Sedation, Delirium, and Cognitive Function After Critical Illness

The Effectiveness of Acupressure on Sleep Quality in Cancer Patients: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

AIMS

To examine the effectiveness of acupressure on sleep quality in cancer patients and to identify the population-level and intervention-level characteristics associated with the intervention outcome of sleep quality.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, EMBASE, APA PsycInfo, Web of Science, CINAHL, Cochrane Library, China National Knowledge Infrastructure and WanFang were searched for eligible randomised controlled trials from inception to April 2024.

METHODS

Methodological quality was assessed using the Cochrane Risk of Bias Tool for Randomised Trials 2.0. A random-effects model was used for the meta-analysis. Subgroup analyses and the meta-regression aimed to investigate potential heterogeneity and identify characteristics that may be associated with more favourable acupressure outcomes.

RESULTS

In total, 22 randomised controlled trials involving 2113 participants were included in this meta-analysis. Compared with various control groups, acupressure exhibited a significant beneficial effect on sleep quality in cancer patients at post-intervention (SMD = -1.38, 95% CI [-1.81, -0.95], p < 0.001) and at 4-week follow-up (SMD = -0.33, 95% CI [-0.56, -0.10], p = 0.004). Acupressure also showed statistically significant improvements in sleep efficiency (SMD = 0.77, 95% CI [0.27, 1.26], p = 0.002) and total sleep time (SMD = 0.68, 95% CI [0.15, 1.22], p = 0.010) at post-intervention. None of the characteristics significantly affected the overall effect size on sleep quality.

CONCLUSIONS

Acupressure appears to be a promising intervention for enhancing sleep quality among cancer patients. Future studies should elucidate the long-term effects of acupressure on sleep quality, identify effective acupressure characteristics and determine which types of cancer patients benefit from this intervention.

IMPACT

This study provides a comprehensive summary of evidence supporting the use of acupressure to enhance sleep quality in cancer patients and demonstrates its effectiveness in clinical nursing practice.

REPORTING METHOD

PRISMA 2020 statement.

PATIENT OR PUBLIC CONTRIBUTION

No Patient or Public Contribution.

Unmasking the hidden aftermath: postintensive care unit sequelae, discharge preparedness, and long-term follow-up

A significant portion of individuals who have experienced critical illness encounter new or exacerbated impairments in their physical, cognitive, or mental health, commonly referred to as postintensive care syndrome. Moreover, those who survive critical illness often face an increased risk of adverse consequences, including infections, major cardiovascular events, readmissions, and elevated mortality rates, during the months following hospitalization. These findings emphasize the critical necessity for effective prevention and management of long-term health deterioration in the critical care environment. Although conclusive evidence from well-designed randomized clinical trials is somewhat limited, potential interventions include strategies such as limiting sedation, early mobilization, maintaining family presence during the intensive care unit stay, implementing multicomponent transition programs (from intensive care unit to ward and from hospital to home), and offering specialized posthospital discharge follow-up. This review seeks to provide a concise summary of recent medical literature concerning long-term outcomes following critical illness and highlight potential approaches for preventing and addressing health decline in critical care survivors.

Cognitive impairment in critically ill patients and former critically ill patients: A concept analysis

OBJECTIVES

This concept analysis aimed to clarify the meaning of the concept of cognitive impairment in critically ill patients throughout the trajectory of their rehabilitation during and after an intensive care unit admission.

REVIEW METHODS USED

This study used concept analysis based on Rodgers' evolutionary method.

DATA SOURCES

A systematic search was conducted in Cumulative Index to Nursing and Allied Health Literature, Public MEDLINE, and American Psychological Associations PsycINFO. The web was searched for grey literature.

REVIEW METHODS

Overall search terms used were "patients with cognitive impairments" AND "intensive care unit". Literature published between 2008 and 2022 was included and screened by title and abstract using systematic review software. The descriptive analysis focussed on surrogate terms/related concepts, attributes, and contextual basis.

