Acute Brain Failure: Pathophysiology, Diagnosis, Management, and Sequelae of Delirium

Effectiveness of a delirium risk assessment and multidisciplinary care approach in reducing delirium incidence among surgical intensive care unit patients: A retrospective pre-post intervention study

BACKGROUND

Delirium is a common complication in intensive care unit (ICU) patients. It can lead to various adverse events. In this study, we investigated the effectiveness of combining the use of the PREdiction of DELIRium (PRE-DELIRIC) model for delirium risk assessment and the use of a multicomponent care bundle for delirium assessment, prevention, and care in terms of reductions in the incidence of delirium among surgical ICU patients.

METHODS

This retrospective study included surgical ICU patients who had received PRE-DELIRIC-guided SMART/SmART care (SMART care: SmART bundle plus multidisciplinary team; SmART care: Sleep/sweet sense of home (creating a comforting and restful environment for patients), Assessment (regular and thorough evaluation of patient needs and conditions), Release (revised endotracheal tube care/removal, restraint device care, and immobility reduction for patient comfort), and Time (reorientation of time to optimize patient care schedules) in our hospital between May 2022 and March 2023 (intervention group) and individuals who had received usual care between January 2021 and April 2022 (historical control group). The SmART intervention involves providing care in the following domains: sleep/sweet sense of home, assessment, release, and time. Patients with a PRE-DELIRIC score of >30% received SMART care, which includes multidisciplinary (physicians, pharmacists, respiratory therapists, and physiotherapists) care in addition to SmART care. For the control group, usual care was provided following the guidelines for the prevention and management of pain, agitation, delirium, immobility, and sleep disruption. The primary outcome was delirium incidence during ICU stay, which was assessed using the Intensive Care Delirium Screening Checklist. The secondary outcomes were the duration of ICU stay, rate of unplanned self-extubation, and status of ICU discharge.

RESULTS

The intervention and control groups comprised 184 and 197 patients, respectively; their mean ages were 63.7 ± 18.4 years and 62.4 ± 19.5 years, respectively. The incidence of delirium was significantly lower (p = 0.001) in the intervention group (22.3%) than in the control group (47.7%).

CONCLUSION

Our findings suggest that the PRE-DELIRIC-guided SMART/SmART care intervention is effective in preventing and managing delirium among surgical ICU patients.

Utilization of NIRS Monitor to Compare the Regional Cerebral Oxygen Saturation Between Dexmedetomidine and Propofol Sedation in Mechanically Ventilated Critically ill Patients with Sepsis- A Prospective Randomized Control Trial

AIM & BACKGROUND

Delirium frequently occurs in the acute phase of sepsis and is associated with increased ICU and hospital length of stay, duration of mechanical ventilation, and higher mortality rates. We utilized the Near-Infrared Spectroscopy monitor to measure and compare the regional cerebral oxygen saturation in mechanically ventilated patients of sepsis receiving either dexmedetomidine or propofol sedation and assessed the association between delirium and regional cerebral oxygen saturation.

METHODS

A single center prospective randomized control trial conducted over a period of two years, 54 patients were included, equally divided between propofol and dexmedetomidine groups. Patients received a blinded study drug, propofol (10 mg/mL) or dexmedetomidine (5 mcg/mL) via infusion pump according to randomization. Infusion rates were adjusted every 10 min based on weight-based titration tables, aiming for target sedation (RASS -2 to 0). Management components included pain monitoring using the CPOT score and delirium assessment using CAM-ICU score.

RESULTS

Dexmedetomidine group showed higher mean regional cerebral oxygen saturation as compared to propofol group (P = .036). No significant differences were found in mechanical ventilation or ICU stay durations, delirium-free days, or sedation cessation reasons. Delirium occurred in 36 patients, with lower mean regional cerebral oxygen saturation as compared to non-delirious patients.

CONCLUSION

The dexmedetomidine group had higher regional cerebral oxygen saturation compared to the propofol group. Delirious patients showed lower cerebral oxygen saturation than non-delirious patients, suggesting a link between sedation type, cerebral oxygenation, and delirium.CTRI registration: REF/2021/11/048655 N.

Reliability and Validity of Hindi Version of the Confusion Assessment Method for Intensive Care Unit (CAM-ICU) for Diagnosis of Delirium: A Cohort Study

Background

The confusion assessment method for the intensive care unit (CAM-ICU) is a bedside tool to diagnose delirium in critically ill patients. This study aims to determine the reliability and validity of the Hindi version of CAM-ICU against the Diagnostic and Statistical Manual (DSM), fourth edition text revision (DSM-IV-TR), and DSM, fifth edition (DSM-5) criteria for diagnosis of delirium.

Methods

Seventy-five Hindi-speaking consenting patients ≥18-year-old with Richmond Agitation Sedation Scale ≥-3 and an anticipated ICU stay > 48 hours were included. Patients with known severe mental illnesses, visual/hearing loss, neurological injury, burns, drug overdose, and Glasgow Coma Scale <9 at the time of screening were excluded. After 48 hours of ICU stay and ensuring at least 2 hours of sedative interruption, within a 4-hour period, two examiners independently assessed delirium using the Hindi version of the scale and an experienced psychiatrist assessed the patients independently and applied the DSM-IV-TR and DSM-5 criteria for diagnosing delirium. Time taken for CAM-ICU assessment, inter-observer reliability, sensitivity, specificity, and positive and negative predictive values were calculated.

Results

The Cohen's κ value was 0.944 (p < 0.001). The Cronbach's α for observer 1 and observer 2 was 0.961 and 0.968, respectively. The sensitivity and negative predictive value of the tool was 100% with both DSM-IV-TR and DSM-5. The specificity was 90.2% and 92% and the positive predictive value was 82.8 and 86.2% with DSM-IV-TR and DSM-5, respectively.

Conclusions

The Hindi version of CAM-ICU is a reliable and valid tool for the diagnosis of delirium in an ICU setting.

Trial registration

The study was registered with the Clinical Trials Registry, India (CTRI) as per the research guidelines laid down by the Indian Council of Medical Research before enrolling the participants. (CTRI number- CTRI/2021/01/030471). The registration date was 14th January 2021. URL of registry is http://ctri.nic.in.

Highlights

Delirium in the ICU is often undiagnosed due to unfamiliarity, lack of understanding of symptoms, non-availability of psychiatric consultation, and validated diagnostic tools in the native language of the patient. This study aims to find the reliability and validity of the Hindi version of CAM-ICU.

How to cite this article

Salhotra R, Bose A, Srivastava S, Mohta M, Pandarinathan K, Rautela RS. Reliability and Validity of Hindi Version of the Confusion Assessment Method for Intensive Care Unit (CAM-ICU) for Diagnosis of Delirium: A Cohort Study. Indian J Crit Care Med 2024;28(10):958-962.

Disparities in Delirium across the Continuum of Care and Associations with Social Determinants of Health

Disparities exist in the identification, treatment, and management of delirium. These disparities can be most holistically and comprehensively understood by using a social-ecological model-which acknowledges multilevel impacts including individual, interpersonal, organizational, community, and policy-level factors-as well as a social determinant of health framework, that considers nonmedical factors that influence health outcomes. This narrative review leverages both frameworks to identify and discuss existing literature pertaining to the intersection of these social risk factors and delirium, focusing specifically on disparities due to racial and/or ethnic identity, language ability, and socioeconomic differences. We also look at disparities and the potential role of these social risk factors throughout the continuum of care, including prehospitalization, hospitalization, and posthospitalization factors. Understanding and analyzing the role of these inequities is critical to ensuring better health outcomes for patients at risk of and/or with delirium.

Association of postoperative delirium with hypotension in critically ill patients after cardiac surgery: a prospective observational study

BACKGROUND

Postoperative delirium (POD), an acute and variable disturbance in cognitive function, is an intricate and elusive phenomenon that occurs after cardiac surgery. Despite progress in surgical techniques and perioperative management, POD remains a formidable challenge, imposing a significant burden on patients, caregivers, and healthcare systems.

METHODS

This prospective observational study involved 307 patients who underwent cardiac surgery. Data on the occurrence of delirium, clinical parameters, and postoperative characteristics were collected. A multivariate analysis was performed to assess the relationship between POH and POD.

RESULTS

Sixty-one patients (21%) developed delirium, with an average onset of approximately 5 days postoperatively and a duration of approximately 6 days. On multivariate analysis, POH was significantly associated with POD, and the adjusted odds ratios indicated that patients with POH were more likely to develop delirium (OR, 5.61; p = 0.006). Advanced age (OR, 1.11; p = 0.002), emergency surgery (OR, 8.31; p = 0.001), and on-pump coronary artery bypass grafting were identified as risk factors of POD. Patients who developed delirium were typically older, more likely to be male, and had higher morbidity rates than those who did not.

CONCLUSION

POH is significantly associated with delirium in critically ill patients after cardiac surgery. Surgical complexity and advanced age contribute to the risk of developing POD and poor postoperative outcomes.

