Relationship between cognitive and non-cognitive symptoms of delirium

Delirium in a surgical context from a nursing perspective: A hybrid concept analysis

Background

The term delirium has been defined in medical diagnosis criteria as a multidimensional disorder, and the term acute confusion is included in nursing classifications. Delirium can be a serious complication assessed in a patient after a surgical procedure. Still, the patient's delirium frequently remains unrecognised. Care of patients with delirium after surgical procedure is complex, and it challenges nursing expertise. From the nurses' viewpoint, delirium is associated with ambiguity of concepts and lack of knowledge. Therefore, reseach on how nurses perceive patients with delirium in a surgical context is needed.

Objective

The aim of this study was to describe the concepts of delirium and acute confusion, as well as the associated dimensions, in adult patients in a surgical context from the nursing perspective.

Design

The study used Schwartz and Barcott's hybrid concept analysis with theoretical, fieldwork, and final analytical phases.

Settings

Surgical wards, surgical intensive care units, and post-anaesthesia care units.

Data sources

A systematic literature search was performed through Pubmed (Medline), Cinahl, PsycInfo, and Embase.

Participants

Registered nurses and licensed practical nurses (n = 105) participated in the fieldwork phase.

Methods

In the theoretical phase, the concepts' working definitions were formulated based on a systematic literature search with the year limitations from 2000 until February 2021. At the fieldwork phase, the nurses' descriptions of patients with delirium were analysed using the deductive content analysis method. At the final analytical phase, findings were combined and reported.

Results

The concepts of delirium, subsyndromal delirium, and acute confusion are well defined in the literature. From the perspective of the nurses in the study, concepts were seen as a continuum not as individual diagnoses. Nurses described the continuum of delirium as a process with acute onset, duration, and recovery with the associated dimensions of symptoms, symptom severity, risk factors, and early signs. The acute phase of delirium was emphasised, and preoperative or prolonged disturbance did not seem to be relevant in the surgical care context. Patients' compliance with care may be decreased with the continuum of delirium, which might challenge both patients' recovery from surgery and the quality of nursing care.

Conclusions

In clinical practice the nurses used term confusion inaccurately. The term acute confusion might be used when illustrating an early stage of delirium. Nurses could benefit from further education where the theoretical knowledge is combined with the clinical practice. The discussion about the delirium, which covers the time both before surgery and after the acute phase should be increased.

Delirium Research in India: A Systematic Review

Delirium is the most common psychiatric diagnoses encountered in patients with various medical-surgical illnesses, in all the treatment set-ups, with relatively higher incidence and prevalence in the intensive care units. As delirium is encountered in multiple specialties, it is important to understand the research on this diagnosis. This study aims to assess the research output involving patients of delirium from India. A comprehensive search was undertaken using Medline (PubMed) and other databases. Search words included were “delirium,” “delirious,” “delirium tremens” AND “India.” No filters were used. Internet and hand searches yielded 305 articles. Out of these articles, 151 had the terms “delirium,” “delirious,” “delirium tremens” in the title and these were included for the review. Additionally, 14 articles were included for the review, although these did not have these terms in the title, but delirium was one of the major outcome parameters in these studies. Majority of the papers were original articles ( n = 81), and these were followed by, case reports ( n = 58), review articles ( n = 10), letter to the editor (not as case reports but as a communication; n = 13), editorials ( n = 2) and one clinical practice guideline. Most of the original papers have either focused on epidemiology (incidence, prevalence, outcome, etc.), symptom profile, with occasional studies focusing on effectiveness of various pharmacological interventions. There is a dearth of research in the field of delirium from India. There is a lack of studies on biomarkers, evaluation of nonpharmacological interventions, and evaluation of prevention strategies. It is the need of the hour to carry out more studies to further our understanding of delirium in the Indian context.

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.

