Delirium phenomenology: what can we learn from the symptoms of delirium?

Medication-induced causes of delirium in patients with and without dementia: a systematic review of published neurology guidelines

BACKGROUND

While medication is a recognized risk factor of delirium, there is currently a lack of detailed information on managing and preventing medication-induced cases.

AIM

This review summarizes the information provided in neurology guidelines on medication-induced delirium in patients with and without dementia to inform guidance on prevention and management strategies.

METHOD

A systematic literature review was conducted across 114 neurological and medical organisations, Guideline Central and PubMed. Guidelines, consensus guidelines, white papers, frameworks, protocols, standard procedures, action plans and strategic documents detailing the prevention and management of medication-induced delirium in adults with or without dementia were included. Title and full-text screening was completed independently by two reviewers using PICOS. AGREE II was used to assess reporting quality. A data extraction tool was designed based on the Cochrane Effective Practice and Organization of Care Review Group (EPOC) checklist and a mixed methods approach to synthesis adopted. The systematic review protocol was registered with International Prospective Register of Systematic Reviews (PROSPERO) [ID: CRD42022366025].

RESULTS

Out of 143 guidelines identified, 30 were included. Information for 140 individual medications was extracted. Medications most frequently cited included sedatives (n = 24/80%), opioids (n = 22/73,3%), psychoactive drugs (n = 21/70%) + anti-convulsants (n = 14/46,7%), anti-cholinergic agents (n = 20/66,7%), antihistamines (n = 18/60%), and steroids (n = 16/53,3%). Despite a consistently high-quality rating (n = 19, 63,3%), the detail provided often lacks specificity about pharmacological mechanisms, individual risk, dosing instructions, associated symptoms, therapeutic alternatives and avoidable drug-drug combinations. In relation to dementia, detailed information on the use of antipsychotics, cholinesterase inhibitors and benzodiazepines was extracted. No papers were excluded based on their quality.

CONCLUSION

No single guideline contains enough information on the risk, prevention, and management of medication-induced delirium to sufficiently support clinical decision making.

Exploring Cognitive Stimulation as a Therapy for the Prevention of Delirium in a Hospital Setting: A Narrative Review

Delirium is a highly prevalent and costly neuropsychiatric condition that affects up to 87% of critically ill hospitalized patients. It impacts various cognitive domains, including attention, memory, perception, and motor functions, with symptoms such as behavioral changes, hallucinations, slurred speech, visual impairments, and fatigue. Non-pharmacological interventions have been shown to reduce the incidence and duration of delirium, with strategies like reality orientation, cognitive stimulation, family support, and physical support. However, the scalability of these interventions in hospital settings is limited by resource constraints, low patient engagement, and the complexity of delivery. Digital technology-based cognitive stimulation offers a potential solution to these barriers, though evidence supporting its effectiveness is currently insufficient. This narrative literature review explores both traditional and novel digital technology-based cognitive stimulation techniques for the prevention and management of delirium in acute hospital settings.

Dexmedetomidine for delirium prevention in adult patients following cardiac surgery: a meta-analysis of randomized controlled trials

OBJECTIVES

To determine whether perioperative administration of dexmedetomidine reduces the incidence of postoperative delirium in adult patients undergoing cardiac surgery.

METHODS

We searched the PubMed, Embase and Cochrane Library databases for randomized controlled trials from the last 10 years up to March 10, 2024. We then conducted a meta-analysis to evaluate the effectiveness and safety of dexmedetomidine in preventing delirium after cardiac surgery in adults. This meta-analysis followed the steps in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA2020) guidelines. This study is registered with INPLASY under number INPLASY202430132.

RESULTS

A total of 2689 patients were included in our analyses. All included studies were randomized controlled trials. Dexmedetomidine can reduce the occurrence of delirium in patients after cardiac surgery(OR 0.75, 95%CI 0.57-0.98, I2 = 12%, P = 0.04). In terms of other end events, length of intensive care unit(ICU) stay(MD -0.16, 95%CI -1.85-1.53, I2 = 0%, P = 0.85) and mortality(OR 1.59, 95%CI 0.74-3.42, I2 = 0%, P = 0.23) were not statistically different with dexmedetomidine compared with placebo. Bradycardia (OR 0.85, 95%CI 0.54 ~ 1.34, I2 = 72%, P = 0.49) and hypotension (OR 1.97, 95%CI 0.96 ~ 4.03, I2 = 84%, P = 0.06) were not significantly different between the two groups.

CONCLUSIONS

Dexmedetomidine is safe for cardiac surgery patients and to some extent reduces the incidence of delirium in cardiac surgery patients, which is more important in preoperative use.

Individualized Summary Assessment of Detailed Neuropsychological Testing for the Etiological Diagnosis of Newly Detected Cognitive Impairment in Hospitalized Geriatric Patients

BACKGROUND

Neuropsychological testing (NPT) of geriatric inpatients can be affected by the acute illness and/or the hospitalization.

OBJECTIVE

To test individualized interpretation of detailed NPT for the differentiation between primary 'neurodegenerative' etiologies (predominantly Alzheimer's disease) and 'other' etiologies (including cerebrovascular disease) of newly detected cognitive impairment in geriatric inpatients without and with delirium in remission.

METHODS

96 geriatric inpatients (81.9±5.6 years, 64.6% females) with clinically uncertain cognitive impairment were included. 31.3% had delirium in remission that was not considered the primary cause of the cognitive impairment. Categorization of the most likely etiology as 'neurodegenerative' or 'other' was established retrospectively by a study neuropsychologist based on individualized summary assessment of detailed NPT compiled in a standardized vignette. The etiological diagnosis based on FDG-PET served as gold standard (54.2% 'neurodegenerative', 45.8% 'other').

RESULTS

Individualized summary assessment by the study neuropsychologist was correct in 80 patients (83.3%, 8 false positive, 8 false negative). The impact of delirium in remission was not significant (p = 0.237). Individualized summary assessment by an independent neuropsychologist resulted in more false positive cases (n = 22) at the same rate of false negative cases (n = 8). Automatic categorization with a decision tree model based on the most discriminative NPT scores was correct in 68 patients (70.8%, 14 false positive, 14 false negative).

CONCLUSION

Individualized summary assessment of detailed NPT in the context of relevant clinical information might be useful for the etiological diagnosis of newly detected cognitive impairment in hospitalized geriatric patients, also in patients with delirium in remission, but requires task-specific expertise.

Predisposing and Precipitating Factors Associated With Delirium: A Systematic Review

Importance

Despite discrete etiologies leading to delirium, it is treated as a common end point in hospital and in clinical trials, and delirium research may be hampered by the attempt to treat all instances of delirium similarly, leaving delirium management as an unmet need. An individualized approach based on unique patterns of delirium pathophysiology, as reflected in predisposing factors and precipitants, may be necessary, but there exists no accepted method of grouping delirium into distinct etiologic subgroups.

Objective

To conduct a systematic review to identify potential predisposing and precipitating factors associated with delirium in adult patients agnostic to setting.

Evidence Review

A literature search was performed of PubMed, Embase, Web of Science, and PsycINFO from database inception to December 2021 using search Medical Subject Headings (MeSH) terms consciousness disorders, confusion, causality, and disease susceptibility, with constraints of cohort or case-control studies. Two reviewers selected studies that met the following criteria for inclusion: published in English, prospective cohort or case-control study, at least 50 participants, delirium assessment in person by a physician or trained research personnel using a reference standard, and results including a multivariable model to identify independent factors associated with delirium.

Findings

A total of 315 studies were included with a mean (SD) Newcastle-Ottawa Scale score of 8.3 (0.8) out of 9. Across 101 144 patients (50 006 [50.0%] male and 49 766 [49.1%] female patients) represented (24 015 with delirium), studies reported 33 predisposing and 112 precipitating factors associated with delirium. There was a diversity of factors associated with delirium, with substantial physiological heterogeneity.