RESULTS

Thirty studies were included, representing variability in study design and country of origin. The analysis uncovered descriptions of the general terminology and the temporal trajectory of the concept, spanning from the acute phase to a long-term perspective. Attributes of the concept were described as delirium and domains of cognition. Antecedents were juxtaposed to risk factors, which were multifactorial. Consequences of cognitive impairment related to patients' quality of life, such as a decline in their ability to function independently, return to work, and manage everyday life. Also, cognitive impairment was identified as a significant public health problem.

CONCLUSION

Cognitive impairment is a complex concept with many surrogate and related terms. Furthermore, the concept is inextricably intertwined with the concepts of delirium and post-intensive care syndrome. Cognitive impairment may manifest as symptoms that can be challenging to identify and assess due to limitations in current screening tools and the absence of a consensus on timing. In relation to assessment and preventive strategies, the findings underline the need to distinguish between acute and long-term cognitive impairment.

REGISTRATION

There is no study registration number.

Nurses' experiences of managing cognitive problems in intensive care unit patients: A qualitative study

OBJECTIVES

Nurses hold a key position in identifying symptoms and initiating preventive strategies for cognitive impairment in delirious and non-delirious intensive care unit patients. However, it remains unclear whether nurses consider cognitive impairment as a distinct concern from delirium. By understanding nurses' perspectives, we may identify barriers and facilitators in caring for patients with cognitive challenges in the intensive care unit. The objective of this study was to explore nurses' experiences of cognitive problems in patients admitted to an intensive care unit.

RESEARCH METHODOLOGY

A phenomenological-hermeneutic study of interviews with ten nurses from intensive care units. Data were collected in March-April 2022 and analysed using a Ricœur-inspired method of interpretation.

FINDINGS

Three themes related to nurses' experiences of cognitive problems emerged through analysis; 1) Cognitive problems and delirium are seen as two sides of the same coin, 2) Searching for the person behind the patient, and 3) Maintaining a sense of normality in a confusing environment.

CONCLUSIONS

The interconnected concept of cognitive impairment and delirium syndrome meant that nurses assessed and managed cognitive problems in intensive care unit patients by focusing on preventing delirium. Apart from delirium screening, nurses relied on relatives' knowledge to assess patients' cognition. Most significantly, our study revealed a previously unexplored approach by nurses to manage patients' cognition, which involved "shielding" patients from the noisy and disruptive intensive care unit environment.

IMPLICATIONS FOR CLINICAL PRACTICE

Effective communication methods, coupled with family involvement may aid nurses in identifying patients' cognitive problems. In the acute phase of critical illness, distinguishing between delirium and cognitive problems may not be clinically relevant, as delirium protocols may protect patients' cognition. Further investigating the concept of shielding may reveal previously unexplored nursing approaches to manage cognitive problems.

Patients' experiences of cognitive impairment following critical illness treated in an intensive care unit: A scoping review

INTRODUCTION

Treatment with modern technology in an intensive care unit has increased critical illness survival. However, many patients are affected by their critical illness for months or years following discharge, as they experience cognitive impairments. Long-term cognitive impairments can severely affect patients' quality of life. Exploring patients' experiences on how and which cognitive impairments affect their everyday lives is important to improve planning of relevant research into interventions that may alleviate the burden of post-intensive cognitive impairments.

AIM

To review the literature on patients' experiences of cognitive impairment following critical illness treated in an intensive care unit.

METHODS

A systematic search was conducted in PubMed, Cinahl, PsycInfo and Embase in March-May 2021. References and citations in relevant studies were explored. The Covidence tool was used by two independent researchers to identify relevant studies for inclusion. The Mixed Methods Appraisal Tool was used for critical appraisal. The JBI methodology for scoping reviews and the PRISMA-ScR checklist were used (Supporting Information File 1).

RESULTS

We identified 11 relevant qualitative and/or quantitative studies. Four themes were found: 'Experiencing poor memory', 'Managing everyday life', 'Unsupported by the healthcare system' and 'Strategies for support in recovery'. Patients used various strategies during their recovery and rehabilitation to regain independence and avoid being a burden. They needed information to support their recovery and rehabilitation; otherwise, they felt unsupported and betrayed by the healthcare system.

CONCLUSION

Patients experienced various cognitive impairments following critical illness in the intensive care unit, affecting and challenging their quality of life and adaption to everyday life.