Impact of a Delirium Protocol on Deliriogenic Medication Use in Hospitalized Older Veterans

Background The Southern Arizona VA Health Care System (SAVAHCS) implemented a delirium prevention and treatment protocol in 2019. Objective The primary objective of this study was to determine if the implementation of a delirium protocol influenced deliriogenic medication use in hospitalized geriatric veterans. The secondary objectives were to compare the rates of delirium diagnosis, hospital length-of-stay, and rates of newly started deliriogenic medications during admission pre- and post-protocol. Methods This study was a retrospective, secondary data analysis study. Veterans 65 years of age and older who were admitted to an inpatient medical ward at the SAVAHCS for 24 hours or more between January 1, 2018 and December 31, 2018 (pre-protocol) or January 1, 2021 and December 31, 2021 (post-protocol) were included. Patients were excluded if they had a diagnosis of alcohol or benzodiazepine withdrawal upon admission. Results A total of 5491 patients were included in this study; 2940 (53.5%) in the pre-protocol group and 2551 (46.5%) in the post-protocol group. Patients received at least one deliriogenic medication during their admission in the post-protocol group (36.2%) compared with the pre-protocol group (34.1%), but there was no statistically significant difference (P = 0.098). There were also no significant differences in the rates of documentation of delirium as a diagnosis at discharge, hospital length-of-stay, or the rates of newly started deliriogenic medications during admission between the groups. Conclusion Implementation of a delirium prevention and treatment protocol at the SAVAHCS did not significantly impact the use of deliriogenic medications in hospitalized geriatric veterans.

High-risk factors for delirium in severely ill patients and the application of emotional nursing combined with pain nursing

BACKGROUND

Delirium is a neuropsychiatric syndrome characterized by acute disturbances of consciousness with rapid onset, rapid progression, obvious fluctuations, and preventable, reversible, and other characteristics. Patients with delirium in the intensive care unit (ICU) are often missed or misdiagnosed and do not receive adequate attention.

AIM

To analyze the risk factors for delirium in ICU patients and explore the application of emotional nursing with pain nursing in the management of delirium.

METHODS

General data of 301 critically ill patients were retrospectively collected, including histories (cardiovascular and cerebrovascular diseases, hypertension, smoking, alcoholism, and diabetes), age, sex, diagnosis, whether surgery was performed, and patient origin (emergency/clinic). Additionally, the duration of sedation, Richmond Agitation Sedation Scale score, combined emotional and pain care, ventilator use duration, vasoactive drug use, drainage tube retention, ICU stay duration, C-reactive protein, procalcitonin, white blood cell count, body temperature, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and Sequential Organ Failure Assessment score were recorded within 24 h after ICU admission. Patients were assessed for delirium according to confusion assessment method for the ICU, and univariate and multivariate logistic regression analyses were performed to identify the risk factors for delirium in the patients.

RESULTS

Univariate logistic regression analysis was performed on the 24 potential risk factors associated with delirium in ICU patients. The results showed that 16 risk factors were closely related to delirium, including combined emotional and pain care, history of diabetes, and patient origin. Multivariate logistic regression analysis revealed that no combined emotional and pain care, history of diabetes, emergency source, surgery, long stay in the ICU, smoking history, and high APACHE II score were independent risk factors for delirium in ICU patients.

CONCLUSION

Patients with diabetes and/or smoking history, postoperative patients, patients with a high APACHE II score, and those with emergency ICU admission need emotional and pain care, flexible visiting modes, and early intervention to reduce delirium incidence.

EEG and acute confusional state at the emergency department

OBJECTIVES

Acute confusional state (ACS) is a common cause of admission to the emergency department (ED). It can be related to numerous etiologies. Electroencephalography (EEG) can show specific abnormalities in cases of non-convulsive status epilepticus (NCSE), or metabolic or toxic encephalopathy. However, up to 80% of patients with a final diagnosis of NCSE have an ACS initially attributed to another cause. The exact place of EEG in the diagnostic work-up remains unclear.

METHODS

Data of consecutive patients admitted to the ED for an ACS in a two-year period and who were referred for an EEG were collected. The initial working diagnosis was based on medical history, clinical, biological and imaging investigations allowing classification into four diagnostic categories. Comparison to the final diagnosis was performed after EEG recordings (and sometimes additional tests) were performed, which allowed the reclassification of some patients from one category to another.

RESULTS

Seventy-five patients (mean age: 71.1 years) were included with the following suspected diagnoses: seizures for 8 (11%), encephalopathy for 14 (19%), other cause for 34 (45%) and unknown for 19 (25%). EEG was recorded after a mean of 1.5 days after symptom onset, and resulted in the reclassification of patients as follows: seizure for 15 (20%), encephalopathy for 15 (20%), other cause for 29 (39%) and unknown cause for 16 (21%). Moreover, ongoing epileptic activity (NCSE or seizure) and interictal epileptiform activity were found in eight (11%) patients initially diagnosed in another category.

DISCUSSION

In our cohort, EEG was a key examination in the management strategy of ACS in 11% of patients admitted to the ED. It resulted in a diagnosis of epilepsy in these patients admitted with unusual confounding presentations.

Machine learning with clinical and intraoperative biosignal data for predicting postoperative delirium after cardiac surgery

Early identification of patients at high risk of delirium is crucial for its prevention. Our study aimed to develop machine learning models to predict delirium after cardiac surgery using intraoperative biosignals and clinical data. We introduced a novel approach to extract relevant features from continuously measured intraoperative biosignals. These features reflect the patient's overall or baseline status, the extent of unfavorable conditions encountered intraoperatively, and beat-to-beat variability within the data. We developed a soft voting ensemble machine learning model using retrospective data from 1,912 patients. The model was then prospectively validated with data from 202 additional patients, achieving a high performance with an area under the receiver operating characteristic curve of 0.887 and an accuracy of 0.881. According to the SHapley Additive exPlanation method, several intraoperative biosignal features had high feature importance, suggesting that intraoperative patient management plays a crucial role in preventing delirium after cardiac surgery.

The role of heart rate variability in predicting delirium: A systematic review and meta-analysis

Brain and heart interact through multiple ways. Heart rate variability, a non-invasive measurement is studied extensively as a predicting model for various health conditions including subarachnoid hemorrhage, cancer, and diabetes. There is limited evidence to predict delirium, an acute fluctuating disorder of brain dysfunction, as it poses a significant challenge in the intensive care unit (ICU) and post-operative setting. In this systematic review of 9 articles, heart rate variability indices were used to investigate the occurrence of post-operative and ICU delirium. This systematic review and meta-analysis reveal evidence of a strong predilection between postoperative and intensive care unit delirium and alterations in the heart rate variability, measured by mean differences for standard deviation of NN-intervals. Other heart rate variability indices [root mean squares of successive differences, low-frequency (LF), high-frequency (HF), and LF:HF ratio] showed lack of or very weak association. A non-invasive tool of brain and heart interaction may refine diagnostic predictions for acute brain dysfunctions like delirium in such population and would be an important step in delirium research.

Diffuse optical tomography for mapping cerebral hemodynamics and functional connectivity in delirium

INTRODUCTION

Delirium is associated with mortality and new onset dementia, yet the underlying pathophysiology remains poorly understood. Development of imaging biomarkers has been difficult given the challenging nature of imaging delirious patients. Diffuse optical tomography (DOT) offers a promising approach for investigating delirium given its portability and three-dimensional capabilities.

METHODS

Twenty-five delirious and matched non-delirious patients (n = 50) were examined using DOT, comparing cerebral oxygenation and functional connectivity in the prefrontal cortex during and after an episode of delirium.

RESULTS

Total hemoglobin values were significantly decreased in the delirium group, even after delirium resolution. Functional connectivity between the dorsolateral prefrontal cortex and dorsomedial prefrontal cortex was strengthened post-resolution compared to during an episode; however, this relationship was still significantly weaker compared to controls.

DISCUSSION

These findings highlight DOT's potential as an imaging biomarker to measure impaired cerebral oxygenation and functional dysconnectivity during and after delirium. Future studies should focus on the role of cerebral oxygenation in delirium pathogenesis and exploring the etiological link between delirium and dementias.

HIGHLIGHTS

We developed a portable diffuse optical tomography (DOT) system for bedside three-dimensional functional neuroimaging to study delirium in the hospital. We implemented a novel DOT task-focused seed-based correlation analysis. DOT revealed decreased cerebral oxygenation and functional connectivity strength in the delirium group, even after resolution of delirium.

Effect of a fall within three months of admission on delirium in critically Ill elderly patients: a population-based cohort study

BACKGROUND

Delirium is common among elderly patients in the intensive care unit (ICU) and is associated with prolonged hospitalization, increased healthcare costs, and increased risk of death. Understanding the potential risk factors and early prevention of delirium is critical to facilitate timely intervention that may reverse or mitigate the harmful consequences of delirium.

AIM

To clarify the effects of pre-admission falls on ICU outcomes, primarily delirium, and secondarily pressure injuries and urinary tract infections.

METHODS

The study relied on data sourced from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Statistical tests (Wilcoxon rank-sum or chi-squared) compared cohort characteristics. Logistic regression was employed to investigate the association between a history of falls and delirium, as well as secondary outcomes, while Kaplan-Meier survival curves were used to assess short-term survival in delirium and non-delirium patients.

RESULTS

Study encompassed 22,547 participants. Delirium incidence was 40%, significantly higher in patients with a history of falls (54.4% vs. 34.5%, p < 0.001). Logistic regression, controlling for confounders, not only confirmed that a history of falls elevates the odds of delirium (OR: 2.11; 95% CI: 1.97-2.26; p < 0.001) but also showed it increases the incidence of urinary tract infections (OR:1.50; 95% CI:1.40-1.62; p < 0.001) and pressure injuries (OR:1.36; 95% CI:1.26-1.47; p < 0.001). Elderly delirium patients exhibited lower 30-, 180-, and 360-day survival rates than non-delirium counterparts (all p < 0.001).

CONCLUSIONS

The study reveals that history of falls significantly heighten the risk of delirium and other adverse outcomes in elderly ICU patients, leading to decreased short-term survival rates. This emphasizes the critical need for early interventions and could inform future strategies to manage and prevent these conditions in ICU settings.

