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

Prophylactic Minocycline for Delirium in Critically Ill Patients: A Randomized Controlled Trial

BACKGROUND

Delirium is a potentially severe form of acute encephalopathy. Minocycline has neuroprotective effects in animal models of neurologic diseases; however, data from human studies remain scarce.

RESEARCH QUESTION

Does the neuroprotective effect of minocycline prevent delirium occurrence in critically ill patients?

STUDY DESIGN AND METHODS

This study was a randomized, placebo-controlled, double-anonymized trial conducted in four ICUs. Patients aged 18 years or older were eligible and randomized to receive minocycline (100 mg, twice daily) or placebo. The primary outcome was delirium incidence within 28 days or before ICU discharge. Secondary outcomes included days in delirium during ICU stay, delirium/coma-free days, length of mechanical ventilation, ICU length of stay, ICU mortality, and hospital mortality. The kinetics of various inflammatory (IL-1β, IL-6, IL-10, and C-reactive protein) and brain-related biomarkers (brain-derived neurotrophic factor and S100B) were used as exploratory outcomes.

RESULTS

A total of 160 patients were randomized, but one patient in the placebo group died before treatment; thus the data from 159 patients were analyzed (minocycline, n = 84; placebo, n = 75). After the COVID-19 pandemic it was decided to stop patient inclusion early. There was a small but significant decrease in delirium incidence: 17 patients (20%) in the minocycline arm compared with 26 patients (35%) in the placebo arm (P = .043). No other delirium-related outcomes were modified by minocycline treatment. Unexpectedly, there was a significant decrease in hospital mortality (39% vs. 23%; P = .029). Among all analyzed biomarkers, only plasma levels of C-reactive protein decreased significantly after minocycline treatment (F = 0.75, P = .78, within time; F = 4.09, P = .045, group × time).

INTERPRETATION

Our findings in this rather small study signal a possible positive effect of minocycline on delirium incidence. Further studies are needed to confirm the benefits of this drug as a preventive measure in critically ill patients.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT04219735; URL: www.

CLINICALTRIALS

gov.

A nomogram for predicting sepsis-associated delirium: a retrospective study in MIMIC III

OBJECTIVE

To develop a nomogram for predicting the occurrence of sepsis-associated delirium (SAD).

MATERIALS AND METHODS

Data from a total of 642 patients were retrieved from the Medical Information Mart for Intensive Care (MIMIC III) database to build a prediction model. Multivariate logistic regression was performed to identify independent predictors and establish a nomogram to predict the occurrence of SAD. The performance of the nomogram was assessed in terms of discrimination and calibration by bootstrapping with 1000 resamples.

RESULTS

Multivariate logistic regression identified 4 independent predictors for patients with SAD, including Sepsis-related Organ Failure Assessment(SOFA) (p = 0.004; OR: 1.131; 95% CI 1.040 to 1.231), mechanical ventilation (P < 0.001; OR: 3.710; 95% CI 2.452 to 5.676), phosphate (P = 0.047; OR: 1.165; 95% CI 1.003 to 1.358), and lactate (P = 0.023; OR: 1.135; 95% CI 1.021 to 1.270) within 24 h of intensive care unit (ICU) admission. The area under the curve (AUC) of the predictive model was 0.742 in the training set and 0.713 in the validation set. The Hosmer - Lemeshow test showed that the model was a good fit (p = 0.471). The calibration curve of the predictive model was close to the ideal curve in both the training and validation sets. The DCA curve also showed that the predictive nomogram was clinically useful.

CONCLUSION

We constructed a nomogram for the personalized prediction of delirium in sepsis patients, which had satisfactory performance and clinical utility and thus could help clinicians identify patients with SAD in a timely manner, perform early intervention, and improve their neurological outcomes.

