Cerebral perfusion changes in older delirious patients using 99mTc HMPAO SPECT

Risk factors for postoperative delirium in patients undergoing orthopedic procedures: a systematic review and meta-analysis

Delirium is a common complication in surgical patients following operative procedures; it often occurs in patients undergoing lower-extremity surgery. It is essential to identify and prevent the risk factors for postoperative delirium (POD) in these cases. We aimed to determine the risk factors for POD in patients who underwent lower-extremity surgery through a systematic review and meta-analysis. We included observational studies identifying risk factors for POD in patients undergoing orthopedic surgery. Data sources included the Cumulative Index to Nursing and Allied Health Literature and MEDLINE. We extracted the variables related to delirium that were analyzed by two or more studies meeting the eligibility criteria. A random-effects model was used to calculate the pooled odds ratio, standardized mean difference, and 95% confidence interval. Data were considered significant when p <  0.05. Twenty-seven studies with a total sample size of 9,044 were evaluated. Our meta-analysis revealed 20 risk factors for patients with POD undergoing orthopedic surgery, including age, cognitive scores, various preoperative laboratory values (such as serum albumin, C-reactive protein, and thyroid hormones), length of hospital stay, surgery and anesthesia duration, blood transfusion, and previous health conditions such as dementia and cardiovascular disease. Gathering preoperative and postoperative data was crucial for identifying high-risk patients for POD. In addition, preventive measures targeting POD risk factors could reduce its occurrence after orthopedic surgery.

A prospective multi-center study quantifying visual inattention in delirium using generative models of the visual processing stream

The visual attentional deficits in delirium are poorly characterized. Studies have highlighted neuro-anatomical abnormalities in the visual processing stream but fail at quantifying these abnormalities at a functional level. To identify these deficits, we undertook a multi-center eye-tracking study where we recorded 210 sessions from 42 patients using a novel eye-tracking system that was made specifically for free-viewing in the (ICU); each session lasted 10 min and was labeled with the delirium status of the patient using the Confusion Assessment Method in ICU (CAM-ICU). To analyze this data, we formulate the task of visual attention as a hierarchical generative process that yields a probabilistic distribution of the location of the next fixation. This distribution can then be compared to the measured patient fixation producing a correctness score which is tallied compared across delirium status. This analysis demonstrated that the visual processing system of patients suffering from delirium is functionally restricted to a statistically significant degree. This is the first study to explore the potential mechanisms underpinning visual inattention in delirium and suggests a new target of future research into a disease process that affects one in four hospitalized patients with severe short and long-term consequences.

Predictiveness of preoperative laboratory values for postoperative delirium

Background

Postoperative delirium (POD) is a common postoperative complication, especially in patients over 60 years, with an incidence ranging from 15% to 50%. In most cases, POD manifests in the first 5 days after surgery. Multiple contributing risk factors for POD have been detected. Besides the predisposing factors such as higher age, cognitive impairment, high blood pressure, atrial fibrillation, and past stroke, pathophysiological mechanisms like neuroinflammation are also considered as contributing factors.

Methods

In a subanalysis of the "PRe- Operative  Prediction of postoperative  DElirium by appropriate  SCreening" (PROPDESC) study, the preoperative laboratory values of sodium, potassium, total protein, hemoglobin concentration (Hgb), and white blood cells as well as the biomarkers creatinine, HbA1c, NT-pro-BNP, high sensitive Troponin T (hsTnT), and C-reactive protein (CRP) were assessed to investigate a possible relationship to the occurrence of POD.

Results

After correction for age, physical status classification, surgery risk after Johns Hopkins, and operative discipline (cardiac surgery vs. noncardiac surgery), male patients with a Hgb <13 g/dL had significantly higher odds for POD (p = 0.025). Furthermore, patients with CRP ≥ 10 mg/L, HbA1c value ≥ 8.5% as well as patients with hypernatraemia (>145 mmol/L) presented significantly higher odds to develop POD (p = 0.011, p < 0.001, and p = 0.021, respectively). A raised (>14-52 ng/L) or high (>52 ng/L) hsTnT value was also associated with a significantly higher chance for POD compared to the patient group with hsTnT <14 ng/L (p < 0.001 and p = 0.016, respectively).

Conclusions

Preoperative Hgb, CRP, HbA1c, sodium, and hsTnT could be used to complement and refine the preoperative screening for patients at risk for POD. Further studies should track these correlations to investigate the potential of targeted POD protection and enabling hospital staff to initiate POD-preventing measures in time.

Prognostic significance of delirium in patients with heart failure: a systematic review and meta-analysis

Background

Delirium is a common symptom of heart failure (HF) and is associated with increased mortality, prolonged hospital stays, and heightened medical costs. The impact of delirium on the prognosis of HF patients is currently controversial. Therefore, we conducted a meta-analysis to evaluate the prognostic significance of delirium in HF.

Methods

Relevant articles were systematically searched in PubMed, Cochrane Library, Web of Science, and Embase based on the PRISMA guidelines. Studies that reported mortality and hospitalization-related outcomes in HF patients with or without delirium using raw or adjusted hazard ratio (HR) and odds ratio (OD) were included. Meta-analysis was then performed to evaluate the effect of delirium in HF patients. Outcomes of interest were all-cause mortality and events of the hospitalization.

Results

Of the 1,501 studies identified, 7 eligible studies involving 12,830,390 HF patients (6,322,846 males and 6,507,544 females) were included in the meta-analysis. There were 91,640 patients with delirium (0.71%) and 12,738,750 patients without delirium (99.28%). HF patients with delirium had higher OR for in-hospital mortality (1.95, 95% CI = 1.30-2.91, P = 0.135), higher pooled HR for 90-day mortality (2.64, 95% CI = 1.06-1.56, P = 0.215), higher pooled HR for 1-year mortality (2.08, 95% CI = 1.34-3.22, P = 0.004), and higher pooled HR for 30-day readmission rate (4.15, 95% CI = 2.85-6.04, P = 0.831) than those without delirium.

Conclusion

Current evidence suggests that combined delirium increases the risk of HF-related mortality and hospitalization-related outcomes in patients with HF. However, more research is needed to assess the impact of delirium on the prognosis of HF patients.