The relationship between intraoperative hypothermia and postoperative delirium: The PNDRFAP study

OBJECTIVE

Our study aimed to investigate the correlation between intraoperative hypothermia and postoperative delirium (POD) in patients undergoing general anesthesia for gastrointestinal surgery.

METHODS

The study comprised 750 participants from the Perioperative Neurocognitive Disorder Risk Factor and Prognosis (PNDRFAP) study database, which ultimately screened 510 individuals in the final analysis. Preoperative cognitive function was evaluated using the Mini-Mental State Examination (MMSE). The occurrence of POD was determined using the Confusion Assessment Method, and the severity of POD was evaluated using the Memorial Delirium Assessment Scale. Logistic regression was employed to scrutinize the association between intraoperative hypothermia and the incidence of POD, and the sensitivity analysis was conducted by introducing adjusted confounding variables. Decision curves and a nomogram model were utilized to assess the predictive efficacy of intraoperative hypothermia for POD. Mediation analysis involving 10,000 bootstrapped iterations was employed to appraise the suggested mediating effect of numeric rating scale (NRS) scores at 24 and 48 h post-surgeries. The receiver-operating characteristic (ROC) was utilized to evaluate the effectiveness of intraoperative hypothermia in predicting POD.

RESULTS

In the PNDRFAP study, the occurrence of POD was notably higher in the intraoperative hypothermia group (62.2%) compared to the intraoperative normal body temperature group (9.8%), with an overall POD incidence of 17.6%. Logistic regression analysis, adjusted for various confounding factors (age [40-90], gender, education, MMSE, smoking history, drinking history, hypertension, diabetes, and the presence of cardiovascular heart disease), demonstrated that intraoperative hypothermia significantly increased the risk of POD (OR = 4.879, 95% CI = 3.020-7.882, p < .001). Mediation analyses revealed that the relationship between intraoperative hypothermia and POD was partially mediated by NRS 24 h after surgery, accounting for 14.09% of the association (p = .002). The area under the curve of the ROC curve was 0.685, which confirmed that intraoperative hypothermia could predict POD occurrence to a certain extent. Decision curve and nomogram analyses, conducted using the R package, further substantiated the predictive efficacy of intraoperative hypothermia on POD.

CONCLUSION

Intraoperative hypothermia may increase the risk of POD, and this association may be partially mediated by NRS scores 24 h after surgery.

A Molecular Framework for Delirium

Over 2.6 million adults over the age of 65 develop delirium each year in the United States (US). Delirium is associated with a significant increase in mortality and the US health care costs associated with delirium are estimated at over $164 billion annually. Despite the prevalence of the condition, the molecular pathophysiology of delirium remains unexplained, limiting the development of pharmacotherapies. Delirious patients can be identified by prominent impairments in attention and working memory (WM), two cognitive domains that localize to the dorsolateral prefrontal cortex (dlPFC). The dlPFC is also a key site for Alzheimer's disease (AD) pathology, and given the high risk of delirium in AD patients, suggests that efforts at understanding delirium might focus on the dlPFC as a final common endpoint for cognitive changes. Preclinical studies of the dlPFC reproduce many of the pharmacological observations made of delirious patients, including sensitivity to anticholinergics and an 'inverted U' pattern of dependence on monoaminergic input, with diminished performance outside a narrow range of signaling. Medications like guanfacine, which influence the dlPFC in the context of attention-deficit/hyperactivity disorder (ADHD), have emerged as therapies for delirium and motivate a detailed understanding of the influence of α-2 agonists on WM. In this review, I will discuss the neural circuitry and molecular mechanisms underlying WM and the function of the dlPFC. Localizing the cognitive deficits that are commonly seen in delirious patients may help identify new molecular targets for this highly prevalent disease.

Antipsychotic Drug Prescription in Pediatric Intensive Care Units: A 10-Year U.S. Retrospective Database Study

Delirium recognition during pediatric critical illness may result in the prescription of antipsychotic medication. These medications have unclear efficacy and safety. We sought to describe antipsychotic medication use in pediatric intensive care units (PICUs) contributing to a U.S. national database. This study is an analysis of the Pediatric Health Information System Database between 2008 and 2018, including children admitted to a PICU aged 0 to 18 years, without prior psychiatric diagnoses. Antipsychotics were given in 16,465 (2.3%) of 706,635 PICU admissions at 30 hospitals. Risperidone (39.6%), quetiapine (22.1%), and haloperidol (20.8%) were the most commonly used medications. Median duration of prescription was 4 days (interquartile range: 2-11 days) for atypical antipsychotics, and haloperidol was used a median of 1 day (1-3 days). Trend analysis showed quetiapine use increased over the study period, whereas use of haloperidol and chlorpromazine (typical antipsychotics) decreased ( p  < 0.001). Compared with no antipsychotic administration, use of antipsychotics was associated with comorbidities (81 vs. 65%), mechanical ventilation (57 vs. 36%), longer PICU stay (6 vs. 3 days), and higher mortality (5.7 vs. 2.8%) in univariate analyses. In the multivariable model including demographic and clinical factors, antipsychotic prescription was associated with mortality (odds ratio [OR] = 1.09, 95% confidence interval [CI]: 1.02-1.18). Use of atypical antipsychotics increased over the 10-year period, possibly reflecting increased comfort with their use in pediatric patients. Antipsychotics were more common in patients with comorbidities, mechanical ventilation, and longer PICU stay, and associated with higher mortality in an adjusted model which warrants further study.

Geriatric nutritional risk index independently predicts delirium in older patients in intensive care units: A multicenter cohort study

BACKGROUND

Malnutrition is associated with clinical outcomes in several diseases. However, the role of malnutrition in the risk of delirium in elderly patients in intensive care units (ICU) remains unclear. This study aimed to elucidate the association between the Geriatric Nutritional Risk Index (GNRI) and the risk of delirium in elderly patients in the ICU.

METHODS

Elderly patients from the Medical Information Mart for Intensive Care IV (MIMIC-IV) and the eICU Collaborative Research Database (eICU-CRD) were included in this study, totaling 11,310 and 5,627, respectively. All subjects were stratified according to their GNRI score: those with no nutritional risk (GNRI > 98), mild nutritional risk (92 ≤ GNRI ≤ 98), moderate nutritional risk (82 ≤ GNRI ≤ 92), and severe nutritional risk (GNRI < 82). The primary outcome was delirium.

RESULTS

The GNRI in MIMIC-IV and eICU-CRD were 93.82 (84.88, 101.26) and 83.39 (75.95, 89.35), respectively. Compared to the cohort without nutritional risk, there was an increased risk of delirium in patients with mild nutritional risk (OR: 1.39, 95 % CI: 1.23-1.58), moderate nutritional risk (OR: 1.72, 95 % CI: 1.52-1.95), and severe nutritional risk (OR: 2.07, 95 % CI: 1.79-2.39). Inclusion of the GNRI score in the multivariate models improved the prediction of delirium. Similar results were found in the eICU-CRD database.

CONCLUSIONS

Nutritional assessment using the GNRI may be an independent predictor of the development of delirium in elderly patients in the ICU. The addition of the GNRI score to the delirium prediction model improves its predictive accuracy.

Reliability and Validity of the Spanish Adaptation of the Stanford Proxy Test for Delirium in Two Clinical Spanish-Speaking Communities

BACKGROUND

Delirium is the most prevalent neuropsychiatric syndrome experienced by patients admitted to inpatient clinical units, occurring in at least 20% of medically hospitalized patients and up to 85% of those admitted to critical care units. Although current guidelines recommend the implementation of universal prevention strategies, the use of management strategies largely depends on constant surveillance and screening. This allows for the timely diagnosis and correction of its underlying causes and implementation of management strategies.

OBJECTIVE

It was to adapt and analyze the Spanish adaptation of the Stanford Proxy Test for Delirium (S-PTDsv) instrument for its use among Spanish-speaking populations. The S-PTD is an instrument consisting of 13 observational items to be completed by a clinician observer, usually the patient's nurse. The completion of the questionnaire takes about 1 minute and does not require the active participation of the person evaluated, which has important clinical advantages compared to other available instruments (e.g., the Confusion Assessment Method).

METHODS

The psychometric properties of the S-PTDsv were evaluated in a population of 123 patients using a quantitative, cross-sectional design. All subjects were over 18 years of age and hospitalized in various inpatient medico-surgical and intensive care unit services, either at the Barcelona Clinical Hospital (Barcelona, Spain) or the UC-Christus Health Network Clinical Hospital (Santiago, Chile, S.A.). The ultimate diagnosis of delirium was made by a member of the Psychiatry Consult Service by means of an independent neuropsychiatric evaluation based on the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, published in 2013, which is the latest version of the diagnostic manual. All study tests were performed by study personnel who were blinded to each other's test results within an hour of each other.

RESULTS

In the receiver operator characteristic (ROC) curve analysis, the S-PTDsv demonstrated excellent classification qualities when compared with the DSM-5 as the classification reference standard. Using a cutoff point of ≥3, the S-PTDsv had a sensitivity of 94% and a specificity of 97%. The area under the curve indicator was equal to 0.95, suggesting the S-PTDsv has an excellent overall performance in accurately identifying cases of delirium. Accordingly, the S-PTDsv's positive predictive value = 0.93, and the negative predictive value = 0.97. The internal reliability measured with Cronbach's alpha was 0.96. Confirmatory factor analysis revealed a 1-dimensional structure with high loadings (>0.72), demonstrating that all items similarly contribute to the total diagnostic dimension, suggesting adequate construct validity. This provided evidence of convergent validity.