Biomarkers of delirium risk in older adults: a systematic review and meta-analysis

Delirium is a neuropsychiatric syndrome associated with increased morbidity and mortality in older patients. The aim of this study was to review predictive biomarkers of delirium in older patients to gain insights into the pathophysiology of this syndrome and provide guidance for future studies. Two authors independently and systematically searched MEDLINE, Embase, Cochrane Library, Web of Science and Scopus databases up to August 2021. A total of 32 studies were included. Only 6 studies were eligible for the meta-analysis, pooled results showed a significant increase in some serum biomarkers (C-reactive protein [CRP], tumour necrosis factor alpha [TNF-α] and interleukin-6 [IL-6]) among patients with delirium (odds ratio = 1.88, 95% CI 1.01 to 1.637; I2 = 76.75%). Although current evidence does not favour the use of any particular biomarker, serum CRP, TNF-α, and IL-6 were the most consistent biomarkers of delirium in older patients.

Challenges in the Detection of Clinically Useful Biomarkers for the Diagnosis of Delirium in Older People in the Emergency Department-A Case-Control Study

Background: The identification of biomarkers associated with delirium in the emergency department could contribute to the understanding, prediction and diagnosis of this disorder. The present study was carried out to identify biomarkers included in easily and quickly obtained standard blood examinations in older patients with delirium in the emergency department. Methods: A case–control study was carried out in the emergency department of Francesc de Borja Hospital (Gandía, Valencia, Spain). Older adults (≥65 years of age) diagnosed with delirium (n = 128) were included. Cases due to alcohol or substance abuse were excluded. Controls were selected on a randomized basis from the remaining patients (n = 128). All laboratory test parameters included in the routine blood and urine tests of the emergency department were collected. Results: The mean age of the patients was 81.24 ± 7.51 years, and 56.2% were males, while the mean age of the controls was 78.97 ± 7.99 years, and 45.3% were males. Significant differences were found between the cases and controls in relation to the following parameters: urea 43 (32–58) mg/dL versus 50 (37–66) mg/dL, respectively; neutrophils 69.6 (62.05–78.75)% versus 75.5 (65.1–83.2)%; monocytes 8.7 (7–10.4)% versus 7.6 (5.5–9.2)%; platelets 213 (159–266) × 10⁹/L versus 224 (182–289) × 10⁹/L; neutrophil–lymphocyte ratio 3.88 (2.45–7.07) versus 5 (2.75–8.83); platelet–lymphocyte ratio 281.4 (210–360) versus 357.1 (257.8–457.1); and mean platelet volume 10.6 (10–11.5) fl versus 10.4 (9.67–10.9) fl. Although the mean values were above desirable levels in both groups, they were higher for most parameters in the control group. No significant differences were observed in C-reactive protein concentration (9.99 (1.69–51) mg/L versus 12.3 (3.09–65.97) mg/L). Conclusions: The identification of delirium biomarkers poses difficulties due to the urgent nature of the disorders found in older people admitted to the emergency department. Research in this field is needed, since it would allow early identification and treatment of delirium.

Identification of risk factors for delirium, cognitive decline, and dementia after cardiac surgery (FINDERI-find delirium risk factors): a study protocol of a prospective observational study

Background

Postoperative delirium is a common complication of cardiac surgery associated with higher morbidity, longer hospital stay, risk of cognitive decline, dementia, and mortality. Geriatric patients, patients undergoing cardiac surgery, and intensive care patients are at a high risk of developing postoperative delirium. Gold standard assessments or biomarkers to predict risk factors for delirium, cognitive decline, and dementia in patients undergoing cardiac surgery are not yet available.

Methods

The FINDERI trial (FINd DElirium RIsk factors) is a prospective, single-center, observational study. In total, 500 patients aged ≥ 50 years undergoing cardiac surgery at the Department of Cardiovascular and Thoracic Surgery of the University of Göttingen Medical Center will be recruited. Our primary aim is to validate a delirium risk assessment in context of cardiac surgery. Our secondary aims are to identify specific preoperative and perioperative factors associated with delirium, cognitive decline, and accelerated dementia after cardiac surgery, and to identify blood-based biomarkers that predict the incidence of postoperative delirium, cognitive decline, or dementia in patients undergoing cardiac surgery.

Discussion

This prospective, observational study might help to identify patients at high risk for delirium prior to cardiac surgery, and to identify important biological mechanisms by which cardiac surgery is associated with delirium. The predictive value of a delirium screening questionnaire in cardiac surgery might be revealed. Finally, the identification of specific blood biomarkers might help to predict delirium, cognitive decline, and dementia in patients undergoing cardiac surgery.

