Prediction of delirium in critically ill patients with elevated C-reactive protein

Predicting postoperative delirium after percutaneous transluminal angioplasty and stenting in patients with intracranial atherosclerotic stenosis

OBJECTIVE

Known as a major surgical complication, postoperative delirium (POD) has not been well studied in patients with intracranial atherosclerotic stenosis (ICAS). This study aimed to investigate the correlation between perioperative clinical characteristics and the occurrence of POD.

METHODS

Patients' demographic characteristics and perioperative testing data were collected. Binary logistic regression was conducted for assessing related risk factors. A nomogram was developed to predict the occurrence of POD after percutaneous transluminal angioplasty and stenting (PTAS) in patients with ICAS.

RESULTS

The occurrence of POD in this study was 30.67%. Among all the clinical and laboratory characteristics in patients, age (OR = 1.234, 95%CI = 1.004-1.517, p = 0.046), gender (OR = 5.676, 95%CI = 1.028-31.334, p = 0.046), preoperative MMSE scores (OR = 2.298, 95%CI = 1.005-5.259, p = 0.049), the degree of stenosis (OR = 6.294, 95%CI = 1.043-37.974, p = 0.045), operating time (OR = 1.088, 95%CI = 1.023-1.157, p = 0.006), and HbA1c levels (OR = 2.226, 95%CI = 1.199-4.130, p = 0.011) were the independent risk factors.

CONCLUSION

Male patients with advanced-age, lower preoperative MMSE scores, severe stenosis, longer operating time, and higher HbA1c levels are closely related to POD after PTAS. Fully perioperative assessments may play an important role in predicting the occurrence of POD.

Machine learning-based model to predict delirium in patients with advanced cancer treated with palliative care: a multicenter, patient-based registry cohort

This study aimed to present a new approach to predict to delirium admitted to the acute palliative care unit. To achieve this, this study employed machine learning model to predict delirium in patients in palliative care and identified the significant features that influenced the model. A multicenter, patient-based registry cohort study in South Korea between January 1, 2019, and December 31, 2020. Delirium was identified by reviewing the medical records based on the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. The study dataset included 165 patients with delirium among 2314 patients with advanced cancer admitted to the acute palliative care unit. Seven machine learning models, including extreme gradient boosting, adaptive boosting, gradient boosting, light gradient boosting, logistic regression, support vector machine, and random forest, were evaluated to predict delirium in patients with advanced cancer admitted to the acute palliative care unit. An ensemble approach was adopted to determine the optimal model. For k-fold cross-validation, the combination of extreme gradient boosting and random forest provided the best performance, achieving the following accuracy metrics: 68.83% sensitivity, 70.85% specificity, 69.84% balanced accuracy, and 74.55% area under the receiver operating characteristic curve. The performance of the isolated testing dataset was also validated, and the machine learning model was successfully deployed on a public website ( http://ai-wm.khu.ac.kr/Delirium/ ) to provide public access to delirium prediction results in patients with advanced cancer. Furthermore, using feature importance analysis, sex was determined to be the top contributor in predicting delirium, followed by a history of delirium, chemotherapy, smoking status, alcohol consumption, and living with family. Based on a large-scale, multicenter, patient-based registry cohort, a machine learning prediction model for delirium in patients with advanced cancer was developed in South Korea. We believe that this model will assist healthcare providers in treating patients with delirium and advanced cancer.

Systemic inflammation and delirium during critical illness

PURPOSE

The purpose of this study was to determine associations between markers of inflammation and endogenous anticoagulant activity with delirium and coma during critical illness.

METHODS

In this prospective cohort study, we enrolled adults with respiratory failure and/or shock treated in medical or surgical intensive care units (ICUs) at 5 centers. Twice per day in the ICU, and daily thereafter, we assessed mental status using the Richmond Agitation Sedation Scale (RASS) and the Confusion Assessment Method-Intensive Care Unit (CAM-ICU). We collected blood samples on study days 1, 3, and 5, measuring levels of C-reactive protein (CRP), interferon gamma (IFN-γ), interleukin (IL)-1 beta (IL-1β), IL-6, IL-8, IL-10, IL-12, matrix metalloproteinase-9 (MMP-9), tumor necrosis factor-alpha (TNF-α), tumor necrosis factor receptor 1 (TNFR1), and protein C using validated protocols. We used multinomial logistic regression to analyze associations between biomarkers and the odds of delirium or coma versus normal mental status the following day, adjusting for age, sepsis, Sequential Organ Failure Assessment (SOFA), study day, corticosteroids, and sedatives.

RESULTS

Among 991 participants with a median age (interquartile range, IQR) of 62 [53-72] years and enrollment SOFA of 9 [7-11], higher concentrations of IL-6 (odds ratio [OR] [95% CI]: 1.8 [1.4-2.3]), IL-8 (1.3 [1.1-1.5]), IL-10 (1.5 [1.2-1.8]), TNF-α (1.2 [1.0-1.4]), and TNFR1 (1.3 [1.1-1.6]) and lower concentrations of protein C (0.7 [0.6-0.8])) were associated with delirium the following day. Higher concentrations of CRP (1.4 [1.1-1.7]), IFN-γ (1.3 [1.1-1.5]), IL-6 (2.3 [1.8-3.0]), IL-8 (1.8 [1.4-2.3]), and IL-10 (1.5 [1.2-2.0]) and lower concentrations of protein C (0.6 [0.5-0.8]) were associated with coma the following day. IL-1β, IL-12, and MMP-9 were not associated with mental status.

CONCLUSION

Markers of inflammation and possibly endogenous anticoagulant activity are associated with delirium and coma during critical illness.

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.

Application of Multiple Omics to Understand Postoperative Delirium Pathophysiology in Humans

Delirium, an acute change in cognition, is common, morbid, and costly, particularly among hospitalized older adults. Despite growing knowledge of its epidemiology, far less is known about delirium pathophysiology. Initial work understanding delirium pathogenesis has focused on assaying single or a limited subset of molecules or genetic loci. Recent technological advances at the forefront of biomarker and drug target discovery have facilitated application of multiple "omics" approaches aimed to provide a more complete understanding of complex disease processes such as delirium. At its basic level, "omics" involves comparison of genes (genomics, epigenomics), transcripts (transcriptomics), proteins (proteomics), metabolites (metabolomics), or lipids (lipidomics) in biological fluids or tissues obtained from patients who have a certain condition (i.e., delirium) and those who do not. Multi-omics analyses of these various types of molecules combined with machine learning and systems biology enable the discovery of biomarkers, biological pathways, and predictors of delirium, thus elucidating its pathophysiology. This review provides an overview of the most recent omics techniques, their current impact on identifying delirium biomarkers, and future potential in enhancing our understanding of delirium pathogenesis. We summarize challenges in identification of specific biomarkers of delirium and, more importantly, in discovering the mechanisms underlying delirium pathophysiology. Based on mounting evidence, we highlight a heightened inflammatory response as one common pathway in delirium risk and progression, and we suggest other promising biological mechanisms that have recently emerged. Advanced multiple omics approaches coupled with bioinformatics methodologies have great promise to yield important discoveries that will advance delirium research.

Prevalence and Risk Factors of Delirium in Patients Admitted to Intensive Care Units: A Multicentric Cross-Sectional Study

Background Delirium is a common and serious complication among critically ill patients in the intensive care unit. Knowledge of the risk factors of delirium can help tremendously in the diagnosis of delirium. Methods In April of 2023, a cross-sectional multicenter study was conducted in eight intensive care units (ICUs) across Pakistan. Delirium was assessed using the intensive care delirium screening checklist. Demographic and clinical data were collected, and multivariable logistic regression analysis was performed to identify predictors of delirium. A total of 256 patients were enrolled in the study. Results The mean age of participants was 56 (S.D. 12) years. The point prevalence of delirium was 39%, and the point prevalence did not vary significantly among the participating intensive care units. Advanced age, higher Acute Physiology and Chronic Health Evaluation - IV (APACHE IV) scores, and higher Richmond Agitation-Sedation Scale (RASS) scores at enrollment were identified as significant predictors of delirium. Conclusion The high prevalence of delirium, observed at 39.0%, emphasizes the importance of proactive screening and effective management strategies in the ICU setting. Healthcare providers in Pakistan should be mindful of these risk factors and implement preventive measures to minimize the occurrence of delirium in critically ill patients. Further research and implementation of targeted interventions are warranted to improve patient outcomes and enhance the overall quality of care in this population.

Meta-analysis of serological biomarkers at hospital admission for the likelihood of developing delirium during hospitalization

Importance

Identifying biomarkers that, at hospital admission, predict subsequent delirium will help to focus our clinical efforts on prevention and management.

Objective

The study aimed to investigate biomarkers at hospital admission that may be associated with delirium during hospitalization.

Data sources

A librarian at the Fraser Health Authority Health Sciences Library performed searches from 28 June 2021 to 9 July 2021, using the following sources: Medline, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register, and the Database of Abstracts of Reviews and Effects.

Study selection

The inclusion criteria were articles in English that investigated the link between serum concentration of biomarkers at hospital admission and delirium during hospitalization. Exclusion criteria were single case reports, case series, comments, editorials, letters to the editor, articles that were not relevant to the review objective, and articles concerning pediatrics. After excluding duplicates, 55 studies were included.