CONCLUSIONS

The performance of the S-PTDsv, as compared to a blinded neuropsychiatric assessment based on DSM-5, indicates that it is an effective instrument for the detection of delirium, in the Spanish-speaking populations. These results are comparable and consistent with previously published studies in the English language version.

Recurrent delirium episodes within the intensive care unit: Incidence and associated factors

PURPOSE

Describe the incidence and factors associated with recurrent delirium in the intensive care unit (ICU).

MATERIALS AND METHODS

Retrospective study of ICU patients diagnosed with delirium. Delirium clearance defined as 48 h of negative delirium assessments following initial episode and recurrent delirium as any positive delirium assessment following clearance. Multivariable logistic regression model assessed independent association of patient and hospital factors on development of recurrent delirium, adjusting for pre-defined covariates.

RESULTS

Among 8591 ICU admissions identified with delirium, 1067 (12.4%) had recurrent symptoms. Factors associated with increased odds of recurrent delirium were age (nonlinear; p = 0.02), shock (OR 1.45, 95% CI [1.20, 1.75]), admission to medical (OR 3.25, 95% CI [2.42, 4.37]), surgical (OR 3.00, 95% CI [2.21, 4.06]), or trauma (OR 2.17, 95% CI [1.58, 3.00]) ICU vs. cardiovascular ICU, increased duration of mechanical ventilation (OR 2.43, 95% CI [2.22, 2.65]), propofol use (OR 1.35, 95% CI [1.02, 1.80]), and antipsychotic medications (haloperidol OR 1.53, 95% CI [1.26, 1.86]; quetiapine OR 2.45, 95% CI [1.98, 3.02]; and olanzapine OR 1.54, 95% CI [1.25, 1.88]).

CONCLUSIONS

Over 10% of delirious ICU patients had recurrent symptoms. Factors associated with recurrence included age, duration of mechanical ventilation and medication exposure.

CLINICAL TRIAL NUMBER

Not applicable.

Incidence of confusional syndrome (delirium) in a Latin American university hospital

BACKGROUND

Little is known about the incidence of delirium and its subtypes in patients admitted to different departments of university hospitals in Latin America.

OBJECTIVE

To determine the incidence of delirium and the frequency of its subtypes, as well as its associated factors, in patients admitted to different departments of a university hospital in Bogotá, Colombia.

METHODS

A cohort of patients over 18 years of age admitted to the internal medicine (IM), geriatrics (GU), general surgery (GSU), orthopaedics (OU) and intensive care unit (ICU) services of a university hospital was followed up between January and June 2018. To detect the presence of delirium, we used the CAM (Confusion Assessment Method) and the CAM-ICU if the patient had decreased communication skills. The delirium subtype was characterised using the RASS (Richmond Agitation and Sedation Scale). Patients were assessed on their admission date and then every two days until discharged from the hospital. Those in whom delirium was identified were referred for specialised intra-institutional interdisciplinary management.

RESULTS

A total of 531 patients admitted during the period were assessed. The overall incidence of delirium was 12% (95% CI, 0.3-14.8). They represented 31.8% of patients in the GU, 15.6% in the ICU, 8.7% in IM, 5.1% in the OU, and 3.9% in the GSU. The most frequent clinical display was the mixed subtype, at 60.9%, followed by the normoactive subtype (34.4%) and the hypoactive subtype (4.7%). The factors most associated with delirium were age (adjusted RR = 1.07; 95% CI, 1.05-1.09), the presence of four or more comorbidities (adjusted RR = 2.04; 95% CI, 1.31-3.20), and being a patient in the ICU (adjusted RR = 2.02; 95% CI, 1.22-3.35).

CONCLUSIONS

The incidence of delirium is heterogeneous in the different departments of the university hospital. The highest incidence occurred in patients that were admitted to the GU. The mixed subtype was the most frequent one, and the main associated factors were age, the presence of four or more comorbidities, and being an ICU patient.

Cerebral autoregulation-based mean arterial pressure targets and delirium in critically ill adults without brain injury: a retrospective cohort study

PURPOSE

Cerebral autoregulation (CA) is a mechanism that acts to maintain consistent cerebral perfusion across a range of blood pressures, and impaired CA is associated with delirium. Individualized CA-derived blood pressure targets are poorly characterized in critically ill patients and the association with intensive care unit (ICU) delirium is unknown. Our objectives were to characterize optimal mean arterial pressure (MAPopt) ranges in critically ill adults without brain injury and determine whether deviations from these targets contribute to ICU delirium.

METHODS

We performed a retrospective cohort analysis of patients with shock of any etiology and/or respiratory failure requiring invasive mechanical ventilation, without a neurologic admitting diagnosis. Patients were screened daily for delirium. Cerebral oximetry and mean arterial pressure data were captured for the first 24 hr from enrolment.

RESULTS

Forty-two patients with invasive blood pressure monitoring data were analyzed. Optimal mean arterial pressure targets ranged from 55 to 100 mm Hg. Optimal mean arterial pressure values were not significantly different based on history of hypertension or delirium status, and delirium was not associated with deviations from MAPopt. Nevertheless, the majority (69%) of blood pressure targets exceeded the current 65 mm Hg Surviving Sepsis guidelines.

CONCLUSION

We observed that MAPopt targets across patients were highly variable, but did not observe an association with the incidence of delirium. Studies designed to evaluate the impact on neurologic outcomes are needed to understand the association with individualized mean arterial pressure targets in the ICU.

STUDY REGISTRATION

ClinicalTrials.gov (NCT02344043); first submitted 22 January 2015.

Evaluating Nutritional Risk Factors for Delirium in Intensive-Care-Unit Patients: Present Insights and Prospects for Future Research

Malnutrition, hypercatabolism, and metabolic changes are well-established risk factors for delirium in critically ill patients. Although the exact mechanisms are not fully understood, there is mounting evidence suggesting that malnutrition can cause a variety of changes that contribute to delirium, such as electrolyte imbalances, immune dysfunction, and alterations in drug metabolism. Therefore, a comprehensive metabolic and malnutrition assessment, along with appropriate nutritional support, may help to prevent or ameliorate malnutrition, reduce hypercatabolism, and improve overall physiological function, ultimately lowering the risk of delirium. For this aim, bioelectrical impedance analysis can represent a valuable strategy. Further research into the underlying mechanisms and nutritional risk factors for delirium is crucial to developing more effective prevention strategies. Understanding these processes will allow clinicians to personalize treatment plans for individual patients, leading to improved outcomes and quality of life in the intensive-care-unit survivors.

Association of Blood Pressure Variability with Delirium in Patients with Critical Illness

BACKGROUND

The objective was to examine the association of blood pressure variability (BPV) during the first 24 h after intensive care unit admission with the likelihood of delirium and depressed alertness without delirium ("depressed alertness").

METHODS

This retrospective, observational, cohort study included all consecutive adult patients admitted to an intensive care unit at Mayo Clinic, Rochester, Minnesota, from July 1, 2004, through October 31, 2015. The primary outcomes were delirium and delirium-free days, and the secondary outcomes included depressed alertness and depressed alertness-free days. Logistic regression was performed to determine the association of BPV with delirium and depressed alertness. Proportional odds regression was used to assess the association of BPV with delirium-free days and depressed alertness-free days.

RESULTS

Among 66,549 intensive care unit admissions, delirium was documented in 20.2% and depressed alertness was documented in 24.4%. Preserved cognition was documented in 55.4% of intensive care unit admissions. Increased systolic and diastolic BPV was associated with an increased odds of delirium and depressed alertness. The magnitude of the association per 5-mm Hg increase in systolic average real variability (the average of absolute value of changes between consecutive systolic blood pressure readings) was greater for delirium (odds ratio 1.34; 95% confidence interval 1.29-1.40; P < 0.001) than for depressed alertness (odds ratio 1.06; 95% confidence interval 1.02-1.10; P = 0.004). Increased systolic and diastolic BPV was associated with fewer delirium-free days but not with depressed alertness-free days.

CONCLUSIONS

BPV in the first 24 h after intensive care unit admission is associated with an increased likelihood of delirium and fewer delirium-free days.

Exploring the Pathophysiology of Delirium: An Overview of Biomarker Studies, Animal Models, and Tissue-Engineered Models

Delirium is an acute brain disorder associated with disorganized thinking, difficulty focusing, and confusion that commonly follows major surgery, severe infection, and illness. Older patients are at high risk for developing delirium during hospitalization, which may contribute to increased morbidity, longer hospitalization, and increased risk of institutionalization following discharge. The pathophysiology underlying delirium remains poorly studied. This review delves into the findings from biomarker studies and animal models, and highlights the potential for tissue-engineered models of the brain in studying this condition. The aim is to bring together the existing knowledge in the field and provide insight into the future direction of delirium research.

The phenotype of delirium based on a close reading of diagnostic criteria

OBJECTIVE

Although delirium is well known to acute care clinicians, the features required for its diagnosis and how to understand and operationalize them remain sticking points in the field. To clarify the delirium phenotype, we present a close reading of past and current sets of delirium diagnostic criteria.

METHODS

We first differentiate the delirium syndrome (i.e., features evaluated at bedside) from additional criteria required for diagnosis. Next, we align related features across diagnostic systems and examine them in context to determine intent. Where criteria are ambiguous, we review common delirium instruments to illustrate how they have been interpreted.