The neuropsychology of delirium: advancing the science of delirium assessment

OBJECTIVE

The diagnosis of delirium depends on eliciting its features through mental status examination and informant history. However, there is marked heterogeneity in how these features are assessed, from binary subjective clinical judgement to more comprehensive methods supported by cognitive testing. The aim of this article is to review the neuropsychological research in delirium and suggest future directions in research and clinical practice.

METHODS

We reviewed the neuropsychological literature on formal assessment and quantification of the different domains in delirium, focusing on the core feature of inattention.

RESULTS

Few studies have characterised and quantified the features of delirium using objective methods commonly employed in neuropsychological research. The existing evidence confirms that patients with delirium usually show impairments on objective tests of attention compared with cognitively intact controls and, in most cases, compared with patients with dementia. Further, abnormal level of arousal appears to be a specific indicator of delirium. The neuropsychological evidence base for impairments in other cognitive domains in delirium, including visual perception, language and thought processes, is small.

CONCLUSIONS

Delirium diagnosis requires accurate testing for its features, but there is little neuropsychological research examining the nature of these features, or evaluating the reliability, validity and discriminatory power of existing assessment processes. More research using the neuropsychological approach has enormous potential to improve and standardise delirium assessment methods of the individual features of delirium, such as inattention, and in developing more robust reference standards to enable greater comparability between studies.

Delirium clinical motor subtypes: a narrative review of the literature and insights from neurobiology

INTRODUCTION

Clinical motor subtypes have been long recognised in delirium and, despite a growing body of research, a lack of clarity exists regarding the importance of these motor subtypes. The aims of this review are to (1) examine how the concept of motor subtypes has evolved, (2) explore their relationship to the clinical context, (3) discuss the relationship between the phenomenology of delirium and motor activity, (4) discuss the application of neurobiology to the theory of delirium motor subtypes, and (5) identify methodological issues and provide solutions for further studies.

METHODS

The following databases were searched: PubMed, PsychInfo, EBSCO, Medline, BioMed central and Science Direct. Inclusion criteria specified peer-reviewed research assessing delirium motor subtypes published between 1990 and 2016.

RESULTS

Sixty-one studies met the inclusion criteria. The majority of studies (n = 50) were found to use validated psychometric tools, while the remainder (n = 11) used clinical criteria. The majority of studies (n = 45) were conducted in the medical setting, while the remainder were in the ICU/post-operative setting (n = 17).

CONCLUSION

Although host sensitivities (e.g. frailty) and exogenous factors (e.g. medication exposure) may determine the type of motor disturbance, it remains unclear to what extent motor subtypes are influenced by other features of delirium. The use of more specialised tools (e.g. delirium motor subtyping scale), may enable researchers to develop an approach to delirium that has a greater nosological consistency. Future studies investigating delirium motor subtypes may benefit from enhanced theoretical considerations of the dysfunctional neural substrate of the delirious state.

A Comparison of the Severe Cognitive Impairment Rating Scale With the Mini-Mental State Examination and Delirium Rating Scale-Revised-98 for Delirium: A Cross-sectional Study

BACKGROUND

Cognitive impairment including attention deficits, disorientation, memory impairment, language disturbance, and impaired visuospatial ability are core symptoms of delirium. The Severe Cognitive Impairment Rating Scale (SCIRS) was developed to assess cognition in patients with severe dementia, but may also be useful in elderly people with delirium.

OBJECTIVE

We investigated the use of the SCIRS to assess cognition in elderly patients with delirium.

METHODS

We recruited 147 participants, aged ≥65 years, referred for psychiatric consultation at a tertiary-care university hospital. The diagnosis and severity of delirium were assessed using the Korean version of the Delirium Rating Scale-Revised-98 (K-DRS-98). Cognitive function was assessed using the SCIRS and the Mini-Mental State Examination (MMSE) in the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Assessment Packet (MMSE-KC).

