Reduced level of arousal and increased mortality in adult acute medical admissions: a systematic review and meta-analysis

Assessment and report of individual symptoms in studies of delirium in postoperative populations: a systematic review

OBJECTIVES

Delirium is most often reported as present or absent. Patients with symptoms falling short of the diagnostic criteria for delirium fall into 'no delirium' or 'control' groups. This binary classification neglects individual symptoms and may be hindering identification of the pathophysiology underlying delirium. This systematic review investigates which individual symptoms of delirium are reported by studies of postoperative delirium in adults.

METHODS

Medline, EMBASE and Web of Science databases were searched on 03 June 2021 and 06 April 2023. Two reviewers independently examined titles and abstracts. Each paper was screened in duplicate and conflicting decisions settled by consensus discussion. Data were extracted, qualitatively synthesised and narratively reported. All included studies were quality assessed.

RESULTS

These searches yielded 4,367 results. After title and abstract screening, 694 full-text studies were reviewed, and 62 deemed eligible for inclusion. This review details 11,377 patients including 2,049 patients with delirium. In total, 78 differently described delirium symptoms were reported. The most reported symptoms were inattention (N = 29), disorientation (N = 27), psychomotor agitation/retardation (N = 22), hallucination (N = 22) and memory impairment (N = 18). Notably, psychomotor agitation and hallucinations are not listed in the current Diagnostic and Statistical Manual for Mental Disorders-5-Text Revision delirium definition.

CONCLUSIONS

The 78 symptoms reported in this systematic review cover domains of attention, awareness, disorientation and other cognitive changes. There is a lack of standardisation of terms, and many recorded symptoms are synonyms of each other. This systematic review provides a library of individual delirium symptoms, which may be used to inform future reporting.

Neurophysiology of male sexual arousal-Behavioral perspective

In the presented review, we analyzed the physiology of male sexual arousal and its relation to the motivational aspects of this behavior. We highlighted the distinction between these processes based on observable physiological and behavioral parameters. Thus, we proposed the experimentally applicable differentiation between sexual arousal (SA) and sexual motivation (SM). We propose to define sexual arousal as an overall autonomic nervous system response leading to penile erection, triggered selectively by specific sexual cues. These autonomic processes include both spinal and supraspinal neuronal networks, activated by sensory pathways including information from sexual partner and sexual context, as well as external and internal genital organs. To avoid misinterpretation of experimental data, we also propose to precise the term "sexual motivation" as all actions performed by the individual that increase the probability of sexual interactions or increase the probability of exposition to sexual context cues. Neuronal structures such as the amygdala, bed nucleus of stria terminalis, hypothalamus, nucleus raphe, periaqueductal gray, and nucleus paragigantocellularis play crucial roles in controlling the level of arousal and regulating peripheral responses via specific autonomic effectors. On the highest level of CNS, the activity of cortical structures involved in the regulation of the autonomic nervous system, such as the insula and anterior cingulate cortex, can visualize an elevated level of SA in both animal and human brains. From a preclinical perspective, we underlie the usefulness of the non-contact erection test (NCE) procedure in understanding factors influencing sexual arousal, including studies of sexual preference in animal models. Taken together results obtained by different methods, we wanted to focus attention on neurophysiological aspects that are distinctly related to sexual arousal and can be used as an objective parameter, leading to higher translational transparency between basic, preclinical, and clinical studies.

Advancing specificity in delirium: The delirium subtyping initiative

BACKGROUND

Delirium, a common syndrome with heterogeneous etiologies and clinical presentations, is associated with poor long-term outcomes. Recording and analyzing all delirium equally could be hindering the field's understanding of pathophysiology and identification of targeted treatments. Current delirium subtyping methods reflect clinically evident features but likely do not account for underlying biology.

METHODS

The Delirium Subtyping Initiative (DSI) held three sessions with an international panel of 25 experts.

