The grades of evidence (A1, A2, B1, B2, C1, C2, D) are defined at the end of the "Major Recommendations" field.
- Nurses should maintain a high index of suspicion for delirium in the older adult, specifically for those with more predisposing factors that increase risk for delirium (Inouye et al., 1993; Registered Nurses Association of Ontario [RNAO], 2003. Evidence Grade = B1).
- Nurses must recognize that delirium may be superimposed on dementia and differentiate baseline from more acute changes in cognitive function (Fick & Foreman, 2000; Fick, Agostini, & Inouye, 2002; RNAO, 2003; Royal College of Physicians, 2006. Evidence Grade = A1).
- Assessment for predisposing/vulnerability factors for delirium should occur on hospital admission and are the most powerful factors for identifying patients at greatest risk for developing delirium (Inouye & Charpentier, 1996; Inouye et al., 1993; Pompei et al., 1994; Schor et al., 1992; Williams-Russo et al., 1992. Evidence Grade = C1).
- Assessment of predisposing/vulnerability factors includes findings from the patient's history and physical assessment. Pre-existing cognitive impairment, severity of presenting illness, and age are the most consistent risk factors identified for the development of delirium (See Table B in the original guideline document) (Bitsch et al., 2004; Contin et al., 2005; Inouye, 2006; Inouye et al., 2007; Kalisvaart et al., 2006; Marcantonio et al., 2000. Evidence Grade = C1).
- Assessment for precipitating factors/noxious insults for delirium should occur on admission and throughout the patient's hospital stay (See Table C in the original guideline document) (Inouye & Charpentier, 1996; Inouye et al., 1993; Inouye et al., 2007. Evidence Grade = C1).
- Nursing admission and daily assessment processes should incorporate the use of standardized instruments for assessing cognition and the presence of delirium (Gehi et al., 1980; Inouye et al., 2001; O'Keeffe et al., 2005; Palmateer & McCartney, 1985; RNAO, 2003; Rockwood et al., 1994; Royal College of Physicians, 2006. Evidence Grade = B1).
- Describing behaviors provides better information than using the term confusion to document cognitive changes (Morency, Levkoff, & Dick, 1994; Palmateer & McCartney, 1985. Evidence Grade = B2).
- Nurses' recognition and assessment of delirium can be enhanced with education on assessing cognition, cognitive impairment, features of delirium, and factors associated with poor recognition of delirium (Fick et al., 2007; Inouye et al., 2001; Morency, Levkoff, & Dick, 1994; Palmateer & McCartney, 1985; Wanich et al., 1992. Evidence Grade = B2).
Instruments for assessing delirium tend to be of two general types: 1) mental status questionnaires and 2) observational tools or symptom checklists. Mental status instruments are helpful because they directly test the patient's cognitive performance. However, performance on mental status tests is strongly affected by age, educational level, ethnicity, and language (Anthony et al., 1982; Bird et al., 1987; Bleecker et al., 1988) and may be difficult for the acutely ill patient to perform. Advantages of observational instruments as compared to mental status questionnaires include: 1) the response burden for patients is minimal, and 2) both cognitive and behavioral function can be observed and evaluated frequently. A primary disadvantage of observational instruments is that they do not directly test cognitive and behavioral function, but are dependent on the judgment of the clinician. This reliance on subjective assessment may produce unreliable assessments for delirium.
The criteria for choosing the most appropriate standardized instrument includes the psychometrics of the tool, the clinical feasibility of using the scale, patient acceptability or response burden, and need for a diagnostic or screening instrument versus one that assists with monitoring cognitive function over time (Foreman, 1993). A variety of measures for assessing delirium may be needed because each instrument is designed for different purposes.
- The Confusion Assessment Method (CAM) (see Appendix A.1 in the original guideline document) is a diagnostic, observational instrument based on the Diagnostic and Statistical Manual of Mental Disorders (DSM)-III-R criteria for delirium and was developed for clinicians without a psychiatric background to assist them in identifying delirium quickly. It does not provide information on severity of delirium and is not useful for repeated measurement. The tool assists with identifying the syndrome's essential and associated features necessary for making a diagnosis of delirium and is useful in distinguishing the difference between delirium and dementia. The instrument consists of nine open ended questions and a diagnostic algorithm that requires subjective clinical judgment by the rater (Inouye et al., 1990; Lemiengre et al., 2006; Ljubisavljevic & Kelly, 2003). The CAM was developed to include an assessment of cognitive status with the Mini-Mental State Examination (MMSE) (Folstein, Folstein, & McHugh, 1975). Following the use of the MMSE, the interviewer uses a decision process to determine if delirium is present. Feature one (acute onset and fluctuating course) and two (inattention) must be present, with either feature three (disorganized thinking) or four (altered level of consciousness) present to diagnose delirium.