RESULTS

An acute disturbance in attention is universally attested across diagnostic systems. A second core feature denotes confusion and has been included across systems as disturbance in awareness, impaired consciousness, and thought disorganization. This feature may be better understood as a disturbance in thought clarity and operationalized in terms of neuropsychological domains thereby clearly linking it to global neurocognitive disturbance. Altered level of activity describes a third core feature, including motor and sleep/wake cycle disturbances. Excluding stupor (wherein mental content cannot be assessed due to reduced arousal) from delirium, as in DSM-5-TR, is appropriate for a psychiatric diagnosis, but the brain injury exclusion in ICD-11 is unjustified.

CONCLUSIONS

The delirium phenotype involves a disturbance in attention, qualitative thought clarity, and quantitative activity level, including in relation to expected sleep/wake cycles. Future diagnostic systems should include a severity threshold and specify that delirium diagnosis refers to a 24-h period.

Non-pharmacological interventions to prevent and treat delirium in older people: An overview of systematic reviews

BACKGROUND

As advanced age is a major risk factor for confusion status, delirium has become prevalent in the older population, contributing to longer hospital stays, cognitive impairment, and higher risks of complications and mortality. Compared with pharmacological methods, non-pharmacological interventions are preferred and are recommended by the National Institute for Health and Care Excellence for the prevention of delirium. Numerous systematic reviews and meta-analyses have been carried out to investigate the effects of non-pharmacological interventions. However, the outcomes were diverse and the quality varied widely, making it challenging to draw firm conclusions from the evidence.

OBJECTIVE

To summarize the contents and evaluate the effects of non-pharmacological interventions to prevent and treat delirium among older people.

DESIGN

Overview of systematic reviews.

METHODS

A comprehensive literature search was conducted in Medline, Cochrane Library, EMBASE, CINAHL, PsycINFO, JBI EBP Database, China's SinoMed, CNKI, and Wangfang databases from inception to 2nd December 2022. Two reviewers performed the study selection, quality appraisal, and data extraction independently. The AMSTAR 2 tool was used to appraise the methodological quality of eligible reviews. The results were presented in narrative synthesis based on types of intervention, including multicomponent and single-component interventions.

RESULTS

Twenty-four systematic reviews were included in this overview, of which four reviews were of high quality. Multicomponent interventions were the most widely disseminated non-pharmacological strategy, which were effective in preventing delirium with 27 %-54 % reduction in delirium incidence. Additionally, the multicomponent strategy also reduced the incidence of falls and pressure ulcers, and showed trends toward shortening the length of stay and improving cognitive function. Among single-component interventions, physical training, geriatric risk assessment, and reorientation protocol revealed positive effects in delirium prevention. However, the effectiveness of non-pharmacological interventions for treating delirium was limited, and while multicomponent methods had inconsistent impacts on the duration and severity of delirium, single-component methods showed no significant impact.

CONCLUSION

Non-pharmacological interventions are effective in reducing the incidence of delirium and improving other health outcomes among older patients. However, the effects on the duration and severity of delirium need more evidence to confirm.

REGISTRATION NUMBER

CRD42022376651 in PROSPERO.

Adverse Drug Event Prevention and Detection in Older Emergency Department Patients

Older adults are given therapies to enhance the quality and longevity of life, but with the benefits of medication therapy also comes the potential for adverse drug events (ADEs). Avoiding ADEs has become a national health priority with substantial impact on health outcomes and health care costs. The presence of multimorbidity, changes in physiologic function, and polypharmacy make older adults more vulnerable to medication-related ADEs. Use of interactive support tools in the form of geriatric-friendly medication order sets and geriatric consultations along with pharmacist-led medication review and optimization are imperative to decrease the occurrence of ADEs and unnecessary prescribing cascades.

Association Between Sedative Medication Administration and Delirium Development in a Medical Intensive Care Unit

Background: Delirium develops frequently in intensive care unit (ICU) patients. Societal guidelines have suggested that benzodiazepines may cause delirium. This study investigates if a change in sedation administration use over time is associated with changes in delirium incidence. Methods: This was a retrospective cohort study conducted over a 4 year time period in a medical ICU. All data was abstracted from a local data warehouse. The primary outcome of the study was the association between annual cumulative benzodiazepine use and incidence of delirium during the study period. Data was analyzed using descriptive characteristics and Spearman's correlation coefficient. Additionally, multivariate logistic regression was performed to identify independent risk factors for delirium development. Results: From 2015 to 2018, annual total benzodiazepine administration decreased from 62,215 mg to 18,105 mg lorazepam equivalents (p = <.01). The cumulative dose of dexmedetomidine increased, with 657,262 mcg administered in 2015 and 1,476,951 mcg in 2018 (p < .01). No differences in annual delirium incidence were found. Risk factors that were significantly correlated with delirium following multivariate logistic regression included acute respiratory distress syndrome, renal failure, hepatic failure, septic shock, severe alcohol withdrawal, vasopressor use, corticosteroid use, benzodiazepine use, antipsychotic use, opiate use, and propofol use. Conclusions: A profound change in sedation medication paradigm did not influence delirium rates in a medical ICU.

Relationship between in-hospital angiotensin converting enzyme inhibitors and Angiotensin receptor blockers administration and delirium in the cardiac ICU

OBJECTIVES

Delirium may be associated with neuroinflammation and reduced blood-brain barrier (BBB) stability. ACE Inhibitors (ACEIs) and Angiotensin Receptor Blockers (ARBs) reduce neuroinflammation and stabilize the BBB, thus slowing the progression of memory loss in patients with dementia. This study evaluated the effect of these medications on delirium prevalence.

METHODS

This was a retrospective study of data from all patients admitted to a Cardiac ICU between 1 January 2020-31 December 2020. The presence of delirium was determined based on the International Classification of Diseases (ICD) 10 codes and nurse delirium screening.

RESULTS

Of the 1684 unique patients, almost half developed delirium. Delirious patients who did not receive either ACEI or ARB had higher odds (odds ratio [OR] 5.88, 95% CI 3.7-9.09, P < .001) of in-hospital death and experienced significantly shorter ICU lengths of stay (LOS) (P = .01). There was no significant effect of medication exposure on the time to delirium onset.

CONCLUSIONS

While ACEIs and ARBs have been shown to slow the progression of memory loss for patients with Alzheimer's disease, we did not observe a difference in time to delirium onset.

Machine learning for prediction of delirium in patients with extensive burns after surgery

AIMS

Machine learning-based identification of key variables and prediction of postoperative delirium in patients with extensive burns.

METHODS

Five hundred and eighteen patients with extensive burns who underwent surgery were included and randomly divided into a training set, a validation set, and a testing set. Multifactorial logistic regression analysis was used to screen for significant variables. Nine prediction models were constructed in the training and validation sets (80% of dataset). The testing set (20% of dataset) was used to further evaluate the model. The area under the receiver operating curve (AUROC) was used to compare model performance. SHapley Additive exPlanations (SHAP) was used to interpret the best one and to externally validate it in another large tertiary hospital.

RESULTS

Seven variables were used in the development of nine prediction models: physical restraint, diabetes, sex, preoperative hemoglobin, acute physiological and chronic health assessment, time in the Burn Intensive Care Unit and total body surface area. Random Forest (RF) outperformed the other eight models in terms of predictive performance (ROC:84.00%) When external validation was performed, RF performed well (accuracy: 77.12%, sensitivity: 67.74% and specificity: 80.46%).

CONCLUSION

The first machine learning-based delirium prediction model for patients with extensive burns was successfully developed and validated. High-risk patients for delirium can be effectively identified and targeted interventions can be made to reduce the incidence of delirium.

Prevalence of delirium in gastroenterology/hepatology units: A cross-sectional study

Prevalence rates of delirium amount to 22.0% within acute-care settings. In contrast, 30-40% of patients with liver cirrhosis may develop hepatic encephalopathy, a condition that has been classified as a syndrome of delirium, based on recent pathophysiology findings. However, the prevalence of delirium in gastroenterology and hepatology units is unknown.The aims of the study were (i) to identify delirium prevalence rates in inpatients of gastroenterology/hepatology wards, (ii) to analyze the delirium motor subtype, and (iii) to assess associations between delirium and patient characteristics.In this monocentric, cross-sectional, epidemiological study, point prevalence was assessed at six time points in three gastroenterology/hepatology units within a German university hospital. Delirium was assessed using the 4 'As' Test (4AT) and delirium subtype by the delirium motor subtype scale. Patient characteristics were collected from patient charts.The sample consisted of 188 patients, aged 18 to 98 years (mean age 64, n=110 male). Of them, 18.1% of patients showed delirium symptoms (61.8% hypoactive, 29.4% mixed, and 8.8% hyperactive). For the participants aged ≥65 years (n=96), prevalence of delirium amounted to 26.0%. Significant associations were observed between delirium and the following characteristics: age (p=0.001), length of hospital stay until assessment (p=0.043), cerebrovascular disease (p=0.002), dementia (p=0.010), diabetes mellitus with chronic complications (p=0.012), and gender (nonsignificant trend, p=0.050), while no association was detected between moderate or severe liver disease and delirium (p=0.414).In conclusion, overall prevalence rates of delirium were rather low and did not increase in patients with liver disease.