Trial registration: Ethics approval for this study was obtained from the IRB of the University of Göttingen Medical Center. The investigators registered this study in the German Clinical Trials Register (DRKS; https://www.drks.de) (DRKS00025095) on April 19th, 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02732-4.

Delirium disorder: Unity in diversity

OBJECTIVE

The first objective of this review is to explore the factors that have led to and maintain the division between delirium and acute encephalopathy. The second is to explore the value of harmonizing them through the model of delirium disorder.

METHOD

This narrative review outlines major distinctions between delirium and acute encephalopathy. It also compares them with the model of delirium disorder, which seeks not only to integrate them but also to offer a broader palette of treatment targets.

RESULTS

Delirium implies an underlying acute encephalopathy, whereas acute encephalopathy presents as a spectrum from subsyndromal delirium to coma. Key factors that differentiate these two models include tradition, nuances of the models themselves, linguistic connotations, evoked responses from clinicians, implications of preventability and responsibility, cultural perceptions of non-pharmacological vs pharmacological interventions and economic incentives. A validated set of pathophysiological subtypes may ultimately help link the delirium-spectrum phenotype with various acute encephalopathies.

CONCLUSIONS

Developing a coherent clinical and scientific approach to this set of conditions demands that we first develop a coherent understanding of the conditions themselves and how they relate to one another. Such an approach must embrace the tension between a convergent phenotype and its diverse biological underpinnings.

Post-COVID-19 conditions in Ecuadorian patients: an observational study

BACKGROUND

Post-COVID-19 disease is not yet clearly described, presenting significant clinical variability across populations and patients. This paper compares post-COVID symptoms in three patient groups with mild, moderate, and severe infections in Ecuadorian outpatients.

METHODS

An epidemiological, observational, descriptive, and cross-sectional study was performed, and carried out in Quito, Ecuador. 1,366 non-hospitalized participants between 12 to 85 years, diagnosed with COVID-19 infection by molecular RT-PCR were included in the study. Demographic characteristics, including age groups, sex, ethnic group, work type, residence type, comorbidities, diagnosis, symptoms, and treatment were studied.

FINDINGS

1,366 outpatient Ecuadorian patients were analysed with SARS-CoV2 infection confirmed with a PCR+ test. The mean age was 39 (± 10) years, distributed by age groups ranging between 12 and 85 years; 81.41% were between 18 and 54 years. 50.29% were men, and 49.71% were women.

INTERPRETATION

64.3% of patients had symptoms between 4 to 6 weeks after infection, 21.1% showed ongoing symptoms between 6 to 12 weeks, and 14.6% had symptoms for more than 12 weeks. The most common symptom was fatigue in 67.3% of patients, followed by headache in 45.2%, body pain in 42.3%, and sleep disorders (insomnia, sleep apnoea, restless leg syndrome) in 36.5%. 69.3% of patients showed mild infection, 21.7% moderate, and 9.0% severe infection. On average, patients' daily life activities showed a 6.8% mean degree of impact following infection. A sedentary lifestyle (walking less than 30 minutes a day) was the most critical risk factor (40.3%), followed by being a health worker (11.87%). Patients aged ≥55 years with HTN, CKD, smoking, and sedentary lifestyle were 4.39, 1.92, 9.19, 4.07, and 2.42 times more likely to have a severe infection level. At least 30% of patients do not feel recovered from COVID-19 infection.

FUNDING

The author declares that the financial resources for the preparation of this research come from their self-management.

Postoperative delirium and quality of life after transcatheter and surgical aortic valve replacement: A prospective observational study

OBJECTIVE

In older patients, postoperative delirium is a frequently occurring complication after surgical aortic valve replacement, leading to an excess in postoperative morbidity and mortality. It remains controversial whether transcatheter aortic valve implantation and minimally invasive surgical aortic valve replacement can reduce the risk of postoperative delirium. This study aimed to compare the incidence of postoperative delirium after transcatheter aortic valve implantation and surgical aortic valve replacement and the impact on long-term outcomes.