Lipopolysaccharide-Induced Delirium-like Behaviour in a Rat Model of Chronic Cerebral Hypoperfusion Is Associated with Increased Indoleamine 2,3-Dioxygenase Expression and Endotoxin Tolerance

Indoleamine 2,3-dioxygenase (IDO) and the tryptophan-kynurenine pathway (TRP-KP) are upregulated in ageing and could be implicated in the pathogenesis of delirium. This study evaluated the role of IDO/KP in lipopolysaccharide (LPS)-induced delirium in an animal model of chronic cerebral hypoperfusion (CCH), a proposed model for delirium. CCH was induced by a permanent bilateral common carotid artery ligation (BCCAL) in Sprague Dawley rats to trigger chronic neuroinflammation-induced neurodegeneration. Eight weeks after permanent BCCAL, the rats were treated with a single systemic LPS. The rats were divided into three groups: (1) post-BCCAL rats treated with intraperitoneal (i.p.) saline, (2) post-BCCAL rats treated with i.p. LPS 100 μg/kg, and (3) sham-operated rats treated with i.p. LPS 100 μg/kg. Each group consisted of 10 male rats. To elucidate the LPS-induced delirium-like behaviour, natural and learned behaviour changes were assessed by a buried food test (BFT), open field test (OFT), and Y-maze test at 0, 24-, 48-, and 72 h after LPS treatment. Serum was collected after each session of behavioural assessment. The rats were euthanised after the last serum collection, and the hippocampi and cerebral cortex were collected. The TRP-KP neuroactive metabolites were measured in both serum and brain tissues using ELISA. Our data show that LPS treatment in CCH rats was associated with acute, transient, and fluctuated deficits in natural and learned behaviour, consistent with features of delirium. These behaviour deficits were mild compared to the sham-operated rats, which exhibited robust behaviour impairments. Additionally, heightened hippocampal IDO expression in the LPS-treated CCH rats was associated with reduced serum KP activity together with a decrease in the hippocampal quinolinic acid (QA) expression compared to the sham-operated rats, suggested for the presence of endotoxin tolerance through the immunomodulatory activity of IDO in the brain. These data provide new insight into the underlying mechanisms of delirium, and future studies should further explore the role of IDO modulation and its therapeutic potential in delirium.

Preclinical and translational models for delirium: Recommendations for future research from the NIDUS delirium network

Delirium is a common, morbid, and costly syndrome that is closely linked to Alzheimer's disease (AD) and AD-related dementias (ADRD) as a risk factor and outcome. Human studies of delirium have advanced our knowledge of delirium incidence and prevalence, risk factors, biomarkers, outcomes, prevention, and management. However, understanding of delirium neurobiology remains limited. Preclinical and translational models for delirium, while challenging to develop, could advance our knowledge of delirium neurobiology and inform the development of new prevention and treatment approaches. We discuss the use of preclinical and translational animal models in delirium, focusing on (1) a review of current animal models, (2) challenges and strategies for replicating elements of human delirium in animals, and (3) the utility of biofluid, neurophysiology, and neuroimaging translational markers in animals. We conclude with recommendations for the development and validation of preclinical and translational models for delirium, with the goal of advancing awareness in this important field.

Factors associated with intensive care unit delirium in patients with acute myocardial infarction

Some patients admitted to intensive care units (ICU) would develop delirium, which is associated with poor prognosis. The purpose of this retrospective study was to identify factors associated with ICU delirium in patients with acute myocardial infarction (AMI). We included 753 AMI and divided those into the ICU-delirium group (n = 110) and the non-ICU-delirium group (n = 643) according to the presence of ICU delirium. The ICU delirium was evaluated by confusion assessment method for the intensive care unit. Patient characteristics and clinical outcomes were compared between the 2 groups, and factors associated with ICU delirium were sought by multivariate analysis. The prevalence of female sex was significantly higher in the ICU-delirium group (43.6%) than in the non-ICU-delirium group (20.2%) (p < 0.001). The incidence of in-hospital death was significantly higher in the ICU-delirium group (17.3%) than in the non-ICU-delirium group (0.5%) (p < 0.001). The multivariate logistic regression analysis revealed that age [every 10 years increase: odds ratio (OR) 1.439, 95% confidence interval (CI) 1.127-1.837, p = 0.004], female sex (OR 2.237, 95%CI 1.300-3.849, p = 0.004), triple vessel disease (OR 2.317, 95%CI 1.365-3.932, p = 0.002), body mass index < 18.5 kg/m² (OR 2.910, 95%CI 1.410-6.008, p = 0.004), use of mechanical support (OR 2.812, 95%CI 1.500-5.270, p = 0.001), respiratory failure (OR 5.342, 95%CI 3.080-9.265, p < 0.001), and use of continuous renal replacement therapy (OR 5.901, 95%CI 2.520-13.819, p < 0.001) were significantly associated with ICU delirium. In conclusion, ICU delirium was associated with in-hospital death. Older age, female sex, triple vessel disease, leanness, use of mechanical support, respiratory failure, and continuous renal replacement therapy were significantly associated with the occurrence of ICU delirium.

Readmission and In-Hospital Outcomes After Transcatheter Aortic Valve Replacement in Patients With Dementia

BACKGROUND/PURPOSE

The prevalence of dementia and aortic stenosis (AS) increases with each decade of age. Transcatheter aortic valve replacement (TAVR) is a definitive treatment for AS, but there are scarce data on morbidity, mortality, and readmission risk after TAVR in patients with dementia.

METHODS/MATERIALS

We identified all admissions for TAVR in patients with AS in the National Readmissions Database in 2017-2018 and stratified them according to the presence or absence of a secondary diagnosis of dementia. Inpatient outcomes were compared using logistic regression. Cox proportional-hazards models were used to compare 30-, 60-, and 90-day readmissions.

RESULTS

A total of 48,923 index hospitalizations for TAVR were identified, of which 2192 (4.5 %) had a secondary diagnosis of dementia. Presence of dementia was associated with higher odds of delirium, pacemaker placement, acute kidney injury, and fall in hospital. The hazard of 30-day readmission was not significantly different between patients with and without dementia, but patients with dementia experienced a higher hazard of 60-day readmission (HR 1.15, 95 % CI 1.03-1.26, p = 0.011) in the unadjusted model and higher hazard of 90-day readmission in both unadjusted (HR 1.18, 95 % CI 1.08-1.30, p < 0.001) and adjusted models (aHR 1.14, 95 % CI 1.04-1.25, p = 0.004).

CONCLUSIONS

Patients with dementia who undergo TAVR are at higher risk of in-hospital adverse outcomes and 60- and 90-day readmissions compared with patients without dementia. These estimates should be integrated into shared decision-making discussions with patients and families.

The Key Drivers of Brain Injury by Systemic Inflammatory Responses after Sepsis: Microglia and Neuroinflammation

Sepsis is a leading cause of intensive care unit admission and death worldwide. Most surviving patients show acute or chronic mental disorders, which are known as sepsis-associated encephalopathy (SAE). Although accumulating studies in the past two decades focused on the pathogenesis of SAE, a systematic review of retrospective studies which exclusively focuses on the inflammatory mechanisms of SAE has been lacking yet. This review summarizes the recent advance in the field of neuroinflammation and sheds light on the activation of microglia in SAE. Activation of microglia predominates neuroinflammation. As the gene expression profile changes, microglia show heterogeneous characterizations throughout all stages of SAE. Here, we summarize the systemic inflammation following sepsis and also the relationship of microglial diversity and neuroinflammation. Moreover, a collection of neuroinflammation-related dysfunction has also been reviewed to illustrate the possible mechanisms for SAE. In addition, promising pharmacological or non-pharmacological therapeutic strategies, especially those which target neuroinflammation or microglia, are also concluded in the final part of this review. Collectively, clarification of the vital relationship between neuroinflammation and SAE-related mental disorders would significantly improve our understanding of the pathophysiological mechanisms in SAE and therefore provide potential targets for therapies of SAE aimed at inhibiting neuroinflammation.