RELEVANCE TO CLINICAL PRACTICE

Knowledge gained by exploring patients' experience of cognitive impairments following critical illness in the intensive care unit can contribute to improve clinical practice by targeting and optimising patients' rehabilitation process.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public involvement in this scoping review.

A scoping review of perceptions from healthcare professionals on antipsychotic prescribing practices in acute care settings

BACKGROUND

Antipsychotic medications are frequently prescribed in acute care for clinical indications other than primary psychiatric disorders such as delirium. Unfortunately, they are commonly continued at hospital discharge and at follow-ups thereafter. The objective of this scoping review was to characterize antipsychotic medication prescribing practices, to describe healthcare professional perceptions on antipsychotic prescribing and deprescribing practices, and to report on antipsychotic deprescribing strategies within acute care.

METHODS

We searched MEDLINE, EMBASE, PsycINFO, CINAHL, and Web of Science databases from inception date to July 3, 2021 for published primary research studies reporting on antipsychotic medication prescribing and deprescribing practices, and perceptions on those practices within acute care. We included all study designs excluding protocols, editorials, opinion pieces, and systematic or scoping reviews. Two reviewers screened and abstracted data independently and in duplicate. The protocol was registered on Open Science Framework prior to data abstraction (10.17605/OSF.IO/W635Z).

RESULTS

Of 4528 studies screened, we included 80 studies. Healthcare professionals across all acute care settings (intensive care, inpatient, emergency department) perceived prescribing haloperidol (n = 36/36, 100%) most frequently, while measured prescribing practices reported common quetiapine prescribing (n = 26/36, 76%). Indications for antipsychotic prescribing were delirium (n = 48/69, 70%) and agitation (n = 20/69, 29%). Quetiapine (n = 18/18, 100%) was most frequently prescribed at hospital discharge. Three studies reported in-hospital antipsychotic deprescribing strategies focused on pharmacist-driven deprescribing authority, handoff tools, and educational sessions.

CONCLUSIONS

Perceived antipsychotic prescribing practices differed from measured prescribing practices in acute care settings. Few in-hospital deprescribing strategies were described. Ongoing evaluation of antipsychotic deprescribing strategies are needed to evaluate their efficacy and risk.

Optimal bispectral index level of sedation and cerebral oximetry in traumatic brain injury: a non-invasive individualized approach in critical care?

Background

Impaired cerebral autoregulation has been linked with worse outcomes, with literature suggesting that current therapy guidelines fail to significantly impact cerebrovascular reactivity. The cerebral oximetry index (COx_a) is a surrogate measure of cerebrovascular reactivity which can in theory be obtained non-invasively using regional brain tissue oxygen saturation and arterial blood pressure. The goal of this study was to assess the relationship between objectively measured depth of sedation through BIS and autoregulatory capacity measured through COx_a.

Methods

In a prospectively maintained observational study, we collected continuous regional brain tissue oxygen saturation, intracranial pressure, arterial blood pressure and BIS in traumatic brain injury patients. COx_a was obtained using the Pearson’s correlation between regional brain tissue oxygen saturation and arterial blood pressure and ranges from − 1 to 1 with higher values indicating impairment of cerebrovascular reactivity. Using BIS values and COx_a, a curve-fitting method was applied to determine the minimum value for the COx_a. The associated BIS value with the minimum COx_a is called BISopt. This BISopt was both visually and algorithmically determined, which were compared and assessed over the whole dataset.

Results

Of the 42 patients, we observed that most had a parabolic relationship between BIS and COx_a. This suggests a potential “optimal” depth of sedation where COx_a is the most intact. Furthermore, when comparing the BISopt algorithm with visual inspection of BISopt, we obtained similar results. Finally, BISopt % yield (determined algorithmically) appeared to be independent from any individual sedative or vasopressor agent, and there was agreement between BISopt found with COx_a and the pressure reactivity index (another surrogate for cerebrovascular reactivity).

Conclusions

This study suggests that COx_a is capable of detecting disruption in cerebrovascular reactivity which occurs with over-/under-sedation, utilizing a non-invasive measure of determination and assessment. This technique may carry implications for tailoring sedation in patients, focusing on individualized neuroprotection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40635-022-00460-9.

