Dorothy F. Tullmann, Cheri Blevins, and Kathleen Fletcher
EDUCATIONAL OBJECTIVES
On completion of this chapter, the reader should be able to:
1. Discuss risk factors of delirium in older hospitalized adults
2. Describe the negative sequelae of delirium in older adults during hospitalization
3. Discuss the importance of early recognition of delirium
4. List four nonpharmacological interventions to prevent and/or treat delirium
5. Identify long-term negative sequelae of delirium in older adults who have been hospitalized
OVERVIEW
Delirium is a common complication in hospitalized older adults and is one of the major contributors to poor outcomes of health care and institutionalization for older patients. The incidence and severity of delirium can be reduced by identifying modifiable risk factors, screening regularly for delirium, and implementing multicomponent interventions. If delirium does develop, early recognition is of paramount importance in order to treat the underlying pathology and minimize delirium’s sequelae. Although many researchers are seeking to identify effective pharmacological agents to prevent and/or treat delirium, nonpharmacological, multicomponent interventions have the strongest evidence of accomplishing these goals. Nurses play a key role in the prevention, early recognition, and treatment of this potentially devastating condition in older hospitalized adults.
BACKGROUND AND STATEMENT OF PROBLEM
Definition
Delirium is a neurocognitive disorder that develops over a short period of time (hours to days), fluctuates in severity throughout the day, and is primarily a disturbance of attention. Delirium also manifests as a disturbance in cognition (memory defect, disorientation, etc.) that cannot be explained by a preexisting neurocognitive disorder; rather, delirium is a physiological consequence of substance intoxication or withdrawal, medication, another medical condition, or multiple etiologies (American Psychiatric Association, 2013). A patient may present with hyperactive, hypoactive, or mixed motoric subtypes of delirium (Hosie, Davidson, Agar, Sanderson, & Phillips, 2013; Meagher, 2009). Nurses typically associate delirium with hyperactivity and distressing, time-consuming, and harmful patient behaviors. However, the hypoactive subtype, with its lack of overt psychomotor activity, is also common (Hosie et al., 2013; Meagher, 2009; Pandharipande et al., 2007) and has a higher risk of mortality, especially when superimposed on dementia (Yang et al., 2009).
Etiology and Epidemiology
Prevalence and Incidence
Among medical inpatients, delirium is present on admission to the hospital in 10% to 31% of older patients, and during hospitalization, 11% to 42% of older adults develop delirium (Siddiqi, House, & Holmes, 2006). Among hip surgery patients, the incidence of delirium is 4% to 53%. Those with hip fractures and preexisting cognitive impairment have the highest risk of delirium (Bruce, Ritchie, Blizard, Lai, & Raven, 2007). Older adults admitted to medical intensive care units (ICUs) have both prevalent and incident delirium of 31% (McNicoll et al., 2003; Salluh et al., 2010). In surgical ICUs (SICUs), the prevalence of delirium on admission is only 2.6%, but 28.3% develop delirium during their SICU stay (Balas et al., 2007). Up to 81.7% of mechanically ventilated patients in medical and SICUs experience delirium (Ely et al., 2004; Pisani, Murphy, Araujo, & Van Ness, 2010), and more than half of older patients in medical ICUs still have delirium when transferred (Pisani et al., 2010). From 13.3% to 42.3% of palliative care patients have delirium on admission, 26% to 62% during hospitalization, and 58.8% to 88% have delirium closer to death (Hosie et al., 2013). The incidence of delirium superimposed on dementia ranges from 22% to 89% (Fick, Agostini, & Inouye, 2002).
Pathophysiology
The pathogenesis of delirium is poorly understood and likely involves a complex interaction between neurotransmitter systems and psychoneuroimmunological pathways (AGS/NIA Delirium Conference Writing Group, Planning Committee and Faculty and AGS/NIA Delirium Conference Writing Group, 2015). More research is needed to determine the exact mechanisms and biomarkers to help identify different delirium pathways and whether or not there are differences between the biomarkers of risk, presence, and severity of delirium.