The inter-relationship between delirium and dementia: the importance of delirium prevention

Delirium and dementia are two frequent causes of cognitive impairment among older adults and have a distinct, complex and interconnected relationship. Delirium is an acute confusional state characterized by inattention, cognitive dysfunction and an altered level of consciousness, whereas dementia is an insidious, chronic and progressive loss of a previously acquired cognitive ability. People with dementia have a higher risk of developing delirium than the general population, and the occurrence of delirium is an independent risk factor for subsequent development of dementia. Furthermore, delirium in individuals with dementia can accelerate the trajectory of the underlying cognitive decline. Delirium prevention strategies can reduce the incidence of delirium and associated adverse outcomes, including falls and functional decline. Therefore, delirium might represent a modifiable risk factor for dementia, and interventions that prevent or minimize delirium might also reduce or prevent long-term cognitive impairment. Additionally, understanding the pathophysiology of delirium and the connection between delirium and dementia might ultimately lead to additional treatments for both conditions. In this Review, we explore mechanisms that might be common to both delirium and dementia by reviewing evidence on shared biomarkers, and we discuss the importance of delirium recognition and prevention in people with dementia.

In this Review, Fong and Inouye explore mechanisms that might be common to both delirium and dementia. They present delirium as a possible modifiable risk factor for dementia and discuss the importance of delirium prevention strategies in reducing this risk.

Delirium and dementia are frequent causes of cognitive impairment among older adults and have a distinct, complex and interconnected relationship.

Delirium prevention strategies have been shown to reduce not only the incidence of delirium but also the incidence of adverse outcomes associated with delirium such as falls and functional decline.

Adverse outcomes associated with delirium, such as the onset of dementia symptoms in individuals with preclinical dementia, and/or the acceleration of cognitive decline in individuals with dementia might also be delayed by the implementation of delirium prevention strategies.

Evidence regarding the association of systemic inflammatory and neuroinflammatory biomarkers with delirium is variable, possibly as a result of co-occurring dementia pathology or disruption of the blood–brain barrier.

Alzheimer disease pathology, even prior to the onset of symptoms, might have an effect on delirium risk, with potential mechanisms including neuroinflammation and gene–protein interactions with the APOE ε4 allele.

Novel strategies, including proteomics, multi-omics, neuroimaging, transcranial magnetic stimulation and EEG, are beginning to reveal how changes in cerebral blood flow, spectral power and connectivity can be associated with delirium; further work is needed to expand these findings to patients with delirium superimposed upon dementia.

What is the impact of perioperative cerebral oxygen desaturation on postoperative delirium in old population: a systemic review and meta-analysis

BACKGROUND

Perioperative cerebral oxygen saturation (ScO₂) has been reported to associate with postoperative delirium (POD) which is a common postoperative complication, however, the results were inconclusive. Therefore, we aimed to conduct an up-to-date review and meta-analyze the relationship between perioperative ScO₂ and POD.

METHODS

We systematically searched PubMed, Embase and Web of science through January 13, 2022. The pooled results were estimated through a random-effects model meta-analysis and expressed as odds ratios (ORs) and standard mean differences (SMDs), accompanied with 95% confident intervals (CIs).

RESULTS

Finally, of 467 searched articles, ten articles were included. A total of six studies reported the baseline ScO₂ value and the pooled result showed that preoperative baseline ScO₂ was lower in POD groups (SMD = - 0.41, 95% CI - 0.64 to - 0.18). And beyond that, the pooled OR across four literatures about preoperative low ScO₂ on POD was 3.44 (95% CI 1.69, 7.02). In contrast, insignificant differences were detected in baseline/lowest ScO₂ value during intraoperative and postoperative period. Additionally, there were no statistically significant associations for intraoperative and postoperative low ScO₂ effect on POD risk. Meta-regress analysis has found no significant impact factors.

CONCLUSIONS

Based on current evidence, POD patients have a lower ScO₂, and ScO₂ desaturation may increase POD incidence, indicating the role of ScO₂ underlying pathological mechanisms. For generalizability of evidence, we should rely on high-quality, considering more comprehensively longitudinal, interdisciplinary studies.

Delirium and its association with short-term outcomes in younger and older patients with acute heart failure

Younger patients (18 to 65 years old) are often excluded from delirium outcome studies. We sought to determine if delirium was associated with short-term adverse outcomes in a diverse cohort of younger and older patients with acute heart failure (AHF). We conducted a multi-center prospective cohort study that included adult emergency department patients with confirmed AHF. Delirium was ascertained using the Brief Confusion Assessment Method (bCAM). The primary outcome was a composite outcome of 30-day all-cause death, 30-day all-cause rehospitalization, and prolonged index hospital length of stay. Multivariable logistic regression was performed, adjusting for demographics, cognitive impairment without delirium, and HF risk factors. Older age (≥ 65 years old)*delirium interaction was also incorporated into the model. Odds ratios (OR) with their 95% confidence intervals (95%CI) were reported. A total of 1044 patients with AHF were enrolled; 617 AHF patients were < 65 years old and 427 AHF patients were ≥ 65 years old, and 47 (7.6%) and 40 (9.4%) patients were delirious at enrollment, respectively. Delirium was significantly associated with the composite outcome (adjusted OR = 1.64, 95%CI: 1.02 to 2.64). The older age*delirium interaction p-value was 0.47. In conclusion, delirium was common in both younger and older patients with AHF and was associated with poorer short-term outcomes in both cohorts. Younger patients with acute heart failure should be included in future delirium outcome studies.

Silent cerebral ischemia detected by magnetic resonance imaging can predict postoperative delirium after total arch replacement for aneurysm

Objective

To identify whether preoperative magnetic resonance imaging findings of the brain can predict postoperative delirium in patients who undergo arch replacement for aneurysms.

Methods

Overall, 193 patients who underwent aortic replacement for the first time at a single institution between April 2014 and September 2020 were enrolled in this retrospective study. After we excluded patients with acute aortic dissection, no preoperative magnetic resonance imaging findings of the brain, and postoperative cerebral infarction, 50 patients were included and divided into 2 groups, according to their confusion scale results: postoperative delirium (group D) and nonpostoperative delirium (group ND). Preoperative magnetic resonance imaging findings of the brain were classified into lacunar stroke, periventricular hyperintensity, and deep subcortical white matter hyperintensity groups; the latter 2 groups were further classified based on the Fazekas scale, grade 0 to 3.

Results

There were 23 patients (46%) in group D and 27 (54%) in group ND. The mean age was significantly greater in group D than in group ND (75 vs 70 years; P = .007). The mean operative time was significantly longer in group D than in group ND (447 vs 384 minutes; P = .024). As for preoperative magnetic resonance imaging findings of the brain, there were significantly more lacunar stroke cases in group D than in group ND (P = .027). In multivariable logistic regression with stepwise selection, high-grade periventricular hyperintensity was significantly related to postoperative delirium (odds ratio, 9.38; 95% confidence interval, 1.55-56.56; P = .015).