Data extraction and synthesis

This meta-analysis followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocol. Independent extraction, with the consensus of multiple reviewers, was used to determine the final studies included. The weight and heterogeneity of the manuscripts were calculated using inverse covariance with a random-effects model.

Main outcomes and measures

Differences in mean serum concentration of biomarkers at hospital admission between patients who did and did not develop delirium during hospitalization.

Results

Our search found evidence that patients who developed delirium during hospitalization had, at hospital admission, significantly greater concentrations of certain inflammatory biomarkers and one blood-brain barrier leakage marker than patients who did not develop delirium during hospitalization (differences in the mean: cortisol: 3.36 ng/ml, p < 0.0001; CRP: 41.39 mg/L, p < 0.00001; IL-6: 24.05 pg/ml, p < 0.00001; S100β 0.07 ng/ml, p < 0.00001). These differences were independent of other confounding variables such as the patient's severity of illness. A significantly lower serum concentration, at hospital admission, of acetylcholinesterase (difference in the means -0.86 U/ml, p = 0.004) was also associated with an increased vulnerability to developing delirium during hospitalization.

Conclusion and relevance

Our meta-analysis supports the hypothesis that patients with hypothalamic-pituitary axis dysfunction, increased blood-brain barrier permeability, and chronic overload of the cholinergic system, at hospital admission, are more vulnerable to developing delirium during hospitalization.

Plasma biomarkers and delirium in critically ill patients after cardiac surgery: A prospective observational cohort study

BACKGROUND

Delirium is common in postoperative critically ill patients and may affect by intraoperative events. Biomarkers are vital indicators in the development and prediction of delirium.

OBJECTIVES

This study aimed to investigate the associations between various plasma biomarkers and delirium.

METHODS

We performed a prospective cohort study on cardiac surgery patients. Delirium assessment was performed twice daily using the confusion assessment method for the intensive care unit (ICU), and the Richmond Agitation Sedation Scale was used to assess the depth of sedation and agitation. Blood samples were collected on the day after ICU admission, and the concentrations of cortisol, interleukin (IL)-1β, IL-6, tumor necrosis factor α, soluble tumor necrosis factor receptor-1 (sTNFR-1), and sTNFR-2 were measured.

RESULTS

Delirium in the ICU was noted in 93 (29.2%, 95% CI 24.2-34.3) out of 318 patients (mean age 52 years, SD 12.0). The longer duration of cardiopulmonary bypass, aortic clamping and surgery, and higher plasma, erythrocytes, and platelet transfusion requirements were among the significant differences in intraoperative events between patients with and without delirium. Median levels of IL-6 (p = 0.017), TNF-α (p = 0.048), sTNFR-1 (p < 0.001), and sTNFR-2 (p = 0.001) were significantly higher in patients with delirium than in those without it. After adjusting for demographic variables and intraoperative events, only sTNFR-1 (odds ratio 6.83, 95% CI: 1.14-40.90) was associated with delirium.

CONCLUSIONS

Plasma IL-6, TNF-α, sTNFR-1, and sTNFR-2 levels were higher in ICU-acquired delirium patients after cardiac surgery. sTNFR-1 was a potential indicator of the disorder.

Prediction of Delirium in the Critically Ill Obstetric Patients: An Old Friend to the Rescue?

How to cite this article: Sinha S, Bhattacharjee S. Prediction of Delirium in the Critically Ill Obstetric Patients: An Old Friend to the Rescue? Indian J Crit Care Med 2023;27(5):301-302.

Correlation of C-reactive Protein with Delirium in Obstetrics Intensive Care Unit: A Tertiary Center Experience

Background

Delirium is a neuropsychiatric illness. It affects critically ill patients on ventilator and increases mortality. The aim of this study was to evaluate the association of C-reactive protein (CRP) level with delirium in critically obstetrics women and its role in prediction of delirium.

Materials and methods

Arospective observational study was conducted in the intensive care unit (ICU), and the duration of study was one year. Total 145 subjects were recruited, 33 patients were excluded, and 112 subjects were studied. For study, group A (n = 36) includes critically ill obstetric women who had delirium on admission; group B (n = 37) includes critically ill obstetric women who developed delirium within 7 days; and group C (n = 39) that includes critically ill obstetric women who did not develop delirium after follow-up of 7 days was served as control. Disease severity was assessed by using acute physiologic assessment and chronic health evaluation (APACHE) II score, and Richmond Agitation-Sedation Scale (RASS) was used to assess awakeness. In awake patients (RASS of ≥3), delirium was assessed by the use of confusion assessment method for ICU tools. C-reactive protein measured by particle enhanced turbidimetric immunoassay-two point kinetic method.

Results

The mean ages of group A, B, and C were 26.44 ± 4.72, 27.46 ± 4.97, and 28.26 ± 5.67 years, respectively. C-reactive protein levels on the day of delirium development (group B) were found to be significantly higher than day 1 CRP levels of groups A and C. The mean Global Attentiveness Rating (GAR) was significantly lower in groups A and B as compared to that in group C (p < 0.001). On evaluating the correlation of CRP with GAR, it was found to be inverse and mild in strength for the correlation between CRP and GAR (r = -0.403, p < 0.001). At a cut-off value of >181 mg/L, CRP had sensitivity of 93.2% and specificity of 69.2%. The positive predictive value was 85% and the negative predictive value was 84.4% that differentiate delirium from non-delirium.

Conclusion

C-reactive protein is a useful tool for screening and prediction of delirium in critically ill obstetric patients.

How to cite this article

Shyam R, Patel ML, Solanki M, Sachan R, Ali W. Correlation of C-reactive Protein with Delirium in Obstetrics Intensive Care Unit: A Tertiary Center Experience. Indian J Crit Care Med 2023;27(5):315-321.

Postoperative C-Reactive Protein Predicts Postoperative Delirium in Colorectal Cancer Following Surgery

Background

Postoperative delirium (POD) is a common complication in operative patients. Neuroinflammation has been reported to be a potential mechanism associated with the development of POD. Identifying available inflammatory markers such as C-reactive protein (CRP) would aid clinicians in early detection of POD. Previous studies have demonstrated that CRP may be a promising predictive marker for POD. Thus, this study aimed to explore the association between CRP and POD among those elderly colorectal cancer (CRC) patients.

Methods

643 patients with CRC were included in this study. CRP levels were measured before operation and on postoperative day 1. The univariate and multivariate regression analyses were used to identify risk factors for POD.

Results

Of 643 patients with CRC, 112 cases (17.4%) had POD. CRC patients with POD showed older age, higher CRP level on postoperative day 1, and higher percentage of smoking, diabetes mellitus, and chronic obstructive pulmonary disease (COPD) than CRC patients without POD. Preoperative CRP level was not associated with the POD. Univariate and multivariate regression analyses showed that older age (> 70 years), diabetes mellitus, COPD, and higher CRP level on postoperative day 1 (> 48 mg/L) were risk factors for POD in CRC patients.

Conclusion

Postoperative CRP level is an independent indicator for POD among CRC patients, suggesting the predictive role of postoperative CRP levels for POD in elderly CRC patients undergoing surgery.

Proteomics for the Discovery of Clinical Delirium Biomarkers: A Systematic Review of Major Studies

Delirium represents a significant health care burden, diagnosed in more than 2 million elderly Americans each year. In the surgical population, delirium remains the most common complication among elderly patients, and is associated with longer hospital stays, higher costs of care, increased mortality, and functional impairment. The pathomechanism of disease is poorly understood, with current diagnostic approaches somewhat subjective and arbitrary, and definitive diagnostic biomarkers are currently lacking. Despite the recent interest in delirium research, biomarker discovery for it remains new. Most attempts to discover biomarkers are targeted studies that seek to assess the involvement of one or more members of a focused panel of candidates in delirium. For a more unbiased, system-biology view, we searched literature from Medical Literature Analysis and Retrieval System Online (MEDLINE), Cochrane Central, Web of Science, SCOPUS, and Dimensions between 2016 and 2021 for untargeted proteomic discovery studies for biomarkers of delirium conducted on human geriatric subjects. Two reviewers conducted an independent review of all search results and resolved discordance by consensus. From an overall search of 1172 publications, 8 peer-reviewed studies met our defined inclusion criteria. The 370 unique perioperative biomarkers identified in these reports are enriched in pathways involving activation of the immune system, inflammatory response, and the coagulation cascade. The most frequently identified biomarker was interleukin-6 (IL-6). By reviewing the distribution of protein biomarker candidates from these studies, we conclude that a panel of proteins, rather than a single biomarker, would allow for discriminating delirium cases from noncases. The paucity of hypothesis-generating studies in the peer-reviewed literature also suggests that a system-biology view of delirium pathomechanisms has yet to fully emerge.

Association of C-reactive protein to albumin ratio with postoperative delirium and mortality in elderly patients undergoing hip fracture surgery: A retrospective cohort study in a single large center

BACKGROUND

Postoperative delirium is a common complication in elderly patients who have undergone hip fracture surgery. Since postoperative delirium is associated with poor outcomes and the treatment is very complicated, identifying the patients at high risk for delirium and providing more attentive care to prevent postoperative delirium is essential. In this study, we aimed to assess the association of an elevated C-reactive protein (CRP)/albumin ratio with the increased incidence of postoperative delirium in elderly people who had undergone hip fracture surgery.