RESULTS

Meeting participants suggest further characterization of delirium features to complement the existing Diagnostic and Statistical Manual of Mental Disorders Fifth Edition Text Revision diagnostic criteria. These should span the range of delirium-spectrum syndromes and be measured consistently across studies. Clinical features should be recorded in conjunction with biospecimen collection, where feasible, in a standardized way, to determine temporal associations of biology coincident with clinical fluctuations.

DISCUSSION

The DSI made recommendations spanning the breadth of delirium research including clinical features, study planning, data collection, and data analysis for characterization of candidate delirium subtypes.

HIGHLIGHTS

Delirium features must be clearly defined, standardized, and operationalized. Large datasets incorporating both clinical and biomarker variables should be analyzed together. Delirium screening should incorporate communication and reasoning.

Predicting hospital mortality and length of stay: A prospective cohort study comparing the Intensive Care Delirium Screening Checklist versus Confusion Assessment Method for the Intensive Care Unit

OBJECTIVE

The objective of this study was to compare two tools, the Intensive Care Delirium Screening Checklist (ICDSC) and Confusion Assessment Method for the intensive care unit (ICU) (CAM-ICU), for their predictive validity for outcomes related to delirium, hospital mortality, and length of stay (LOS).

METHODS

The prospective study conducted in six medical ICUs at a tertiary care hospital in Taiwan enrolled consecutive patients (≥20 years) without delirium at ICU admission. Delirium was screened daily using the ICDSC and CAM-ICU in random order. Arousal was assessed by the Richmond Agitation-Sedation Scale (RASS). Participants with any one positive result were classified as ICDSC- or CAM-ICU-delirium groups.

RESULTS

Delirium incidence evaluated by the ICDSC and CAM-ICU were 69.1% (67/97) and 50.5% (49/97), respectively. Although the ICDSC identified 18 more cases as delirious, substantial concordance (κ = 0.63; p < 0.001) was found between tools. Independent of age, Acute Physiology and Chronic Health Evaluation II score, and Charlson Comorbidity Index, both ICDSC- and CAM-ICU-rated delirium significantly predicted hospital mortality (adjusted odds ratio: 4.93; 95% confidence interval [CI]:1.56 to 15.63 vs. 2.79; 95% CI: 1.12 to 6.97, respectively), and only the ICDSC significantly predicted hospital LOS with a mean of 17.59 additional days compared with the no-delirium group. Irrespective of delirium status, a sensitivity analysis of normal-to-increased arousal (RASS≥0) test results did not alter the predictive ability of ICDSC- or CAM-ICU-delirium for hospital mortality (adjusted odds ratio: 2.97; 95% CI: 1.06 to 8.37 vs. 3.82; 95% CI: 1.35 to 10.82, respectively). With reduced arousal (RASS<0), neither tool significantly predicted mortality or LOS.

CONCLUSIONS

The ICDSC identified more delirium cases and may have higher predictive validity for mortality and LOS than the CAM-ICU. However, arousal substantially affected performance. Future studies may want to consider patients' arousal when deciding which tool to use to maximise the effects of delirium identification on patient mortality.

Positive scores on the 4AT delirium assessment tool at hospital admission are linked to mortality, length of stay and home time: two-centre study of 82,770 emergency admissions

BACKGROUND

Studies investigating outcomes of delirium using large-scale routine data are rare. We performed a two-centre study using the 4 'A's Test (4AT) delirium detection tool to analyse relationships between delirium and 30-day mortality, length of stay and home time (days at home in the year following admission).

METHODS

The 4AT was performed as part of usual care. Data from emergency admissions in patients ≥65 years in Lothian, UK (n = 43,946) and Salford, UK (n = 38,824) over a period of $\sim$3 years were analysed using logistic regression models adjusted for age and sex.