Conclusions

Silent cerebral ischemia detected by preoperative magnetic resonance imaging of the brain was a significant risk factor for postoperative delirium.

Sepsis-Associated Encephalopathy: A Mini-Review of Inflammation in the Brain and Body

Sepsis is defined as a life-threatening multi-organ dysfunction triggered by an uncontrolled host response to infectious disease. Systemic inflammation elicited by sepsis can cause acute cerebral dysfunction, characterized by delirium, coma, and cognitive dysfunction, known as septic encephalopathy. Recent evidence has reported the underlying mechanisms of sepsis. However, the reasons for the development of inflammation and degeneration in some brain regions and the persistence of neuroinflammation remain unclear. This mini-review describes the pathophysiology of region-specific inflammation after sepsis-associated encephalopathy (SAE), clinical features, and future prospects for SAE treatment. The hippocampus is highly susceptible to inflammation, and studies that perform treatments with antibodies to cytokine receptors, such as interleukin-1β, are in progress. Future development of clinically applicable therapies is expected.

The Relationship between Perioperative Blood Transfusion and Postoperative Delirium in Patients Undergoing Spinal Fusion Surgery: Clinical Data Warehouse Analysis

Background and Objectives: For preventing postoperative delirium (POD), identifying the risk factors is important. However, the relationship between blood transfusion and POD is still controversial. The aim of this study was to identify the risk factors of POD, to evaluate the impact of blood transfusion in developing POD among people undergoing spinal fusion surgery, and to show the effectiveness of big data analytics using a clinical data warehouse (CDW). Materials and Methods: The medical data of patients who underwent spinal fusion surgery were obtained from the CDW of the five hospitals of Hallym University Medical Center. Clinical features, laboratory findings, perioperative variables, and medication history were compared between patients without POD and with POD. Results: 234 of 3967 patients (5.9%) developed POD. In multivariate logistic regression analysis, the risk factors of POD were as follows: Parkinson’s disease (OR 5.54, 95% CI 2.15–14.27; p < 0.001), intensive care unit (OR 3.45 95% CI 2.42–4.91; p < 0.001), anti-psychotics drug (OR 3.35 95% CI 1.91–5.89; p < 0.001), old age (≥70 years) (OR 3.08, 95% CI 2.14–4.43; p < 0.001), depression (OR 2.8 95% CI 1.27–6.2; p < 0.001). The intraoperative transfusion (OR 1.1, 95% CI 0.91–1.34; p = 0.582), and the postoperative transfusion (OR 0.91, 95% CI 0.74–1.12; p = 0.379) had no statistically significant effect on the incidence of POD. Conclusions: There was no relationship between perioperative blood transfusion and the incidence of POD in spinal fusion surgery. Big data analytics using a CDW could be helpful for the comprehensive understanding of the risk factors of POD, and for preventing POD in spinal fusion surgery.

Prediction of Postoperative Delirium after Gastrointestinal Surgery Using the Mie Constructional Apraxia Scale

Background

Postoperative delirium (POD) is a transient postoperative complication that occurs after surgical procedures. Risk factors reported for POD include dementia and cognitive decline. The purpose of this study was to identify predictors of POD by examining the use of preoperative neuropsychological tests, including the Mie Constructional Apraxia Scale (MCAS), and patient background factors.

Method

The study was performed as a retrospective cohort study. The subjects were 33 patients (mean age, 75.8 ± 10.9 years; male:female ratio, 26:7) who underwent gastrointestinal surgery at Matsusaka City Hospital between December 2019 and April 2021. Data were collected retrospectively from medical records. The study was started after receiving approval from the institution's ethics committee. The survey items included general patient information, nutritional assessment, surgical information, and neuropsychological tests. Subjects were classified into 2 groups according to the presence or absence of POD. If a significant difference was observed between the 2 groups, the sensitivity, specificity, and area under the curve were calculated using a receiver operating characteristic (ROC) curve.

Result

There were 10 patients in the POD group (male:female ratio, 6:4) and 23 patients in the non-POD group (20:3). The POD group had a shorter education history (p = 0.047) and significantly higher MCAS scores (p = 0.007) than the non-POD group. The ROC curve showed a sensitivity of 90%, a specificity of 69%, and an area under the curve of 0.798 when the MCAS cutoff value was set at 3 points.

Conclusion

Preoperative MCAS results were capable of predicting the occurrence of POD after gastrointestinal surgery. In addition, a relatively short education background was also considered a risk factor for POD.

Rapidly progressive brain atrophy in septic ICU patients: a retrospective descriptive study using semiautomatic CT volumetry

Background

Sepsis is often associated with multiple organ failure; however, changes in brain volume with sepsis are not well understood. We assessed brain atrophy in the acute phase of sepsis using brain computed tomography (CT) scans, and their findings’ relationship to risk factors and outcomes.

Methods

Patients with sepsis admitted to an intensive care unit (ICU) and who underwent at least two head CT scans during hospitalization were included (n = 48). The first brain CT scan was routinely performed on admission, and the second and further brain CT scans were obtained whenever prolonged disturbance of consciousness or abnormal neurological findings were observed. Brain volume was estimated using an automatic segmentation method and any changes in brain volume between the two scans were recorded. Patients with a brain volume change < 0% from the first CT scan to the second CT scan were defined as the “brain atrophy group (n = 42)”, and those with ≥ 0% were defined as the “no brain atrophy group (n = 6).” Use and duration of mechanical ventilation, length of ICU stay, length of hospital stay, and mortality were compared between the groups.

Results

Analysis of all 42 cases in the brain atrophy group showed a significant decrease in brain volume (first CT scan: 1.041 ± 0.123 L vs. second CT scan: 1.002 ± 0.121 L, t (41) = 9.436, p < 0.001). The mean percentage change in brain volume between CT scans in the brain atrophy group was –3.7% over a median of 31 days, which is equivalent to a brain volume of 38.5 cm³. The proportion of cases on mechanical ventilation (95.2% vs. 66.7%; p = 0.02) and median time on mechanical ventilation (28 [IQR 15–57] days vs. 15 [IQR 0–25] days, p = 0.04) were significantly higher in the brain atrophy group than in the no brain atrophy group.

Conclusions

Many ICU patients with severe sepsis who developed prolonged mental status changes and neurological sequelae showed signs of brain atrophy. Patients with rapidly progressive brain atrophy were more likely to have required mechanical ventilation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03828-7.