METHODS

A total of 629 patients who underwent hip fracture surgery between January 2014 and December 2018 were retrospectively analyzed. Patients were classified into two groups according to preoperative CRP/albumin cut-off levels (<1.5 and ≥1.5). We performed a propensity score matching analysis to compare the incidence of postoperative delirium and overall mortality between the two groups. Multivariate logistic regression and Cox regression analyses were performed to examine the association of the preoperative CRP/albumin ratio with postoperative delirium and overall mortality.

RESULTS

There were significant differences in the incidence of postoperative delirium (18.0 % vs. 35.8 %, P < 0.001) and overall mortality (26.7 % vs. 46.9 %, P < 0.001) between the groups before matching. We also observed significant differences in the incidence of postoperative delirium (20.7 % vs. 32.7 %, P = 0.019) and overall mortality (34.7 % vs. 46.0 %, P = 0.046) between the groups after matching. A high CRP/albumin ratio (≥1.5) was significantly associated with a higher incidence of postoperative delirium (adjusted odds ratio [OR]: 2.11, 95 % confidence interval [CI]: 1.40-3.18, P < 0.001) and a higher rate of overall mortality (adjusted hazard ratio [HR]: 1.44, 95 % CI: 1.07-1.93, P = 0.015).

CONCLUSION

Preoperative CRP/albumin ratio might be an independent risk factor of postoperative delirium and surgical prognosis in elderly patients undergoing hip fracture surgery.

Relationship Among Clinically Obtained Biomarkers of Inflammation, Hypercoagulability, and Macrophage Activation, and Delirium in Critically Ill Patients With COVID-19

Critically ill patients with COVID-19 experience high rates of delirium and coma. Whether delirium occurs through novel mechanisms in COVID-19 is not known. We analyzed the relationship among biomarkers of inflammation (C-reactive protein [CRP]), hypercoagulability (d-dimer), and lung macrophage activation (ferritin), and the primary composite outcome of delirium/coma next day. We also measured associations between biomarkers and next day delirium and coma independently, and delirium severity.

DESIGN

Retrospective, observational cohort study.

SETTING

ICUs at two large, urban, academic referral hospitals.

PATIENTS

All consecutive adult patients admitted to the ICU from March 1, 2020, to June 7, 2020, with COVID-19 with clinical biomarkers and delirium assessments performed.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Daily concentrations of CRP, d-dimer, and ferritin were obtained. Coma (assessed by Richmond Agitation-Sedation Scale) and delirium (assessed by Confusion Assessment Method for the ICU/Confusion Assessment Method for the ICU-7) were measured bid. A cohort of 197 ICU patients with COVID-19 were included. Higher d-dimer (odds ratio [OR], 1.57; 95% CI, 1.17-2.12; p < 0.01) and ferritin quartiles (OR, 1.36; 95% CI, 1.02-1.81; p < 0.01) were associated with greater odds of the composite outcome of delirium/coma next day. d-dimer was associated with greater odds of next day delirium (OR, 1.49; 95% CI, 1.14-1.94; p < 0.01) and coma independently (OR, 1.52; 95% CI, 1.08-2.14; p = 0.017). Higher ferritin quartiles were associated with greater odds of next day delirium (OR, 1.33; 95% CI, 1.04-1.70; p = 0.026) and coma independently (OR, 1.59; 95% CI, 1.14-2.23; p < 0.01). Higher CRP quartiles were associated with coma (OR, 1.36; 95% CI, 1.03-1.79; p = 0.030) and delirium severity the next day (β = 0.30; se, 0.07; p ≤ 0.01).

CONCLUSIONS

Our hypothesis-generating study found d-dimer and ferritin were associated with delirium/coma the following day, as well as delirium and coma independently. CRP was associated with next day coma and delirium severity. Larger studies to validate these results are needed.

Serum C-reactive protein adds predictive information for post-stroke delirium: The PROPOLIS study

OBJECTIVE

Delirium is common and serious complication after stroke. Accurate prediction of delirium is important for prevention and monitoring of high-risk patients. Our study aimed to determine if addition of C-reactive protein (CRP) to a model based on easy-to-access clinical predictors improves accuracy of delirium prediction in acute stroke patients.

METHODS

We analyzed data of patients participating in the Prospective Observational Polish Study on post-stroke delirium. We included patients admitted within 24 h after stroke or transient ischemic attack (TIA) in whom serum CRP was measured on admission. We examined core features of delirium during first 7 days of hospitalization. We assessed if addition of CRP to two clinical models improved metrics of discrimination and reclassification. Model A included age and stroke severity and Model B included stroke severity, atrial fibrillation, diabetes mellitus, pre-stroke dependency, and hemorrhagic stroke.

RESULTS

We included 459 patients. We diagnosed delirium in 29.2% of them. Patients who developed delirium had higher CRP level than those without delirium (median: 13.2 vs. 4.4 mg/L, p < 0.001). CRP >7.09 mg/L was associated with an increased risk of delirium (adjusted OR: 2.98, 95%CI: 1.71-5.19, p < 0.001). After adding CRP to clinical models, an area under receiver operator curve increased from 0.77 to 0.80 (p = 0.038) for Model A and from 0.81 to 0.84 (p = 0.016) for Model B. There was also improvement in reclassification.

CONCLUSIONS

Addition of CRP to clinical predictors moderately improved prediction of post-stroke delirium. CRP could be considered as a potential biomarker to stratify risk of delirium after stroke.

Delirium risk factors in hospitalized patient: a comprehensive evaluation of underlying diseases and medications in different wards of a large Urban Hospital Center in Iran

BACKGROUND

Delirium is a neurobehavioral syndrome, which is characterized by a fluctuation of mental status, disorientation, confusion and inappropriate behavior, and it is prevalent among hospitalized patients. Recognizing modifiable risk factors of delirium is the key point for improving our preventive strategies and restraining its devastating consequences. This study aimed to identify and investigate various factors predisposing hospitalized patients to develop delirium, focusing mostly on underlying diseases and medications.

METHOD

In a prospective, observational trial, we investigated 220 patients who had been admitted to the internal, emergency, surgery and hematology-oncology departments. We employed the Confusion Assessment Method (CAM) questionnaire, The Richmond Agitation Sedation Scale (RASS), the General Practitioner Assessment of Cognition (GPCOG), demographic questionnaire, patient interviews and medical records. Multivariate logistic regression models were used to analyze the predictive value of medications and underlying diseases for daily transition to delirium.; demographics were analyzed using univariate analysis to identify those independently associated with delirium.

RESULTS

Two hundred twenty patients were enrolled; the emergency department had the most incident delirium (31.3%), and the surgery section had the least (2.4%); delirium was significantly correlated with older ages and sleep disturbance. Among multiple underlying diseases and the medications evaluated in this study, we found that a history of dementia, neurological diseases and malignancies increases the odds of transition to delirium and the use of anticoagulants decreases the incident delirium.

CONCLUSION

Approximately 1 out of 10 overall patients developed delirium; It is important to evaluate underlying diseases and medications more thoroughly in hospitalized patients to assess the risk of delirium.

Point prevalence of delirium among critically ill patients in Saudi Arabia: A multicenter observational study

Background:

Delirium in critically ill patients is independently associated with poor clinical outcomes. There is a scarcity of published data on the prevalence of delirium among critically ill patients in Saudi Arabia. Therefore, we sought to determine, in a multicenter fashion, the prevalence of delirium in critically ill patients in Saudi Arabia and explore associated risk factors.

Methods:

A cross-sectional point prevalence study was conducted on January 28, 2020, at 14 intensive care units (ICUs) across 3 universities and 11 other tertiary care hospitals in Saudi Arabia. Delirium was screened once using the Intensive Care Delirium Screening Checklist. We excluded patients who were unable to participate in a valid delirium assessment, patients admitted with traumatic brain injury, and patients with documented dementia in their medical charts.

Results:

Of the 407 screened ICU patients, 233 patients were enrolled and 45.9% were diagnosed with delirium. The prevalence was higher in mechanically ventilated patients compared to patients not mechanically ventilated (57.5% vs. 33.6%; P < 0.001). In a multivariate model, risk factors independently associated with delirium included age (adjusted odds ratio [AOR], 1.021; 95% confidence interval [CI], 1.01–1.04; P = 0.008), mechanical ventilation (AOR, 2.39; 95% CI, 1.34–4.28; P = 0.003), and higher severity of illness (AOR, 1.01; 95% CI, 1.001–1.021; P = 0.026).

Conclusion:

In our study, delirium remains a prevalent complication, with distinct risk factors. Further studies are necessary to investigate long-term outcomes of delirium in critically ill patients in Saudi Arabia.

Depression and anxiety increase the odds of developing delirium in ICU patients; a prospective observational study

BACKGROUND

Delirium is prevalent among hospitalised patients, especially in critically ill patients. Preventing delirium by recognising its modifiable risk factors could improve life quality, decrease mortality and restrain its devastating consequences.

METHOD

We investigated 50 patients who had been hospitalised in the general ICU and monitored them for developing delirium. We employed CAM and CAM-ICU Scales to assess delirium, RASS score to determine the consciousness level, HADS questionnaire for anxiety and depression, and the demographic data questionnaire.