- The Delirium Index (DI) (see Appendix A.2 in the original guideline document) is adapted from the CAM and intended as a measure of the severity of delirium based on patient observation from a nonpsychiatrist clinician, without additional information from family members, nursing staff, or medical charts (McCusker et al., 2004; McCusker et al., 1998). The DI includes seven domains: disorders of attention, thought, consciousness, orientation, memory, perception, and psychomotor activity. Each domain is scored from 0 (absent) to 3 (present and severe). The total score ranges from 0-21 and a higher score indicates greater severity.
- The Mini-Mental State Examination (MMSE) (see Appendix A.3 in the original guideline document) is the most frequently used mental status questionnaire in clinical practice. The patient needs to be verbally responsive. The MMSE includes 11 questions that focus on orientation, registration, attention and calculation, recall, and language. A score of 24-30 indicates the person is cognitively intact, 18-23 correlates with mild cognitive impairment, and 0-17 represents severe impairment (Folstein, Folstein, & McHugh, 1975). The use of serial MMSEs is responsive to acute changes in cognition in older hospitalized adults and is helpful in the diagnosis and monitoring of the recovery from delirium (O'Keeffe et al., 2005). Specific items of the MMSE are helpful in screening for delirium and they include the question about the current year and date, the backward spelling task, and copying a design (Fayers et al., 2005).
- The Neelon and Champagne (NEECHAM) Confusion Scale (see Appendix A.4 in the original guideline document) is a nursing instrument useful for measuring the level of confusion in cognitive processing, behavior, and physiologic control. Through bedside observation and interaction with the patient, the scale incorporates data from a nurse's assessment of patient responses. The instrument assists with assessing the risk, presence, and severity of confusion. The instrument includes nine scaled items divided into three subscales or levels that measure information processing, behavior and performance, and vital function.
- The information processing subscale focuses on response and attention, processing information and following commands, orientation, and memory.
- The behavior and performance subscale focuses on appearance, motor, and verbal abilities.
- The vital function subscale focuses on vital signs, oxygen stability, and continence.
Scores range from 0-30 points. A score ranging from 0-19 indicates severe to moderate confusion, 20-24 indicates mild or early development of confusion, 25-26 indicates normal function with a risk for developing acute confusion, and 27-30 indicates normal functioning (Neelon et al., 1996).
- The Delirium-O-Meter (DOM) (see Appendix A.5 in the original guideline document) is a 12-item behavioral observation scale for determining the severity of delirium that nurses without a background in gerontological nursing could use. The scale was designed to be sensitive to hyperactive and hypoactive symptoms of delirium and the Diagnostic and Statistical Manual of Mental Disorders-IV delirium criteria. The domains of the scale include sustained attention, shifting of attention, orientation, consciousness disturbance, apathy, hypokinesia/psychomotor retardation, incoherence, fluctuating functioning, restlessness, delusions, hallucinations and anxiety/fear. Each item is scored on a four-point scale from 0 (absent) to 3 (present and severe). Total scores range from 0-36 (de Jonghe et al., 2005).
- The Mini-Cog (see Appendix A.6 in the original guideline document) is a screening tool for cognitive impairment and is recommended for use in all elderly patients admitted to the hospital. The tool requires minimal training of the tester, minimal equipment (paper and pencil or pen) and takes approximately 3 to 5 minutes to administer. Patients are asked to listen carefully, remember, and repeat three unrelated words the tester provides. Next, the patient is asked to draw the face of a clock on a blank sheet of paper or on a sheet that has the clock circle already drawn. The patient is asked to write the numbers on the clock and to draw the hands of the clock to indicate a specific time. The patient is again asked to repeat the three words. Each correctly recalled word is equal to 1 point; an abnormal clock is 0 points and a normal clock is 2 points. Possible scores range from 0-5, with 0-2 suggesting high and 3-5 indicating low likelihood of cognitive impairment. The Mini-Cog has been examined in a variety of settings with different populations (Borson et al., 2000; Borson et al., 2003; Borson et al., 2005). The Mini-Cog predicts delirium in older adults, and patients with abnormal results are five times more likely to develop delirium compared to those with normal scores (Alagiakrishnan et al., 2007).