Delirium in elderly patients with COPD combined with respiratory failure undergoing mechanical ventilation: a prospective cohort study

Background

COPD combined with respiratory failure is very common in intensive care unit (ICU). We aimed to evaluate the current status and influencing factors of delirium in elderly COPD patients with undergoing mechanical ventilation.

Methods

Patients with COPD combined with respiratory failure and mechanically ventilated who were admitted to the ICU of our hospital were selected. The characteristics of included patients were assessed. Pearson correlation analysis was performed to evaluate the characteristics of patients and delirium. Logistic regression analysis was conducted to identify the risk factors of delirium in elderly patients with COPD combined with respiratory failure undergoing mechanical ventilation.

Results

A total of 237 COPD combined with respiratory failure patients were included, the incidence of delirium was 21.94%. Pearson correlation analysis indicated that age (r = 0.784), BMI (r = 0.709), hypertension (r = 0.696), APACHE II score (r = 0.801), CPOT (r = 0.513), sedation(r = 0.626) and PaO₂ (r = 0.611) were all correlated with the occurrence of delirium (all p < 0.05). Logistic regression analysis indicated that age ≥ 75y (OR 3.112, 95% CI 2.144–4.602), BMI ≤ 19 kg/m² (OR 2.742, 95% CI 1.801–3.355), hypertension(OR 1.909, 95% CI 1.415–2.421), APACHE II score ≥ 15 (OR 2.087, 95% CI 1.724–2.615), CPOT ≥ 5 (OR 1.778, 95% CI 1.206–2.641), sedation(OR 3.147, 95% CI 2.714–3.758), PaO₂ ≤ 75 mmHg(OR 2.196, 95%CI 1.875–3.088) were the risk factors of delirium in elderly patients with COPD combined with respiratory failure undergoing mechanical ventilation (all p < 0.05).

Conclusions

Delirium is common in patients with COPD and respiratory failure undergoing mechanical ventilation, and there are many related influencing factors. Medical staff should pay more attention to patients with risk factors and take intervention measures as soon as possible to reduce the incidence of delirium.

Antipsychotic prescribing practices and patient, family member and healthcare professional perceptions of antipsychotic prescribing in acute care settings: a scoping review protocol

INTRODUCTION

Antipsychotic medications are commonly prescribed off-label in acutely ill patients for non-psychiatric clinical indications such as delirium or insomnia. New prescription initiation of antipsychotics in acute care settings increases the proportion of patients discharged home on antipsychotics without approved clinical indication. Long-term use of antipsychotics is associated with increased risk of sudden cardiac death, falls and cognitive impairment. An understanding of acute care off-label antipsychotic prescribing practices and healthcare professional, patient and family perceptions related to antipsychotic prescribing and deprescribing is necessary to facilitate in-hospital deprescribing initiatives.

METHODS AND ANALYSIS

We present the protocol for a scoping review following the methodology proposed by Arksey and O'Malley and the Scoping Review Methods Manual by the Joanna Briggs Institute. We will search five databases including MEDLINE, EMBASE, CINAHL, PsycINFO and Web of Science from inception to 3 July 2021 (ie, planned search date). We will include both peer-reviewed and non-peer-reviewed qualitative and quantitative studies to identify antipsychotic prescribing practices, and to describe healthcare professional, patient and family perceptions towards antipsychotic prescribing and deprescribing in the acute care setting. Protocols, systematic and scoping reviews will be excluded. Two reviewers will calibrate and perform study screening and data abstraction for quantitative and qualitative outcomes of eligible studies. Quantitative outcomes will include study identifiers, demographics and descriptive statistics of antipsychotic prescribing practices. Qualitative synthesis describing perceptions on antipsychotic prescribing practices will include deductive thematic analysis with mapping of themes to the domains of the Theoretical Domains Framework, a 14-domain behaviour and behaviour change framework.

ETHICS AND DISSEMINATION

No ethical approval will be required for this study as only data from published studies in which informed consent was obtained by primary investigators will be retrieved and analysed. The results of this scoping review will inform integrated knowledge translation initiatives aimed at in-hospital antipsychotic medication deprescribing.

