Patients enter the healthcare setting expecting to receive care and return home well, but some come in as one person and leave as someone else entirely due to hospital-acquired delirium.1 Although not uncommon, this disorder often goes undiagnosed because its signs and symptoms are similar to other disorders, such as dementia and depression. Communication between healthcare providers is imperative to prevent delirium, support at-risk patients, and reduce the associated complications and costs. Often most familiar with the patient, families and other loved ones may be the first to recognize changes in the patient's behavior. Nurses play an important part in assessing patients for delirium and providing education.
Hospital-acquired delirium impacts patients throughout the healthcare continuum; however, this article focuses on adult patients in acute care hospitals and the role of nurses in identifying delirium and implementing the appropriate interventions.
Pathogenesis and etiology
The exact reason why delirium occurs is unclear. It's speculated that the mechanism involves the reversible impairment of multiple neurotransmitters. These may include cholinergic deficiencies, excess dopamine, or cytokine activity.2 A genetic association with apolipoprotein E epsilon 4 allele has also been identified.3
Delirium is fairly common and well studied in hospital settings, with 30% of older patients experiencing it at some point during their stay.4 There's also an increased risk for patients older than age 65, as well as those with underlying or preexisting neurologic disorders.4,5 Approximately 50% of older patients have been diagnosed with comorbidities such as stroke, dementia, or Parkinson disease.4 Similarly, surgical patients from this population are also at an increased risk, especially those who are frail due to falls or complex procedures.4
Younger adults may also develop delirium, typically due to factors such as drug use, dehydration, or infection.6 Because adverse drug reactions are a common cause of delirium, some risk factors can be identified during medication reconciliation. Several drugs are known to cause or prolong delirium, including opioids, benzodiazepines, dopamine agonists, and corticosteroids.4,7
Although all patients in acute care facilities should be monitored for delirium, the presence of certain widely underrecognized precipitating factors may raise red flags.4 These include dehydration, infection, immobility, malnutrition, sensory impairment, and urinary catheterization.4-6 In approximately 20% of cases, the underlying cause is unknown.6
Signs of delirium may include clouded and fluctuating levels of consciousness, limited attention span, and disorientation. Patients may also experience delusions or hallucinations. Focal syndromes present similarly to delirium, but these can be ruled out with a neurologic exam to identify patients with the characteristic deficits in consciousness, attention, visual fields, and cranial nerve and motor function.4
According to the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5), delirium has key characteristic clinical features. Patients may experience fluctuating difficulties with attention, awareness, and cognition lasting for short periods such as days or weeks. These can't be explained by “another preexisting, evolving, or established neurocognitive disorder.” Additionally, they can't be identified as the result of any alternative conditions, adverse reactions, or potential intoxication or withdrawal based on the patient's history, physical exam findings, or lab results.8
Requiring a clinical diagnosis, delirium is defined as an “acute, transient, usually reversible, fluctuating disturbance in attention, cognition, and consciousness level.”6 However, due to its similar presentation to depression or dementia, delirium can be difficult to identify.6,9 As such, a patient's health history, physical assessment findings, and medication reconciliation may provide clues to the underlying etiology.
Although delirium is diagnosed based on DSM-5 criteria, lab testing and imaging studies may help determine the underlying etiology.6,8,9 Lab tests for patients with delirium include serum electrolytes, creatinine, glucose, and calcium levels, in addition to a complete blood cell count, urinalysis, and urine culture.4 Additional testing for drug toxicology, arterial blood gases, and liver and hepatic function may also be beneficial.4 Other tests, such as neuroimaging studies, electroencephalograms, and lumbar punctures, may be helpful if the underlying etiology for delirium is still unclear.
The most important aspect of patient-centered care for delirium is prevention. (See Minimizing the risk.) Screening for risk factors will help identify patients who may require precautions, such as medication adjustments, or more active monitoring for early signs of delirium. If delirium occurs, timely identification and treatment of the underlying etiology is a priority.