Dementia and COVID-19, a Bidirectional Liaison: Risk Factors, Biomarkers, and Optimal Health Care

Cognitive impairment following SARS-CoV-2 infection is being increasingly recognized as an acute and possibly also long-term sequela of the disease. Direct viral entry as well as systemic mechanisms such as cytokine storm are thought to contribute to neuroinflammation in these patients. Biomarkers of COVID-19-induced cognitive impairment are currently lacking, but there is some limited evidence that SARS-CoV-2 could preferentially target the frontal lobes, as suggested by behavioral and dysexecutive symptoms, fronto-temporal hypoperfusion on MRI, EEG slowing in frontal regions, and frontal hypometabolism on 18F-FDG-PET. Possible confounders include cognitive impairment due to hypoxia and mechanical ventilation and post-traumatic stress disorder. Conversely, patients already suffering from dementia, as well as their caregivers, have been greatly impacted by the disruption of their care caused by COVID-19. Patients with dementia have experienced worsening of cognitive, behavioral, and psychological symptoms, and the rate of COVID-19-related deaths is disproportionately high among cognitively impaired people. Multiple factors, such as difficulties in remembering and executing safeguarding procedures, age, comorbidities, residing in care homes, and poorer access to hospital standard of care play a role in the increased morbidity and mortality. Non-pharmacological interventions and new technologies have shown a potential for the management of patients with dementia, and for the support of their caregivers.

Delirium, Cerebral Perfusion, and High-Frequency Vital-Sign Monitoring in the Critically Ill. The CONFOCAL-2 Feasibility Study

Rationale: Studies suggest that reduced cerebral perfusion may contribute to delirium development in the intensive care unit (ICU). However, evidence is limited because of factors including small sample size and limited inclusion of covariates.Objectives: To assess the feasibility of a multicenter prospective observational study using a multimodal data collection platform. Feasibility was assessed by enrollment, data-capture, and follow-up rates. The full study will aim to assess the association between noninvasively derived surrogate markers of cerebral perfusion, delirium development, and long-term cognitive outcomes in critically ill patients.Methods: Adult patients in the ICU were enrolled if they had shock and/or respiratory failure requiring invasive mechanical ventilation for >24 hours. For the first 72 hours, a near-infrared spectroscopic sensor was placed on the forehead to continuously monitor regional cerebral oxygenation (rSo₂) and high-frequency (1 Hz) vital signs were concurrently captured via an arterial line. Cerebral perfusion was estimated using three variables, including mean rSo₂, duration of disturbed autoregulation, and time/magnitude away from optimal mean arterial pressure (MAP). Patients were screened for delirium in the ICU and ward daily for up to 30 days. Cognitive function was assessed 3 and 12 months after ICU admission to identify cognitive impairment.Results: Fifty-nine patients were enrolled across four sites in 1 year. Data-capture rates varied across modalities but exceeded 80% for rSo₂, blood gas, and delirium data capture. Vital-sign capture and 3-month follow-up rates were lower at 53% and 55%, respectively. Eighty-three percent (49 of 59) of patients experienced delirium, with a median severity of 0.56 in the ICU. Mean physiological (±standard deviation) values were: rSo₂ (70.4% ± 7.0%), heart rate (83.9 ± 16.45 beats/min), MAP (76.4 ± 12.8 mm Hg), peripheral oxygenation saturation (96.5% ± 2.1%), proportion of recording time spent with disturbed autoregulation (10.1% ± 7.3%) and proportion of area under the curve outside optimal MAP (39.6% ± 22.4%). Thirty-two (54%) individuals had cerebral autoregulation curves where a targeted optimal MAP was identified. Barriers to data collection included missing vital-sign data and low follow-up rates.Conclusions: Given our current protocol, a multicenter study examining the association between cerebral oxygenation, delirium, and long-term cognitive impairment is not feasible. However, by performing an early assessment of feasibility, we identified strategies to increase capture rates to ensure success as the study begins the next phase of study recruitment.Clinical trial registered with clinicaltrials.gov (NCT03141619).

Why is delirium more frequent in the elderly?

An aging-related reduction in the brain's functional reserve may explain why delirium is more frequent in the elderly than in younger people insofar as the reserve becomes inadequate to cover the metabolic requirements that are critically increased by stressors. The aim of this paper is to review the normal aging-related changes that theoretically compromise complex mental activities, neuronal and synaptic densities, and the neurocomputational flexibility of the functional reserve. A pivotal factor is diminished connectivity, which is substantially due to the loss of synapses and should specifically affect association systems and cholinergic fibres in delirious patients. However, micro-angiopathy with impaired blood flow autoregulation, increased blood/brain barrier permeability, changes in cerebrospinal fluid dynamics, weakened mitochondrial performance, and a pro-inflammatory involution of the immune system may also jointly affect neurons and their synaptic assets, and even cause the progression of delirium to dementia regardless of the presence of co-existing plaques, tangles, or other pathological markers. On the other hand, the developmental growth in functional reserve during childhood and adolescence makes the brain increasingly resistant to delirium, and residual reserve can allow the elderly to recover. These data support the view that functional reserve is the variable that confronts stressors and governs the risk and intensity of and recovery from delirium. Although people of any age are at risk of delirium, the elderly are at greater risk because aging and age-dependent structural changes inevitably affect the brain's functional reserve.

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.

Clinical utility of brain computed tomography in prediction of post-stroke delirium

Delirium is a common and serious complication of stroke. Early prediction of delirium is important for preventive strategies and close monitoring of high-risk patients. Pre-existing degenerative and vascular changes in the brain could predispose to delirium. We aimed to determine if computed tomography (CT)-based indices could provide additional information about a risk of stroke-associated delirium beyond easiest-to-access clinical predictors. Using semi-quantitative scales (global cortical atrophy, age-related white matter changes, and Scheltens scale), we assessed global and regional brain atrophy and white matter changes in 88 stroke patients with delirium and 142 patients without delirium matched for age and stroke severity. Patients with delirium had greater global and local brain atrophy (the right temporal region, the left parieto-occipital region, the right frontal and occipital horn, and the right and left temporal horn) than patients without delirium. Scores of white matter changes did not differ between groups with exception of greater white matter damage in the right parieto-occipital area in patients with delirium. The discriminatory properties of studied radiological indices were modest (areas under receiver operator curves: 0.58-0.64). CT-based indices of brain atrophy and white matter changes do not provide additional information about a risk of post-stroke delirium beyond the most important clinical predictors.

Preoperative brain MRI features and occurrence of postoperative delirium

OBJECTIVE

Delirium is a frequent complication after surgery with important negative outcomes for affected patients and society. However, it is still largely unknown why some patients have a predisposition for delirium and others not. To increase our understanding of the neural substrate of postoperative delirium, we studied the association between preoperative brain MRI features and the occurrence of delirium after major surgery.

METHODS

A group of 413 patients without dementia (Mean 72 years, SD: 5) was included in a prospective observational two-center study design. The study was conducted at Charité Universitätsmedizin (Berlin, Germany) and the University Medical Center Utrecht (Utrecht, The Netherlands). We measured preoperative brain volumes (total brain, gray matter, white matter), white matter hyperintensity volume and shape, brain infarcts and cerebral perfusion, and used logistic regression analysis adjusted for age, sex, intracranial volume, study center and type of surgery.

RESULTS

Postoperative delirium was present in a total of 70 patients (17%). Preoperative cortical brain infarcts increased the risk of postoperative delirium, although this did not reach statistical significance (OR (95%CI): 1.63 (0.84-3.18). Furthermore, we found a trend for an association of a more complex shape of white matter hyperintensities with occurrence of postoperative delirium (OR (95%CI): 0.97 (0.95-1.00)). Preoperative brain volumes, white matter hyperintensity volume, and cerebral perfusion were not associated with occurrence of postoperative delirium.