RESULTS

4AT completion rates were 77% in Lothian and 49% in Salford. 4AT scores indicating delirium (≥4/12) were present in 18% of patients in Lothian, and 25% of patients in Salford. Thirty-day mortality with 4AT ≥4 was 5.5-fold greater than the 4AT 0/12 group in Lothian (adjusted odds ratio (aOR) 5.53, 95% confidence interval [CI] 4.99-6.13) and 3.4-fold greater in Salford (aOR 3.39, 95% CI 2.98-3.87). Length of stay was more than double in patients with 4AT scores of 1-3/12 (indicating cognitive impairment) or ≥ 4/12 compared with 4AT 0/12. Median home time at 1 year was reduced by 112 days (Lothian) and 61 days (Salford) in the 4AT ≥4 group (P < 0.001).

CONCLUSIONS

Scores on the 4AT used at scale in practice are strongly linked with 30-day mortality, length of hospital stay and home time. The findings highlight the need for better understanding of why delirium is linked with poor outcomes and also the need to improve delirium detection and treatment.

Neurologic Syndromes Predict Higher In-Hospital Mortality in COVID-19

OBJECTIVE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is protean in its manifestations, affecting nearly every organ system. However, nervous system involvement and its effect on disease outcome are poorly characterized. The objective of this study was to determine whether neurologic syndromes are associated with increased risk of inpatient mortality.

METHODS

A total of 581 hospitalized patients with confirmed SARS-CoV-2 infection, neurologic involvement, and brain imaging were compared to hospitalized non-neurologic patients with coronavirus disease 2019 (COVID-19). Four patterns of neurologic manifestations were identified: acute stroke, new or recrudescent seizures, altered mentation with normal imaging, and neuro-COVID-19 complex. Factors present on admission were analyzed as potential predictors of in-hospital mortality, including sociodemographic variables, preexisting comorbidities, vital signs, laboratory values, and pattern of neurologic manifestations. Significant predictors were incorporated into a disease severity score. Patients with neurologic manifestations were matched with patients of the same age and disease severity to assess the risk of death.

RESULTS

A total of 4,711 patients with confirmed SARS-CoV-2 infection were admitted to one medical system in New York City during a 6-week period. Of these, 581 (12%) had neurologic issues of sufficient concern to warrant neuroimaging. These patients were compared to 1,743 non-neurologic patients with COVID-19 matched for age and disease severity admitted during the same period. Patients with altered mentation (n = 258, p = 0.04, odds ratio [OR] 1.39, confidence interval [CI] 1.04-1.86) or radiologically confirmed stroke (n = 55, p = 0.001, OR 3.1, CI 1.65-5.92) had a higher risk of mortality than age- and severity-matched controls.

CONCLUSIONS

The incidence of altered mentation or stroke on admission predicts a modest but significantly higher risk of in-hospital mortality independent of disease severity. While other biomarker factors also predict mortality, measures to identify and treat such patients may be important in reducing overall mortality of COVID-19.

Association between components of the delirium syndrome and outcomes in hospitalised adults: a systematic review and meta-analysis

Background

Delirium is a heterogeneous syndrome with inattention as the core feature. There is considerable variation in the presence and degree of other symptom domains such as altered arousal, psychotic features and global cognitive dysfunction. Delirium is independently associated with increased mortality, but it is unclear whether individual symptom domains of delirium have prognostic importance. We conducted a systematic review and meta-analysis of studies in hospitalised adults in general settings to identify the relationship between symptom domains of delirium and outcomes.

(PROSPERO: CRD42018093935).

Methods

We searched MEDLINE, EMBASE, PsycINFO, CINAHL, clinicaltrials.gov and the Cochrane Central Register of Controlled Trials from inception to November 2019. We included studies of hospitalised adults that reported associations between symptom domains of delirium and 30-day mortality (primary outcome), and other outcomes including mortality at other time points, length of stay, and dementia. Reviewer pairs independently screened articles, extracted data, and assessed risk of bias (Risk of Bias Assessment tool for Non-randomized Studies) and quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation framework. We performed random-effects meta-analyses stratified by delirium domain where possible.