Conclusions and Relevance

In this systematic review, a comprehensive list of potential predisposing and precipitating factors associated with delirium was found across all clinical settings. These findings may be used to inform more precise study of delirium's heterogeneous pathophysiology and treatment.

Relationship between preoperative anxiety and onset of delirium after cardiovascular surgery in elderly patients: focus on personality and coping process

BACKGROUND

Postoperative delirium is associated with increased mortality. Therefore, it is important to manage delirium during the entire perioperative period. Preoperative anxiety is associated with poor prognosis in postoperative patients who have undergone cardiovascular surgery. This study aims to investigate the relationship between preoperative anxiety and onset of delirium after cardiovascular surgery in elderly patients (aged 65 years or older), considering the individual psychological characteristics, such as personality and stress coping skills in response to anxiety, as confounding factors.

METHODS

This prospective study included patients aged >65 years in a preoperative state before undergoing cardiovascular surgery. Subjects were divided into two groups based on whether they experienced postoperative delirium, or not. We compared clinical and demographic factors, preoperative psychiatric and psychological factors, and intraoperative and perioperative physical factors between the control and delirium groups. Multiple imputations were used to account for missing data.

RESULTS

Out of 168 subjects enrolled in this study, 26 (15.5%) developed postoperative delirium. Univariate analysis showed significant differences in age (P = 0.027), cognitive function (P = 0.007), agreeableness (P = 0.029), and the Acute Physiology and Chronic Health Evaluation-II (APACHE-II) score (P = 0.023) between the delirium and control groups. Multiple logistic regression analysis did not identify a significant association between preoperative anxiety and the onset of postoperative delirium. However, age (odds ratio (OR) = 1.114, P = 0.018), agreeableness (OR = 0.555, P = 0.008), and the APACHE-II score (OR = 1.227, P = 0.008) were identified as risk factors for postoperative delirium.

CONCLUSION

Agreeableness, one of the personality traits associated with preoperative anxiety, appears to be involved in the development of postoperative delirium as an independent psychological factor, regardless of age or physical factors.

Effect of midazolam on delirium in critically ill patients: a propensity score analysis

Objective

To observe the association between exposure to midazolam within 24 hours prior to delirium assessment and the risk of delirium.

Methods

We performed a systematic cohort study with two sets of cohorts to estimate the relative risks of outcomes among patients administered midazolam within 24 hours prior to delirium assessment. Propensity score matching was performed to generate a balanced 1:1 matched cohort and identify potential prognostic factors. The outcomes included the odds of delirium, mortality, length of intensive care unit stay, length of hospitalization, and odds of being discharged home.

Results

A total of 78,364 patients were included in this study, of whom 22,159 (28.28%) had positive records. Propensity matching successfully balanced covariates for 9348 patients (4674 per group). Compared with no administration of midazolam, midazolam administration was associated with a significantly higher risk of delirium, higher mortality, and a longer intensive care unit stay. Patients treated with midazolam were relatively less likely to be discharged home. There was no significant difference in hospitalization duration.

Conclusions

Midazolam may be an independent risk factor for delirium in critically ill patients.

Phenomenological examinations of delirium in advanced cancer patients: exploratory structural equation modelling and latent profile analysis

Background

This study examined phenomenological manifestations of delirium in advanced cancer patients by examining the factor structure of the Delirium Rating Scale-Revised-98 (DRS-R-98) and profiles of delirium symptoms.

Methods

Ninety-three patients with advanced cancer admitted to inpatient palliative care units in South Korea were examined by psychiatrists using the DRS-R-98 and the Confusion Assessment Method (CAM). The factor structure of the DRS-R-98 was examined by exploratory structural equation modelling analysis (ESEM) and profiles of delirium were examined by latent profile analysis (LPA).

Results

CAM-defined delirium was present in 66.6% (n = 62) of patients. Results from the ESEM analysis confirmed applicability of the core and noncore symptom factors of the DRS-R-98 to advanced cancer patients. LPA identified three distinct profiles of delirium characterizing the overall severity of delirium and its core and noncore symptoms. Class 1 (n = 55, 59.1%) showed low levels of all delirium symptoms. Class 2 (n = 17, 18.3%) showed high levels of core symptoms only, whereas Class 3 (n = 21, 22.6%) showed high levels of both core and noncore symptoms except motor retardation.

Conclusions

Clinical care for delirium in advanced cancer patients may benefit from consideration of the core and noncore symptom factor structure and the three distinct phenomenological profiles of delirium observed in the present study.

Assessing delirium with nursing care instruments: Evaluation of the cognitive and associated domains

OBJECTIVE

Nursing instruments have the potential for daily screening of delirium; however, they have not yet been evaluated. Therefore, after assessing the functional domains of the electronic Patient Assessment - Acute Care (ePA-AC), this study evaluates the cognitive and associated domains.

METHODS

In this prospective cohort study in the intensive care unit, 277 patients were assessed and 118 patients were delirious. The impacts of delirium on the cognitive domains, consciousness and cognition, communication and interaction, in addition to respiration, pain, and wounds were determined with simple logistic regressions and their respective odds ratios (ORs).

RESULTS

Delirium was associated with substantial impairment throughout the evaluated domains. Delirious patients were somnolent (OR 6), their orientation (OR 8.2-10.6) and ability to acquire knowledge (OR 5.5-11.6) were substantially impaired, they lost the competence to manage daily routines (OR 8.2-22.4), and their attention was compromised (OR 12.8). In addition, these patients received psychotropics (OR 3.8), were visually impaired (OR 1.8), unable to communicate their needs (OR 5.6-7.6), displayed reduced self-initiated activities (OR 6.5-6.9) and challenging behaviors (OR 6.2), as well as sleep-wake disturbances (OR 2.2-5), Furthermore, delirium was associated with mechanical ventilation, abdominal/thoracic injuries or operations (OR 4.2-4.4), and sensory perception impairment (OR 3.9-5.8).

SIGNIFICANCE OF RESULTS

Delirium caused substantial impairment in cognitive and associated domains. In addition to the previously described functional impairments, these findings will aid the implementation of nursing instruments in delirium screening.

Delirium disorder

Objective

As the US population ages and with no definitive delirium treatments on the horizon, the delirium epidemic is on course to expand over the coming decades. Recognizing the import of this condition, a recent position statement from 10 medical societies—among whom the American Academy of Neurology was represented—issued recommendations on preferred nomenclature of delirium and acute encephalopathy: it concluded by preferring both terms. Urgently needed is an integrated model that addresses the near-total segregation of these separate bodies of literature, ideally one that offers an interdisciplinary framework to bring these 2 terms and those who use them together.

Methods

We review the historical forces that have led these terms to diverge and consider the unique benefits of each approach as well as their liabilities when considered in isolation. We then explore the potential implications of integrating these concepts and propose a hybrid model to capitalize on the strengths of both the model of delirium and that of acute encephalopathy.

Results

The model we propose—delirium disorder—builds on the recommendations of this recent position statement and provides a unifying framework designed to have clinical utility and interdisciplinary appeal. It also broadens the translational landscape by identifying 4 distinct treatment targets: underlying causes, procognitive factors, delirium (phenotype alone), and neurophysiologic targets.

Conclusions

This person-centered model aims to integrate delirium and acute encephalopathy within a single framework and shared nomenclature. It is hoped that this model aids in harmonizing research efforts and advancing clinical practice.

Family caregiver's experience of caring for an older adult with delirium: A systematic review

AIM

To enhance understanding of how family caregivers perceive the experience of caring for an older adult with delirium across care settings and to identify the challenges in recognising and managing delirium to inform future research and best practices.