Preventing and treating delirium in clinical settings for older adults

Delirium is a serious consequence of many acute or worsening chronic medical conditions, a side effect of medications, and a precipitant of worsening functional and cognitive status in older adults. It is a syndrome characterized by fluctuations in cognition and impaired attention that develops over a short period of time in response to an underlying medical condition, a substance (prescribed, over the counter, or recreational), or substance withdrawal and can be multi-factorial. We present a narrative review of the literature on nonpharmacologic and pharmacologic approaches to prevention and treatment of delirium with a focus on older adults as a vulnerable population. Older adult patients are most at risk due to decreasing physiologic reserves, with delirium rates of up to 80% in critical care settings. Presentation of delirium can be hyperactive, hypoactive, or mixed, making identification and study challenging as patients with hypoactive delirium are less likely to come to attention in an inpatient or long-term care setting. Studies of delirium focus on prevention and treatment with nonpharmacological or medication interventions, with the preponderance of evidence favoring multi-component nonpharmacological approaches to prevention as the most effective. Though use of antipsychotic medication in delirium is common, existing evidence does not support routine use, showing no clear benefit in clinically significant outcome measures and with evidence of harm in some studies. We therefore suggest that antipsychotics be used to treat agitation, psychosis, and distress associated with delirium at the lowest effective doses and shortest possible duration and not be considered a treatment of delirium itself. Future studies may clarify the use of other agents, such as melatonin and melatonin receptor agonists, alpha-2 receptor agonists, and anti-epileptics.

Intraoperative suggestions to prevent postoperative delirium in patients undergoing transaortic valvular replacement: a randomized placebo-controlled trial

BACKGROUND

Postoperative delirium (POD) is a serious complication following anaesthesia and surgery and significantly influences postoperative outcome especially in the elderly population. Intraoperative music and positive suggestions influence postoperative outcomes by attenuating analgesic demand and increasing patient satisfaction.

AIMS

Here, we examined the effect of intraoperative music and positive suggestions on the development of POD in aged patients undergoing transcatheter aortic valve replacement (TAVR) procedure under general anaesthesia.

METHODS

For this randomized placebo-controlled study, eligible patients without cognitive deficit, indicated by a MMSE < 10 points, were anesthetized using remifentanil and sevoflurane. Anaesthetic depth was guide with bispectral index. An audiotape with positive suggestions was applied from a MP3 player via headphones. POD, pain and PONV was assessed. CAM-ICU and Nu-DESC were done twice daily for the first 5 days.

RESULTS

Of 140 patients 118 patients could be analysed (57 male, 80.6 ± 5.1 years). POD was diagnosed in 16 patients (12.7%). POD was significantly more often observed in male (12, 21.1%) than in female (4, 6.6%, p = 0.02) and in patients with a low MMSE (23.6 ± 4.5 vs. 26.8 ± 2.8, p = 0.001). Anaesthetic depth did not influence the incidence of POD. Intraoperative music and suggestions did not affect the rate of POD, pain, analgesic requirement or PONV.

DISCUSSION

In patients undergoing TAVR male sex and low MMSE scoring are associated with an increase in POD.

CONCLUSIONS

Intraoperative music and positive suggestions do not influence the incidence of POD in this patient group.

STUDY REGISTRATION

DRKS: 00024444, start of registration: 4.02.202, final registration: 17.09.2021.

Frailty-originated early rehabilitation reduces postoperative delirium in brain tumor patients: Results from a prospective randomized study

Objective

To investigate the impact of frailty-originated, evidence-based early activity training on postoperative delirium in patients who have undergone brain tumor resection.

Methods

A randomized controlled trial was conducted at the Second Affiliated Hospital of Zhejiang University School of Medicine, from July 2019 to June 2020. Data on the patients' general information, incidence and duration of delirium, duration of hospital stay, and activities of daily living were collected. From the first day after surgery, the patients were randomly assigned to either the traditional care group or the frailty-originated rehabilitation towards intracranial tumors using distinct evidence (FORTITUDE) group. Non-parametric, chi-square, and log-rank tests were used to compare the onset time and duration of postoperative delirium and activities of daily living performed by the participants between the two groups.

Results

In total, 291 patients, 150 and 141 in the control group and FORTITUDE group, respectively, participated in the study. Patients in the FORTITUDE group had a lower incidence of postoperative delirium (15.6% vs. 28.7%, P ​= ​0.007), delayed onset of delirium (Z ​= ​-2.108, P ​= ​0.035), shorter duration of postoperative delirium (χ² ​= ​26.67, P ​< ​0.001), shorter hospital stay (Z ​= ​-2.037, P ​= ​0.042), and higher scores in the activities of daily living one week (Z ​= ​-2.304, P ​= ​0.021) and one month (Z ​= ​-2.724, P ​= ​0.006) after surgery than in the control group.

Conclusions

The FORTITUDE program was safe and effective in reducing the incidence and duration of postoperative delirium and improving the quality of life of patients who underwent brain tumor resection.

Emergence delirium and postoperative delirium associated with high plasma NfL and GFAP: an observational study

Background

Neuroinflammation and neuronal injury have been reported to be associated with the development of postoperative delirium in both preclinical and clinical settings. This study aimed to investigate the potential correlation between biomarkers of neurofilament light chain and glial fibrillary acidic protein and emergence and postoperative delirium in elderly patients undergoing surgery.

Methods

Patients who developed emergence delirium (n = 30) and postoperative delirium (n = 32), along with their matched controls, were enrolled after obtaining ethics approval and written informed consent. Delirium was assessed using the Confusion Assessment Method for the Intensive Care Unit or Confusion Assessment Method scale, and blood samples were collected before and after surgery for plasma neurofilament light chain and glial fibrillary acidic protein measurements using a single-molecule array.

Results

The study found that in patients with emergence delirium, the increase in plasma neurofilament light chain protein levels during surgery was significantly higher than in non-delirium patients (P = 0.002). Additionally, in patients with postoperative delirium, both the increase in plasma neurofilament light chain protein levels (P < 0.001) and the increase in plasma glial fibrillary acidic protein levels during surgery (P = 0.008) were significantly higher than in non-delirium patients. Multivariate logistic regression analysis showed that the increase in plasma neurofilament light chain protein was associated with emergence delirium (adjusted OR = 1.872, P = 0.005), and the increase in plasma glial fibrillary acidic protein was associated with postoperative delirium (adjusted OR = 1.419, P = 0.016). Moreover, the American Society of Anesthesiologists Physical Status Classification and surgical duration were also found to be associated with delirium in elderly patients.

Conclusion

Our findings suggest that emergence delirium is linked to elevated levels of neurofilament light chain, a biomarker of axonal injury, during surgery. Furthermore, in addition to axonal injury, postoperative delirium was also associated with an increase in glial fibrillary acidic protein, a marker of astrocyte activation.

The Impact of Blood Transfusion in Developing Postoperative Delirium in Patients with Hip Fracture Surgery

BACKGROUND

Many studies have been conducted to explore the risk factors associated with postoperative delirium (POD) in order to understand its underlying causes and develop prevention strategies, especially for hip fracture surgery. However, the relationship between blood transfusion and POD has been heatedly debated. The purpose of this study was to evaluate the risk factors of POD and the relationship between blood transfusions and the occurrence of POD in hip fracture surgery through big data analysis.

METHODS

Medical data (including medication history, clinical and laboratory findings, and perioperative variables) were acquired from the clinical data warehouse (CDW) of the five hospitals of Hallym University Medical Center and were compared between patients without POD and with POD.

RESULTS

The occurrence of POD was 18.7% (228 of 2398 patients). The risk factors of POD included old age (OR 4.38, 95% CI 2.77-6.91; p < 0.001), American Society of Anesthesiology physical status > 2 (OR 1.84 95% CI 1.4-2.42; p < 0.001), dementia (OR 1.99, 95% CI 1.53-2.6; p < 0.001), steroid (OR 0.53 95% CI 0.34-0.82; p < 0.001), Antihistamine (OR 1.53 95% CI 1.19-1.96; p < 0.001), and postoperative erythrocyte sedimentation rate (mm/h) (OR 0.97 95% CI 0.97-0.98; p < 0.001) in multivariate logistic regression analysis. The postoperative transfusion (OR 2.53, 95% CI 1.88-3.41; p < 0.001) had a significant effect on the incidence of POD.

CONCLUSIONS

big data analytics using a CDW was a good option to identify the risk factors of POD and to prevent POD in hip fracture surgery.

Confusion assessment method accurately screens for hepatic encephalopathy and predicts short-term mortality in hospitalized patients with cirrhosis

Hepatic encephalopathy (HE), a subtype of delirium, is common in cirrhosis and associated with poor outcomes. Yet, objective bedside screening tools for HE are lacking. We examined the relationship between an established screening tool for delirium, Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) and short-term outcomes while comparing its performance with previously established measures of cognitive function such as West Haven criteria (WHC). Prospectively enrolled adults with cirrhosis who completed the CAM-ICU from 6/2014-6/2018 were followed for 90 days. Blinded provider-assigned West Haven Criteria (WHC) and other measures of cognitive function were collected. Logistic regression was used to test associations between CAM-ICU status and outcomes. Mortality prediction by CAM-ICU status was assessed using Area under the Receiver Operating Characteristics curves (AUROC). Of 469 participants, 11% were CAM-ICU( +), 55% were male and 94% were White. Most patients were Childs-Pugh class C (59%). CAM-ICU had excellent agreement with WHC (Kappa = 0.79). CAM-ICU( +) participants had similar demographic features to those CAM-ICU(-), but had higher MELD (25 vs. 19, p < 0.0001), were more often admitted to the ICU (28% vs. 7%, p < 0.0001), and were more likely to be admitted for HE and infection. CAM-ICU( +) participants had higher mortality (inpatient:37% vs. 3%, 30-day:51% vs. 11%, 90-day:63% vs. 23%, p < 0.001). CAM-ICU status predicted mortality with AUROC of 0.85, 0.82 and 0.77 for inpatient, 30-day and 90-day mortality, respectively. CAM-ICU easily screens for delirium/HE, has excellent agreement with WHC, and identifies a hospitalized cirrhosis cohort with high short-term mortality.