CONCLUSION

Our study suggests that patients with preoperative cortical brain infarcts and those with a more complex white matter hyperintensity shape may have a predisposition for developing delirium after major surgery.

Regional Metabolic Patterns of Abnormal Postoperative Behavioral Performance in Aged Mice Assessed by 1H-NMR Dynamic Mapping Method

Abnormal postoperative neurobehavioral performance (APNP) is a common phenomenon in the early postoperative period. The disturbed homeostatic status of metabolites in the brain after anesthesia and surgery might make a significant contribution to APNP. The dynamic changes of metabolites in different brain regions after anesthesia and surgery, as well as their potential association with APNP are still not well understood. Here, we used a battery of behavioral tests to assess the effects of laparotomy under isoflurane anesthesia in aged mice, and investigated the metabolites in 12 different sub-regions of the brain at different time points using proton nuclear magnetic resonance (1H-NMR) spectroscopy. The abnormal neurobehavioral performance occurred at 6 h and/or 9 h, and recovered at 24 h after anesthesia/surgery. Compared with the control group, the altered metabolite of the model group at 6 h was aspartate (Asp), and the difference was mainly displayed in the cortex; while significant changes at 9 h occurred predominantly in the cortex and hippocampus, and the corresponding metabolites were Asp and glutamate (Glu). All changes returned to baseline at 24 h. The altered metabolic changes could have occurred as a result of the acute APNP, and the metabolites Asp and Glu in the cortex and hippocampus could provide preliminary evidence for understanding the APNP process.

Intraoperative blood transfusion predicts postoperative delirium among older patients undergoing elective orthopedic surgery: A prospective cohort study

OBJECTIVES

To evaluate the roles of preoperative anemia and intraoperative blood transfusion in the development of postoperative delirium among older patients undergoing elective orthopedic surgery.

METHODS

This prospective cohort study recruited subjects aged 60 years old and above who were admitted for elective orthopedic surgery in a tertiary medical center during April 2011 to December 2013. Demographic data (age, gender, body mass index [BMI], and educational level), surgery-related factors (American Society of Anesthesiology [ASA] class, type of anesthesia and surgery, and intraoperative blood transfusion), results of geriatric assessment (hearing/visual impairment, cognition, depressive mood, comorbidity, malnutrition, polypharmacy, activities of daily living [ADL], and instrumental activities of daily living [IADL]), laboratory data, length of hospital stay, and the development of postoperative delirium were collected for analysis.

RESULTS

Overall, 461 patients (mean age: 73.5 ± 7.5 years, 42.1% males) were enrolled for study, and 37 (8.0%) of them developed postoperative delirium. We categorized all subjects into four groups based on anemia on admission and blood transfusion during operation or not. Multivariate logistic regression showed that subjects with anemia on admission and received intraoperative blood transfusion were at higher risk of developing postoperative delirium (adjusted odds ratio 3.090; 95% confidence interval [CI], 1.070-8.926) and those without anemia on admission but received intraoperative blood transfusion were at marginal risk (adjusted odds ratio 2.906; 95% CI, 0.912-9.259) after adjustment for covariates.

CONCLUSIONS

Anemic older patients receiving intraoperative blood transfusion during operation were at the greatest risk for postoperative delirium when they underwent elective orthopedic surgery. Further intervention study is needed to reduce the risk of postoperative delirium for these patients.

A systematic review of neuroimaging in delirium: predictors, correlates and consequences

OBJECTIVE

Neuroimaging advances our understanding of delirium pathophysiology and its consequences. A previous systematic review identified 12 studies (total participants N = 764, delirium cases N = 194; years 1989-2007) and found associations with white matter hyperintensities (WMH) and cerebral atrophy. Our objectives were to perform an updated systematic review of neuroimaging studies in delirium published since January 2006 and summarise the available literature on predictors, correlates or outcomes.

METHODS

Studies were identified by keyword and MeSH-based electronic searches of EMBASE, MEDLINE and PsycINFO combining terms for neuroimaging, brain structure and delirium. We included neuroimaging studies of delirium in adults using validated delirium assessment methods.

RESULTS

Thirty-two studies (total N = 3187, delirium N = 1086) met the inclusion criteria. Imaging included magnetic resonance imaging (MRI; N = 9), computed tomography (N = 4), diffusion tensor imaging (N = 3), transcranial Doppler (N = 5), near infrared spectroscopy (N = 5), functional-MRI (N = 2), single photon emission computed tomography (N = 1), proton MRI spectroscopy (N = 1), arterial spin-labelling MRI (N = 1) and 2-¹³ fluoro-2-deoxyglucose positron emission tomography (N = 1). Despite heterogeneity in study design, delirium was associated with WMH, lower brain volume, atrophy, dysconnectivity, impaired cerebral autoregulation, reduced blood flow and cerebral oxygenation and glucose hypometabolism. There was evidence of long-term brain changes following intensive care unit delirium.

CONCLUSIONS

Neuroimaging is now used more widely in delirium research due to advances in technology. However, imaging delirious patients presents challenges leading to methodological limitations and restricted generalisability. The findings that atrophy and WMH burden predict delirium replicates findings from the original review, while advanced techniques have identified other substrates and mechanisms that warrant further investigation.

Delirium in the Elderly

Delirium is defined as an acute disturbance in attention and cognition, with significant associated morbidity and mortality. This article discusses the basic epidemiology of delirium and approaches to diagnosing, assessing, and working up patients for delirium. It delineates the pathophysiology and underlying predisposing and precipitating factors for delirium. It also discusses recent advances in prevention and treatment, particularly multicomponent, nonpharmacological interventions.

2-18F-fluoro-2-deoxyglucose positron emission tomography in delirium

Delirium is a common, serious, yet poorly understood syndrome. Growing evidence suggests cerebral metabolism is fundamentally disturbed; however, it has not been investigated using 2-¹⁸F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) in delirium. This prospective study thus explored FDG PET patterns of cerebral glucose metabolism in older inpatients with delirium. A particular emphasis was on the posterior cingulate cortex (PCC), a key region for attention, which is a central feature of delirium. Delirium scans were compared with post-delirium scans using visual analysis and semi-quantitative analysis with NeuroQ; 13 participants (8 female, median 84 y) were scanned during delirium, and 6 scanned again after resolution. On visual analysis, cortical hypometabolism was evident in all participants during delirium (13/13), and improved with delirium resolution (6/6). Using NeuroQ, glucose metabolism was higher post-delirium in the whole brain and bilateral PCC compared to during delirium ( p < 0.05). Greater metabolism in both PCCs correlated with better performance on a neuropsychological test of attention, the WAIS-IV Digit Span Test forwards, and with shorter delirium duration. This research found widespread, reversible cortical hypometabolism during delirium and PCC hypometabolism was associated with inattention during delirium.