METHOD

A systematic literature review was conducted in five databases per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Primary or secondary peer-reviewed articles published between 1987 and October 2018 describing the experiences of family caregivers caring for older adults with delirium or delirium superimposed on dementia were included in the review. Mixed Method Appraisal Tool (MMAT) was used to evaluate the methodological quality. A thematic synthesis of results was conducted to extract relevant data as per the aims of the study.

RESULTS

Eighteen articles met the eligibility criteria, which were reviewed and analysed in regard to purpose, sample, research design, variables and results. Seven themes emerged in the process. The current challenges and gaps in our knowledge of this phenomenon have also been highlighted, which should be helpful to inform best practices, and finally, an agenda for future research is proposed.

CONCLUSION

Family caregivers are an important partner in the detection and management of delirium. The impact of caring for an older adult with delirium on the family caregivers should not be overlooked. This paper highlights the dearth of research on family caregiver's experience of caring for older adults with delirium and even less in the context of delirium superimposed on dementia. More research is required to further understand the family caregiver's experience and their challenges in order to support them in their caregiving role and to determine their needs and preferences of being involved in the plan of care.

IMPLICATIONS FOR PRACTICE

These findings suggest that family caregivers are a valuable resource in the recognition and management of delirium and should be included as care partners in the health care team, while also catering to their health and well-being in the process.

Association of Cognitive and Noncognitive Symptoms of Delirium: A Study from Consultation-liaison Psychiatry Set-up

Aims:

This study aims to evaluate the cognitive functions of patients with delirium using Hindi Mental Status Examination (HMSE), to study the correlation of cognitive functions assessed by HMSE with noncognitive symptoms as assessed using Delirium Rating Scale-Revised 1998 (DRS-R-98) and to study the association of cognitive functions assessed using HMSE and DRS-R98.

Methods:

A total of 76 consecutive patients fulfilling the diagnosis of delirium were evaluated on DRS-R-98, HMSE, and Short Informant Questionnaire on Cognitive Decline in the Elderly (retrospective IQCODE).

Results:

The mean DRS-R-98 score 33.9 (standard deviation [SD] - 7.2) and the mean DRS-R-98 severity score was 25.9 (SD - 7.2). The mean score on HMSE was 19.3 (7.98). There were significant correlations of all the domains of HMSE with DRS-R-98 total score, DRS-R-98 severity score, DRS-R-98 cognitive subscale score, DRS-R-98 noncognitive domain subscale score, and DRS severity score without attention score. When the association of each item of DRS-R-98 and HMSE was evaluated, except for the items of delusions, lability of affect and motor retardation, there were significant negative association between all the items of DRS-R-98 and HMSE, indicating that higher severity of cognitive symptoms as assessed on HMSE is associated with higher severity of all the cognitive symptoms and most of the noncognitive symptoms as assessed by DRS-R-98.

Conclusion:

The present study suggests that attention deficits in patients with delirium influence the severity of cognitive and noncognitive symptoms of delirium. Further, the present study suggests an increase in the severity of cognitive symptoms in other domains is also associated with an increase in the severity of noncognitive symptoms of delirium.

Delirium in the intensive care setting dependent on the Richmond Agitation and Sedation Scale (RASS): Inattention and visuo-spatial impairment as potential screening domains

OBJECTIVE

In the intensive care setting, delirium is a common occurrence; however, the impact of the level of alertness has never been evaluated. Therefore, this study aimed to assess the delirium characteristics in the drowsy, as well as the alert and calm patient.

METHOD

In this prospective cohort study, 225 intensive care patients with Richmond Agitation and Sedation Scale (RASS) scores of -1 - drowsy and 0 - alert and calm were evaluated with the Delirium Rating Scale-Revised-1998 (DRS-R-98) and the Diagnostic and Statistical Manual 4th edition text revision (DSM-IV-TR)-determined diagnosis of delirium.

RESULTS

In total, 85 drowsy and 140 alert and calm patients were included. Crucial items for the correct identification of delirium were sleep-wake cycle disturbances, language abnormalities, thought process alterations, psychomotor retardation, disorientation, inattention, short- and long-term memory, as well as visuo-spatial impairment, and the temporal onset. Conversely, perceptual disturbances, delusions, affective lability, psychomotor agitation, or fluctuations were items, which identified delirium less correctly. Further, the severities of inattentiveness and visuo-spatial impairment were indicative of delirium in both alert- or calmness and drowsiness.

SIGNIFICANCE OF RESULTS

The impairment in the cognitive domain, psychomotor retardation, and sleep-wake cycle disturbances correctly identified delirium irrespective of the level alertness. Further, inattentiveness and - to a lesser degree - visuo-spatial impairment could represent a specific marker for delirium in the intensive care setting meriting further evaluation.

General Anesthesia Does Not Have Persistent Effects on Attention in Rodents

Background: Studies in animals have shown that general anesthesia can cause persistent spatial memory impairment, but the influence of anesthetics on other cognitive functions is unclear. This study tested whether exposure to general anesthesia without surgery caused a persistent deficit in attention in rodents.

Methods: To evaluate whether anesthesia has persistent effects on attention, rats were randomized to three groups. Group A was exposed for 2 h to isoflurane anesthesia, and tested the following seven days for attentional deficits. Group B was used as a control and received room air before attentional testing. Since there is some evidence that a subanesthetic dose of ketamine can improve cognition and reduce disorders of attention after surgery, rats in group C were exposed to isoflurane anesthesia in combination with a ketamine injection before cognitive assessment. Attention was measured in rats using the 5-Choice Serial Reaction Time Task, for which animals were trained to respond with a nose poke on a touchscreen to a brief, unpredictable visual stimulus in one of five possible grid locations to receive a food reward. Attention was analyzed as % accuracy, % omission, and premature responses.

Results: Evaluating acute attention by comparing baseline values with data from the day after intervention did not reveal any differences in attentional measurements. No significant differences were seen in % accuracy, % omission, and premature responses for the three groups tested for 7 consecutive days.

Conclusion: These data in healthy rodents suggest that general anesthesia without surgery has no persistent effect on attention and the addition of ketamine does not alter the outcome.

Motor activity across delirium motor subtypes in geriatric patients assessed using body-worn sensors: a Norwegian cross-sectional study

OBJECTIVES

It remains unclear if geriatric patients with different delirium motor subtypes express different levels of motor activity. Thus, we used two accelerometer-based devices to simultaneously measure upright activity and wrist activity across delirium motor subtypes in geriatric patients.

DESIGN

Cross-sectional study.

SETTINGS

Geriatric ward in a university hospital in Norway.

PARTICIPANTS

Sixty acutely admitted patients, ≥75 years, with DSM-5-delirium.

OUTCOME MEASURES

Upright activity measured as upright time (minutes) and sit-to-stand transitions (numbers), total wrist activity (counts) and wrist activity in a sedentary position (WAS, per cent of the sedentary time) during 24 hours ongoing Delirium Motor Subtype Scalesubtyped delirium.

RESULTS

Mean age was 86.7 years. 15 had hyperactive, 20 hypoactive, 17 mixed and 8 had no-subtype delirium. We found more upright time in the no-subtype group than in the hypoactive group (119.3 vs 37.8 min, p=0.042), but no differences between the hyperactive, the hypoactive and the mixed groups (79.1 vs 37.8 vs 50.1 min, all p>0.28). The no-subtype group had a higher number of transitions than the hypoactive (54.3 vs 17.4, p=0.005) and the mixed groups (54.3 vs 17.5, p=0.013). The hyperactive group had more total wrist activity than the hypoactive group (1.238×10⁴ vs 586×10⁴ counts, p=0.009). The hyperactive and the mixed groups had more WAS than the hypoactive group (20% vs 11%, p=0.032 and 19% vs 11%, p=0.049).