Aberrant inflammatory responses in intoxicated burn-injured patients parallel impaired cognitive function

Burn-injured patients with alcohol use disorder (AUD) have increased morbidity and mortality compared to alcohol-abstaining individuals with similar injuries. It is hypothesized that this is due, in part, to alcohol-induced dysregulation of the systemic inflammatory response, leading to worsened clinical outcomes, including increased susceptibility to infection, and heightened cognitive impairment. To examine the effects of alcohol on inflammatory markers after burn injury, we used multiplex assays to measure a panel of 48 cytokines, chemokines, and growth factors in the plasma of burn patents within 24 h of admission to the University of Colorado Burn Center. Thirty patients were enrolled between July 2018 to February 2020 and were stratified based on presence of AUD and total body surface area (TBSA) burn of ≥20% into four groups: [AUD-, TBSA <20%, N = 12], [AUD+, TBSA <20%, N = 3], [AUD-, TBSA ≥20%, N = 8], [AUD+, TBSA ≥20%, N = 7]. In addition, Confusion Assessment Method (CAM) scores were collected to evaluate patient delirium during the course of hospitalization. Multivariate statistical analysis demonstrated a number of cytokines and other factors that were significantly different between the groups. For example, the anti-inflammatory cytokine interleukin 1 receptor antagonist (IL-1ra) was dampened in the AUD+, TBSA ≥20% cohort with a 75.2% decrease compared to AUD-, TBSA ≥20%, and an 83.9% decrease compared to AUD-, TBSA <20% (p = 0.008). Additionally, plasma levels of the pro-inflammatory mediator CXCL12 (C-X-C motif chemokine ligand 12, also known as stromal cell-derived factor 1, SDF-1) was higher in the AUD + groups (p = 0.03) and similarly, IL-18 levels were greater in AUD+, TBSA ≥20% (p = 0.009). Eotaxin (also known as cytokine CC motif ligand 11, CCL11) was markedly elevated in the AUD+, TBSA ≥20% cohort with a 2.4-fold increase over the AUD-, TBSA ≥20%, and a 1.7-fold rise compared to the AUD-, TBSA <20% cohorts (p = 0.04). Interestingly, there was also a marked rise in CAM + delirium scores (85.7%) among the AUD + patients with TBSA ≥20% (p = 0.02). Not surprisingly, we found that hospital stays increased with AUD+ and larger burns (p = 0.0009). Our findings reveal that burn patients who misuse alcohol have aberrant inflammatory responses that may lead to greater immune dysregulation and worse clinical outcomes.

Delirium prevention and management in hospitalized older adults

ABSTRACT

Delirium is a common neurocognitive disorder among hospitalized older adults, and it can have devastating effects. The purpose of this article is to inform NPs in the hospital setting to recognize, prevent, and manage delirium in older adults. The roles of nonpharmacologic and pharmacologic interventions are described.

An Interdisciplinary Reappraisal of Delirium and Proposed Subtypes

An interdisciplinary plenary session entitled "Rethinking and Rehashing Delirium" was held during the 2021 Annual Meeting of the Academy of Consultation-Liaison Psychiatry to facilitate dialog on the prevalent approach to delirium. Panel members included a psychiatrist, neurointensivist, and critical care specialist, and attendee comments were solicited with the goal of developing a statement. Discussion was focused on a reappraisal of delirium and, in particular, its disparate terminology and history in relation to acute encephalopathy. The authors endorse a recent joint position statement that describes acute encephalopathy as a rapidly evolving (<4 weeks) pathobiological brain process that presents as subsyndromal delirium, delirium, or coma and suggest the following points of refinement: (1) to suggest that "delirium disorder" describe the diagnostic construct including its syndrome, precipitant(s), and unique pathophysiology; (2) to restrict the term "delirium" to describing the clinical syndrome encountered at the bedside; (3) to clarify that the disfavored term "altered mental status" may occasionally be an appropriate preliminary designation where the diagnosis cannot yet be specified further; and (4) to provide rationale for rejecting the terms acute brain injury, failure, or dysfunction. The final common pathway of delirium appears to involve higher-level brain network dysfunction, but there are many insults that can disrupt functional connectivity. We propose that future delirium classification systems should seek to characterize the unique pathophysiological disturbances ("endotypes") that underlie delirium and delirium's individual neuropsychiatric symptoms. We provide provisional means of classification in hopes that novel subtypes might lead to specific intervention to improve patient experience and outcomes. This paper concludes by considering future directions for the field. Key areas of opportunity include interdisciplinary initiatives to harmonize efforts across specialties and settings, enhance underrepresented groups in research, integration of delirium and encephalopathy in coding, development of relevant quality and safety measures, and exploration of opportunities for translational science.

Postoperative Delirium in Patients Receiving Hip Bipolar Hemiarthroplasty for Displaced Femoral Neck Fractures: The Risk Factors and Further Clinical Outcomes

BACKGROUND

Postoperative delirium in patients who have hip fractures may lead to poor outcomes. This study aimed to determine perioperative risk factors and clinical outcomes of postoperative delirium in patients undergoing hip bipolar hemiarthroplasty for displaced femoral neck fractures.

METHODS

Among 1,353 patients who underwent hemiarthroplasty at our institution during 2013-2021, we identified 78 patients with postoperative delirium diagnosed with the confusion assessment method. The mean delirium duration was 28 hours (range: 15-520). We also included 1:2 sex- and age-matched patients who did not have postoperative delirium after the same surgery as a matching cohort for comparison. Patient comorbidities, perioperative data, delirium occurrence, and outcomes were collected for analyses.

RESULTS

A Charlson Comorbidity Index (CCI) score ≥6 (odds ratio (OR): 2.08, P = .017), nighttime surgery (OR: 3.47, p =<.001), surgical delays (OR: 1.01, P = .012), preoperative anemia (OR: 2.1, P = .012), and blood transfusions (OR: 2.47, P = .01) may increase the risk of postoperative delirium. The presentation of delirium was associated with sepsis (OR: 3.77, P = .04), longer hospital stays (P < .001), higher 1-year mortality (OR: 3.97, P = .002), and overall mortality (OR: 2.1, P = .02).

CONCLUSION

Postoperative delirium predicted poor outcomes. Our results emphasized the importance of early identification of patients at risk and optimization of the medical conditions before and after surgery.

Postoperative Delirium After Intracranial Surgery: A Retrospective Cohort Study

BACKGROUND

The clinical relevance of postoperative delirium (POD) in neurosurgery remains unclear and should be investigated because these patients are vulnerable. Hence, we investigated the impact of POD, by means of incidence and health outcomes, and identified independent risk factors.

METHODS

Adult patients undergoing an intracranial surgical procedure in the Erasmus Medical Center Rotterdam between June 2017 and September 2020 were retrospectively included. POD incidence, defined by a Delirium Observation Screening Scale (DOSS) ≥3 or antipsychotic treatment for delirium within 5 days after surgery, was calculated. Logistic regression analysis on the full data set was conducted for the multivariable risk factor and health outcome analyses.

RESULTS

After including 2901 intracranial surgical procedures, POD was present in 19.4% with a mean onset in days of 2.62 (standard deviation, 1.22) and associated with more intensive care unit admissions and more discharge toward residential care. Onset of POD was not associated with increased length of hospitalization or mortality. We identified several independent nonmodifiable risk factors such as age, preexisting memory problems, emergency operations, craniotomy compared with burr-hole surgery, and severe blood loss. Moreover, we identified modifiable risk factors such as low preoperative potassium and opioid and dexamethasone administration.

CONCLUSIONS

Our POD incidence rates and correlation with more intensive care unit admission and discharge toward residential care suggest a significant impact of POD on neurosurgical patients. We identified several modifiable and nonmodifiable risk factors, which shed light on the pathophysiologic mechanisms of POD in this cohort and could be targeted for future intervention studies.

Altered Tryptophan-Kynurenine Pathway in Delirium: A Review of the Current Literature

Delirium, a common form of acute brain dysfunction, is associated with increased morbidity and mortality, especially in older patients. The underlying pathophysiology of delirium is not clearly understood, but acute systemic inflammation is known to drive delirium in cases of acute illnesses, such as sepsis, trauma, and surgery. Based on psychomotor presentations, delirium has three main subtypes, such as hypoactive, hyperactive, and mixed subtype. There are similarities in the initial presentation of delirium with depression and dementia, especially in the hypoactive subtype. Hence, patients with hypoactive delirium are frequently misdiagnosed. The altered kynurenine pathway (KP) is a promising molecular pathway implicated in the pathogenesis of delirium. The KP is highly regulated in the immune system and influences neurological functions. The activation of indoleamine 2,3-dioxygenase, and specific KP neuroactive metabolites, such as quinolinic acid and kynurenic acid, could play a role in the event of delirium. Here, we collectively describe the roles of the KP and speculate on its relevance in delirium.

Effect of Transcranial Direct Current Stimulation on Motor Recovery in Altered Conscious Patients after Traumatic Brain Injury and Cerebrovascular Accident: A Randomized Clinical Trial

Background and Purpose Altered levels of consciousness resulting from a vascular insult to the brain can vary from confusion to coma. A disruption in the function of the brain stem reticular activating system in the brain stem or both cerebral hemispheres and thalami causes coma. This study is aimed at finding the effect of transcranial direct current stimulation (tDCS) on motor recovery in altered conscious patients after traumatic brain injury and cerebrovascular accident.