Clinicians can use certain acronyms to remember appropriate strategies for treatment. For example, THINK DR. DRE is an acronym that provides an easy progression of thought processes and strategies to consider in cases of delirium. (See THINK DR. DRE.)10
Clinical protocols, practices, and standard procedures must be developed with clear steps to mitigate delirium and understand the appropriate actions to address it. Typically, staff buy-in on the importance of adopted delirium protocols doesn't present a challenge. Instead, difficulties arise in the effort to find time to adopt the necessary practices.1
Healthcare organizations are beginning to implement a multidisciplinary approach to delirium, designating a nurse champion to teams of healthcare professionals. These teams carefully review and assess patients for delirium and develop an action plan based on the individual's clinical status, current treatment plan, and evidence-based interventions. Nurses who are uncertain about the best interventions for patients with delirium can call on their nurse champion as a resource. Using this approach, one hospital reduced its rate of patient delirium by 60%, resulting in thousands of dollars in savings per patient since 2012.1
Thiamine supplementation is an appropriate treatment strategy for patients with delirium.11 However, benzodiazepines aren't recommended unless they have been prescribed to reduce acute symptoms of alcohol withdrawal and prevent complications.11,12 Other drug therapies, such as psychotropic medications, should be administered only when patients may pose a threat to themselves or others due to extreme agitation.11
Differentiating the three Ds
To effectively manage delirium, it must first be differentiated from dementia and depression.3 Delirium is usually reversible, whereas dementia is generally irreversible.9 (See Delirium or dementia?) Episodes of major depression require the presence of at least five depressive symptoms, including depressed mood or loss of interest, for a minimum of 2 consecutive weeks.13,14 These disorders can occur simultaneously; for example, individuals may present with one disorder, such as dementia, and become susceptible to delirium and/or depression.
Screening tools are available to help clinicians determine whether patients have delirium, dementia, or depression. (See Resources for differentiation.) Because these disorders have many similar, nonspecific signs and symptoms, family input is an important resource for diagnosis. To promote patient- and family-centered care and facilitate education and comprehension, information should be provided proactively to all members of the patient's multidisciplinary healthcare team.
Although healthcare providers play a part in patient education, nurses have a key role. There's a direct relationship between the information disseminated by nurses and the level of patient and family understanding.15 This places the primary responsibility with nurses, who determine what to teach, when to teach it, and how to educate patients regarding their health. Nurses must also take into consideration patients' language proficiency, speed of speech, and questions to determine their level of understanding and any necessary explanations or clarifications needed.16
The ability to differentiate delirium from dementia or depression is a critical competency for nurses. Not only is this skill important in clinical assessments and diagnoses, but it's also essential to help patients and families monitor for delirium during hospitalization and postdischarge and know who to contact if they have questions or problems.
Meeting the challenge
Hospital-acquired delirium presents a common challenge for nurses. Education is essential for patients, their families and loved ones, and the entire healthcare team. An increased focus on prevention must be implemented, as well as root-cause analysis following the occurrence of delirium. For the greatest strides in addressing hospital-acquired delirium, communication between the acute and postacute care settings within the healthcare system must be established to identify and provide support for at-risk patients.
Minimizing the risk1,5,16,17
Regular monitoring for six major risk factors can help reduce the incidence of delirium by up to 33%. These include cognitive impairment, sleep deprivation, dehydration, immobility, vision impairment, and hearing impairment. Preventive actions can reduce the incidence of delirium in at-risk patients. These include weaning patients off mechanical ventilators in a timely fashion, avoiding the use of restraints, removing urinary catheters as soon as they're no longer needed, ambulating patients early, using large clocks for orientation, minimizing alarms, providing access to eyeglasses and hearing aids, and turning off the lights at night and opening shades during the day.
Resources for differentiation18,19
- ConsultGeri: The Confusion Assessment Method for the ICU (CAM-ICU)
- The Journal of Neuropsychiatry and Clinical Neurosciences: Validation of the Delirium Rating Scale-Revised-98
- Journal of Pain and Symptom Management: Fast, Systematic, and Continuous Delirium Assessment in Hospitalized Patients: The Nursing Delirium Screening Scale
- British Medical Journal: Improving Early Recognition of Delirium Using SQiD (Single Question to identify Delirium): A Hospital-based Quality Improvement Project
- Journal of Pain and Symptom Management: Memorial Delirium Assessment Scale (MDAS)
- National Center for Biotechnology Information: Mini-Mental State Exam (MMSE)
- US Department of Veterans Affairs: Montreal Cognitive Assessment (MoCA) Administration and Scoring Instructions
INSTRUCTIONS Management of hospital-acquired delirium
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16. Hamzehpour H, Valiee S, Roshani D, Majedi MA. The effect of care plan based on Roy Adaptation Model on the incidence and severity of delirium in intensive care unit patients: a randomised controlled trial. J Clin Diagn Res
17. Inouye SK, Bogardus ST Jr, Charpentier PA, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. N Engl J Med
18. Wilterdink JL. The mental status examination in adults. UpToDate. 2019. www.uptodate.com
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