Results

From 7092 citations we included 6 studies (6002 patients, 1112 with delirium). Higher mortality (ranging from in-hospital to follow-up beyond 12 months) was associated with altered arousal (pooled Odds Ratio (OR) 2.80, 95% Confidence Interval (CI) 2.33–3.37; moderate-quality evidence), inattention (pooled OR 2.57, 95% CI 1.74–3.80; low-quality evidence), and in single studies with disorientation, memory deficits and disorganised thoughts. Risk of bias varied across studies but was moderate-to-high overall, mainly due to selection bias, lack of blinding of assessments and unclear risk of selective outcome reporting. We found no studies on the association between psychotic features, visuospatial deficits or affective disturbances in delirium and outcomes, or studies reporting non-mortality outcomes.

Conclusions

Few studies have related symptom domains of delirium to outcomes, but the available evidence suggests that altered arousal and inattention in delirium are associated with higher mortality than normal arousal and attention in people with or without delirium. Measurable symptom domains of delirium may have value in predicting survival and stratifying patients for treatment. We recommend that future delirium studies report outcomes by symptom domain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02095-z.

Delirium

Delirium, a syndrome characterized by an acute change in attention, awareness and cognition, is caused by a medical condition that cannot be better explained by a pre-existing neurocognitive disorder. Multiple predisposing factors (for example, pre-existing cognitive impairment) and precipitating factors (for example, urinary tract infection) for delirium have been described, with most patients having both types. Because multiple factors are implicated in the aetiology of delirium, there are likely several neurobiological processes that contribute to delirium pathogenesis, including neuroinflammation, brain vascular dysfunction, altered brain metabolism, neurotransmitter imbalance and impaired neuronal network connectivity. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) is the most commonly used diagnostic system upon which a reference standard diagnosis is made, although many other delirium screening tools have been developed given the impracticality of using the DSM-5 in many settings. Pharmacological treatments for delirium (such as antipsychotic drugs) are not effective, reflecting substantial gaps in our understanding of its pathophysiology. Currently, the best management strategies are multidomain interventions that focus on treating precipitating conditions, medication review, managing distress, mitigating complications and maintaining engagement to environmental issues. The effective implementation of delirium detection, treatment and prevention strategies remains a major challenge for health-care organizations globally.

Association Between Level of Arousal and 30-Day Survival in Acutely Ill Older Adults

OBJECTIVE

To investigate the association between impaired arousal on admission and 30-day mortality in acutely ill older adults.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

Patients age +65 years admitted to the geriatric ward of a tertiary university hospital from 2010 to 2018 in Sao Paulo, Brazil.

METHODS

Participants were evaluated on admission according to a standardized comprehensive geriatric assessment model. Delirium was detected using the short version of the Confusion Assessment Method (Short-CAM). We used 2 alternative criteria to define impaired arousal: lethargy, stupor, or coma according to the Short-CAM; and a Glasgow Coma Scale (GCS) score of ≤13. Our primary outcome was time-to-death in 30 days, and we used Cox proportional hazards models to explore the association between impaired arousal and decreased survival.

RESULTS

We included 1554 admissions with a mean age of 81 years and of whom 61% were women. Overall, prevalent delirium was observed in 28% of the cases. We found that in 33% of admissions, patients were lethargic, stuporous, or comatose, and that in 23%, they had GCS scores of ≤13. General 30-day mortality was 19% but reached 32% in patients with GCS scores of ≤13. Impaired arousal was independently associated with lower survival in 30 days, both when defined using Short-CAM criteria [lethargy + stupor + coma: hazard ratio (HR) 2.33, 95% confidence interval (CI) 1.66‒3.27] and GCS scores (GCS 12‒13: HR 1.62, 95% CI 1.13‒2.33; GCS ≤ 11: HR 2.53, 95% CI 1.68‒3.80). In interaction analyses, we confirmed our results in patients who had impaired arousal but were neither delirious (lethargy + stupor + coma: HR 2.16, 95% CI 1.44‒3.24; GCS ≤ 11: HR 3.07; 95% CI 1.50‒6.29) nor demented (lethargy + stupor + coma: HR 1.95, 95% CI 1.15‒3.28).