- The Form for Documenting Predisposing and Precipitating Factors for Delirium (see Appendix A.7 in the original guideline document) is a documentation tool for use as a chart form in the patient's record. The authors of this guideline created the form based on the delirium framework. The form includes a section to record the actual factors that place a patient at risk for delirium on hospital admission, the time delirium developed, and the precipitating factors that exist for the patient 24 hours prior to the development of delirium. The tool assists nurses and other clinicians in creating the individualized plan of care and identifying interventions focused on eliminating or decreasing the effect of the contributing factors.
Description of the Intervention
This evidence-based practice guideline includes non-pharmacologic and pharmacologic interventions for the prevention and management of delirium. Older adults at high risk for delirium require interventions that eliminate or lessen the effects of potential precipitating factors.
Interventions – Prevention
Delirium rarely has one single cause for the condition, but has a multi-factorial etiology (Inouye & Charpentier, 1996). Studies suggest that primary prevention of delirium is probably the most effective strategy for reducing the overall incidence of delirium of hospitalized medical/surgical patients (See Appendix E in the original guideline document) (Cole et al., 2002; Inouye et al., 1999; Milisen et al., 2001. Evidence Grade = B2).
- Guidelines without support systems (e.g., education and resources for implementation) fail to improve the process and outcomes of care in patients at risk for the development of delirium (Young & George, 2003. Evidence Grade = C1).
- Clinicians' implementation or adherence to multicomponent intervention strategies is essential to improve patient outcomes (Inouye et al., 2003. Evidence Grade = B2).
- In order for nurses and physicians to appropriately intervene and treat delirium, education is an essential system level intervention necessary to improve patient outcomes (Lundstrom et al., 1999; Lundstrom et al., 2005; Milisen et al., 2001. Evidence Grade = B2).
- Intervention strategies aimed at prevention for patients at high risk is the most effective approach (Cole et al., 2002; Milisen et al., 2005; Pitkala et al., 2006. Evidence Grade = A2).
Multi-component Interventions for Prevention of Delirium
Delirium primarily has a multifactorial etiology where the presence of predisposing factors and interaction with precipitating factors increases the patient vulnerability to the development of delirium. The multifactorial nature of delirium has led to studies of hospitalized patients focusing on multiple interventions aimed at reducing and/or eliminating factors that can be changed. Individual studies that examined a multifactorial approach and interventions include:
- Staff education and practice guidance for nurses and physicians focusing on:
- Delirium and dementia and its risk factors, treatment, and care
- Caregiver-patient interaction such as offering patients the opportunity to recognize and comprehend information and to be re-oriented in the current reality
- Reorganize nursing care to support individualized patient needs
- Guidance for nursing staff for providing care (Lundstrom et al., 2005. Evidence Grade = B2)
- Nurse-led interdisciplinary intervention including:
- Education of the nursing staff
- Systematic cognitive screening
- Consultative services by a delirium resource nurse
- A geriatric nurse specialist, or a psychogeriatrician
- A scheduled pain protocol (Milisen et al., 2001. Evidence Grade = B2)
- A geriatric consulting team with daily visits from a geriatrician who made targeted recommendations based on a structured protocol including:
- Adequate central nervous system (CNS) oxygen delivery
- Fluid/electrolyte balance
- Treatment of severe pain
- Elimination of unnecessary medications
- Regulation of bowel/bladder function
- Adequate nutritional intake
- Early mobilization and rehabilitation
- Prevention, early detection, and treatment of major postoperative complications; appropriate environmental stimuli; and treatment of agitated delirium (Marcantonio et al., 2001. Evidence Grade = A2)
- Multicomponent interventions recommended by a psychiatric consultation-liaison nurse including:
- Ongoing patient assessments
- Advice to nursing and medical staff
- Implementation of a research-based nursing protocol for delirium that included:
- Daily review of medications and laboratory values
- Environmental modifications
- Patient safety suggestions
- Patient mobilization
- Recommendation for referral to liaison psychiatry for further evaluation (Kurlowicz, 2001. Evidence Grade = C1)
- Multicomponent intervention targeted at risk factors and including protocols for:
- Ambulation, whenever possible (Inouye et al., 2000; Inouye et al., 1999; Rubin et al., 2006. Evidence Grade = B2)
- Intervention program including:
- Prevention of hypoxemia
- Cooperation between medical specialists and geriatricians
- Individual care and planning of rehabilitation
- Improved environment
- Nutrition program
- Improved continuity of care
- Prevention and treatment of complications associated with delirium
- Staff education on delirium (Lundstrom et al., 1999. Evidence Grade = B2)
- Multicomponent guideline including patient assessment, the identification of risk factors and implementation of prevention and management strategies for delirium (Simon, Jewell, & Brokel, 1997. Evidence Grade = C1)
Although most studies used different combinations of interventions in their multicomponent approach, some interventions were consistent across studies. These interventions include:
- Nurse and/or physician education on delirium, including identification of assessment, risk, and underlying causes of delirium (Lundstrom et al., 1999; Lundstrom et al., 2005; Milisen et al., 2001. Evidence Grade = B2).