Association Between Processed Electroencephalogram-Based Objectively Measured Depth of Sedation and Cerebrovascular Response: A Systematic Scoping Overview of the Human and Animal Literature

Background: Current understanding of the impact that sedative agents have on neurovascular coupling, cerebral blood flow (CBF) and cerebrovascular response remains uncertain. One confounding factor regarding the impact of sedative agents is the depth of sedation, which is often determined at the bedside using clinical examination scoring systems. Such systems do not objectively account for sedation depth at the neurovascular level. As the depth of sedation can impact CBF and cerebral metabolism, the need for objective assessments of sedation depth is key. This is particularly the case in traumatic brain injury (TBI), where emerging literature suggests that cerebrovascular dysfunction dominates the burden of physiological dysfunction. Processed electroencephalogram (EEG) entropy measures are one possible solution to objectively quantify depth of sedation. Such measures are widely employed within anesthesia and are easy to employ at the bedside. However, the association between such EEG measures and cerebrovascular response remains unclear. Thus, to improve our understanding of the relationship between objectively measured depth of sedation and cerebrovascular response, we performed a scoping review of the literature.

Methods: A systematically conduced scoping review of the existing literature on objectively measured sedation depth and CBF/cerebrovascular response was performed, search multiple databases from inception to November 2020. All available literature was reviewed to assess the association between objective sedation depth [as measured through processed electroencephalogram (EEG)] and CBF/cerebral autoregulation.

Results: A total of 13 articles, 12 on adult humans and 1 on animal models, were identified. Initiation of sedation was found to decrease processed EEG entropy and CBF/cerebrovascular response measures. However, after this initial drop in values there is a wide range of responses in CBF seen. There were limited statistically reproduceable associations between processed EEG and CBF/cerebrovascular response. The literature body remains heterogeneous in both pathological states studied and sedative agent utilized, limiting the strength of conclusions that can be made.

Conclusions: Conclusions about sedation depth, neurovascular coupling, CBF, and cerebrovascular response are limited. Much further work is required to outline the impact of sedation on neurovascular coupling.

Prospective Validation of the Preschool Confusion Assessment Method for the ICU to Screen for Delirium in Infants Less Than 6 Months Old

OBJECTIVES

ICU delirium is a predictor of greater morbidity and higher mortality in the pediatric population. The diagnostic obstacles and validity of delirium monitoring among neonates and young infants have yet to be fully delineated. We sought to validate the Preschool Confusion Assessment Method for the ICU in neonates and young infants and determine delirium prevalence in this young population.

DESIGN

Prospective cohort study to validate the Preschool Confusion Assessment Method for the ICU for the assessment of ICU delirium in neonates and young infants compared with the reference standard, Child and Adolescent Psychiatry.

SETTING

Tertiary medical center PICU, including medical, surgical, and cardiac patients.

PARTICIPANTS

Infants less than 6 months old admitted to the PICU regardless of admission diagnosis.

MEASUREMENTS AND MAIN RESULTS

We enrolled 49 patients with a median age of 1.8 months (interquartile range, 0.7-4.1 mo), 82% requiring mechanical ventilation. Enrolled patients were assessed for delirium in blinded-fashion by the research team using the Preschool Confusion Assessment Method for the ICU and independently assessed by the psychiatry reference rater using Diagnostic and Statistical Manual of Mental Disorders-5 criteria. A total of 189 paired assessments were completed, and the Preschool Confusion Assessment Method for the ICU performed with a sensitivity of 95% (95% CI, 89-100%), specificity of 81% (68-90%), "negative and positive predictive values" of 97% (94-100%) and 69% (55-79%), respectively, compared with the reference rater. Delirium prevalence was 47%, with higher rates of 61% observed among neonates (< 1 mo old) and 39% among infants 1-6 months old.

CONCLUSIONS

The Preschool Confusion Assessment Method for the ICU is a valid screening tool for delirium monitoring in infants less than 6 months old. Delirium screening was feasible in this population despite evolving neurocognition and arousal architecture. ICU delirium was prevalent among infants. The consequence of acute brain dysfunction during crucial neurocognitive development remains unclear. Future studies are necessary to determine the long-term impact of ICU delirium and strategies to reduce associated harm in critically ill infants.