CONCLUSIONS AND IMPLICATIONS

Level of arousal on admission was an independent predictor of 30-day survival in acutely ill older adults, regardless of delirium or baseline dementia. Clinicians should be aware that even if unsure of whether a patient has delirium, arousal assessment can provide crucial clinical and prognostic insight.

Assessment of Delirium Using the Confusion Assessment Method in Older Adult Inpatients in Malaysia

The detection of delirium in acutely ill older patients is challenging with the lack of informants and the necessity to identify subtle and fluctuating signs. We conducted a cross-sectional study among older patients admitted to a university hospital in Malaysia to determine the presence, characteristics, and mortality outcomes of delirium. Consecutive patients aged ≥65years admitted to acute medical wards were recruited from August to September 2016. Cognitive screening was performed using the mini-mental test examination (MMSE) and the Confusion Assessment Method (CAM). The CAM-Severity (CAM-S) score was also performed in all patients. Of 161 patients recruited, 43 (26.7%) had delirium. At least one feature of delirium from the CAM-S short and long severity scores were present in 48.4% and 67.1%, respectively. Older age (OR: 1.07, 95% CI: 1.01–1.14), immobility (OR: 3.16, 95% CI: 1.18–8.50), cognitive impairment (OR: 5.04, 95% CI: 2.07–12.24), and malnutrition (OR: 3.37; 95% CI: 1.15–9.85) were significantly associated with delirium. Older patients with delirium had a higher risk of mortality (OR: 7.87, 95% CI: 2.42–25.57). Delirium is common among older patients in our setting. A large proportion of patients had altered mental status on admission to hospital although they did not fulfill the CAM criteria of delirium. This should prompt further studies on strategies to identify delirium and the use of newer, more appropriate assessment tools in this group of vulnerable individuals.

Delirium detection in older acute medical inpatients: a multicentre prospective comparative diagnostic test accuracy study of the 4AT and the confusion assessment method

BACKGROUND

Delirium affects > 15% of hospitalised patients but is grossly underdetected, contributing to poor care. The 4 'A's Test (4AT, www.the4AT.com ) is a short delirium assessment tool designed for routine use without special training. The primary objective was to assess the accuracy of the 4AT for delirium detection. The secondary objective was to compare the 4AT with another commonly used delirium assessment tool, the Confusion Assessment Method (CAM).

METHODS

This was a prospective diagnostic test accuracy study set in emergency departments or acute medical wards involving acute medical patients aged ≥ 70. All those without acutely life-threatening illness or coma were eligible. Patients underwent (1) reference standard delirium assessment based on DSM-IV criteria and (2) were randomised to either the index test (4AT, scores 0-12; prespecified score of > 3 considered positive) or the comparator (CAM; scored positive or negative), in a random order, using computer-generated pseudo-random numbers, stratified by study site, with block allocation. Reference standard and 4AT or CAM assessments were performed by pairs of independent raters blinded to the results of the other assessment.

RESULTS

Eight hundred forty-three individuals were randomised: 21 withdrew, 3 lost contact, 32 indeterminate diagnosis, 2 missing outcome, and 785 were included in the analysis. Mean age was 81.4 (SD 6.4) years. 12.1% (95/785) had delirium by reference standard assessment, 14.3% (56/392) by 4AT, and 4.7% (18/384) by CAM. The 4AT had an area under the receiver operating characteristic curve of 0.90 (95% CI 0.84-0.96). The 4AT had a sensitivity of 76% (95% CI 61-87%) and a specificity of 94% (95% CI 92-97%). The CAM had a sensitivity of 40% (95% CI 26-57%) and a specificity of 100% (95% CI 98-100%).

CONCLUSIONS

The 4AT is a short, pragmatic tool which can help improving detection rates of delirium in routine clinical care.

TRIAL REGISTRATION

International standard randomised controlled trial number (ISRCTN) 53388093 . Date applied 30/05/2014; date assigned 02/06/2014.