Risk Factors
The most common risk factors for delirium in acute hospital units are dementia, older age, comorbid illness, severity of medical illness, infection, “high risk” medication use, diminished activities of daily living, immobility, sensory impairment, urinary catheterization, urea and electrolyte imbalance, and malnutrition. Statistically significant risk factors are dementia, illness severity, urinary catheterization, low albumin level, and length of hospital stay (Ahmed, Leurent, & Sampson, 2014). In older patients admitted for hip surgery, early cognitive impairment, such as memory impairments, incoherence, disorientation, as well as an underlying physical illness and age, are especially strong predictors of delirium (de Jonghe et al., 2007; Kalisvaart et al., 2006). Other possible risk factors include sleep deprivation (Weinhouse et al., 2009), elevated blood urea nitrogen (BUN)/creatinine ratio, polypharmacy, physical restraints, and anemia (Inouye et al., 1990; Inouye, Viscoli, Horwitz, Hurst, & Tinetti, 1993; O’Keeffe & Lavan, 1996).
Outcomes
The outcomes of delirium in hospitalized older adults are grave. Those who develop delirium have an increased mortality rate (up to 22.7 months postdischarge [Witlox et al., 2010]), increased hospital length of stay, and transfer to long-term care facilities (Shi, Presutti, Selchen, & Saposnik, 2012; Witlox et al., 2013). Other sequelae of delirium are depression, decreased functional and cognitive status, and increased geriatric syndrome complications (Anderson, Ngo, & Marcantonio, 2012; Cole, McCusker, Ciampi, & Belzile, 2008; Witlox et al., 2010; Witlox et al., 2013). ICU patients who develop delirium have a higher mortality and complication rate, spend longer periods of time on mechanical ventilation, have increased ICU and hospital lengths of stay, and are more likely to be discharged to a long-term care facility (Ely et al., 2004; Shehabi et al., 2013; Zhang, Pan, & Ni, 2013). From 22% to 89% of older hospitalized adults with dementia also have delirium superimposed on the dementia (Fick et al., 2002), are at increased risk for developing delirium, and have worse outcomes when they do (Morandi et al., 2014; Yang et al., 2009).
ASSESSMENT OF THE PROBLEM
The first critically important step in the assessment of delirium is identifying the risk factors for delirium because eliminating or reducing these risk factors and intervening appropriately may prevent delirium or reduce its length or severity (Milisen, Lemiengre, Braes, & Foreman, 2005). Recognizing the features of delirium is important in order to further identify, eliminate, or reduce the precipitating factor(s) such as pain, infection, or other acute illnesses. This can best be done by routinely assessing patients at risk for delirium with a standardized screening tool for delirium although this is currently occurring only in 17% of hospitals (Neuman, Speck, Karlawish, Schwartz, & Shea, 2010) and nurses fail to recognize delirium 75% of the time (Rice et al., 2011).
The gold standard for diagnosing delirium is a full evaluation by a mental health expert using the criteria found in the most recent, fifth edition, of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association [APA], 2013). However, given the rapid onset and typically fluctuating course of delirium, particularly in the hospital setting, a number of user-friendly and relatively rapid screening tools have been developed and utilized by nurses for over the past two decades.
The Confusion Assessment Method (CAM; Inouye et al., 1990) is the most widely used delirium screening instrument in hospitalized older adults, having been used in more than 5,000 original articles and translated into 13 languages (Inouye, 2015). The long CAM has 10 items and is preferred in research studies, whereas short CAM contains only the four items of the diagnostic algorithm. A version of the CAM for patients in ICUs (CAM-ICU; Ely, Gautam, et al., 2001) is recommended for use with critically ill older adults (Jacobi et al., 2002; Schuurmans, Deschamps, Markham, Shortridge-Baggett, & Duursma, 2003). The CAM instrument identifies the key features of delirium—acute onset and fluctuating course, inattention, disorganized thinking, and altered level of consciousness and is supported by the best evidence (Wong, Holroyd-Leduc, Simel, & Straus, 2010). Other robust and usable scales include the Delirium Rating Scale (DRS), the Memorial Delirium Assessment Scale (MDAS), and the NEECHAM Confusion Scale (Adamis, Sharma, Whelan, & Macdonald, 2010; Breitbart et al., 1997; Neelon, Champagne, Carlson, & Funk, 1996; Trzepacz et al., 2001).