CONCLUSIONS

Geriatric patients with delirium demonstrated a low level of upright activity, with no differences between the hyperactive, hypoactive and mixed groups, possibly due to poor gait function. The hyperactive and mixed groups had more WAS than the hypoactive group, indicating true differences in motor activity across delirium motor subtypes, also in geriatric patients. Wrist activity appears more suitable than an upright activity for both diagnostic purposes and activity monitoring in geriatric delirium.

Refining Delirium: A Transtheoretical Model of Delirium Disorder with Preliminary Neurophysiologic Subtypes

The development of delirium indicates neurophysiologic disruption and predicts unfavorable outcomes. This relationship between delirium and its outcomes has inspired a generation of studies aimed at identifying, predicting, and preventing both delirium and its associated sequelae. Despite this, evidence on delirium prevention and management remains limited. No medication is approved for the prevention or treatment of delirium or for its associated psychiatric symptoms. This unmet need for effective delirium treatment calls for a refined approach. First, we explain why a one-size-fits-all approach based on a unitary biological model of delirium has contributed to variance in delirium studies and prevents further advance in the field. Next, in parallel with the shift from dementia to "major neurocognitive disorder," we propose a transtheoretical model of "delirium disorder" composed of interactive elements-precipitant, neurophysiology, delirium phenotype, and associated psychiatric symptoms. We explore how these relate both to the biopsychosocial factors that promote healthy cognition ("procognitive factors") and to consequent neuropathologic sequelae. Finally, we outline a preliminary delirium typology of specific neurophysiologic disturbances. Our model of delirium disorder offers several avenues for novel insights and clinical advance: it univocally differentiates delirium disorder from the phenotype of delirium, highlights delirium neurophysiology as a treatment target, separates the core features of delirium from associated psychiatric symptoms, suggests how procognitive factors influence the core elements of delirium disorder, and makes intuitive predictions about how delirium disorder leads to neuropathologic sequelae and cognitive impairment. Ultimately, this model opens several avenues for modern neuroscience to unravel this disease of antiquity.

Ability of suvorexant to prevent delirium in patients in the intensive care unit: a randomized controlled trial

Aim

There are no effective, tolerable, and established medications for preventing delirium in critically ill patients admitted to the intensive care unit (ICU). We investigated whether suvorexant was effective in preventing ICU delirium.

Methods

This randomized controlled study evaluated 70 adult patients (age ≥20 years) admitted to the mixed medical ICU of the Tokyo Medical University Hospital (Tokyo, Japan) between May 2015 and February 2017. Patients were randomized using a sealed envelope method to receive either suvorexant (n = 34; 15 mg for elderly patients and 20 mg for younger adults) or conventional treatment (n = 36) for a 7-day period. The primary outcome was delirium incidence based on the definition in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders.

Results

No significant between-group differences were observed in the demographic or clinical characteristics. Kaplan-Meier estimates revealed that time to delirium onset was significantly longer in the suvorexant group than in the conventional group (P < 0.05).

Conclusion

Suvorexant might be effective in preventing delirium in ICU patients.

Impact of psychotic symptoms on clinical outcomes in delirium

Delirium is an acute disturbance in attention and awareness in response to one or more physiological stressors that is closely related to poor clinical outcomes. The aim of this study is to investigate whether delirium patients with psychotic symptoms (PS) would have unique clinical characteristics and outcomes. A retrospective chart review was performed on the patients with delirium due to general medical conditions to assess clinical characteristics and outcomes. All patients were assessed by Delirium Rating Scale-revised-98 and classified as having PS when scored two or more on at least one of the psychotic symptom items (perceptual disturbances, delusions, and thought process abnormalities). Of 233 patients with delirium, 116 (49.8%) manifested PS. Patients with PS were younger, more likely to use antipsychotics to manage delirium, and had more hyperactive motor subtype than patients without PS. Logistic regression analysis showed that odds ratio of psychotic symptoms for having in-hospital mortality was 0.27 (95% CI = 0.08-0.94) after controlling age, sex, disease severity, comorbidity, number of medications, etiologies, motor subtypes, delirium severity and use of antipsychotics. The present study demonstrated that PS of delirium was associated with unique clinical characteristics and may affect the clinical course in a psychiatry-referral sample.

Underdiagnosis of delirium in the elderly in acute care hospital settings: lessons not learned

BACKGROUND

Delirium is a common and poorly diagnosed cause of behavioral change in elderly. This study aimed to estimate the prevalence, diagnostic accuracy and factors associated with the onset of delirium in the elderly admitted to an urgency unit.

METHODS

Cross-sectional study including clinically stable subjects aged ≥60 years between April and June of 2014. Diagnosis of delirium based on the Confusion Assessment Method (CAM, gold standard) was compared to the subjective assessment made by physicians on duty as recorded in the medical chart. Association of sociodemographic, psychological/behavioural, and clinical variables with delirium was assessed using multivariate analysis.

RESULTS

A sample of 110 participants with a mean age of 72.7 ± 8.3 years was studied. Of these, 56.4% were men and 28.2% had a diagnosis of delirium on CAM. Significant associations were observed between delirium and male gender (P-value = 0.019), poor or very poor self-perception of health (P-value = 0.033), previous diagnosis of dementia (P-value = 0.001), previous history of stroke (P-value = 0.014), and acute bacterial infection (P-value = 0.008). Physician diagnosis had a sensitivity of 35.5%, specificity of 100%, and accuracy of 81.8% to detect delirium. Rate of misdiagnosis was 64.5%.

CONCLUSION

Delirium was underdiagnosed in this urgent care hospital setting.

Melatonin and the Prevention and Management of Delirium: A Scoping Study

Background

The therapeutic benefit of melatonin in the prevention and treatment of delirium is uncertain.

Objective

To perform a scoping study to describe the existing literature regarding the use of melatonin and ramelteon in the prevention and treatment of delirium.

Methods

We performed a scoping study using the Arksey and O’Malley framework to explore our objective. Two independent panels searched MEDLINE, OVID, EMBASE, PubMed, Google Scholar, and Cochrane Library for relevant articles up to November 2017 describing the use of melatonin and ramelteon in the prevention or management of delirium. We extracted relevant summary data from the studies and attempted to draw conclusion regarding benefit.

Results

We summarized evidence from 20 relevant articles. There were a total of nine articles: five randomized controlled trials (RCTs), two retrospective medical record reviews, one non-randomized observational study, and one case report describing the role of either melatonin or ramelteon in preventing delirium. There were a total of 11 studies studying the role of either melatonin or ramelteon in the management of established delirium. None of these were RCT and were predominantly case series and case reports. Four of the five trials studying the effect of melatonin analogs in preventing delirium reported a beneficial effect but study heterogeneity limited any broad recommendations. Similarly, the lack of any well-designed trials limits any recommendations regarding the effect of melatonin analogs in treating delirium.

Conclusion

Large, well-designed clinical trials are required to explore the potential beneficial effects of melatonin and ramelteon on delirium prevention and management.

Delirium in the intensive care setting and the Richmond Agitation and Sedation Scale (RASS): Drowsiness increases the risk and is subthreshold for delirium

INTRODUCTION

Sedation is a core concept in the intensive care setting, however, the impact of sedation on delirium has not yet been studied to date.

METHODS

In this prospective cohort study, 225 patients with Richmond Agitation and Sedation (RASS) scores of -1 - drowsiness and 0 - alert- and calmness were assessed with the Delirium Rating Scale-Revised 1998 (DRS-R-98) and DSM-IV-TR-determined diagnosis of delirium assessing drowsiness versus alertness.