RESULTS

We found that 20% of ICU patients developed delirium and found a meaningful correlation between the incident delirium, older ages, visual impairment, and higher anxiety and depression scores (HADS) of first and second days of hospitalisation. By utilising logistic regression, we found that older ages, visual impairment, higher anxiety and depression scores (HADS) of the first day of hospitalisation were statistically significant to predict the risk model of developing delirium.

CONCLUSION

Depressive and anxiety symptoms were associated with higher odds of transitioning to delirium; so, at the admission time, it may be useful to screen patients for the symptoms of affective disorders, particularly, who are at higher risks for developing delirium.

Prospective Analysis Between Neutrophil-to-Lymphocyte Ratio on Admission and Development of Delirium Among Older Hospitalized Patients With COVID-19

Objective: To examine any prospective association between neutrophil-to-lymphocyte ratio (NLR) at hospital admission and subsequent delirium in older COVID-19 hospitalized patients comparing by sex and age groups. Methods: The sample consisted of 1,785 COVID-19 adult inpatients (minimum sample size required of 635 participants) admitted to a public general hospital in Madrid (Spain) between March 16th and April 15th, 2020. Variables were obtained from electronic health records. Binary logistic regression models were performed between baseline NLR and delirium adjusting for age, sex, medical comorbidity, current illness severity, serious mental illness history and use of chloroquine and dexamethasone. An NLR cut-off was identified, and stratified analyses were performed by age and sex. Also, another biomarker was tested as an exposure (the systemic immune-inflammation index -SII). Results: 55.3% of the patients were men, with a mean age of 66.8 years. Roughly 13% of the patients had delirium during hospitalization. NLR on admission predicted subsequent delirium development (adjusted OR = 1.02, 95 percent CI: 1.00-1.04, p = 0.024). Patients between 69 and 80 years with NLR values > 6.3 presented a twofold increased risk for delirium (p = 0.004). There were no sex differences in the association between baseline NLR and delirium (p > 0.05) nor SII predicted delirium development (p = 0.341). Conclusion: NLR is a good predictor of delirium during hospitalization, especially among older adults, independently of medical comorbidity, illness severity, and other covariates. Routine blood tests on admission might provide valuable information to guide the decision-making process to be followed with these especially vulnerable patients.

Biomarkers in delirium: A systematic review

BACKGROUND

Delirium is a common neuropsychiatric disorder associated with prolonged hospital stays, and increased morbidity and mortality. Diagnosis is frequently missed due to varying disease presentation and lack of standardized testing. We examined biomarkers as diagnostic or prognostic indicators of delirium, and provide a rational basis for future studies.

METHOD

Systematic review of literature published between Jan 2000 and June 2019. Searches included: PubMed; Web of Science; CINAHL; EMBASE; COCHRANE and Medline. Additional studies were identified by searching bibliographies of eligible articles.

RESULTS

2082 relevant papers were identified from all sources. Seventy-three met the inclusion criteria, all of which were observational. These assessed a range of fourteen biomarkers. All papers included were in the English language. Assessment methods varied between studies, including: DSM criteria; Confusion Assessment Method (CAM) or CAM-Intensive Care Unit (ICU). Delirium severity was measured using the Delirium Rating Scale (DRS). Delirium was secondary to post-operative dysfunction or acute medical conditions.

CONCLUSION

Evidence does not currently support the use of any one biomarker. However, certain markers were associated with promising results and may warrant evaluation in future studies. Heterogeneity across study methods may have contributed to inconclusive results, and more clarity may arise from standardization of methods of clinical assessment. Adjusting for comorbidities may improve understanding of the pathophysiology of delirium, in particular the role of confounders such as inflammation, cognitive disorders and surgical trauma. Future research may also benefit from inclusion of other diagnostic modalities such as EEG as well as analysis of genetic or epigenetic factors.

Association between ankle brachial index and development of postoperative intensive care unit delirium in patients with peripheral arterial disease

Patients with vascular diseases are prone to developing postoperative delirium (POD). Ankle brachial index (ABI) is a non-invasive clinical indicator of lower-extremities peripheral arterial disease (PAD) and has been identified as an indicator of cognitive impairment. We investigated the association between ABI and POD. 683 PAD patients who underwent elective leg arterial bypass surgery between October 1998 and August 2019 were collected for retrospective analysis. Demographic information, comorbidities, preoperative ABI and the Rutherford classification within one month prior to surgery were obtained. POD was assessed using the Confusion assessment method -intensive care unit. Logistic regression and receiver operating characteristics (ROC) curve analysis were used to assess the association between ABI and POD. The mean value of ABI was significantly lower in patients with POD than it was those without POD. Older age, more medical comorbidities, longer length of surgery, decreased ABI, and higher Rutherford class were all significantly associated with POD. The area under ROC (0.74) revealed that ABI below 0.35 was associated with development of POD. Lower preoperative ABI was associated with POD in PAD patients who underwent arterial bypass surgery.

Neutrophil-lymphocyte ratio as a predictor of delirium in older internal medicine patients: a prospective cohort study

BACKGROUNDS

Delirium is a common neuropsychiatric syndrome in older hospitalized patients. Previous studies have suggested that inflammation and oxidative stress contribute to the pathophysiology of delirium. However, it remains unclear whether neutrophil-lymphocyte ratio (NLR), an indicator of systematic inflammation, is associated with delirium. This study aimed to investigate the value of NLR as an independent risk factor for delirium among older hospitalized patients.

METHODS

We conducted a prospective study of 740 hospitalized patients aged ≥ 70 years in the geriatric ward of West China Hospital of Sichuan University. Neutrophil and lymphocyte counts were collected within 24 h after hospital admission. Delirium was assessed on admission and every 48 h thereafter. We used the receiver operating characteristic analysis to assess the ability of the NLR for predicting delirium. The optimal cut-point value of the NLR was determined based on the highest Youden index (sensitivity + specificity - 1). Patients were categorized according to the cut-point value and quartiles of NLR, respectively. We then used logistic regression to identify the unadjusted and adjusted associations between NLR as a categorical variable and delirium.

RESULTS

The optimal cut-point value of NLR for predicting delirium was 3.626 (sensitivity: 75.2 %; specificity: 63.4 %; Youden index: 0.386). The incidence of delirium was significantly higher in patients with NLR > 3.626 than NLR ≤ 3.626 (24.5 % vs. 5.8 %; P < 0.001). Significantly fewer patients in the first quartile of NLR experienced delirium than in the third (4.3 % vs. 20.0 %; P < 0.001) and fourth quartiles of NLR (4.3 % vs. 24.9 %; P < 0.001). Results from the multivariable logistic regression models showed that NLR was independently associated with delirium.

CONCLUSIONS

NLR is a simple and practical marker that can predict the development of delirium in older internal medicine patients.

Derivation and Validation of an Ensemble Model for the Prediction of Agitation in Mechanically Ventilated Patients Maintained Under Light Sedation

OBJECTIVES

Light sedation is recommended over deep sedation for invasive mechanical ventilation to improve clinical outcome but may increase the risk of agitation. This study aimed to develop and prospectively validate an ensemble machine learning model for the prediction of agitation on a daily basis.

DESIGN

Variables collected in the early morning were used to develop an ensemble model by aggregating four machine learning algorithms including support vector machines, C5.0, adaptive boosting with classification trees, and extreme gradient boosting with classification trees, to predict the occurrence of agitation in the subsequent 24 hours.

SETTING

The training dataset was prospectively collected in 95 ICUs from 80 Chinese hospitals on May 11, 2016, and the validation dataset was collected in 20 out of these 95 ICUs on December 16, 2019.

PATIENTS

Invasive mechanical ventilation patients who were maintained under light sedation for 24 hours prior to the study day and who were to be maintained at the same sedation level for the next 24 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 578 invasive mechanical ventilation patients from 95 ICUs in 80 Chinese hospitals, including 459 in the training dataset and 119 in the validation dataset, were enrolled. Agitation was observed in 36% (270/578) of the invasive mechanical ventilation patients. The stepwise regression model showed that higher body temperature (odds ratio for 1°C increase: 5.29; 95% CI, 3.70-7.84; p < 0.001), greater minute ventilation (odds ratio for 1 L/min increase: 1.15; 95% CI, 1.02-1.30; p = 0.019), higher Richmond Agitation-Sedation Scale (odds ratio for 1-point increase: 2.43; 95% CI, 1.92-3.16; p < 0.001), and days on invasive mechanical ventilation (odds ratio for 1-d increase: 0.95; 95% CI, 0.93-0.98; p = 0.001) were independently associated with agitation in the subsequent 24 hours. In the validation dataset, the ensemble model showed good discrimination (area under the receiver operating characteristic curve, 0.918; 95% CI, 0.866-0.969) and calibration (Hosmer-Lemeshow test p = 0.459) in predicting the occurrence of agitation within 24 hours.

CONCLUSIONS

This study developed an ensemble model for the prediction of agitation in invasive mechanical ventilation patients under light sedation. The model showed good calibration and discrimination in an independent dataset.

Development and validation of a predictive score for ICU delirium in critically ill patients

Background

The incidence of delirium in intensive care unit (ICU) patients is high and associated with a poor prognosis. We validated the risk factors of delirium to identify relevant early and predictive clinical indicators and developed an optimized model.