Altered cortical brain activity in end stage liver disease assessed by multi-channel near-infrared spectroscopy: Associations with delirium

Delirium is a common and serious psychiatric syndrome caused by an underlying medical condition. It is associated with significant mortality and increased healthcare resource utilization. There are few biological markers of delirium, perhaps related to the etiologic heterogeneity of the syndrome. Functional near-infrared spectroscopy (fNIRS) is an optical topography system to measure changes in the concentration of oxygenated hemoglobin ([oxy-Hb]) in the cerebral cortex. We examined whether altered cortical brain activity in delirious patients with end stage liver disease (ESLD) is detected by fNIRS. We found that the [oxy-Hb] change during the verbal fluency task (VFT) was reduced in patients with ESLD compared with healthy controls (HC) in the prefrontal and bi-temporal regions. The [oxy-Hb] change during the sustained attention task (SAT) was elevated in patients with ESLD compared to HC in the prefrontal and left temporal regions. Notably, [oxy-Hb] change in the left dorsolateral prefrontal cortex during SAT showed a positive correlation with the severity of delirium. Our results suggest that [oxy-Hb] change in the prefrontal cortex during the sustained attention task measured with fNIRS might serve as a biological marker associated with delirium in ESLD patients.

A Novel Stress-Diathesis Model to Predict Risk of Post-operative Delirium: Implications for Intra-operative Management

Introduction: Risk assessment for post-operative delirium (POD) is poorly developed. Improved metrics could greatly facilitate peri-operative care as costs associated with POD are staggering. In this preliminary study, we develop a novel stress-diathesis model based on comprehensive pre-operative psychiatric and neuropsychological testing, a blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) carbon dioxide (CO₂) stress test, and high fidelity measures of intra-operative parameters that may interact facilitating POD. Methods: The study was approved by the ethics board at the University of Manitoba and registered at clinicaltrials.gov as NCT02126215. Twelve patients were studied. Pre-operative psychiatric symptom measures and neuropsychological testing preceded MRI featuring a BOLD MRI CO₂ stress test whereby BOLD scans were conducted while exposing participants to a rigorously controlled CO₂ stimulus. During surgery the patient had hemodynamics and end-tidal gases downloaded at 0.5 hz. Post-operatively, the presence of POD and POD severity was comprehensively assessed using the Confusion Assessment Measure -Severity (CAM-S) scoring instrument on days 0 (surgery) through post-operative day 5, and patients were followed up at least 1 month post-operatively. Results: Six of 12 patients had no evidence of POD (non-POD). Three patients had POD and 3 had clinically significant confusional states (referred as subthreshold POD; ST-POD) (score ≥ 5/19 on the CAM-S). Average severity for delirium was 1.3 in the non-POD group, 3.2 in ST-POD, and 6.1 in POD (F-statistic = 15.4, p < 0.001). Depressive symptoms, and cognitive measures of semantic fluency and executive functioning/processing speed were significantly associated with POD. Second level analysis revealed an increased inverse BOLD responsiveness to CO₂ pre-operatively in ST-POD and marked increase in the POD groups when compared to the non-POD group. An association was also noted for the patient population to manifest leucoaraiosis as assessed with advanced neuroimaging techniques. Results provide preliminary support for the interacting of diatheses (vulnerabilities) and intra-operative stressors on the POD phenotype. Conclusions: The stress-diathesis model has the potential to aid in risk assessment for POD. Based on these initial findings, we make some recommendations for intra-operative management for patients at risk of POD.

Cerebral blood flow MRI in the nondemented elderly is not predictive of post-operative delirium but is correlated with cognitive performance

Three-dimensional Arterial Spin Labeling (ASL) MRI was performed before surgery in a cohort of 146 prospectively enrolled subjects ≥ 70 years old scheduled to undergo elective surgery. We investigated the prospective association between ASL-derived measures of cerebral blood flow (CBF) before surgery with postoperative delirium incidence and severity using whole-brain and globally normalized voxel-wise analysis. We also investigated the cross-sectional association of CBF with patients' baseline performance on specific neuropsychological tests, and with a composite general cognitive performance measure (GCP). Out of 146 subjects, 32 (22%) developed delirium. We found no significant association between global and voxel-wise CBF with delirium incidence or severity. We found the most significant positive associations between CBF of the posterior cingulate and precuneus and the Hopkins Verbal Learning Test - Revised total score, Visual Search and Attention Test (VSAT) score and the GCP composite. VSAT score was also strongly associated with right parietal lobe CBF. ASL can be employed in a large, well-characterized older cohort to examine associations between CBF and age-related cognitive performance. Although ASL CBF measures in regions previously associated with preclinical Alzheimer's Disease were correlated with cognition, they were not found to be indicators of baseline pathology that may increase risk for delirium.

Delirium in critically ill patients

Delirium is common in critically ill patients and associated with increased length of stay in the intensive care unit (ICU) and long-term cognitive impairment. The pathophysiology of delirium has been explained by neuroinflammation, an aberrant stress response, neurotransmitter imbalances, and neuronal network alterations. Delirium develops mostly in vulnerable patients (e.g., elderly and cognitively impaired) in the throes of a critical illness. Delirium is by definition due to an underlying condition and can be identified at ICU admission using prediction models. Treatment of delirium can be improved with frequent monitoring, as early detection and subsequent treatment of the underlying condition can improve outcome. Cautious use or avoidance of benzodiazepines may reduce the likelihood of developing delirium. Nonpharmacologic strategies with early mobilization, reducing causes for sleep deprivation, and reorientation measures may be effective in the prevention of delirium. Antipsychotics are effective in treating hallucinations and agitation, but do not reduce the duration of delirium. Combined pain, agitation, and delirium protocols seem to improve the outcome of critically ill patients and may reduce delirium incidence.

Cerebral Blood Flow Autoregulation in Sepsis for the Intensivist: Why Its Monitoring May Be the Future of Individualized Care

Cerebral blood flow (CBF) autoregulation maintains consistent blood flow across a range of blood pressures (BPs). Sepsis is a common cause of systemic hypotension and cerebral dysfunction. Guidelines for BP management in sepsis are based on historical concepts of CBF autoregulation that have now evolved with the availability of more precise technology for its measurement. In this article, we provide a narrative review of methods of monitoring CBF autoregulation, the cerebral effects of sepsis, and the current knowledge of CBF autoregulation in sepsis. Current guidelines for BP management in sepsis are based on a goal of maintaining mean arterial pressure (MAP) above the lower limit of CBF autoregulation. Bedside tools are now available to monitor CBF autoregulation continuously. These data reveal that individual BP goals determined from CBF autoregulation monitoring are more variable than previously expected. In patients undergoing cardiac surgery with cardiopulmonary bypass, for example, the lower limit of autoregulation varied between a MAP of 40 to 90 mm Hg. Studies of CBF autoregulation in sepsis suggest patients frequently manifest impaired CBF autoregulation, possibly a result of BP below the lower limit of autoregulation, particularly in early sepsis or with sepsis-associated encephalopathy. This suggests that the present consensus guidelines for BP management in sepsis may expose some patients to both cerebral hypoperfusion and cerebral hyperperfusion, potentially resulting in damage to brain parenchyma. The future use of novel techniques to study and clinically monitor CBF autoregulation could provide insight into the cerebral pathophysiology of sepsis and offer more precise treatments that may improve functional and cognitive outcomes for survivors of sepsis.