RESULTS

By itself, drowsiness increased the odds for developing delirium eightfold (OR 7.88 p<0.001) and rates of delirium were 68.2 and 21.4%, respectively. Further, in the drowsy patient, delirium was more severe. In the presence of drowsiness, delirium was characterized by sleep-wake cycle disturbances and language abnormalities. These two features, in addition to psychomotor retardation, allowed the correct classification of delirium at RASS-1. The same features, in addition to thought abnormalities and the impairment in the cognitive domain, orientation, attention, short- and long-term memory representing the core domains of delirium, or the temporal onset were very sensitive towards delirium, however lacked specificity. Conversely, delusions, perceptual abnormalities and lability of affect representing the non-core domain were very specific for delirium in the drowsy, however, not very sensitive. In the absence of delirium, drowsiness caused attentional impairment and language abnormalities.

CONCLUSION

Drowsiness increased the odds for developing delirium eightfold and caused more severe delirium, which was characterized by sleep-wake cycle and language abnormalities. Further, drowsiness by itself caused attentional impairment and language abnormalities, thus, with its disturbance in consciousness was subthreshold for delirium.

Detecting delirium in elderly outpatients with cognitive impairment

BACKGROUND

Delirium may be more prevalent in elderly outpatients than has long been assumed. However, it may be easily missed due to overlap with dementia. Our aim was to study delirium symptoms and underlying somatic disorders in psycho-geriatric outpatients.

METHODS

We performed a case-control study among outpatients that were referred to a psychiatric institution between January 1st and July 1st 2010 for cognitive evaluation. We compared 44 cases with DSM-IV delirium (24 with and 20 without dementia) to 44 controls with dementia only. All participants were aged 70 years or older. We extracted from the medical files (1) referral characteristics including demographics, medical history, medication use, and referral reasons, (2) delirium symptoms, scored with the Delirium Rating Scale-Revised-98, and (3) underlying disorders categorized as: drugs/intoxication, infection, metabolic/endocrine disturbances, cardiovascular disorders, central nervous system disorders, and other health problems.

RESULTS

At referral, delirium patients had significantly higher numbers of chronic diseases and medications, and more often a history of delirium and a recent hospital admission than controls. Most study participants, including those with delirium, were referred for evaluation of (suspected) dementia. The symptoms that occurred more frequently in cases were: sleep disturbances, perceptual abnormalities, delusions, affect lability, agitation, attention deficits, acute onset, and fluctuations. Drug related (68%), infectious (61%), and metabolic-endocrine (50%) disturbances were often involved.

CONCLUSIONS

Detection of delirium and distinction from dementia in older outpatients was feasible but required detailed caregiver information about the presence, onset, and course of symptoms. Most underlying disorders could be managed at home.

Mum's absence(s): conceptual insights into absence as loss during a loved one's delirium

AIMS AND OBJECTIVES

To examine qualitative research findings about family experiences of absence or loss during older person delirium, and provide a critical discussion of the similarities and differences in these experiences with conceptual understandings of absence and loss.

BACKGROUND

Families who care for older people with chronic illnesses experience many losses. However, the nondeath loss experiences of family during an older loved one's delirium, an acute condition accompanied by marked changes in demeanour, have received little consideration.

DESIGN

Discursive position paper.

METHODS

The findings from two qualitative research studies about family experiences during an older loved one's delirium are discussed in relation to the concepts of absence and nondeath loss.

RESULTS

The uncharacteristic behaviours and cognitive changes that accompany delirium may estrange family who, despite the older person's corporeal presence, sense the profound absence or loss of their loved one. Although the notion of absence, a nondeath loss, is similar to the experiences of family of people with chronic conditions, there are differences that distinguish these encounters. The similarities and differences between absence during delirium and the concepts of psychological absence, nonfinite loss and psychosocial death are discussed. Psychosocial death, reversibility/irreversibility and partial marked change, are suggested as conceptual descriptions for the absence families experience during an older loved one's delirium.

CONCLUSIONS

The sense of absence or loss that family may experience during their older loved one's delirium needs to be recognised, understood and addressed by healthcare staff. Understanding or appreciating conceptualisations of absence, as a nondeath loss, may enhance understandings of family member needs during delirium and enable better support strategies.

RELEVANCE TO CLINICAL PRACTICE

Conceptualisations of absence enhance understandings of family distress and needs during their older loved one's delirium. The potential for family members to experience their loved one's absence during delirium, a nondeath loss, needs to be considered by healthcare staff. Family experiences of absence during delirium need to be recognised by healthcare staff, acknowledged as a potential source of distress, and considered when involving family in the older person's care. Nurses are ideally placed to respond compassionately and provide appropriate family member re-assurance, support and information during delirium. Information should include possible impacts on family and coping strategies.

Incidence, risk factors, and phenomenological characteristics of postoperative delirium in patients receiving intravenous patient-controlled analgesia: a prospective cohort study

BACKGROUND

Intravenous patient-controlled analgesia (IVPCA) is a common method of relieving pain which is a risk factor of postoperative delirium (POD). However, research concerning POD in IVPCA patients is limited.

OBJECTIVE

We aimed to determine the incidence, risk factors, and phenomenological characteristics of POD in patients receiving IVPCA.

METHODS

A prospective, cohort study was conducted in post-general anesthesia IVPCA patients aged ≥60 years. POD was measured by the Nursing Delirium Screening Scale (NuDESC; 0-10). Delirium, pain severity at rest and/or on movement, and side effects of IVPCA during 3 postoperative days were examined twice-daily by the acute pain service team. Pain severity is measured by an 11-point verbal numerical rating scale (11-point VNRS) (0-10). An 11-point VNRS >3 was considered inadequate pain relief. If POD (detected by NuDESC ≥1) is suspected, consulting a neurologist or a psychiatrist to confirm suspected POD is required.

RESULTS

In total, 1,608 patients were included. The incidence rate of POD was 2.2%. Age ≥70 years and American Society of Anesthesiologists physical status >III were the risk factors of POD in IVPCA patients. Approximately three-quarters of all POD cases occurred within the first 2 postoperative days. For pain at rest, patients with inadequate pain relief had significantly greater rates of POD than patients with adequate pain relief (day 1, 8.4% vs 1.5%, P<0.001; day 2, 9.6% vs 2.0%, P=0.028; day 3, 4.1% vs 2.1%, P=0.412). However, the incidence of POD was not associated with movement-evoked pain relief. Most (79.9%) POD cases in IVPCA patients showed either one or two symptoms. The symptoms of POD were ranked from high to low as disorientation (65.7%), illusions/hallucinations (37.1%), inappropriate communication (31.4%), inappropriate behavior (25.7%), and psychomotor retardation (14.2%).

CONCLUSION

The incidence rate of POD in IVPCA patients was low. Further research is warranted concerning POD and IVPCA pain management.

Under-detection of delirium and impact of neurocognitive deficits on in-hospital mortality among acute geriatric and medical wards

BACKGROUND

Delirium is a neuropsychiatric disorder, triggered by medical precipitants causes. Study aims were to describe the prevalence and impact on in-hospital mortality of delirium identified through ICD-9 codes as well as evidence of neurocognitive deficits demonstrated in a population of older patients admitted to acute medical wards.

METHODS

This was a prospective cohort multicenter study of 2521 older patients enrolled in the "Registro Politerapie SIMI (REPOSI)" during the years 2010 and 2012. The diagnosis of delirium was obtained by ICD-9 codes. Cognitive function was evaluated with the Short Blessed Test (SBT) and single SBT items were used as measures of deficits in attention, orientation and memory. Combination of deficits in SBT items was used as a proxy for delirium. Logistic regression was used to evaluate the association with in-hospital mortality of delirium and combined deficits in SBT items.