Another delirium scale, growing in popularity, is the Nursing Delirium Screening Scale (Nu-DESC; Gaudreau, Gagnon, Harel, Tremblay, & Roy, 2005). The Nu-DESC is based on the Confusion Rating Scale (CRS; Gagnon, Allard, Masse, & DeSerres, 2000), the only delirium screening scale that does not require patient participation as it evaluates the presence of confusional symptoms. The CRS can be completed in less than 2 minutes during routine nursing care, and assesses four symptoms of delirium: disorientation, inappropriate behavior, inappropriate communication, and illusions or hallucinations. The CRS uses a score of 0 when there are no symptoms, 1 if there is one mild symptom, and 2 when a symptom is present and pronounced. A score of 2 or more is considered positive.
The NuDESC added a fifth symptom, psychomotor retardation, to account for the hypoactive variant of delirium (Gaudreau et al., 2005). When compared with blinded assessments of 59 patients with psychiatrists using the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM–IV; APA, 1994) criteria and research nurses using the CAM and MDAS assessments, the NuDESC showed 85.7% sensitivity and 86.8% specificity. When comparing the NuDESC to the CAM-ICU in ICU patients, the NuDESC had a sensitivity of 83% (compared to 81% for the CAM-ICU); however, the specificity of the NuDESC (81%) was significantly lower than that of CAM-ICU (96%; Luetz et al., 2010); so the CAM-ICU remains the preferred screening tool for delirium in critically ill patients.
Bedside nurses are in the best position to recognize delirium because they possess the skill and responsibility of ongoing patient assessment and are in key positions to recognize risk factors for delirium and the earliest cognitive changes heralding the onset of delirium. Early identification of risk factors and screening for the earliest onset of delirium are critical to implementing strategies to minimize the occurrence of this devastating pathology in hospitalized older adults.
Interventions
The Cochrane Review found that there are no strong-evidence randomized controlled trials (RCTs) from delirium prevention studies to guide clinical practice (Siddiqi, Stockdale, Britton, & Holmes, 2007). And although there is some preliminary evidence that some pharmacological agents may be effective in reducing delirium, it is not strong (Gosch & Nicholas, 2014). However, there is mounting evidence that multicomponent, nonpharmacological interventions are still the best practice for preventing and managing delirium as well as improving patient outcomes (Holroyd-Leduc, Khandwala, & Sink, 2010).
The American Geriatrics Society (AGS) views delirium as the most essential topic in the care of older hospitalized adults and strongly recommends nonpharmacological, multicomponent interventions (American Geriatrics Society Expert Panel, 2014). It is noteworthy that virtually all of the components of these recommended nonpharmacological interventions to prevent and manage delirium are basic nursing practices that should be part of every nurse’s routine care of hospitalized patients. Supporting studies (Inouye et al., 1999; Lundstrom et al., 2005; Marcantonio, Flacker, Wright, & Resnick, 2001; Milisen et al., 2005; Rubin, Neal, Fenlon, Hassan, & Inouye, 2011; Rubin et al., 2006; Zaubler et al., 2013) have included the following types of interventions:
1. Mobility
2. Reorientation
3. Cognitive stimulation
4. Maintenance of nutrition and hydration
5. Sleep enhancement
6. Vision and hearing adaptation
7. Nursing education
8. Geriatric consultation
CASE STUDY
Mr. Z is an 82-year-old patient admitted to your unit for prostate surgery. He is a retired accountant, lives with his wife, and is very active. He drives a car, plays golf, and regularly participates in activities at the senior center. His type 2 diabetes is well controlled on Actoplus Met (pioglitazone hydrochloride and metformin hydrochloride). Mr. Z reports that he has decreased his fluid intake so he can avoid waking several times during the night to urinate. He also has a history of hypertension, moderate hearing loss (hearing aids bilaterally), and previous surgery for inguinal hernia repair. He wears bifocal glasses for distance and reading. He is alert, oriented, and expresses a good understanding of his upcoming surgery. His preoperative laboratory values are within normal limits except for a low hematocrit and a slightly elevated BUN/creatinine (BUN/Cr) ratio. His medications include Actoplus Met (pioglitazone hydrochloride and metformin hydrochloride) for his diabetes and Calan (verapamil) for hypertension.
What Factors Present on Admission to the Hospital Put Mr. Z at Risk of Developing Delirium?
Age: Older adults are at greater risk of delirium, particularly if they have underlying dementia or depression. Physiological changes that occur with aging can affect the ability of older adults to respond to physical and physiological stress and to maintain homeostasis.