RESULTS

There was a strong correlation of SCIRS scores with K-DRS-98 cognition domain (r = -0.796), severity scores (r = -0.742), total scores (r = -0.734), and the MMSE-KC (r = 0.905). Analysis of variance incorporating the severity of delirium suggested that while the MMSE showed a floor effect, the SCIRS could discriminate between moderate and severe delirium.

CONCLUSION

The SCIRS is a useful instrument to assess cognitive function in elderly patients with moderate to severe delirium.

Delirium after a traumatic brain injury: predictors and symptom patterns

BACKGROUND

Delirium in traumatic brain injury (TBI) is common, may be predictable, and has a multifaceted symptom complex. This study aimed to examine: 1) the sum score of Glasgow Coma Scale (GCS) and if its component scores could predict delirium in TBI patients, and 2) the prominent symptoms and their courses over the first days after TBI.

METHODS

TBI patients were recruited from neurosurgical ward inpatients. All participants were hospitalized within 24 hours after their TBI. Apart from the sum score of GCS, which was obtained at the emergency department (ED), the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, diagnostic criteria for delirium were applied daily. The severity of delirium symptoms was assessed daily using the Delirium Rating Scale - Revised-98 (DRS-R-98).

RESULTS

The participants were 54 TBI patients with a mean GCS score of 12.7 (standard deviation [SD] =2.9). A total of 25 patients (46.3%) met the diagnosis of delirium and had a mean age of 36.7 years (SD =14.8). Compared with 29 non-delirious patients, 25 delirious patients had a significantly lower mean GCS score (P=0.04), especially a significantly lower verbal component score (P=0.03). Among 18 delirious patients, four symptoms of the DRS-R-98 cognitive domain (orientation, attention, long-term memory, and visuospatial ability) were moderate symptoms (score ≥2) at the first day of admission. After follow-up, three cognitive (orientation, attention, and visuospatial ability) and two noncognitive symptoms (lability of affect and motor agitation) rapidly resolved.

CONCLUSION

Almost half of patients with mild to moderate head injuries may develop delirium in the first 4 days after TBI. Those having a low GCS score, especially the verbal component score, at the ED were likely to have delirium in this period. Most cognitive domains of delirium described in the DRS-R-98 were prominent within the first 4 days of TBI with delirium. Three cognitive and two noncognitive symptoms of delirium decreased significantly.

Delirium diagnosis defined by cluster analysis of symptoms versus diagnosis by DSM and ICD criteria: diagnostic accuracy study

BACKGROUND

Information on validity and reliability of delirium criteria is necessary for clinicians, researchers, and further developments of DSM or ICD. We compare four DSM and ICD delirium diagnostic criteria versions, which were developed by consensus of experts, with a phenomenology-based natural diagnosis delineated using cluster analysis of delirium features in a sample with a high prevalence of dementia. We also measured inter-rater reliability of each system when applied by two evaluators from distinct disciplines.

METHODS

Cross-sectional analysis of 200 consecutive patients admitted to a skilled nursing facility, independently assessed within 24-48 h after admission with the Delirium Rating Scale-Revised-98 (DRS-R98) and for DSM-III-R, DSM-IV, DSM-5, and ICD-10 criteria for delirium. Cluster analysis (CA) delineated natural delirium and nondelirium reference groups using DRS-R98 items and then diagnostic systems' performance were evaluated against the CA-defined groups using logistic regression and crosstabs for discriminant analysis (sensitivity, specificity, percentage of subjects correctly classified by each diagnostic system and their individual criteria, and performance for each system when excluding each individual criterion are reported). Kappa Index (K) was used to report inter-rater reliability for delirium diagnostic systems and their individual criteria.

RESULTS

117 (58.5 %) patients had preexisting dementia according to the Informant Questionnaire on Cognitive Decline in the Elderly. CA delineated 49 delirium subjects and 151 nondelirium. Against these CA groups, delirium diagnosis accuracy was highest using DSM-III-R (87.5 %) followed closely by DSM-IV (86.0 %), ICD-10 (85.5 %) and DSM-5 (84.5 %). ICD-10 had the highest specificity (96.0 %) but lowest sensitivity (53.1 %). DSM-III-R had the best sensitivity (81.6 %) and the best sensitivity-specificity balance. DSM-5 had the highest inter-rater reliability (K =0.73) while DSM-III-R criteria were the least reliable.