RESULTS

Delirium was coded in 2.9%, while deficits in attention, orientation, and memory were found in 35.4%, 29.7% and 77.5% of patients. Inattention and either disorientation or memory deficits were found in 14.1%, while combination of the 3 deficits in 19.8%. Delirium, as per ICD-9 codes, was not a predictor of in-hospital mortality. In contrast, objective deficits of inattention, in combination with orientation and memory disorders, were stronger predictors after adjusting for covariates.

CONCLUSIONS

The documentation of delirium is poor in medical wards of Italian acute hospitals. Neurocognitive deficits on objective testing (in a pattern suggestive of undiagnosed delirium) should be used to raise awareness of delirium, given their association with in-hospital mortality.

[Delirium: a common complication of severe pathological conditions]

Delirium is a complex syndrome caused most often by secondary neuronal dysfuncions due to systemic disorders. Because of the central nervous system manifestations of the general disease processes that are getting through the blood-brain barrier, the vigilance of attention flucutates and, therefore, the integration of incoming stimuli fails - resulting in inadequate behavioral answers. Delirium is one of the most common and serious complications of diseases, particularly in the elderly and patients in critical state. It cannot be traced back to a single etiologic process; one should consider all those pathophysiologic mechanisms that are interacting with one another simultaneously impairing the integrated functioning of the brain. Despite the high prevalence rate of delirium and the marked adverse effects on the outcome of the underlying disorders, management and therapy are basically lacking professional guidelines. The syndrome is a threatening state, requiring increased clinical attention and often intensive care. Beside evidence based therapeutic methods, conscious, targeted screening of the known risk factors and measures against them when they present themselves may exert remarkable influence on the prevention of delirium, which is also an exceptionally important aspect of the care of patients in critical state.

Management of delirium in palliative care: a review

Delirium is a complex but common disorder in palliative care with a prevalence between 13 and 88 % but a particular frequency at the end of life (terminal delirium). By reviewing the most relevant studies (MEDLINE, EMBASE, PsycLit, PsycInfo, Cochrane Library), a correct assessment to make the diagnosis (e.g., DSM-5, delirium assessment tools), the identification of the possible etiological factors, and the application of multicomponent and integrated interventions were reported as the correct steps to effectively manage delirium in palliative care. In terms of medications, both conventional (e.g., haloperidol) and atypical antipsychotics (e.g., olanzapine, risperidone, quetiapine, aripiprazole) were shown to be equally effective in the treatment of delirium. No recommendation was possible in palliative care regarding the use of other drugs (e.g., α-2 receptors agonists, psychostimulants, cholinesterase inhibitors, melatonergic drugs). Non-pharmacological interventions (e.g., behavioral and educational) were also shown to be important in the management of delirium. More research is necessary to clarify how to more thoroughly manage delirium in palliative care.

Delirium and dementia with Lewy bodies: distinct diagnoses or part of the same spectrum?

Dementia with Lewy bodies (DLB) is recognised as the second most common form of dementia in older people. Delirium is a condition of acute brain dysfunction for which a pre-existing diagnosis of dementia is a risk factor. Conversely delirium is associated with an increased risk of developing dementia. The reasons for this bidirectional relationship are not well understood. Our aim was to review possible similarities in the clinical presentation and pathophysiology between delirium and DLB, and explore possible links between these diagnoses. A systematic search using Medline, Embase and Psychinfo was performed. References were scanned for relevant articles, supplemented by articles identified from reference lists and those known to the authors. 94 articles were selected for inclusion in the review. Delirium and DLB share a number of clinical similarities, including global impairment of cognition, fluctuations in attention and perceptual abnormalities. Delirium is a frequent presenting feature of DLB. In terms of pathophysiological mechanisms, cholinergic dysfunction and genetics may provide a common link. Neuroimaging studies suggest a brain vulnerability in delirium which may also occur in dementia. The basal ganglia, which play a key role in DLB, have also been implicated in delirium. The role of Cerebrospinal fluid (CSF) and serum biomarkers for both diagnoses is an interesting area although some results are conflicting and further work in this area is needed. Delirium and DLB share a number of features and we hypothesise that delirium may, in some cases, represent early or 'prodromal' DLB. Further research is needed to test the novel hypothesis that delirium may be an early marker for future DLB, which would aid early diagnosis of DLB and identify those at high risk.

Ramelteon for the treatment of delirium in elderly patients: a consecutive case series study

OBJECTIVE

Melatonin is effective in the prevention and treatment of delirium. Ramelteon has few adverse effects and higher affinity for MT1 and MT2 receptors than melatonin. The aim of the present study was to determine the efficacy of ramelteon in elderly patients with delirium caused by different primary diseases/conditions.

METHOD

We treated 10 consecutive elderly patients having delirium with ramelteon.

RESULTS

Of the 10 patients, six showed improvement, and no marked adverse effects were observed.

CONCLUSIONS

Our study suggested that ramelteon was a safe and useful alternative to melatonin for the treatment of delirium in elderly patients. Randomized, controlled studies are necessary to confirm the therapeutic benefits of ramelteon.

Delirium and depression: inter-relationship and clinical overlap in elderly people

Delirium and depression are complex neuropsychiatric syndromes common in the elderly and are associated with poor health-care outcomes. Accurate diagnosis is essential to the provision of optimum health care for individuals with these conditions but is complicated by substantial clinical overlap in symptoms and comorbidities. A careful assessment of the patient's symptoms, including their context and time course, is needed for accurate diagnosis. Previous depression is common in patients with delirium and depressive illness is a recognised sequelae of delirium. The two syndromes seem to be caused by similar pathophysiological mechanisms, involving disturbances in stress and inflammatory responses, monoaminergic and melatonergic signalling, which point to new avenues for therapeutic intervention. Improved methods to assess delirium and depression in populations at high risk by virtue of their age, diminished cognitive reserve and physical frailty is a key target to achieve improved health-care outcomes in elderly individuals.

Deathbed wills: assessing testamentary capacity in the dying patient

BACKGROUND

Deathbed wills by their nature are susceptible to challenge. Clinicians are frequently invited to give expert opinion about a dying testator's testamentary capacity and/or vulnerability to undue influence either contemporaneously, when the will is made, or retrospectively upon a subsequent challenge, yet there is minimal discourse in this area to assist practice.

METHODS

The IPA Capacity Taskforce explored the issue of deathbed wills to provide clinicians with an approach to the assessment of testamentary capacity at the end of life. A systematic review searching PubMed and Medline using the terms: "deathbed and wills," "deathbed and testamentary capacity," and "dying and testamentary capacity" yielded one English-language paper. A search of the individual terms "testamentary capacity" and "deathbed" yielded one additional relevant paper. A focused selective review was conducted using these papers and related terms such as "delirium and palliative care." We present two cases to illustrate the key issues here.

RESULTS

Dying testators are vulnerable to delirium and other physical and psychological comorbidities. Delirium, highly prevalent amongst terminal patients and manifesting as either a hyperactive or hypoactive state, is commonly missed and poorly documented. Whether the person has testamentary capacity depends on whether they satisfy the Banks v Goodfellow legal criteria and whether they are free from undue influence. Regardless of the clinical diagnosis, the ultimate question is can the testator execute a specific will with due consideration to its complexity and the person's circumstances?

CONCLUSIONS

Dual ethical principles of promoting autonomy of older people with mental disorders whilst protecting them against abuse and exploitation are at stake here. To date, there has been scant discourse in the scientific literature regarding this issue.