Methods

In the derivation cohort, 223 patients were assigned to two groups (with or without delirium) based on the CAM-ICU results. Multivariate logistic regression analysis was conducted to identify independent risk predictors, and the accuracy of the predictors was then validated in a prospective cohort of 81 patients.

Results

A total of 304 patients were included: 223 in the derivation group and 81 in the validation group, 64(21.1%)developed delirium. The model consisted of six predictors assessed at ICU admission: history of hypertension (RR = 4.367; P = 0.020), hypoxaemia (RR = 3.382; P = 0.018), use of benzodiazepines (RR = 5.503; P = 0.013), deep sedation (RR = 3.339; P = 0.048), sepsis (RR = 3.480; P = 0.018) and mechanical ventilation (RR = 3.547; P = 0.037). The mathematical model predicted ICU delirium with an accuracy of 0.862 (P < 0.001) in the derivation cohort and 0.739 (P < 0.001) in the validation cohort. No significant difference was found between the predicted and observed cases of ICU delirium in the validation cohort (P > 0.05).

Conclusions

Patients’ risk of delirium can be predicted at admission using the early prediction score, allowing the implementation of early preventive interventions aimed to reduce the incidence and severity of ICU delirium.

Preoperative Acute Pain Is Associated with Postoperative Delirium

Background

Studies have provided some evidence that pain is a risk factor for postoperative delirium (POD). Therefore, we investigated the relationship between preoperative pain and POD after noncardiac surgery.

Methods

POD was assessed with the Montreal Cognitive Assessment, and preoperative cognition was assessed with the Mini-Mental State Examination. Plasma C-reactive protein (CRP) was detected by enzyme-linked immunosorbent assay before surgery. Preoperative pain was classified by its duration before surgery as chronic pain (lasting more than 1 month), acute pain (lasting less than 1 month), or no pain (no obvious pain). Multiple linear regression was used to adjust for confounding.

Results

From October 15, 2018, through August 12, 2019, a total of 67 patients were randomized; 7 were excluded because they were discharged before the seventh postoperative day. The prevalence of POD was significantly higher in the acute pain group (13 of 20; 65%) than in the chronic pain group (5 of 20; 25%) or the no pain group (6 of 20; 30%) (P = 0.019), indicating that delirium is associated with preoperative acute pain. The plasma level of preoperative CRP was also higher in the acute pain group than in the other two groups (mean [interquartile range]: 10.7 [3.3, 29.3] vs 1 [0.5, 3.8]mg/l; P &lt; 0.001), suggesting that elevated preoperative plasma levels of CRP were associated with delirium.

Conclusions

Preoperative acute pain was associated with POD, and increased plasma levels of CRP provide a marker. In addition, we found that illiteracy and advanced age were risk factors for POD.

Elevated Level of Serum C-reactive Protein Predicts Postoperative Delirium among Patients Receiving Cervical or Lumbar Surgery

Objective

To explore the relationship between elevated serum C-reactive protein (CRP) level and postoperative delirium (POD).

Methods

206 patients scheduled to receive cervical or lumbar vertebra surgery under general anesthesia for more than 2 hours in a single medical center were observed and analyzed. Patients' serum CRP, delirious status (using the confusion assessment method (CAM)), and delirious score (using the memorial delirium assessment scale (MDAS)) were examined before surgery and 1-2 days after surgery. The association of a serum CRP elevation value from before to after surgery (D-CRP) with delirium occurrence within 2 days after surgery was assessed with a binary logistic regression model, while the association of D-CRP with the postoperative delirious score was assessed with a linear regression model. The effect of D-CRP on predicting delirium occurrence was evaluated with the area under the receiver operating characteristic (ROC) curve (AUC).

Results

D-CRP was significantly positively associated with postoperative delirium occurrence (OR = 1.047, 95%CI = 1.013, 1.082), and D-CRP was also significantly linearly associated with the postoperative delirious score (β = 0.014, 95%CI = 0.006, 0.023). AUC of ROC was 0.711 (P = 0.014), suggesting that D-CRP had moderate efficacy on predicting postoperative delirium occurrence (P < 0.05).

Conclusions

Elevated serum CRP after surgery may be a risk factor for and a predictor of postoperative delirium.

Dexmedetomidine For The Treatment Of Acute Lung Injury: A Fact Or Fiction?

Dexmedetomidine has been widely used in the intensive care unit (ICU), with the primary aim to keep patients on an appropriate level of sedation. Both observational and randomized controlled trials have observed that the use of dexmedetomidine is associated with improved outcomes for mechanically ventilated patients [1]. In ICU patients receiving prolonged mechanical ventilation, dexmedetomidine was not inferior to other sedatives in maintaining sedation level, but was associated with shortened MV duration and improved ability to communicate pain [2]. MV is an important factor for delirium and dexmedetomidine was found to be associated with lower risk of delirium [3, 4]. Prophylactic low-dose dexmedetomidine is able to reduce the occurrence of delirium during the first 7 days after surgery for patients aged over 65 years who are admitted to the ICU after surgery [4]. Thus, the beneficial effect of might be explained by the reduction of delirium in the treated group. In fact, delirium can be considered as a type of acute organ dysfunction mediated via inflammatory response. There has been evidence that inflammatory biomarkers such as C-reactive protein was positively correlated with the occurrence of delirium [5].

Identification of distinct clinical phenotypes in mechanically ventilated patients with acute brain dysfunction using cluster analysis

Acute brain dysfunction (ABD) is a frequent and severe syndrome occurring in critically ill patients and early identification of high-risk patients is paramount. In the present analysis, we propose a clinically applicable model for early phenotype identification of ABD at the bedside in mechanically ventilated patients, improving the recognition of patients with prolonged ABD.Prospective cohort with 629 mechanically ventilated patients in two medical-surgical intensive care units at academic centers. We applied cluster analysis to identify phenotypes using clinical and biological data. We then tested the association of phenotypes and its respective clinical outcomes. We performed a validation on a new cohort of patients select on subsequent patients admitted to the participants intensive care units.A model with 3 phenotypes best described the study population. A 4-variable model including medical admission, sepsis diagnosis, simplified acute physiologic score II and basal serum C-reactive protein (CRP) accurately classified each phenotype (area under curve 0.82; 95% CI, 0.79-0.86). Phenotype A had the shorter duration of ABD (median, 1 day), while phenotypes B and C had progressively longer duration of ABD (median, 3 and 6 days, respectively; P < .0001). There was an association between the duration of ABD and the baseline CRP levels and simplified acute physiology score II score (sensitivity and specificity of 80%). To increase the sensitivity of the model, we added CRP kinetics. By day 1, a CRP < 1.0 times the initial level was associated with a shorter duration of ABD (specificity 0.98).A model based on widely available clinical variables could provide phenotypes associated with the duration of ABD. Phenotypes with longer duration of ABD (phenotypes B and C) are characterized by more severe inflammation and by significantly worse clinical outcomes.

A systematic review of the overlap of fluid biomarkers in delirium and advanced cancer-related syndromes

BACKGROUND

Delirium is a serious and distressing neurocognitive disorder of physiological aetiology that is common in advanced cancer. Understanding of delirium pathophysiology is largely hypothetical, with some evidence for involvement of inflammatory systems, neurotransmitter alterations and glucose metabolism. To date, there has been limited empirical consideration of the distinction between delirium pathophysiology and that of the underlying disease, for example, cancer where these mechanisms are also common in advanced cancer syndromes such as pain and fatigue. This systematic review explores biomarker overlap in delirium, specific advanced cancer-related syndromes and prediction of cancer prognosis.

METHODS

A systematic review (PROSPERO CRD42017068662) was conducted, using MEDLINE, PubMed, Embase, CINAHL, CENTRAL and Web of Science, to identify body fluid biomarkers in delirium, cancer prognosis and advanced cancer-related syndromes of interest. Studies were excluded if they reported delirium tremens only; did not measure delirium using a validated tool; the sample had less than 75% of participants with advanced cancer; measured tissue, genetic or animal biomarkers, or were conducted post-mortem. Articles were screened for inclusion independently by two authors, and data extraction and an in-depth quality assessment conducted by one author, and checked by two others.

RESULTS

The 151 included studies were conducted in diverse settings in 32 countries between 1985 and 2017, involving 28130 participants with a mean age of 69.3 years. Seventy-one studies investigated delirium biomarkers, and 80 studies investigated biomarkers of an advanced cancer-related syndrome or cancer prognosis. Overall, 41 biomarkers were studied in relation to both delirium and either an advanced cancer-related syndrome or prognosis; and of these, 24 biomarkers were positively associated with either delirium or advanced cancer syndromes/prognosis in at least one study. The quality assessment showed large inconsistency in reporting.

CONCLUSION

There is considerable overlap in the biomarkers in delirium and advanced cancer-related syndromes. Improving the design of delirium biomarker studies and considering appropriate comparator/controls will help to better understanding the discrete pathophysiology of delirium in the context of co-existing illness.