METHODS

Between September 2018 and January 2020, we conducted an observational, prospective cohort study in patients aged 70 years or more undergoing transcatheter aortic valve implantation or surgical aortic valve replacement. The primary end point was the incidence of in-hospital postoperative delirium during 5 postoperative days assessed with the Confusion Assessment Method. Secondary end points included perioperative inflammation, postoperative complications, health status (EuroQol 5-dimensional questionnaire 5 levels), and mortality up to 6 months. Transcatheter aortic valve implantation and surgical aortic valve replacement were compared using propensity weighting to account for important baseline differences (European System for Cardiac Operative Risk Evaluation II, age, and frailty).

RESULTS

We included 250 patients with a mean (standard deviation) age of 80 (±5.8) years and a European System for Cardiac Operative Risk Evaluation score of 5 (±4.7). In the propensity-weighted analysis, those undergoing surgical aortic valve replacement (N = 166) had a higher incidence of postoperative delirium compared with transcatheter aortic valve implantation (N = 84) (51% vs 15%: P < .0001). Furthermore, patients undergoing surgical aortic valve replacement experienced more inflammation, a greater depth of anesthesia, and more intraoperative hypotension. After surgical aortic valve replacement, 41% of patients experienced an improved health status compared with 12% after transcatheter aortic valve implantation (P < .0001). No outcome differences were noted within the surgical aortic valve replacement groups.

CONCLUSIONS

Transcatheter aortic valve implantation is associated with a lower risk for postoperative delirium. Nevertheless, patients undergoing surgical aortic valve replacement experience the greatest improvement in quality of life. Heart teams should consider these outcomes in shared decision-making in the choice of transcatheter aortic valve implantation or surgical aortic valve replacement.

Study protocol: understanding the pathophysiologic mechanisms underlying delirium in older people undergoing hip fracture surgery

BACKGROUND

Postoperative delirium (POD) is a common complication of older people undergoing hip fracture surgery, which negatively affects clinical- and healthcare-related outcomes. Unfortunately, POD pathophysiology is still largely unknown, despite previous studies showing that neuroinflammation, neuroendocrine dysfunction, increased reactive oxidative stress (ROS), and endothelial dysfunctions may be involved. There is also evidence that many of the pathophysiological mechanisms which are involved in delirium are involved in sarcopenia too. This article describes the protocol of a pilot study to evaluate the feasibility of a larger one that will explore the pathophysiological mechanisms correlating POD with sarcopenia. We will analyse whether various biomarkers reflecting neuroinflammation, ROS, neuroendocrine disorders, and microvasculature lesions will be simultaneously expressed in in the blood, cerebrospinal fluid (CSF), and muscles of patients developing POD.

METHODS

Two centres will be involved in this study, each recruiting a convenient sample of ten older patients with hip fracture. All of them will undergo a baseline Comprehensive Geriatric Assessment, which will be used to construct a Rockwood-based Frailty Index (FI). Blood samples will be collected for each patient on the day of surgery and 1 day before. Additionally, CSF and muscle fragments will be taken and given to a biologist for subsequent analyses. The presence of POD will be assessed in each patient every morning until hospital discharge using the 4AT. Delirium subtypes and severity will be assessed using the Delirium Motor Subtype Scale-4 and the Delirium-O-Meter, respectively. We will also evaluate the patient's functional status at discharge, using the Cumulated Ambulation Score.

DISCUSSION

This study will be the first to correlate biomarkers of blood, CSF, and muscle in older patients with hip fracture.

First delirium episode in Parkinson's disease and parkinsonism: incidence, predictors, and outcomes