What do we really know about the treatment of delirium with antipsychotics? Ten key issues for delirium pharmacotherapy

Despite the significant burden of delirium among hospitalized adults, no pharmacologic intervention is approved for delirium treatment. Antipsychotic agents are the best studied but there are uncertainties as to how these agents can be optimally applied in everyday practice. We searched Medline and PubMed databases for publications from 1980 to April 2012 to identify studies of delirium treatment with antipsychotic agents. Studies of primary prevention using pharmacotherapy were not included. We identified 28 prospective studies that met our inclusion criteria, of which 15 were comparison studies (11 randomized), 2 of which were placebo-controlled. The quality of comparison studies was assessed using the Jadad scale. The DRS (N = 12) and DRS-R98 (N = 9) were the most commonly used instruments for measuring responsiveness. These studies suggest that around 75% of delirious patients who receive short-term treatment with low-dose antipsychotics experience clinical response. Response rates appear quite consistent across different patient groups and treatment settings. Studies do not suggest significant differences in efficacy for haloperidol versus atypical agents, but report higher rates of extrapyramidal side effects with haloperidol. Comorbid dementia may be associated with reduced response rates but this requires further study. The available evidence does not indicate major differences in response rates between clinical subtypes of delirium. The extent to which therapeutic effects can be explained by alleviation of specific symptoms (e.g. sleep or behavioral disturbances) versus a syndromal effect that encompasses both cognitive and noncognitive symptoms of delirium is not known. Future research needs to explore the relationship between therapeutic effects and changes in pathophysiological markers of delirium. Less than half of reports were rated as reasonable quality evidence on the Jadad scale, highlighting the need for future studies of better quality design, and in particular incorporating placebo-controlled work.

Efficacy and safety of haloperidol versus atypical antipsychotic medications in the treatment of delirium

BACKGROUND

Most previous studies on the efficacy of antipsychotic medication for the treatment of delirium have reported that there is no significant difference between typical and atypical antipsychotic medications. It is known, however, that older age might be a predictor of poor response to antipsychotics in the treatment of delirium. The objective of this study was to compare the efficacy and safety of haloperidol versus three atypical antipsychotic medications (risperidone, olanzapine, and quetiapine) for the treatment of delirium with consideration of patient age.

METHODS

This study was a 6-day, prospective, comparative clinical observational study of haloperidol versus atypical antipsychotic medications (risperidone, olanzapine, and quetiapine) in patients with delirium at a tertiary level hospital. The subjects were referred to the consultation-liaison psychiatric service for management of delirium and were screened before enrollment in this study. A total of 80 subjects were assigned to receive either haloperidol (N = 23), risperidone (N = 21), olanzapine (N = 18), or quetiapine (N = 18). The efficacy was evaluated using the Korean version of the Delirium Rating Scale-Revised-98 (DRS-K) and the Korean version of the Mini Mental Status Examination (K-MMSE). The safety was evaluated by the Udvalg Kliniske Undersogelser side effect rating scale.

RESULTS

There were no significant differences in mean DRS-K severity or K-MMSE scores among the four groups at baseline. In all groups, the DRS-K severity score decreased and the K-MMSE score increased significantly over the study period. However, there were no significant differences in the improvement of DRS-K or K-MMSE scores among the four groups. Similarly, cognitive and non-cognitive subscale DRS-K scores decreased regardless of the treatment group. The treatment response rate was lower in patients over 75 years old than in patients under 75 years old. Particularly, the response rate to olanzapine was poorer in the older age group. Fifteen subjects experienced a few adverse events, but there were no significant differences in adverse event profiles among the four groups.

CONCLUSIONS

Haloperidol, risperidone, olanzapine, and quetiapine were equally efficacious and safe in the treatment of delirium. However, age is a factor that needs to be considered when making a choice of antipsychotic medication for the treatment of delirium.

TRIAL REGISTRATION

Clinical Research Information Service, Republic of Korea, (http://cris.nih.go.kr/cris/en/search/basic_search.jsp, Registered Trial No. KCT0000632).

Delirium: a disturbance of circadian integrity?

Delirium is a serious neuropsychiatric syndrome of acute onset that occurs in approximately one in five general hospital patients and is associated with serious adverse outcomes that include loss of adaptive function, persistent cognitive problems and increased mortality. Recent studies indicate a three-domain model for delirium that includes generalised cognitive impairment, disturbed executive cognition, and disruption of behaviours that are under circadian control such as sleep-wake cycle and motor activity levels. As a consequence, attention has focused upon the possible role of the circadian timing system (CTS) in the pathophysiology of delirium. We explored this possibility by reviewing evidence that (1) many symptoms that occur in delirium are influenced by circadian rhythms, (2) many features of recognised circadian rhythm disorders are similar to characteristic features of delirium, (3) common risk factors for delirium are known to disrupt circadian systems, (4) physiological disturbances of circadian systems have been noted in delirious patients, and (5) positive effects in the treatment of delirium have been demonstrated for melatonin and related agents that influence the circadian timing system. A programme of future studies that can help to clarify the relevance of circadian integrity to delirium is described. Such work can provide a better understanding of the pathophysiology of delirium while also identifying opportunities for more targeted therapeutic efforts.

Reliability of delirium rating scale (DRS) and delirium rating scale-revised-98 (DRS-R98) using variance-based multivariate modelling

Delirium's characteristic fluctuation in symptom severity complicates the assessment of test-retest reliability of scales using classical analyses, but application of modelling to longitudinal data offers a new approach. We evaluated test-retest reliability of the delirium rating scale (DRS) and delirium rating scale-revised-98 (DRS-R98), two widely used instruments with high validity and inter-rater reliability. Two existing longitudinal datasets for each scale included DSM-IV criteria for delirium diagnosis and repeated measurements using the DRS or DRS-R98. To estimate the reliability coefficients RT and RΛ for each scale we used a macros provided by Dr. Laenen at http://www.ibiostat.be/software/measurement.asp. For each dataset a linear mixed-effects model was fitted to estimate the variance-covariance parameters. A total of 531 cases with between 4 and 9 measurement points across studies including both delirious and non-delirious patients. Comorbid dementia in the datasets varied from 27% to 55%. Overall RT for the DRS were 0.71 and 0.50 and for DRS-R98 0.75 and 0.84. RΛ values for DRS were 0.99 and 0.98 and for DRS-R98 were 0.92 and 0.96. Individual RT measures for DRS-R98 and DRS across visits within studies showed more range than overall values. Our models found high overall reliability for both scales. Multiple factors impact a scale's reliability values including sample size, repeated measurements, patient population, etc in addition to rater variability.

Delirium after cardiac surgery: have we overlooked obstructive sleep apnea?

Obstructive sleep apnea is common in patients with cardiovascular disease. It is well known that cardiac surgery is a risk factor for delirium. Researchers have shown that obstructive sleep apnea is an independent risk factor for the occurrence of delirium. In this manuscript we speculate on how obstructive sleep apnea may increase the risk of delirium in patients with cardiac surgery. If this is found to be confirmed, we would have another target through which we can decrease the risk of delirium in this population.

Obstructive sleep apnea and delirium: exploring possible mechanisms

INTRODUCTION

Obstructive sleep apnea (OSA) is a medical disorder strongly associated with multiple comorbidities and postoperative complications. Current evidence suggests that OSA disturbs fundamental biochemical processes, leading to low-grade systemic inflammation and oxidative stress. Animal models have shown that OSA may lead to apoptosis of central neurons. In clinical studies, oxygen desaturation index and sleep fragmentation have been shown to be independently associated with cognitive dysfunction. Moreover, in several studies, patients with OSA were shown to have decreased brain activation in multiple brain areas.

OSA AND DELIRIUM

The possibility of an association between OSA and delirium has been highlighted in several case reports. The first prospective study of the possible link between apnea and delirium showed that the presence of OSA was independently associated with the occurrence of delirium after knee replacement surgery.

CONCLUSIONS

Therefore, we suggest that OSA should be considered as a risk factor for delirium, and clinicians should assess patients for OSA and related risk factors prior to surgery. However, further research is required to shed light on the mechanisms connecting these disorders and on whether the treatment of OSA affects the incidence of delirium.