Dehydration: An elevated BUN/Cr ratio indicates dehydration (from decreased fluid intake), a frequent contributing factor (along with electrolyte imbalance) to delirium of hospitalized older adults.
Anemia: Because of a low hematocrit, the body has diminished ability to deliver adequate oxygen to the brain, making delirium more likely.
Sensory deficits: Those with vision and hearing loss are more likely to misinterpret sensory input, which places them at increased risk for delirium.
It is important to understand that it might not be one particular factor but the interplay of patient vulnerability (predisposing factors) and precipitating factors—common during hospitalization—that place the older adult at risk for delirium.
What Can You Do to Help Prevent Delirium in Mr. Z?
Assist Mr. Z, as needed, to be as physically active as possible
– Check his orientation regularly and reorient as needed
– Encourage cognitive activities such as reading or crossword puzzles
Make sure Mr. Z’s glasses and hearing aids are on and functioning.
Explore reasons for the low hematocrit and discuss correction preoperatively.
– Assure correction of dehydration and adequate hydration preoperatively
– Ensure adequate sleep and rest
– Review Mr. Z’s nutritional status and work with the interprofessional team to correct preoperatively
– If possible, consult with a geriatric specialist (geriatrician or geriatric nurse practitioner) for a thorough geriatric assessment of Mr. Z
You provide care for Mr. Z again 2 days after surgery. He is confused and picking at the air and oriented to self only. An indwelling urinary catheter and peripheral intravenous line are in place. In his report, the day-shift nurse mentioned considering a physical restraint because Mr. Z was increasingly restless and impulsive. He was CAM positive, indicating that he may have delirium. The licensed independent practitioner was notified and confirmed delirium using the DSM-5 criteria (APA, 2013).
What Are the Clinical Features of Delirium?
Disturbance of consciousness characterized by reduced clarity and awareness of the environment: reduced ability to focus, sustain, and shift attention. Patients have trouble following instructions or making sense of their environment, even with cues. They may also get “stuck” on a particular concern or thought.
Cognitive changes: Memory deficit, disorientation, language disturbance, and/or perceptual disturbance
Perceptual disturbances: Hallucinations and delusions are common. Patients can be hyperactive and agitated or lethargic (hypoactive) and less active. The latter presentation is of particular concern because it is often not recognized by health care providers as delirium. The presentation may also be mixed, with the patient fluctuating from one to the other behavioral state.
Delirium can be characterized by disturbances in the sleep–wake cycle and rapidly shifting emotional disturbances, with escalation of the disturbed behavior at night (sundowning).
The clinical hallmarks of delirium are that the cited changes occur rapidly over several hours or days. There is a decreased attention span and a fluctuating course (waxing and waning of confusion).
It is also important to consider that delirium may occur concurrently with dementia or depression. In fact, these patients are at increased risk for developing delirium. Family and caregivers can be invaluable in helping to identify or distinguish cognitive changes in circumstances when the patient is not well known to you.
What Additional Factors May Now Be Contributing to Mr. Z’s Delirium?
Anesthesia and other medications: It takes several hours to days for the body to clear the effects of anesthesia. Inasmuch as older adults have a larger percentage of body fat than younger persons do, and many drugs are fat-soluble, drug effects will last longer. Also, older adults tend to have less cellular water; hence, water-soluble drugs will be more concentrated and have a more pronounced effect. Consider the possibility of alcohol withdrawal (often a hidden problem) as a contributing factor.
Pain: What is Mr. Z’s pain-control regimen and status? What is the dose and frequency of the pain medication? Is the dose appropriate?
Hypoxemia: Mr. Z is at risk because of limited mobility and possible atelectasis after surgery. What is his oxygen saturation (SpO2)? Does he have crackles or diminished breath sounds?
Infection, inflammation, or other medical illness: Postoperative infections, intraoperative myocardial infarctions (MIs), or strokes are possible causes of delirium in this case. Could Mr. Z have a urinary tract infection (UTI) post prostate surgery, particularly because he has a Foley catheter? An inflammatory response to a new medical problem may be the cause of the delirium.
Unfamiliar surroundings: Particularly for those with sensory deficits, unfamiliar environments can lead to misinterpretations of information, which may contribute to delirium.
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