Effect of Nonsedation on Cognitive Function in Survivors of Critical Illness

OBJECTIVES

Critical illness can cause severe cognitive impairments. The objective of this trial was to assess the effect of nonsedation versus sedation with a daily wake-up call during mechanical ventilation on cognitive function in adult survivors of critical illness.

DESIGN

Single-center substudy of the multicenter, randomized Non-sedation Versus Sedation With a Daily Wake-up Trial in Critically Ill Patients Receiving Mechanical Ventilation trial. Three months after ICU-discharge participants were tested for cognitive function by a neuropsychologist.

SETTING

Mixed 14-bed ICU in teaching hospital.

PATIENTS

A total of 205 critically ill, orally intubated, and mechanically ventilated adults.

INTERVENTIONS

Patients were randomized within the first 24 hours from intubation to either nonsedation with sufficient analgesia or light sedation with a daily wake-up call during mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

A total of 118 patients survived to follow-up and 89 participated (75%). The participating survivors in the two groups did not differ regarding baseline data or premorbid cognitive impairments. Sedated patients had received more sedatives, whereas doses of morphine and antipsychotics were equal. The primary outcome was that no significant difference was found in the number of patients with mild/moderate cognitive impairments (six nonsedated patients vs four sedated patients) or severe cognitive impairments (16 nonsedated patients vs 17 sedated patients; p = 0.71). Secondary outcomes were cognitive test scores, and no differences were found between the scores in nonsedated and sedated patients. Hypothetical worst case scenarios where all patients, who had not participated in follow-up assessment, were assumed to have severe cognitive impairments were analyzed, but still no difference between the groups was found. We found more patients with delirium in the sedated group (96% vs 69% of patients; p = 0.002) and increased duration of delirium in sedated patients (median 5 vs 1 d; p < 0.001). Delirium subtypes were equally distributed between the groups, with hypoactive delirium most frequent (61%), followed by mixed delirium (39%).

CONCLUSIONS

Nonsedation did not affect cognitive function 3 months after ICU-discharge.

What outcomes should be evaluated in critically ill patients?

Randomized clinical trials in intensive care prioritize disease-focused outcomes rather than patient-centered outcomes. A paradigm shift considering the evaluation of measures after hospital discharge and measures focused on quality of life and common symptoms, such as pain and dyspnea, could better reflect the wishes of patients and their families. However, barriers related to the systematization of the interpretation of these outcomes, the heterogeneity of measurement instruments and the greater difficulty in performing the studies, to date, seem to hinder this change. In addition, the joint participation of patients, families, researchers, and clinicians in the definition of study outcomes is not yet a reality.

Antipsychotic Drugs in Prevention of Postoperative Delirium-What Is Known in 2020?

Delirium is one of the most frequently reported neuropsychiatric complications in the perioperative period, especially in the population of elderly patients who often suffer from numerous comorbidities undergoing extensive or urgent surgery. It can affect up to 80% of patients who require hospitalization in an intensive care setting postoperatively. Delirium increases mortality, morbidity, length of hospital stay, and cost of treatment. An episode of delirium in the acute phase may lower the general quality of life and increases the risk of cognitive decline long-term. Since pharmacological treatment of delirium is not highly effective, focus of research has shifted towards developing preventive strategies. We aimed to perform a review of the topic based on the most recent literature. We conclude that, based on the available data, it seems impossible to make strong recommendations for using antipsychotic drugs in prophylaxis. Further research should answer the question what, if any, benefit patients receive from the pharmacological prevention of delirium, and which agents should be used.

Pneumonia-induced endothelial amyloids reduce dendritic spine density in brain neurons