CONCLUSIONS

Using our CA-defined, phenomenologically-based delirium designations as the reference standard, we found performance discordance among four diagnostic systems when tested in subjects where comorbid dementia was prevalent. The most complex diagnostic systems have higher accuracy and the newer DSM-5 have higher reliability. Our novel phenomenological approach to designing a delirium reference standard may be preferred to guide revisions of diagnostic systems in the future.

The association between an ultrabrief cognitive screening in older adults and hospital outcomes

BACKGROUND

Though often recommended, hospital cognitive assessment is infrequently completed due to clinical and time constraints.

OBJECTIVE

This analysis aimed to evaluate the relationship between performance on ultrabrief cognitive screening instruments and hospital outcomes.

DESIGN

This is a secondary data analysis of a quality improvement project.

SETTING

Tertiary Veterans Administration hospital in New England.

PATIENTS

Patients, ≥ 60 years old, admitted to the hospital.

INTERVENTION

None.

MEASUREMENTS

Upon admission, patients were administered 2 cognitive screening tools. The modified Richmond Agitation and Sedation Scale (mRASS) is a measure of arousal that can be completed in 15 seconds. The months of the year backward (MOYB) is a measure of attention that can be administered in ≤1 minute. In-hospital outcomes included restraints and mortality, whereas discharge outcomes included length of stay, discharge not home, and variable direct costs. Risk ratios were calculated for dichotomous outcomes and unadjusted Poisson regression for continuous outcomes.

RESULTS

Patients (n = 3232) were screened. Altered arousal occurred in 15% of patients (n = 495); incorrect MOYB was recorded in 45% (n = 1457). Relative to those with normal arousal and attention, those with abnormal mRASS and incorrect MOYB had increased length of stay (incident rate ratio [IRR]: 1.23, 95% confidence interval [CI]: 1.17-1.30); restraint use (risk ratio [RR]: 5.05, 95% CI: 3.29-7.75), in-hospital mortality (RR: 3.46, 95% CI: 1.24-9.63), and decreased discharge home (RR: 2.97, 95% CI: 2.42-3.64). Hospital variable direct costs were slightly, but not significantly, higher (IRR: 1.02, 95% CI: 0.88-1.17).

CONCLUSION

Impaired performance on ultrabrief cognitive assessments of arousal and attention provide valuable insights regarding hospital outcomes.

Impaired Arousal in Older Adults Is Associated With Prolonged Hospital Stay and Discharge to Skilled Nursing Facility

BACKGROUND

Poor cognitive function is associated with negative consequences across settings of care, but research instruments are arduous for routine clinical implementation. This study examined the association between impaired arousal, as measured using an ultra-brief screen, and risk of 2 adverse clinical outcomes: hospital length of stay and discharge to a skilled nursing facility (SNF).

DESIGN, SETTING, AND PARTICIPANTS

A secondary data analysis was conducted using 2 separate groups of medical ward patients: a Veterans Affairs medical center in the northeast (N = 1487, between 2010 and 2012) 60 years and older and a large tertiary care, university-based medical center (N = 669, between 2007 and 2013) 65 years and older in the southeastern United States.

MEASUREMENTS

The impact of impaired arousal, defined by the Richmond Agitation Sedation Scale as anything other than "awake and alert," was determined using Cox Proportional Hazard Regression for time to hospital discharge and logistic regression for discharge to a SNF. Hazard ratios (HRs) and odds ratios (OR) with their 95% confidence intervals (CI) are reported, respectively. Both models were adjusted age, sex, and dementia.

