventions used to resolve the various causes of delirium. This distinction is important because strategies to treat the underlying causes of delirium, such as antibiotics or I.V. fluids, will not affect patients' behaviors, and strategies used to manage patients' delirium-related behaviors, such as use of de-escalation techniques or antipsychotics, will not affect the underlying causes for their delirium. This section will address delirium management interventions. The optimal treatment approach will depend on the underlying delirium cause(s).
Nonpharmacologic interventions. Despite expert delirium prevention efforts, hospitalized older adults may still develop delirium. Prevention strategies should be continued in these patients. The most effective interventions for delirium management involve modifying the patient's environment, enhancing sensory function, individualizing cognitive stimulation, using behavioral de-escalation techniques, and enhancing comfort and sleep.31
An additional approach is to assign a staff member or volunteer, sometimes called a "sitter," to provide one-on-one direct supervision for the patient with delirium. In many cases, sitters are deployed with the purpose of preventing falls. However, evidence to support sitter programs for fall prevention or delirium management is limited, and a formal sitter program can be cost-prohibitive.32,33
Pharmacologic interventions. Nonpharmacologic interventions, along with treating the underlying causes of delirium, are essential in managing the condition. However, a patient with hyperactive or mixed delirium may become so aggressive, violent, or disoriented to their situation that they pose a danger to themselves or others. If nonpharmacologic interventions are insufficient to keep the patient and others safe, use of an antipsychotic medication may be necessary (see Use of medications for delirium management).3,34 All of these medications carry a risk for oversedation, QT interval prolongation, and extrapyramidal symptoms, as well as a boxed warning for increased mortality in older adults with dementia. Despite their short-term calming effect on aggressive behaviors, these medications do not actually treat the underlying delirium, and there is no evidence to support the routine use of antipsychotics for delirium treatment in hospitalized older adults.35 Additionally, the use of antipsychotic medications for delirium management is off-label.
Benzodiazepines can produce a paradoxical agitated state in older adults with delirium, and they should be avoided except under specific circumstances, including alcohol withdrawal, active prolonged seizure activity, or when following a benzodiazepine taper schedule.36 They should not be used for insomnia unless the patient has been using them as a home medication for this purpose, and even then, they should be used with extreme caution in older adults.
Other non-antipsychotic medications show promise in managing delirium-associated agitation. These include trazodone, ramelteon, melatonin, and suvorexant.37 These agents are believed to work by regulating the patient's sleep-wake cycle to allow for more restful and restorative nighttime sleep. Therefore, these medications should be used at bedtime instead of during the day.
Physical restraints. Physical restraints are the last resort for managing delirium-related aggression.38 A person with delirium, particularly one who has underlying dementia, can become more agitated or injured when they are physically restrained, so staff must continue to use nonpharmacologic interventions whenever restraints are employed. The NP must ensure that physical restraints are ordered according to institutional policy. Since physical restraints do not guarantee the patient's safety, the patient should be monitored closely, and physical restraints should be discontinued as soon as the aggressive episode is resolved.38
Delirium and care transitions
The risk of delirium increases when older adults are moved from one hospital unit to another, especially when moved either to or from an ICU. Older adults who are transferring to the ICU are doing so because of a worsening or life-threatening medical illness, and this is likely to be associated with new or worsening delirium. These patients may be unable to communicate effectively with others about their symptoms, which complicates diagnostic decision-making and delays treatment. In these situations, ensuring that an accurate and complete patient history is communicated to the critical care provider is of the utmost importance. When transferring a patient from the medical-surgical unit to the ICU, providers should include a description of the patient's baseline cognitive status in their verbal handoff so that critical care providers can more accurately evaluate the patient's evolving cognitive status compared with their status at baseline. If possible, the transferring provider should also provide their own assessment of the patient's delirium status, severity, and its potential causes before the receiving provider assumes care.
Patients who are transferring from the ICU to the medical-surgical unit are more likely to be returning to their baseline cognitive status. In these cases, the antipsychotic or sedating medications that were used in the ICU to manage severe hyperactive delirium are no longer indicated, may actually be associated with increased patient harm, and may be inadvertently prescribed upon hospital discharge.39 Providers must be able to identify and discontinue these medications before the patient is transferred out of the intensive care setting, and every attempt should be made to avoid restarting these medications outside of the ICU.
More than 30% of older adults who are started on a new antipsychotic medication during a hospitalization will continue that medication after discharge.40 This is especially true if the patient was in a CCU or was discharged to a skilled nursing facility. Moreover, the risk of being discharged on an antipsychotic medication that was started during the hospitalization increases with disease severity and duration of inpatient benzodiazepine use.41 Patients who are discharged on antipsychotic medications are particularly vulnerable to adverse events, including strokes, cognitive decline, orthostatic hypotension, bradycardia, falls, hyponatremia, extrapyramidal symptoms (especially in patients with Parkinson disease), and death.42 Because the risk of adverse health outcomes increases when a patient is discharged with a new antipsychotic medication, providers must be extremely judicious about prescribing these medications upon discharge. Moreover, the discharging provider should clearly communicate their recommendations and rationale for continuing or discontinuing any new antipsychotic medications to the provider who will provide postdischarge follow-up care. A standard statement in the discharge summary such as, "The antipsychotic is intended to be used for a short time after discharge, and it should be weaned by the follow-up provider as behavioral symptoms of delirium resolve," may be helpful in stopping the prolonged use of antipsychotics after hospital discharge.40
Implications for NPs
Since there is no single unifying cause that is central to all cases of delirium, efforts to develop a "one-size-fits-all" approach to its prevention and treatment have been unsuccessful. Therefore, NPs must employ a multicomponent approach to delirium prevention and management that includes consistent use of nonpharmacologic interventions, surveillance using standardized delirium assessment tools, and judicious prescribing and deprescribing of medication. This list of multicomponent interventions is extensive and somewhat vague, but within each intervention are boundless opportunities to individualize care based on the patient's unique circumstances. The NP must also ensure that these interventions are continued across care transitions. NPs who care for older adults in the hospital setting must remain up-to-date on the literature about delirium prevention and management as it evolves to ensure that they are informed of the latest best practices surrounding interventions.
Finally, NPs must acknowledge the stark reality that hospitalized older adults who develop delirium are, almost without exception, clinically deteriorating, and the patient's likelihood of survival depends on accurate recognition, timely workup, and effective treatment of the underlying causes.
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