The trajectory of C-reactive protein serum levels in older hip fracture patients with postoperative delirium

OBJECTIVES

Important precipitating risk factors for delirium such as infections, vascular disorders, and surgery are accompanied by a systemic inflammatory response. Systemic inflammatory mediators can induce delirium in susceptible individuals. Little is known about the trajectory of systemic inflammatory markers and their role in the development and outcome of delirium.

METHODS

This is a prospective cohort study of older patients undergoing acute surgery for hip fracture. Baseline characteristics were assessed preoperatively. During hospital admission, presence of delirium was assessed daily according to the Confusion Assessment Method criteria. This study compared the trajectory of serum levels of the C-reactive protein (CRP) between people with and without postoperative delirium. Blood samples were taken at baseline and at postoperative day 1 through postoperative day 5.

RESULTS

Forty-one out of 121 patients developed postoperative delirium after hip fracture surgery. Longitudinal analysis of the trajectory of serum CRP levels using the Generalized Estimating Equations (GEE) method identified that higher CRP levels were associated with postoperative delirium. CRP levels were higher from postoperative day 2 through postoperative day 5. No significant differences in serum CRP levels were found when we compared patients with short (1-2 days) and more prolonged delirium (3 days or more).

CONCLUSIONS

Delirium is associated with an increased systemic inflammatory response, and our results suggest that CRP plays a role in the underlying (inflammatory-vascular) pathological pathway of postoperative delirium.

Knowledge, Attitudes, and Practices of Chinese Critical Care Nurses Regarding Physical Restraint

BACKGROUND

This multicenter cross-sectional study sought to determine the knowledge, attitudes, and practices regarding the use of physical restraints by Chinese nurses in intensive care units (ICUs) of tertiary hospitals.

METHOD

A scale technique was used to measure the knowledge, attitudes, and practices of 383 RNs from eight tertiary hospitals in Chongqing, China.

RESULTS

A total of 383 valid questionnaires were returned, for a response rate of 89.49%. Approximately 8.1% of the nurses were male, 67.1% had a bachelor's degree or above, and 55.09% were ICU specialists. The average age was 28.62 years (SD = 4.56). The mean scores were 74.33 of 111 (SD = 9.552), 24.41 of 40 (SD = 4.872), and 65.66 of 130 (SD = 20.880) regarding knowledge, attitudes, and nursing practices, respectively. For the attitude scale, the scores of nurses who were certified ICU specialists and had extensive working experience were higher than those with less experience; the difference was statistically significant (p < .05).

CONCLUSION

Results indicated that nurses employed in the ICUs of tertiary hospitals in Chongqing, China, have relatively insufficient knowledge, comparatively incorrect attitudes, and unreasonable means of practicing physical restraint. Continuing education should focus strongly on the relationship between physical restraint and unplanned extubation, and guidelines on physical restraint urgently need to be developed. [J Contin Educ Nurs. 2019;50(3):121-126.].

Biomarker Predictors of Delirium in Acutely Ill Patients: A Systematic Review

Delirium is a serious and common disorder that affects up to 80% of acutely ill patients, mainly the aged. In recent years, several studies pointed out possible biomarkers that could be used alone or in combination with other resources in the diagnosis and follow-up of critically ill patients who develop delirium. In this context, a systematic review was conducted to determine the predictive value of several biomarkers in acutely (critically and noncritically) ill adult patients with delirium. Studies that used the confusion assessment method (CAM) and CAM-intensive care unit as the diagnostic method were considered. The most recent search was performed in November 2017. There was no language restriction. Initially, 626 articles were screened and 39 were included in the study. A comprehensive evaluation of the abstracts resulted in the exclusion of 202 studies, leaving 39 articles as potentially relevant. Inflammatory markers, S100β and cortisol, could predict delirium occurrence in a specific subgroup population of critically ill patients.

Role of Epileptic Activity in Older Adults With Delirium, a Prospective Continuous EEG Study

Background/Objectives: Delirium occurs in up to 50 % of hospitalized old patients and is associated with increased morbidity and mortality. Acute medical conditions favor delirium, but the pathophysiology is unclear. Preliminary evidence from retrospective and prospective studies suggests that a substantial minority of old patients with unexplained delirium have non-convulsive seizures or status epilepticus (NCSE). Yet, seeking epileptic activity only in unexplained cases of delirium might result in misinterpretation of its actual prevalence. We aimed to systematically investigate the role of epileptic activity in all older patients with delirium regardless of the underlying etiology.

Design, Setting: Prospective observational study in a tertiary medical center. Adults >65 years with delirium underwent at least 24 h of continuous electro-encephalographic monitoring (cEEG). Background patterns and ictal and interictal epileptic discharges were identified, as well as clinical and biological characteristics.

Participants: Fifty patients were included in the study.

Results: NCSE was found in 6 (12%) patients and interictal discharges in 15 (30%). There was no difference in the prevalence of epileptic activity rates between delirium associated with an acute medical condition and delirium of unknown etiology.

Conclusion: Epileptic activity may play a substantial role in the pathophysiology of delirium by altering brain functioning and neuronal metabolism. No clinical or biological marker was found to distinguish delirious patients with or without epileptic activity, underlining the importance of cEEG in this context.

C-reactive protein may be a prognostic factor for the whole gastroenteropancreatic neuroendocrine tumor group

BACKGROUND

Long non-coding RNAs (lncRNAs) are a kind of single-stranded RNA of more than 200 nucleotides in length and have no protein-coding function. Amounting studies have indicated that lncRNAs could play a vital role in the initiation and development of cancers, including gastric cancer (GC). Considering the crucial functions of lncRNAs, the identification and exploration of novel lncRNAs in GC is necessary.

AIM

To identify independent prognostic markers for the whole gastroenteropancreatic neuroendocrine tumor (GEP-NET) group.

METHODS

Ninety-three patients diagnosed with GEP-NETs within a specified period were included in this study. Patient data were retrospectively analyzed. The relationships between all independent variables and 5-year survival status calculated during the follow-up period (months) were assessed. In addition, the relationships between the independent variables were investigated.

RESULTS

When 5-year survival rate was compared, a statistically significant relationship between the age at diagnosis, male gender, tumor size, tumor stage, liver and/or distant metastasis, and tumor grade determined by the Ki-67 level and mitotic count, and the level of C-reactive protein (CRP), was observed. The mean survival (overall survival) of the study group was 102.5 ± 6.3 (SD) mo. The percentages of 1, 3 and 5-year survival were 90%, 72%, and 61%, respectively. In 63 of 93 patients, Ki-67 and the mitotic count determined the same grade. The Ki-67 levels in 29 patients and the mitotic count in only 1 patient were in the higher grade. The risk of death increased by 4% for every 1 year increase at the diagnosis age and was 2.0-fold higher for male patients, 3.0-fold higher for G3 according to the mitotic count, 3.7-fold higher for G3 according to the Ki-67 level, 12.7-fold higher for cases with tumor stage 3 or 4 by a 1 cm increase in the ratio of 9% in tumor size, and 6.1-fold higher for patients with liver metastasis for every 1 mg/dL increase in the ratio of 1.5% in CRP level. There was a significant difference between pancreatic and stomach NETs in favor of stomach tumors in terms of survival.

CONCLUSION

Tumor site, stage, grade and Ki-67 level affected patient survival, and it was observed that CRP affected disease progression (particularly if it was > 20 mg/dL). However, a relationship between surgical resection of the lesion and survival was not shown. Larger scale prospective studies are required to determine whether CRP level may be a poor prognostic factor for the entire GEP-NET group.

The Association Between C-Reactive Protein and Postoperative Delirium Differs by Catechol-O-Methyltransferase Genotype

OBJECTIVE

Catechol-O-methyltransferase (COMT), a key enzyme in degrading catecholamines associated with the stress response, may influence susceptibility to delirium. Individuals with the COMT (rs4680) Val/Val genotype (designated "warriors") withstand the onset of neuropsychiatric disorders and cognitive decline, whereas individuals with Met/Met and Val/Met genotypes ("nonwarriors") are more susceptible to these conditions. We evaluated whether COMT genotype modifies the established association between acute phase reactant (stress marker) C-reactive protein (CRP) and postoperative delirium.

METHODS

This was a prospective cohort study conducted at two academic medical centers. The study involved 547 patients aged 70 or older undergoing major noncardiac surgery. We collected blood, extracted DNA, and performed COMT genotyping using allele-specific polymerase chain reaction assays, considering warriors versus nonwarriors. High plasma CRP, measured on postoperative day 2 using enzyme-linked immunosorbent assay, was defined by the highest sample-based quartile (≥234.12 mg/L). Delirium was determined using the Confusion Assessment Method, augmented by a validated chart review. We used generalized linear models adjusted for age, sex, surgery type, and race/ethnicity, stratified by COMT genotype, to determine whether the association between CRP and delirium differed by COMT.

RESULTS

Prevalence of COMT warriors was 26%, and postoperative delirium occurred in 23%. Among COMT warriors, high CRP was not associated with delirium (relative risk [RR] 1.0, 95% confidence interval [CI] 0.4-2.6). In contrast, among nonwarriors, we found the expected relationship of high CRP and delirium (RR 1.5, 95% CI 1.1-2.2).

CONCLUSION

COMT warriors may be protected against the increased risk of delirium associated with high CRP on postoperative day 2. With further confirmation, COMT genotype may help target interventions for delirium prevention in the vulnerable nonwarrior group.