Materials and Methods A total of 100 patients admitted to the neurology and neurosurgery unit of the university hospital were screened and 40 subjects who satisfied inclusion criteria were recruited and randomly divided into two groups, group A (experimental) (n = 20) and group B (control)(n = 20), by computerized randomization. Written informed consent was taken from all the caregivers before recruitment. After taking the preliminary assessment, anodal tDCS is given to the motor area (C3/C4 ipsilesional), sensory area (P3/P4 ipsilesional), and left dorsolateral prefrontal cortex (F3) according to the 10/20 electroencephalogram montage for two sessions of 20 min/day for 7 consecutive days. Routine physiotherapy was also given the same as group B.

Results At baseline, there were no significant group differences in the baseline characteristics. The groups passed the normality test. The results were tested for statistical significance between the groups by Mann–Whitney U test and by one-way analysis of variance and Tukey Honest Significant Difference for post-hoc comparison; the results were statistically different with p-value less than 0.05 with a large effect size.

Conclusion We conclude, based on the results of this study, that tDCS can be effective in motor recovery in altered consciousness patients. It is noninvasive, cost-effective with minimal contraindications, and does not interfere with other modalities in the intensive care unit. Hence, it can be administered safely under the supervision of a qualified therapist.

Diagnostic accuracy of the "4 A's Test" delirium screening tool for the postoperative cardiac surgery ward

BACKGROUND

Delirium is prevalent and underdetected among cardiac surgery patients on the postoperative ward. This study aimed to validate the 4 A's Test delirium screening tool and evaluate its accuracy both when used by research assistants and when subsequently implemented by nursing staff on the ward.

METHODS

This single-center, prospective observational study evaluated the performance of the 4 A's Test administered by research assistants (phase 1) and nursing staff (phase 2). Assessments were undertaken during the patients' first 3 postoperative days on the postcardiac surgery ward along with previous routine nurse-led Confusion Assessment Method assessments. These index tests were compared with a reference standard diagnosis of delirium based on Diagnostic and Statistical Manual of Mental Disorders 5th Edition criteria. Surveys regarding delirium screening were administered to nurses pre- and postimplementation of the 4 A's Test in phase 2 of the study.

RESULTS

In phase 1, a total of 137 patients were enrolled, of whom 24.8% experienced delirium on the postoperative cardiac ward. The 4 A's Test had a sensitivity of 85% (95% confidence interval, 73-93) and a specificity of 90% (95% confidence interval, 85-93) compared with the reference standard. The nurse-assessed Confusion Assessment Method had a sensitivity of 23% (95% confidence interval, 13-37) and specificity of 100% (95% confidence interval, 99-100). In phase 2, nurses (n = 51) screened 179 patients for delirium using the 4 A's Test. Compared with the reference rater, the 4 A's Test had a sensitivity of 58% (95% confidence interval, 28-85) and specificity of 94% (95% confidence interval, 85-98). Postimplementation, 64% of nurses thought that the 4 A's Test improved their confidence in delirium detection, and 76% of nurses would consider routine 4 A's Test use.

CONCLUSIONS

The 4 A's Test demonstrated moderate sensitivity and high specificity to detect delirium in a real-world setting after cardiac surgery on the postoperative ward. A modified model of use with less frequent administration, along with increased engagement of the postoperative team, is recommended to improve early delirium detection on the cardiac surgery postoperative ward.

Analysis of citation trends to identify articles on delirium worth reading using DDPP model with temporal heatmaps (THM): A bibliometric analysis

BACKGROUND

Delirium is one of the most common geriatric syndromes in older patients, accounting for 25% of hospitalized older patients, 31 to 35% of patients in the intensive care unit, and 8% to 17% of older patients in the emergency department (ED). A number of articles have been published in the literature regarding delirium. However, it is unclear about article citations evolving in the field. This study proposed a temporal heatmap (THM) that can be applied to all bibliographical studies for a better understanding of cited articles worth reading.

METHODS

As of November 25, 2022, 11,668 abstracts published on delirium since 2013 were retrieved from the Web of Science core collection. Research achievements were measured using the CJAL score. Social network analysis was applied to examine clusters of keywords associated with core concepts of research. A THM was proposed to detect articles worth reading based on recent citations that are increasing. The 100 top-cited articles related to delirium were displayed on an impact beam plot (IBP).

RESULTS

The results indicate that the US (12474), Vanderbilt University (US) (634), Anesthesiology (2168), and Alessandro Morandi (Italy) (116) had the highest CJAL scores in countries, institutes, departments, and authors, respectively. Articles worthy of reading were highlighted on a THM and an IBP when an increasing trend of citations over the last 4 years was observed.

CONCLUSION

The THM and IBP were proposed to highlight articles worth reading, and we recommend that more future bibliographical studies utilize the 2 visualizations and not restrict them solely to delirium-related articles in the future.

Antipsychotic Medication Use Among Older Adults Following Infection-Related Hospitalization

Importance

There are limited data on discontinuation rates of antipsychotic medications (APMs) used to treat delirium due to acute hospitalization in the routine care of older adults.

Objective

To investigate discontinuation rates and patient characteristics of APMs used to treat delirium following infection-related hospitalization among older US adults.

Design, Setting, and Participants

This retrospective cohort study was conducted using US claims data (Optum's deidentified Clinformatics Data Mart database) for January 1, 2004, to May 31, 2022. Patients were aged 65 years or older without prior psychiatric disorders and had newly initiated an APM prescription within 30 days of an infection-related hospitalization. Statistical analysis was performed on December 15, 2022.

Exposures

New use (no prior use any time before cohort entry) of oral haloperidol and atypical APMs (aripiprazole, olanzapine, quetiapine, risperidone, etc).

Main Outcomes and Measures

The primary outcome was APM discontinuation, defined as a gap of more than 15 days following the end of an APM dispensing. Survival analyses and Kaplan-Meier analyses were used.

Results

Our study population included 5835 patients. Of these individuals, 790 (13.5%) were new haloperidol users (mean [SD] age, 81.5 [6.7] years; 422 women [53.4%]) and 5045 (86.5%) were new atypical APM users (mean [SD] age, 79.8 [7.0] years; 2636 women [52.2%]). The cumulative incidence of discontinuation by 30 days after initiation was 11.4% (95% CI, 10.4%-12.3%) among atypical APM users and 52.1% (95% CI, 48.2%-55.7%) among haloperidol users (P < .001 for difference between haloperidol vs atypical APMs). We observed an increasing trend in discontinuation rates from 2004 to 2022 (5% increase [95% CI, 3%-7%] per year) for haloperidol users (adjusted hazard ratio, 1.05 [1.03-1.07]; P < .001) but not for atypical APM users (1.00 [0.99-1.01]; P = .67). Prolonged hospitalization and dementia were inversely associated with the discontinuation of haloperidol and atypical APMs.

Conclusions and Relevance

The findings of this cohort study suggest that the discontinuation rate of newly initiated APMs for delirium following infection-related hospitalization was lower in atypical APM users than in haloperidol users, with prolonged hospitalization and dementia as major associated variables. The discontinuation rate was substantially higher in recent years for haloperidol but not for atypical APMs.

[Delirium in the context of intensive care medicine-Part 1: epidemiology, definitions, pathophysiology]

The prevalence of delirium syndromes is high, they are often underdiagnosed and therefore medically as well as economically highly relevant syndromes due to the long-term sequelae. In the majority of cases, delirium has a multifactorial etiology, which is why a comprehensive search for the cause is of highest priority. Surgery, administration of potentially proinflammatory drugs as well as the intensive care environment, including the underlying disease and drugs used, represent relevant etiological factors. Pathophysiology and psychopathology are complex and vary depending on the etiological factors present. Prominent impairment of attention and consciousness are central symptoms of delirium allowing the differentiation from important differential diagnoses, such as encephalopathy, depression, psychosis and dementia.

Cerebrospinal fluid quinolinic acid is strongly associated with delirium and mortality in hip-fracture patients

BACKGROUNDThe kynurenine pathway (KP) has been identified as a potential mediator linking acute illness to cognitive dysfunction by generating neuroactive metabolites in response to inflammation. Delirium (acute confusion) is a common complication of acute illness and is associated with increased risk of dementia and mortality. However, the molecular mechanisms underlying delirium, particularly in relation to the KP, remain elusive.METHODSWe undertook a multicenter observational study with 586 hospitalized patients (248 with delirium) and investigated associations between delirium and KP metabolites measured in cerebrospinal fluid (CSF) and serum by targeted metabolomics. We also explored associations between KP metabolites and markers of neuronal damage and 1-year mortality.RESULTSIn delirium, we found concentrations of the neurotoxic metabolite quinolinic acid in CSF (CSF-QA) (OR 2.26 [1.78, 2.87], P < 0.001) to be increased and also found increases in several other KP metabolites in serum and CSF. In addition, CSF-QA was associated with the neuronal damage marker neurofilament light chain (NfL) (β 0.43, P < 0.001) and was a strong predictor of 1-year mortality (HR 4.35 [2.93, 6.45] for CSF-QA ≥ 100 nmol/L, P < 0.001). The associations between CSF-QA and delirium, neuronal damage, and mortality remained highly significant following adjustment for confounders and multiple comparisons.CONCLUSIONOur data identified how systemic inflammation, neurotoxicity, and delirium are strongly linked via the KP and should inform future delirium prevention and treatment clinical trials that target enzymes of the KP.FUNDINGNorwegian Health Association and South-Eastern Norway Regional Health Authorities.