RESULTS

The 2156 total patients included in these groups had a mean age of 76 years, of whom 16.4% in group 1 and 28.5% in group 2 had impaired arousal. In the first group, patients with normal arousal spent an average of 5.9 days (standard deviation 6.2) in the hospital, while those with impaired arousal spent 8.5 days (9.2). On any given day, patients with impaired arousal had 27% lower chance of being discharged (adjusted HR 0.73 (95% CI 0.63-0.84). In the second group, individuals with normal arousal spent 3.8 (4.1) days in the hospital compared with 4.7 (4.6) for those with impaired arousal; indicating a 21% lower chance of being discharged [adjusted HR 0.79 (95% CI 0.66-0.95). With regard to risk of discharge to SNF, those with impaired arousal in group 1 had a 65% higher risk than those without impaired arousal [adjusted OR 1.65 (95% CI 1.21-2.25)], and those in group 2 had a nonsignificant 27% higher risk [adjusted OR 1.27 (0.80-2.03)]. Because of the quality improvement nature, this analysis did not control for comorbidities, which is a significant limitation.

CONCLUSIONS

In this study of over 2000 older hospitalized patients, the simple observation of an abnormal arousal level may be an independent predictor of a longer hospital stay and discharge to SNF.

Objective assessment of attention in delirium: a narrative review

OBJECTIVE

Inattention is a core feature of delirium, and valid assessment of attention is central to diagnosis. Methods of measuring attention in delirium can be divided into two broad categories: (i) objective neuropsychological testing; and (ii) subjective grading of behaviour during interview and clinical examination. Here, we review and critically evaluate studies of objective neuropsychological testing of attention in delirium. We examine the implications of these studies for delirium detection and monitoring in clinical practice and research, and how these studies inform understanding of the nature of attentional deficits in delirium.

METHODS

Searches of MEDLINE and ISI Web of Knowledge databases were performed to identify studies in which objective tests of attention had been administered to patients with delirium, who had been diagnosed using DSM or ICD criteria.

RESULTS

Sixteen publications were identified. The attention tests administered in these studies were grouped into the following categories: measures of attention span, vigilance tests, other pen-and-paper tests (e.g. Trail Making Test) and computerised tests of speeded reaction, vigilance and sustained attention. Patients with delirium showed deficits on all tasks, although most tasks were not considered pure measures of attention. Five papers provided data on differential diagnosis from dementia. Cancellation tests, spatial span tests and computerised tests of sustained attention discriminated delirium from dementia. Five studies presented reliability or validity statistics.

CONCLUSIONS

The existing evidence base on objective assessment of attention in delirium is small. Objective testing of attention is underdeveloped but shows considerable promise in clinical practice and research.

Delirium: Predictors of delay in referral to consultation liaison psychiatry services

OBJECTIVE

To evaluate the predictors of delay in psychiatry referral for patients with delirium.

MATERIALS AND METHODS

The consultation liaison psychiatry registry and case notes of 461 patients referred to psychiatry consultation liaison services and diagnosed as having delirium were reviewed. Data pertaining to sociodemographic variables, clinical variables, Delirium Rating Scale-Revised 98 version, etiologies associated with delirium were extracted.

RESULTS

Older age, presence of and higher severity of sleep disturbance, presence of and higher severity of motor retardation, presence of visuospatial disturbances, presence of fluctuation of symptoms, being admitted to medical ward/medical intensive care units, and absence of comorbid axis-1 psychiatry diagnoses were associated with longer duration of psychiatric referral after the onset of delirium. Of these only four variables (presence of sleep disturbance, presence of motor retardation, being admitted to medical ward intensive care units and absence of comorbid axis-1 psychiatry diagnoses) were associated with longer duration of psychiatric referral in the regression analysis.

CONCLUSION

The variables associated with delay in psychiatry referral for delirium suggest that there is a need to improve the understanding of the physicians and surgeons about the signs and symptoms, risk factors, and prognostic factors of delirium.