Risk factors for delirium: are therapeutic interventions part of it?

Background: Delirium is associated with increased morbidity and mortality in critically ill patients. Research on risk factors for delirium allows clinicians to identify high-risk patients, which is the basis for early prevention and diagnosis. Besides the risk factors for delirium that are commonly studied, here we more focused on the less-studied therapeutic interventions for critically ill patients which are potentially modifiable. Materials and methods: A total of 320 non-comatose patients admitted to the ICU for more than 24 hrs during 9 months were eligible for the study. Delirium was screened once daily using the CAM-ICU. Demographics, admission clinical data, and daily interventions were collected. Results: Ninety-two patients (28.75%) experienced delirium at least once. Delirious patients were more likely to have longer duration of mechanical ventilation, ICU stay, and hospital stay. Most of the less-studied therapeutic interventions were linked to delirium in the univariate analysis, including gastric tube, artificial airway, deep intravenous catheter, arterial line, urinary catheter, use of vasoactive drugs, and sedative medication. After adjusting with age and ICU length of stay, mechanical ventilation (OR: 5.123; 95% CI: 2.501-10.494), Acute Physiology and Chronic Health Evaluation (APACHE) II score≥20 at admission (OR: 1.897; 95% CI: 1.045-3.441), and gastric tube (OR: 1.935, 95% CI: 1.012-3.698) were associated with increased risk of delirium in multivariate analysis. Conclusion: Delirium was associated with prolonged mechanical ventilation, ICU stay, and hospital stay. Multivariate risk factors were gastric tube, mechanical ventilation, and APACHE II score. Although being a preliminary study, this study suggests the necessity of earliest removal of tubes and catheters when no longer needed.

Delirium in the critically ill patient

Delirium is an acute and transient brain dysfunction that is characterized by disturbances in consciousness, affecting both its content (i.e., attention) and level (i.e., arousal). It affects as many as 50% of those admitted to an intensive care unit (ICU). Once believed to be an inconsequential outcome of critical illness, it is now recognized that delirium is harmful in both the short- and long-term. Despite occurring frequently in critically ill patients, delirium often goes unrecognized. Well-validated delirium screening tools, designed for use in the ICU, should be used to reliably detect delirium. The first step in delirium treatment is to identify and address potentially modifiable risk factors. Multiple trials have shown that benzodiazepines are a risk factor for delirium in a dose-dependent manner. Sedation with nonbenzodiazepine-based strategies are an effective means by which to reduce delirium. Nonpharmacologic strategies such as those which seek to reduce sensory impairment, sleep deprivation, and immobility are effective. Pharmacologic treatment with antipsychotics, though commonly used, is not supported by findings from placebo-controlled trials. Recent data support from multiple trials support the use of the "ABCDEF bundle" as a means by which to reduce delirium.

Nomogram for the prediction of postoperative hypoxemia in patients with acute aortic dissection

BACKGROUND

Postoperative hypoxemia is quite common in patients with acute aortic dissection (AAD) and is associated with poor clinical outcomes. However, there is no method to predict this potentially life-threatening complication. The study aimed to develop a regression model in patients with AAD to predict postoperative hypoxemia, and to validate it in an independent dataset.

METHODS

All patients diagnosed with AAD from December 2012 to December 2017 were retrospectively screened for potential eligibility. Preoperative and intraoperative variables were included for analysis. Logistic regression model was fit by using purposeful selection procedure. The original dataset was split into training and validating datasets by 4:1 ratio. Discrimination and calibration of the model was assessed in the validating dataset. A nomogram was drawn for clinical utility.

RESULTS

A total of 211 patients, involving 168 in non-hypoxemia and 43 in hypoxemia group, were included during the study period (incidence: 20.4%). Duration of mechanical ventilation (MV) was significantly longer in the hypoxemia than non-hypoxemia group (41(10.5140) vs. 12(3.75,70.25) hours; p = 0.002). There was no difference in the hospital mortality rate between the two groups. The purposeful selection procedure identified 8 variables including hematocrit (odds ratio [OR]: 0.89, 95% confidence interval [CI]: 0.80 to 0.98, p = 0.011), PaO₂/FiO₂ ratio (OR: 0.99, 95% CI: 0.99 to 1.00, p = 0.011), white blood cell count (OR: 1.21, 95% CI: 1.06 to 1.40, p = 0.008), body mass index (OR: 1.32, 95% CI: 1.15 to 1.54; p = 0.000), Stanford type (OR: 0.22, 95% CI: 0.06 to 0.66; p = 0.011), pH (OR: 0.0002, 95% CI: 2*10^- 8 to 0.74; p = 0.048), cardiopulmonary bypass time (OR: 0.99, 95% CI: 0.98 to 1.00; p = 0.031) and age (OR: 1.03, 95% CI: 0.99 to 1.08; p = 0.128) to be included in the model. In an independent dataset, the area under curve (AUC) of the prediction model was 0.869 (95% CI: 0.802 to 0.936). The calibration was good by visual inspection.

CONCLUSIONS

The study developed a model for the prediction of postoperative hypoxemia in patients undergoing operation for AAD. The model showed good discrimination and calibration in an independent dataset that was not used for model training.

Perioperative predictors of delirium and incidence factors in adult patients post cardiac surgery

Background

Delirium is a quite common complication in adult patients post-cardiac surgery. The purpose of our study was to identify perioperative characteristics and also focus on incidence factors that could predict delirium in the cardiac surgery intensive care unit (CICU) postoperatively.

Methods

We conducted a prospective study of 179 consecutive patients, who underwent open-heart surgical operation and were admitted to the CICU of a general tertiary hospital in Athens, Greece. The patients were screened for delirium by using the diagnostic tools of Rich-mond Agitation Sedation Scale (RASS score) and the Confusion Assessment Method - ICU (CAM-ICU). The delirium assessment was carried out on the 1st and the 2nd postoperative day, and was conducted twice every nursing shift. A short questionnaire on sociodemographics and clinical patient characteristics was used for data collection purposes.

Results

A total of 179 patients who underwent open-heart surgical operation with cardiopulmonary bypass (CPB) were enrolled in our study. The 2-day incidence of postoperative delirium in ICU was 11.2% (n=20/179). The main independent predictors of delirium on the 2nd postoperative day were neutrophil-to-lymphocyte ratio (p=0.001) and urea levels (p=0.016). Additionally, increased perioperative creatinine (p=0.006) and sodium (p=0.039) levels were significantly associated with delirium occurrence. Furthermore, elevated EuroSCORE (p=0.001), extended length of stay (LOS) in ICU (p<0.001), and extended LOS with endotracheal tube (p=0.001) were also statistically significant indicators.

Conclusion

Patients with extended LOS with endotracheal tube and prolonged stay in ICU in accordance with peaked urea, neutrophil-to-lymphocyte ratio, creatinine, and sodium levels seem to have a significantly greater probability of developing delirium in the ICU. Further research is needed in the field of postoperative cardiac patients in order to determine the causality and etiology of certain risk factors for delirium.

Influence of physical restraint on delirium of adult patients in ICU: A nested case-control study

AIMS AND OBJECTIVES

To investigate the impact of physical restraint on delirium of adult patients in intensive care unit.

BACKGROUND

Delirium is a common clinical syndrome in intensive care unit, correlated with various adverse clinical outcomes. Physical restraint is a precipitating factor for delirium; however, the effect of physical restraint on delirium, such as duration, number and appliance is still unclear.

DESIGN

A nested case-control study.

METHODS

A cohort of 593 intensive care unit patients were observed for 12 months, and 447 of them who received physical restraint were included for analysis. Delirium was assessed using the Confusion Assessment Method for the intensive care unit. During hospitalisation in intensive care unit, newly-onset delirium patients (the delirium group), and nondelirium patients of similar age, same gender, and conditions of mechanical ventilation and sedative drug usage (the nondelirium group) were included as the matching criteria. Patient data were acquired by reviewing medical and nursing electronic records.

RESULTS

Among the 447 patients that had been physically restrained, 178 (39.8%) developed delirium. Delirium risk in patients with restraint ≥6 days was 26.30 times higher than in those <6 days. Patients who had two and three times of restraint had a 2.38-fold and 3.62-fold higher risk of delirium than those with one time of restraint. However, the appliance, site, time to apply and remove restraint had no effect on the incidence of delirium.

CONCLUSIONS

The incidence of delirium is high when patients use physical restraint. Duration and number of restraint are positively related to delirium. Restrictions on the use of restraint in intensive care unit are required to reduce the occurrence of delirium.

RELEVANCE TO CLINICAL PRACTICE

To reduce delirium risk of patients in intensive care unit, nurses need to assess the risk of physical restraint and consider alternative measures, thereby to achieve the minimisation of the use of restraint.

Inflammatory markers in postoperative delirium (POD) and cognitive dysfunction (POCD): A meta-analysis of observational studies

Background

The aim of this study was to summarize and discuss the similarities and differences in inflammatory biomarkers in postoperative delirium (POD) and cognitive dysfunction (POCD).

Methods

A systematic retrieval of literature up to June 2017 in PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure database, and the Wanfang database was conducted. Extracted data were analyzed with STATA (version 14). The standardized mean difference (SMD) and the 95% confidence interval (95% CI) of each indicator were calculated using a random effect model. We also performed tests of heterogeneity, sensitivity analysis, assessments of bias, and meta-regression in this meta-analysis.