To define the incidence, predictors and prognosis of the first hospital delirium episode in Parkinson’s disease (PD) and atypical parkinsonism (AP), we identified the first hospital episode of delirium after diagnosis in the Parkinsonism Incidence in North-East Scotland (PINE) study, a prospective community-based incidence cohort of parkinsonism, using chart-based criteria to define delirium. Of 296 patients (189=PD, 107=AP [dementia with Lewy bodies, progressive supranuclear palsy, multiple system atrophy, vascular parkinsonism]), 152 developed delirium (PD = 98, AP = 54). Incidence of first hospital delirium episode per 100 person years was 8.1 (95% confidence interval [CI] 6.6–9.9) in PD and 18.5 (95% CI 13.9–24.7) in AP. Independent predictors of delirium were atypical parkinsonism (Hazard ratio [HR] vs PD = 2.83 [95% CI 1.60–5.03], age in PD but not in AP (HR for 10-year increase 2.29 [95% CI 1.74–3.02]), baseline MMSE (HR = 0.94 [95% CI 0.89–0.99]), APOE ε4 in PD (HR 2.16 [95% CI 1.15–4.08]), and MAPT H1/H1 in PD (HR 2.08 [95% CI 1.08–4.00]). Hazards of dementia and death after delirium vs before delirium were increased (dementia: HR = 6.93 [95% CI 4.18–11.48] in parkinsonism; death: HR = 3.76 [95% CI 2.65–5.35] in PD, 1.59 [95% CI 1.04–2.42] in AP). Delirium is a common non-motor feature of PD and AP and is associated with increased hazards of dementia and mortality. Whether interventions for early identification and treatment improve outcomes requires investigation.

Meta-analysis of ICU Delirium Biomarkers and Their Alignment With the NIA-AA Research Framework

BACKGROUND

Between 30% and 80% of survivors of critical illness experience cognitive impairment, but the underlying mechanisms remain unknown.

OBJECTIVE

To determine whether intensive care unit (ICU) delirium biomarkers align with the National Institute on Aging-Alzheimer's Association (NIA-AA) research framework for diagnostic biomarkers for Alzheimer disease and other related dementias (ADRD).

METHODS

Ovid MEDLINE, PsycInfo, Embase, and the Cochrane Library were systematically searched for articles published between January 1, 2000, and February 20, 2020, on the relationship between delirium and biomarkers listed in the NIA-AA framework. Only studies that addressed delirium in the ICU setting and fluid biomarkers were included in these analyses.

RESULTS

Of 61 256 records screened, 38 studies met inclusion criteria, 8 of which were suitable for meta-analysis. In pooled analysis, significant associations were found between ICU delirium and amyloid β-peptide 1-40 (standard mean difference [SMD], 0.42; 95% CI, 0.09-0.75), interleukin (IL)-1 receptor antagonist (SMD, 0.58; 95% CI, 0.21-0.94), and IL-6 (SMD, 0.31; 95% CI, 0.06-0.56). No significant association was observed in pooled analyses between ICU delirium and the other biomarkers. Few studies have examined ICU delirium and pathologic tau or neurodegeneration biomarkers.

CONCLUSIONS

Inflammatory biomarkers and amyloid β are associated with ICU delirium and point to potential overlapping mechanisms between delirium and ADRD. Critical care providers should consider integrating diagnostic approaches used in ADRD in their assessment of post-ICU cognitive dysfunction.

The Protective Effect of PK-11195 on Cognitive Impairment in Rats Survived of Polymicrobial Sepsis

Sepsis is an organ dysfunction caused by a host's unregulated response to infection, causing long-term brain dysfunction with microglial activation, the release of inflammatory components, and mitochondrial changes. Neuroinflammation can increase the expression of the 18-kD translocator protein (TSPO) in the mitochondria, leading to the activation of the microglia and the release of inflammatory components. The antagonist PK-11195 can modulate TSPO and reduce microglial activation and cognitive damage presented in an animal model of sepsis. The aim of this was to evaluate the effects of PK-11195 on long-term brain inflammation and cognitive impairment in an animal model of sepsis. Wistar rats, 60 days old, were submitted to cecal ligation and puncture (CLP) surgery, divided into groups control/saline, control/PK-11195, sepsis/saline, and sepsis/PK-11195. Immediately after surgery, the antagonist PK-11195 was administered at a dose of 3 mg/kg. Ten days after CLP surgery, the animals were submitted to behavioral tests and determination of brain inflammatory parameters. The sepsis/saline group presented cognitive damage. However, there was damage prevention in animals that received PK-11195. Besides, the sepsis increased the levels of cytokines and M1 microglia markers and caused oxidative damage. However, PK-11195 had the potential to decrease inflammation. These events show that the modulation of neuroinflammation during sepsis by PK-11195, possibly related to changes in TSPO, improves mitochondrial function in the animals' brains. In conclusion, the antagonist PK-11195 attenuated brain inflammation and prevented cognitive impairment in animals subjected to sepsis.