Pseudomonas aeruginosa pneumonia elicits endothelial cell release of cytotoxic amyloids that can be recovered from the bronchoalveolar lavage and cerebrospinal fluids of critically ill patients. Introduction of these cytotoxic amyloids into the lateral ventricle impairs learning and memory in mice. However, it is unclear whether the amyloids of lung origin (1) are neurotropic, and (2) cause structural remodeling of hippocampal dendrites. Thus, we used electrophysiological studies in brain slices and structural analysis of post-mortem tissues obtained from animals exposed to endothelium-derived amyloids to assess these issues. The amyloids were administered via three different routes, by intracerebroventricular, intratracheal, and intraperitoneal injections. Synaptic long-term potentiation was abolished following intracerebroventricular amyloid injection. Fluorescence dialysis or Golgi-impregnation labeling showed reduced dendritic spine density and destabilized spines of hippocampal pyramidal neurons 4 weeks after intracerebroventricular amyloid injection. In comparison, endothelial amyloids introduced to the airway caused the most prominent dendritic spine density reduction, yet intraperitoneal injection of these amyloids did not affect spine density. Our findings indicate that infection-elicited lung endothelial amyloids are neurotropic and reduce neuronal dendritic spine density in vivo. Amyloids applied into the trachea may either be disseminated through the circulation and cross the blood-brain barrier to access the brain, initiate feed-forward amyloid transmissibility among cells of the blood-brain barrier or access the brain in other ways. Nevertheless, lung-derived amyloids suppress hippocampal signaling and cause injury to neuronal structure.

Development of delirium: Association with old age, severe burns, and intensive care

BACKGROUND

Delirium is defined as a disturbance of attention and awareness that develops over a short period of time, is a change from the baseline, and typically fluctuates over time. Burn care involves a high prevalence of known risk factors for delirium such as sedation, inflammation, and prolonged stay in hospital. Our aim was to explore the extent of delirium and the impact of factors associated with it for adult patients who have been admitted to hospital with burns.

METHODS

In this retrospective study, all adult patients who had been admitted with burns during a four-year period were studied, including both those who were treated with intensive care and intermediate care only (no intensive care). Daily records of the assessment of delirium using the Nursing Delirium Screening Scale (Nu-DESC) were analysed together with age, sex, the percentage of total body surface area burned, operations, and numbers of wound care procedures under anaesthesia, concentrations of plasma C-reactive protein, and other clinical variables. Logistic regression was used to analyse factors that were associated with delirium and its effect on mortality, and linear regression was used to analyse its effect on the duration of hospital stay.

RESULTS

Fifty-one patients (19%) of the total 262 showed signs of delirium (Nu-DESC score of 2 or more) at least once during their stay in hospital. Signs of delirium were recorded in 42/89 patients (47%) who received intensive care, and in 9/173 (5%) who had intermediate care. Independent factors for delirium in the multivariable regression were: age over 74 years; number of operations and wound care procedures under anaesthesia; and the provision of intensive care (area under the curve 0.940, 95% CI 0.899-0.981). Duration of hospital stay, adjusted for age and burn size, was 13.2 (95% CI 7.4-18.9, p < 0.001) days longer in the group who had delirium. We found no independent effects of delirium on mortality.

CONCLUSION

We found a strong association between delirium and older age, provision ofr intensive care, and number of interventions under anaesthesia. A further 5% of patients who did not receive intensive care also showed signs of delirium, which is a finding that deserves to be thoroughly investigated in the future.

Age and Sex Influence the Hippocampal Response and Recovery Following Sepsis

Although in-hospital mortality rates for sepsis have decreased, survivors often experience lasting physical and cognitive deficits. Moreover, older adults are more vulnerable to long-term complications associated with sepsis. We employed a murine model to examine the influence of age and sex on the brain’s response and recovery following sepsis. Young (~ 4 months) and old (~ 20 months) mice (C57BL/6) of both sexes underwent cecal ligation and puncture (CLP) with restraint stress. The hippocampal transcriptome was examined in age- and sex-matched controls at 1 and 4 days post-CLP. In general, immune- and stress-related genes increased, while neuronal, synaptic, and glial genes decreased 1 day after CLP-induced sepsis. However, specific age and sex differences were observed for the initial responsiveness to sepsis as well as the rate of recovery examined on day 4. Young females exhibited a muted transcriptional response relative to young males and old females. Old females exhibited a robust shift in gene transcription on day 1, and while most genes recovered, genes linked to neurogenesis and myelination continued to be downregulated by day 4. In contrast, old males exhibited a more delayed or prolonged response to sepsis, such that neuronal and synaptic genes continued to decrease while immune response genes continued to increase on day 4. These results suggest that aging is associated with delayed recovery from sepsis, which is particularly evident in males.