Results

A total of 54 observational studies were included. By meta-analysis we found significantly increased C-reactive protein (CRP) (9 studies, SMD 0.883, 95% CI 0.130 to 1.637, P = 0.022 in POD; 10 studies, SMD -0.133, 95% CI -0.512 to 0.246, P = 0.429 in POCD) and interleukin (IL)-6 (7 studies, SMD 0.386, 95% CI 0.054 to 0.717, P = 0.022 in POD; 16 studies, SMD 0.089, 95% CI -0.133 to 0.311, P = 0.433 in POCD) concentrations in both POD and POCD patients. We also found that the SMDs of CRP and IL-6 from POCD patients were positively correlated with surgery type in the meta-regression (CRP: Coefficient = 1.555365, P = 0.001, 10 studies; IL-6: Coefficient = -0.6455521, P = 0.086, 16 studies).

Conclusion

Available evidence from medium-to-high quality observational studies suggests that POD and POCD are indeed correlated with the concentration of peripheral and cerebrospinal fluid (CSF) inflammatory markers. Some of these markers, such as CRP and IL-6, play roles in both POD and POCD, while others are specific to either one of them.

Development and validation of risk-stratification delirium prediction model for critically ill patients: A prospective, observational, single-center study

The objective is to develop a model based on risk stratification to predict delirium among adult critically ill patients and whether early intervention could be provided for high-risk patients, which could reduce the incidence of delirium.We designed a prospective, observational, single-center study. We examined 11 factors, including age, APACHE-II score, coma, emergency operation, mechanical ventilation (MV), multiple trauma, metabolic acidosis, history of hypertension, delirium and dementia, and application of Dexmedetomidine Hydrochloride. Confusion assessment method for the intensive care unit (CAM-ICU) was performed to screen patients during their ICU stay. Multivariate logistic regression analysis was used to develop the model, and we assessed the predictive ability of the model by using the area under the receiver operating characteristics curve (AUROC).From May 17, 2016 to September 25, 2016, 681 consecutive patients were screened, 61 of whom were excluded. The most frequent reason for exclusion was sustained coma 30 (4.4%), followed by a length of stay in the ICU < 24 hours 18 (2.6%) and delirium before ICU admission 13 (1.9%). Among the remaining 620 patients (including 162 nervous system disease patients), 160 patients (25.8%) developed delirium, and 64 (39.5%) had nervous system disease. The mean age was 55 ± 18 years old, the mean APACHE-II score was 16 ± 4, and 49.2% of them were male. Spearman analysis of nervous system disease and incidence of delirium showed that the correlation coefficient was 0.186 (P < .01). We constructed a prediction model that included 11 risk factors. The AUROC was 0.78 (95% CI 0.72-0.83).We developed the model using 11 related factors to predict delirium in critically ill patients and further determined that prophylaxis with Dexmedetomidine Hydrochloride in delirious ICU patients was beneficial. Patients who suffer from nervous system disease are at a higher incidence of delirium, and corresponding measures should be used for prevention.

TRIAL REGISTRATION

ChiCTR-OOC-16008535.

High C-Reactive Protein Predicts Delirium Incidence, Duration, and Feature Severity After Major Noncardiac Surgery

OBJECTIVES

To examine associations between the inflammatory marker C-reactive protein (CRP) measured preoperatively and on postoperative day 2 (POD2) and delirium incidence, duration, and feature severity.

DESIGN

Prospective cohort study.

SETTING

Two academic medical centers.

PARTICIPANTS

Adults aged 70 and older undergoing major noncardiac surgery (N = 560).

MEASUREMENTS

Plasma CRP was measured using enzyme-linked immunosorbent assay. Delirium was assessed from Confusion Assessment Method (CAM) interviews and chart review. Delirium duration was measured according to number of hospital days with delirium. Delirium feature severity was defined as the sum of CAM-Severity (CAM-S) scores on all postoperative hospital days. Generalized linear models were used to examine independent associations between CRP (preoperatively and POD2 separately) and delirium incidence, duration, and feature severity; prolonged hospital length of stay (LOS, >5 days); and discharge disposition.

RESULTS

Postoperative delirium occurred in 24% of participants, 12% had 2 or more delirium days, and the mean ± standard deviation sum CAM-S was 9.3 ± 11.4. After adjusting for age, sex, surgery type, anesthesia route, medical comorbidities, and postoperative infectious complications, participants with preoperative CRP of 3 mg/L or greater had a risk of delirium that was 1.5 times as great (95% confidence interval (CI) = 1.1-2.1) as that of those with CRP less than 3 mg/L, 0.4 more delirium days (P < .001), more-severe delirium (3.6 CAM-S points higher, P < .001), and a risk of prolonged LOS that was 1.4 times as great (95% CI = 1.1-1.8). Using POD2 CRP, participants in the highest quartile (≥235.73 mg/L) were 1.5 times as likely to develop delirium (95% CI = 1.0-2.4) as those in the lowest quartile (≤127.53 mg/L), had 0.2 more delirium days (P < .05), and had more severe delirium (4.5 CAM-S points higher, P < .001).

CONCLUSION

High preoperative and POD2 CRP were independently associated with delirium incidence, duration, and feature severity. CRP may be useful to identify individuals who are at risk of developing delirium.

Higher C-Reactive Protein Levels Predict Postoperative Delirium in Older Patients Undergoing Major Elective Surgery: A Longitudinal Nested Case-Control Study

BACKGROUND

Delirium is a common, morbid, and costly postoperative complication. We aimed to identify blood-based postoperative delirium markers in a nested case-control study of older surgical patients using a proteomics approach followed by enzyme-linked immunosorbent assay (ELISA) validation.

METHODS

The Successful Aging after Elective Surgery study enrolled dementia-free adults ≥70 years old undergoing major scheduled noncardiac surgery (N = 566; 24% delirium). Plasma was collected at four time points: preoperative, postanesthesia care unit, postoperative day 2, and 1 month postoperative. Matched pairs were selected for the independent discovery (39 pairs) and replication cohorts (36 pairs), which were subsequently combined into the pooled cohort (75 pairs). Isobaric tags for relative and absolute quantitation-based relative quantitation mass spectrometry proteomics were performed to identify the strongest delirium-related protein, which was selected for ELISA validation. Using the ELISA results, statistical analyses using nonparametric signed rank tests were performed in all cohorts examining the association between the identified protein and delirium.

RESULTS

C-reactive protein emerged from the proteomics analysis as the strongest delirium-related protein. Validation by ELISA confirmed that compared with controls, cases had significantly higher C-reactive protein levels in the discovery, replication, and pooled cohorts at the preoperative (median paired difference [MPD] 1.97 mg/L [p < .05], 0.29 mg/L, 1.56 mg/L [p < .01]), postanesthesia care unit (MPD 2.83 mg/L, 2.22 mg/L [p < .05], 2.53 mg/L [p < .01]) and postoperative day 2 (MPD 71.97 mg/L [p < .01], 35.18 mg/L [p < .05], 63.76 mg/L [p < .01]) time points, but not 1 month postoperative (MPD 2.72 mg/L, -0.66 mg/L, 1.10 mg/L).

CONCLUSIONS

Elevated preoperative and postoperative plasma levels of C-reactive protein were associated with delirium, suggesting that a preinflammatory state and heightened inflammatory response to surgery are potential pathophysiologic mechanisms of delirium.

Slower Decline in C-Reactive Protein after an Inflammatory Insult Is Associated with Longer Survival in Older Hospitalised Patients

Background

Enhancing biological resilience may offer a novel way to prevent and ameliorate disease in older patients. We investigated whether changes in C-reactive protein (CRP), as a dynamic marker of the acute inflammatory response to diverse stressors, may provide a way to operationalize the concept of resilience in older adults. We tested this hypothesis by examining whether such changes could predict prognosis by identifying which individuals are at greater risk of 6-month mortality.

Methods

Analysis of prospective, routinely collected datasets containing data on hospitalization, clinical chemistry and rehabilitation outcomes for rehabilitation inpatients between 1999 and 2011. Maximum CRP response during acute illness and CRP recovery indices (time and slope of CRP decay to half maximum, and to <50mg/L if peak values were greater than 50mg/L) was derived from biochemistry data. 6-month survival plots were conducted on quartiles of CRP recovery indices. Cox proportional hazards models were used to test univariate and multivariate predictors of 6-month mortality. Covariates included age, sex, number of medications, serum calcium, haemoglobin level, renal function, and the presence of previous myocardial infarction, stroke, chronic heart failure, COPD and diabetes.

Results

3723 patients, mean age 84 years, were included. 1535 (41%) were male and 733 (20%) died during six-month follow-up. The lower an individual’s peak CRP reading, and the longer the time taken for their CRP to fall, the better their 6-month survival. The time for CRP to reach half of its maximum value was the best dynamic CRP index of survival (HR 0.93 per week, 95% CI 0.89 to 0.98; p = 0.004); this remained significant even after adjustment for maximum CRP level and covariates listed above.

Conclusion

CRP recovery indices are associated with survival in older people; further work is required to explain differences in physiology between patients with a fast and slow CRP recovery.