Common biomarkers of physiologic stress and associations with delirium in patients with intracerebral hemorrhage

PURPOSE

To examine associations between physiologic stress and delirium in the setting of a direct neurologic injury.

MATERIALS AND METHODS

We obtained initial neutrophil-to-lymphocyte ratio (NLR), glucose, and troponin in consecutive non-comatose patients with non-traumatic intracerebral hemorrhage (ICH) over 1 year, then used multivariable regression models to determine associations between each biomarker and incident delirium. Delirium diagnoses were established using DSM-5-based methods, with exploratory analyses further categorizing delirium as first occurring <24 h ("early-onset") or > 24 h after presentation ("later-onset").

RESULTS

Of 284 patients, delirium occurred in 55% (early-onset: 39% [n = 111]; later-onset: 16% [n = 46]). Patients with delirium had higher NLR (mean 9.0 ± 10.4 vs. 6.4 ± 5.5; p = 0.01), glucose (mean 146.5 ± 59.6 vs. 129.9 ± 41.4 mg/dL; p = 0.008), and a higher frequency of elevated troponin (>0.05 ng/mL; 21% vs. 10%, p = 0.02). In adjusted models, elevated NLR (highest quartile: OR 3.4 [95% CI 1.5-7.8]), glucose (>180 mg/dL: OR 3.1 [95% CI 1.1-8.2]), and troponin (OR 3.0 [95% CI 1.2-7.2]) were each associated with delirium, but only initial NLR was specifically associated with later-onset delirium and with delirium in non-mechanically ventilated patients.

CONCLUSIONS

Stress-related biomarkers corresponding to multiple organ systems are associated with ICH-related delirium. Early NLR elevation may also predict delayed-onset delirium, potentially implicating systemic inflammation as a contributory delirium mechanism.

Rapid Fire: Acute Brain Failure in Older Emergency Department Patients

Delirium is common in older emergency department (ED) patients. Although associated with significant morbidity and mortality, it often goes unrecognized. A consistent approach to evaluation of mental status, including use of validated tools, is key to diagnosing delirium. Identification of the precipitating event requires thorough evaluation, including detailed history, medication reconciliation, physical examination, and medical work-up, for causes of delirium. Management is aimed at identifying and treating the underlying cause. Meaningful improvements in delirium care can be achieved when prevention, identification, and management of older delirious ED patients is integrated by physicians and corresponding frameworks implemented at the health system level.

Poor outcomes of delirium in the intensive care units are amplified by increasing age: A retrospective cohort study

BACKGROUND

Delirium in patients in intensive care units (ICUs) is an acute disturbance and fluctuation of cognition and consciousness. Though increasing age has been found to be related to ICU delirium, there is limited evidence of the effect of age on delirium outcomes. The aim of this study is to investigate the relationship between age categories and outcomes among ICU delirium patients.

METHODS

Data were extracted from the electronic ICU (eICU) Collaborative Research Database with records from 3,931 patients with delirium. Patients were classified into non-aged (<65 years), young-old (65-74 years), middle-old (75-84 years), and very-old (≥85 years) groups. A Cox regression model was built to examine the role of age in death in ICU and in hospital after controlling covariates.

RESULTS

The sample included 1,667 (42.4%) non-aged, 891 (22.7%) young-old, 848 (21.6%) middle-old, and 525 (13.3%) very-old patients. The ICU mortality rate was 8.3% and the hospital mortality rate was 15.4%. Compared with the non-aged group, the elderly patients (≥65 yeras) had higher mortality at ICU discharge (χ² =13.726, P=0.001) and hospital discharge (χ ²=56.347, P<0.001). The Cox regression analysis showed that age was an independent risk factor for death at ICU discharge (hazard ratio [HR]=1.502, 1.675, 1.840, 95% confidence interval [CI] 1.138-1.983, 1.250-2.244, 1.260-2.687; P=0.004, 0.001, 0.002 for the young-, middle- and very-old group, respectively) as well as death at hospital discharge (HR=1.801, 2.036, 2.642, 95% CI 1.454-2.230, 1.638-2.530, 2.047-3.409; all P<0.001).