Early consciousness disorder in acute ischemic stroke: incidence, risk factors and outcome

Background

Little is known about the incidence and risk factors of early consciousness disorder (ECD) in patients with acute ischemic stroke, or about how ECD may affect complications and outcomes.

Methods

Patients admitted to our hospital within 24 h of onset of acute ischemic stroke were consecutively enrolled. ECD was evaluated clinically and using the Glasgow coma scale. Multivariate analysis was used to identify risk factors of ECD, as well as associations between ECD and clinical outcomes.

Results

Of the 569 patients enrolled, 199 (35 %) had ECD. Independent risk factors of ECD were advanced age (OR 1.027, 95 % CI 1.007 to 1.048), National Institutes of Health Stroke Score on admission (OR 1.331, 95 % CI 1.257 to 1.410), and massive cerebral infarct (OR 3.211, 95 % CI 1.642 to 6.279). ECD was associated with higher frequency of stroke-related complications (83.4 % vs. 31.1 %, P < 0.001) and higher in-hospital mortality (17.1 % vs. 0.5 %, P < 0.001). ECD independently predicted 3-month death/disability (OR 3.272, 95 % CI 1.670 to 6.413).

Conclusions

ECD is prevalent in Chinese patients with acute ischemic stroke. Risk factors include advanced age, stroke severity, and massive cerebral infarct. ECD is associated with higher frequency of stroke-related complications and 3-month death/disability.

Absence of association between whole blood viscosity and delirium after cardiac surgery: a case-controlled study

Background

Delirium after cardiothoracic surgery is common and associated with impaired outcomes. Although several mechanisms have been proposed (including changes in cerebral perfusion), the pathophysiology of postoperative delirium remains unclear. Blood viscosity is related to cerebral perfusion and thereby might contribute to the development of delirium after cardiothoracic surgery. The aim of this study was to investigate whether whole blood viscosity differs between cardiothoracic surgery patients with and without delirium.

Methods

In this observational study postoperative whole blood viscosity of patients that developed delirium (cases) were compared with non-delirious cardiothoracic surgery patients (controls). Cases were matched with the controls, yielding a 1:4 case–control study. Serial hematocrit, fibrinogen, and whole blood viscosity were determined pre-operatively and at each postoperative day. Delirium was assessed using the validated Confusion Assessment Method for the Intensive Care Unit or Delirium Screening Observation scale.

Results

In total 80 cardiothoracic surgery patients were screened of whom 12 delirious and 48 matched non-delirious patients were included. No significant difference was found between both groups in fibrinogen (p = 0.36), hematocrit (p = 0.23) and the area under curve of the whole blood viscosity between shear rates 0.02 and 50 s^-1 (p = 0.80) or between shear rates 0.02 and 5 s^-1 (p = 0.78).

Conclusion

In this case control study in cardiothoracic surgery patients changes in whole blood viscosity were not associated with the development of delirium.

Prevalence, determinants, and prognostic significance of delirium in patients with acute heart failure

BACKGROUND

Delirium is a serious syndrome in critically ill patients. However, the prognostic impact of delirium and its determinants in acute heart failure (AHF) patients have not been fully elucidated.

METHODS

We examined 611 AHF patients who were admitted to our institution. Delirium was diagnosed based on the Intensive Care Delirium Screening Checklist (ICDSC).

RESULTS

Delirium developed in 139 patients (23%) during hospitalization. Patients with delirium had higher incidence of non-cardiovascular death (p=0.046) and worsening heart failure (p<0.001) during hospitalization. Among patients who survived at discharge, the incidence of all-cause death, cardiovascular death and non-cardiovascular death after discharge were significantly higher in patients with delirium than those without (log-rank; p<0.001, p=0.001, p<0.001, respectively) during a median follow-up period of 335days. In multivariable model, the development of delirium was an independent determinant of worsening heart failure during hospitalization (OR: 2.44, 95% CI: 1.27-4.63) and all-cause death after discharge (HR: 2.38, 95% CI: 1.30-4.35). Furthermore, multivariate analysis indicated that history of cerebrovascular disease (OR: 2.13, 95% CI: 1.36-3.35), age (OR: 1.43, 95% CI: 1.15-1.80), log BNP (OR: 1.39, 95% CI: 1.09-1.79), serum albumin (OR: 0.84, 95% CI: 0.76-0.93) and blood glucose levels (OR: 1.03, 95% CI: 1.00-1.06) were independent determinants of delirium.

CONCLUSION

In patients with AHF, the development of delirium was associated with poor clinical outcomes, suggesting the importance of early screening and careful monitoring of delirium in such patients.

Executive Dysfunction Following Critical Illness: Exploring Risk Factors and Management Options in Geriatric Populations

Cognitive impairment is a common occurrence that has been shown to occur in over 50 % of patients following critical illness. This impairment occurs across a range of domains including attention, memory, processing speed, and executive dysfunction. In this article, we will discuss the pathophysiology behind cognitive impairment including hypoxemia and cytokines. Secondly, we will describe the risk factors for cognitive impairment including age, length of stay, and delirium. Lastly, we will review emerging data related to the use of cognitive rehabilitation, formation of postintensive care clinics in qualifying patients, and potential neuropharmacologic therapy. While our chapter focuses on cognitive impairment generally, it places a particular emphasis on executive dysfunction, not because impairment occurs solely in this domain but because impairments of an executive nature may be uniquely debilitating.

The impact of delirium on outcomes in acute, non-intubated cardiac patients

BACKGROUND

Because of progress in cardiovascular management, many critically ill geriatric patients undergo various procedures and intensive cardiovascular care treatments. Although delirium frequently affects geriatric patients post-procedurally and after intensive cardiovascular care, the impact of delirium on acute cardiac patients has not been well understood. The objective of this study was to investigate the impact of delirium on outcomes in acute, non-intubated cardiac patients.

METHODS

This was a prospective cohort study including non-surgical cardiac patients aged 65 years or older admitted to the intensive care unit or intensive cardiac care unit. We excluded mechanically ventilated patients. Delirium was evaluated using the confusion assessment method for the intensive care unit. The primary outcome analysed was 60-day mortality. The secondary outcomes analysed were risk and precipitating factors for delirium development.

RESULTS

Of 163 patients, 35 (21.5%) developed delirium. Patients with delirium had higher 60-day mortality rates than those without delirium (22.9% versus 3.9%, P<0.001) and spent an average of 10 days longer in the hospital (32±20 versus 22±16 days, P=0.002). On the multivariable Cox analysis, delirium was independently associated with 60-day mortality (adjusted hazard ratio 3.91; 95% confidence interval 1.06-17.36; P=0.04), which was also confirmed by the propensity score-matched analysis. Dementia, history of cerebrovascular disease, and higher sequential organ failure assessment score were significantly associated with delirium development.

CONCLUSIONS

Acute delirium is common and predicts mortality in non-intubated cardiac patients. Cardiac critical care providers should be aware of this neurological condition.