- Guidance for staff nurses regarding care (Kurlowicz, 2001; Lundstrom et al., 2005; Milisen et al., 2001. Evidence Grade = B2).
- Electrolyte balance (Marcantonio et al., 2001; Simon, Jewell, & Brokel, 1997. Evidence Grade = B2).
- Promotion of nutrition (Lundstrom et al., 1999; Marcantonio et al., 2001. Evidence Grade = A2).
- Orientation to current reality including modifications to the environment such as clocks and calendars (Inouye et al., 1999; Inouye et al., 2000; Kurlowicz, 2001; Lundstrom et al., 2005; Marcantonio et al., 2001. Evidence Grade = B2).
- Consistent caregivers (Lundstrom et al., 1999; Lundstrom et al., 2005; Simon, Jewell, & Brokel, 1997. Evidence Grade = B2).
- Pain management (Marcantonio et al., 2001; Milisen et al., 2001; Simon, Jewell, & Brokel, 1997. Evidence Grade = A2).
- Elimination of unnecessary medications/medication management (Kurlowicz, 2001; Marcantonio et al., 2001; Simon, Jewell, & Brokel, 1997. Evidence Grade = A2).
- Discontinuation of urinary catheter (Inouye et al., 1999; Inouye et al., 2000; Marcantonio et al., 2001. Evidence Grade = A2).
- Early mobilization (Inouye et al., 1999; Inouye et al., 2000; Kurlowicz, 2001; Marcantonio et al., 2001. Evidence Grade = A2).
- Appropriate use of glasses and hearing aids (Inouye et al., 1999; Inouye et al., 2000; Marcantonio et al., 2001. Evidence Grade = A2).
- Sleep promotion (Inouye et al., 1999; Inouye et al., 2000; Simon, Jewell, & Brokel, 1997. Evidence Grade = B2).
Single Component Interventions
While the delirium model outlined in this guideline focuses on identification and management of multiple contributing factors unique to each patient, several essential studies identify important single interventions that demonstrate some effect on decreasing the incidence or lessening the severity of delirium.
- Educational intervention for nurses and physicians for increasing awareness and knowledge of delirium alone leads to improvement in outcomes (Tabet et al., 2005; Young & George, 2003. Evidence Grade = B2).
- Music as a therapy using compact disc players (McCaffrey & Locsin, 2004. Evidence Grade = C2).
- Preoperative patient teaching that includes an explanation about the potential for unusual sensory or cognitive postoperative experiences (Owens & Hutelmyer, 1982. Evidence Grade = B2).
- Family interaction with patient focusing on use of eye contact, frequent touch, and verbal orientation to time, person, and place (Chatham, 1978. Evidence Grade = D).
- Reorientation procedure such as calendars in the room, orientation techniques incorporated into routine care, provision of information of patient progress (Budd & Brown, 1974. Evidence Grade = B2).
- Prophylactic use of haloperidol has some effect on the duration and severity of delirium in postoperative patients who are at intermediate or high risk of developing delirium (Kalisvaart et al., 2005; Lonergan et al., 2007. Evidence Grade = B2).
- Atypical antipsychotic medications reduce the severity of delirium in elderly and/or postoperative patients (Alao & Moskowitz, 2006; Straker, Shapiro, & Muskin, 2006. Evidence Grade = C1).
- Postoperative patients who receive gabapentin for managing pain experience less delirium (Leung et al., 2006. Evidence Grade = A2).
A1: Evidence from well-designed meta-analysis or well-done systematic review with results that consistently support a specific action (e.g., assessment, intervention, or treatment)
A2: Evidence from one or more randomized controlled trials with consistent results
B1: Evidence from a high quality evidence-based practice guideline
B2: Evidence from one or more quasi-experimental studies with consistent results
C1: Evidence from observational studies with consistent results (e.g., correlational, descriptive studies)
C2: Inconsistent evidence from observational studies or controlled trials
D: Evidence from expert opinion, multiple case reports, or national consensus reports
A clinical algorithm for delirium is provided in the original guideline document.