CONCLUSIONS

The risks of death in the ICU and hospital increase with age among delirious patients.

Delirium in older adults

This narrative review provides a broad examination of the most current concepts on the etiopathogenesis, diagnosis, prevention, and treatment of delirium, an acute neuropsychiatric syndrome characterized by fluctuating changes in cognition and consciousness. With the interaction of underlying vulnerability and severity of acute insults, delirium can occur at any age but is particularly frequent in hospitalized older adults. Delirium is also associated with numerous adverse outcomes, including functional impairment, cognitive decline, increased healthcare costs, and death. Its diagnosis is based on clinical and cognitive assessments, preferably following systematized detection instruments, such as the Confusion Assessment Method (CAM). Delirium and its consequences are most effectively fought using multicomponent preventive interventions, like those proposed by the Hospital Elder Life Program (HELP). When prevention fails, delirium management is primarily based on the identification and reversal of precipitating factors and the non-pharmacological control of delirium symptoms. Pharmacological interventions in delirium should be restricted to cases of dangerous agitation or severe psychotic symptoms.

Association of neurogranin with delirium among critically ill patients

Background: Neurogranin (Ng) concentrates at dendritic spines. In patients with Alzheimer disease Ng levels are elevated. The role of Ng in delirium development has not been assessed, therefore we hypothesized that Ng levels are associated with delirium in critically ill patients. Materials & methods: From 94 critically ill patients, 47 developed delirium and 47 controls were included. Blood was collected during the first 24 h of intensive care unit (ICU) admission, and on the day of delirium diagnoses. Ng and IL-1β were determined. Results: Ng and IL-1β levels were higher in the delirium group at ICU admission and on the day of delirium diagnoses. IL-1β and Ng were independently associated with delirium occurrence. Conclusion: Ng levels are associated with delirium development in ICU patients.

Biomarkers of Delirium Duration and Delirium Severity in the ICU

OBJECTIVES

Both delirium duration and delirium severity are associated with adverse patient outcomes. Serum biomarkers associated with delirium duration and delirium severity in ICU patients have not been reliably identified. We conducted our study to identify peripheral biomarkers representing systemic inflammation, impaired neuroprotection, and astrocyte activation associated with delirium duration, delirium severity, and in-hospital mortality.

DESIGN

Observational study.

SETTING

Three Indianapolis hospitals.

PATIENTS

Three-hundred twenty-one critically ill delirious patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We analyzed the associations between biomarkers collected at delirium onset and delirium-/coma-free days assessed through Richmond Agitation-Sedation Scale/Confusion Assessment Method for the ICU, delirium severity assessed through Confusion Assessment Method for the ICU-7, and in-hospital mortality. After adjusting for age, gender, Acute Physiology and Chronic Health Evaluation II score, Charlson comorbidity score, sepsis diagnosis and study intervention group, interleukin-6, -8, and -10, tumor necrosis factor-α, C-reactive protein, and S-100β levels in quartile 4 were negatively associated with delirium-/coma-free days by 1 week and 30 days post enrollment. Insulin-like growth factor-1 levels in quartile 4 were not associated with delirium-/coma-free days at both time points. Interleukin-6, -8, and -10, tumor necrosis factor-α, C-reactive protein, and S-100β levels in quartile 4 were also associated with delirium severity by 1 week. At hospital discharge, interleukin-6, -8, and -10 retained the association but tumor necrosis factor-α, C-reactive protein, and S-100β lost their associations with delirium severity. Insulin-like growth factor-1 levels in quartile 4 were not associated with delirium severity at both time points. Interleukin-8 and S-100β levels in quartile 4 were also associated with higher in-hospital mortality. Interleukin-6 and -10, tumor necrosis factor-α, and insulin-like growth factor-1 were not found to be associated with in-hospital mortality.

CONCLUSIONS

Biomarkers of systemic inflammation and those for astrocyte and glial activation were associated with longer delirium duration, higher delirium severity, and in-hospital mortality. Utility of these biomarkers early in delirium onset to identify patients at a higher risk of severe and prolonged delirium, and delirium related complications during hospitalization needs to be explored in future studies.