Relationship between cognitive and non-cognitive symptoms of delirium

AIM

To study relationship between the cognitive and the non-cognitive symptoms of delirium.

METHODS

Eighty-four patients referred to psychiatry liaison services and met DSM-IVTR criteria of delirium were assessed using the Delirium Rating Scale Revised-1998 (DRSR-98) and Cognitive Test for Delirium (CTD).

RESULTS

The mean DRS-R-98 severity score was 17.19 and DRS-R-98 total score was 23.36. The mean total score on CTD was 11.75. The mean scores on CTD were highest for comprehension (3.47) and lowest for vigilance (1.71). Poor attention was associated with significantly higher motor retardation and higher DRS-R-98 severity scores minus the attention scores. There were no significant differences between those with and without poor attention. Higher attention deficits were associated with higher dysfunction on all other domains of cognition on CTD. There was significant correlation between cognitive functions as assessed on CTD and total DRS-R-98 score, DRS-R-98 severity score and DRS-R-98 severity score without the attention item score. However, few correlations emerged between CTD domains and CTD total scores with cognitive symptom total score of DRS-R-98 (items 9-13) and non-cognitive symptom total score of DRS-R-98 (items 1-8).

CONCLUSIONS

Our study suggests that in delirium, cognitive deficits are quite prevalent and correlate with overall severity of delirium. Attention deficit is a core symptom of delirium.

Predicting delirium duration in elderly hip-surgery patients: does early symptom profile matter?

Background. Features that may allow early identification of patients at risk of prolonged delirium, and therefore of poorer outcomes, are not well understood. The aim of this study was to determine if preoperative delirium risk factors and delirium symptoms (at onset and clinical symptomatology during the course of delirium) are associated with delirium duration. Methods. This study was conducted in prospectively identified cases of incident delirium. We compared patients experiencing delirium of short duration (1 or 2 days) with patients who had more prolonged delirium (≥3 days) with regard to DRS-R-98 (Delirium Rating Scale Revised-98) symptoms on the first delirious day. Delirium symptom profile was evaluated daily during the delirium course. Results. In a homogenous population of 51 elderly hip-surgery patients, we found that the severity of individual delirium symptoms on the first day of delirium was not associated with duration of delirium. Preexisting cognitive decline was associated with prolonged delirium. Longitudinal analysis using the generalised estimating equations method (GEE) identified that more severe impairment of long-term memory across the whole delirium episode was associated with longer duration of delirium. Conclusion. Preexisting cognitive decline rather than severity of individual delirium symptoms at onset is strongly associated with delirium duration.

Delirium-related distress in caregivers: a study from a tertiary care centre in India

PURPOSE

To study the caregiver's distress with symptoms of delirium.

DESIGN AND METHODS

Consenting adult caregivers (>18 years of age) of patients with delirium were evaluated for the distress due to symptoms of delirium.

RESULTS

The study included 72 primary caregivers of patients with delirium. Symptoms of delirium that led to severe or very severe distress in more than two thirds of the caregivers included decreased sleep, increased motor activity, attempts to remove intravenous lines, tubings, etc., and attempts to get out of bed when they were actually required to lie down.

CONCLUSIONS

Overall experience of delirium was very distressing for the caregivers.

Identifying indicators of important diagnostic features of delirium

OBJECTIVES

To use an expert consensus process to identify indicators of delirium features to help enhance bedside recognition of delirium.

DESIGN

Modified Delphi consensus process to assign existing cognitive and delirium assessment items to delirium features in the Confusion Assessment Method (CAM) diagnostic algorithm.

SETTING

Meetings of expert panel.

PARTICIPANTS

Panel of seven interdisciplinary clinical experts.

MEASUREMENTS

Panelists' assignments of each assessment item to indicate CAM features.

RESULTS

From an initial pool of 119 assessment items, the panel assigned 66 items to at least one CAM feature, and many items were assigned to more than one feature. Experts achieved a high level of consensus, with a postmeeting kappa for agreement of 0.98. The study staff compiled the assignment results to create a comprehensive list of CAM feature indicators, consisting of 107 patient interview questions, cognitive tasks, and interviewer observations, with some items assigned to multiple features. A subpanel shortened this list to 28 indicators of important delirium features.

CONCLUSION

A systematic, well-described qualitative methodology was used to create a list of indicators for delirium based on the features of the CAM diagnostic algorithm. This indicator list may be useful as a clinical tool for enhancing delirium recognition at the bedside and for aiding in the development of a brief delirium screening instrument.

Comprehensive approaches to managing delirium in patients with advanced cancer

Delirium is a frequently under-recognized complication in patients with advanced cancer. Uncontrolled delirium eventually leads to significant distress to patients and their families. However, delirium episodes can be reversed in half of these patients by eliminating precipitating factors and using appropriate interventions. The purpose of this narrative review is to discuss the most recent updates in the literature on the management of delirium in patients with advanced cancer. This article addresses the epidemiology, cause, pathophysiology, clinical characteristics, and assessment of delirium as well as various treatment options, including nonpharmacologic intervention and palliative sedation.

A longitudinal study of motor subtypes in delirium: frequency and stability during episodes

OBJECTIVE

Motor-defined subtypes are a promising means of identifying clinically relevant patient subgroups but little is known about their course and stability during a delirium episode.

METHODS

We assessed 100 consecutive adult palliative care patients with DSM-IV delirium twice weekly during their episodes using the Delirium Motor Subtype Scale (DMSS), Delirium Rating Scale-Revised-98 (DRS-R98) and Cognitive Test for Delirium (CTD). DMSS subtypes were assigned for each assessment and analysed for stability within patients during episodes.

RESULTS

Across all assessments (n=303; mean 3 per patient, range 2-9), subtype occurrence was hypoactive (35%), mixed (26%), hyperactive (15%) and no subtype (24%). "No subtype" was associated with significantly lower DRS-R98 severity scores, of which 80% were subsyndromal, whereas mixed subtype assessments were the most impaired on the DRS-R98 and CTD. Subtypes were stable within delirium episodes in 62% of patients: 29% hypoactive, 18% mixed, 10% hyperactive and 6% no-subtype. The DRS-R98 noncognitive subscale scores differed across groups whereas cognitive subscale scores did not (p<0.001).

CONCLUSIONS

We conclude that motor subtypes occur in nearly all patients with full syndromal delirium and are often stable during an episode. Subtypes exhibited comparable levels of cognitive impairment but differed in non-cognitive symptoms, supporting the importance of cognitive testing to detect delirium in less overt cases.

Features of subsyndromal and persistent delirium

BACKGROUND

Longitudinal studies of delirium phenomenology are lacking.

AIMS

We studied features that characterise subsyndromal delirium and persistent delirium over time.

METHOD

Twice-weekly evaluations of 100 adults with DSM-IV delirium using the Delirium Rating Scale-Revised-98 (DRS-R98) and Cognitive Test for Delirium (CTD). The generalised estimating equation method identified symptom patterns distinguishing full syndromal from subsyndromal delirium and resolving from persistent delirium.

RESULTS

Participants (mean age 70.2 years (s.d. = 10.5)) underwent 323 assessments (range 2-9). Full syndromal delirium was significantly more severe than subsyndromal delirium for DRS-R98 thought process abnormalities, delusions, hallucinations, agitation, retardation, orientation, attention, and short- and long-term memory items, and CTD attention, vigilance, orientation and memory. Persistent full syndromal delirium had greater disturbance of DRS-R98 thought process abnormalities, delusions, agitation, orientation, attention, and short- and long-term memory items, and CTD attention, vigilance and orientation.

CONCLUSIONS

Full syndromal delirium differs from subsyndromal delirium over time by greater severity of many cognitive and non-cognitive symptoms. Persistent delirium involves increasing prominence of recognised core diagnostic features and cognitive impairment.