Acute respiratory distress syndrome, sepsis, and cognitive decline: a review and case study

COVID-19 may Enduringly Impact Cognitive Performance and Brain Haemodynamics in Undergraduate Students

To date, 770 million people worldwide have contracted COVID-19, with many reporting long-term "brain fog". Concerningly, young adults are both overrepresented in COVID-19 infection rates and may be especially vulnerable to prolonged cognitive impairments following infection. This calls for focused research on this population to better understand the mechanisms underlying cognitive impairment post-COVID-19. Addressing gaps in the literature, the current study investigated differences in neuropsychological performance and cerebral haemodynamic activity following COVID-19 infection in undergraduate students. 94 undergraduates (age in years: M = 20.58, SD = 3.33, range = 18 to 46; 89 % female) at the University of Otago reported their COVID-19 infection history before completing a neuropsychological battery while wearing a multichannel near-infrared spectroscopy (NIRS) device to record prefrontal haemodynamics. We observed that 40 % retrospectively self-reported cognitive impairment (brain fog) due to COVID-19 and 37 % exhibited objective evidence of cognitive impairment (assessed via computerised testing), with some suggestion that executive functioning may have been particularly affected; however, group-level analyses indicated preserved cognitive performance post COVID-19, which may in part reflect varying compensatory abilities. The NIRS data revealed novel evidence that previously infected students exhibited distinct prefrontal haemodynamic patterns during cognitive engagement, reminiscent of those observed in adults four decades older, and this appeared to be especially true if they reported experiencing brain fog due to COVID-19. These results provide new insights into the potential neuropathogenic mechanisms influencing cognitive impairment following COVID-19.

The effect of all-cause hospitalization on cognitive decline in older adults: a longitudinal study using databases of the National Health Insurance Service and the memory clinics of a self-run hospital

BACKGROUND

Cognitive decline is common in older adults and imposes a burden on public health. Especially for older adults, hospitalization can be related to decreased physical fitness. This study aimed to investigate the quantitative association between hospitalization and cognitive decline.

METHODS

This was a retrospective cohort study. We performed a longitudinal study by using the combined database from the Korean National Health Insurance Service (NHIS) and memory clinic data of its self-run hospital. We identified whether hospitalized, the number of hospitalizations, and the total hospitalization days through the claim information from the NHIS database. We also identified whether hospitalization was accompanied by delirium or surgery with general anesthesia for subgroup analysis. Primary outcome was the clinical dementia rating-sum of boxes (CDR-SB) score. Secondary outcomes were mini-mental state examination (MMSE) score, clinical dementia rating (CDR) grade, and Korean-instrumental activities of daily living (KIADL) score. Multivariable mixed models were established.

RESULTS

Of the 1810 participants, 1200 experienced hospitalization at least once during the observation period. The increase in CDR-SB was significantly greater in the hospitalized group (β = 1.5083, P < .001). The same results were seen in the total number of hospitalizations (β = 0.0208, P < .001) or the total hospitalization days (β = 0.0022, P < .001) increased. In the group that experienced hospitalization, cognitive decline was also significant in terms of CDR grade (β = 0.1773, P < .001), MMSE score (β = - 1.2327, P < .001), and KIADL score (β = 0.2983, P < .001). Although delirium (β = 0.2983, P < .001) and nonsurgical hospitalization (β = 0.2983, P < .001) were associated with faster cognitive decline, hospitalization without delirium and with surgery were also related to faster cognitive decline than in the no hospitalization group.

CONCLUSION

Cognitive decline was quantitatively related to all-cause hospitalization in older adults. Moreover, hospitalizations without delirium and surgery were also related to cognitive decline. It is vital to prevent various conditions that need hospitalization to avoid and manage cognitive dysfunction.

Cell-free fat extract protects septic lethality via restraining NLRP3 inflammasome activation

BACKGROUND

Sepsis is a dysregulated host response to infection with high mortality and current management cannot reach optimal remission. Previous studies have shown that cell-free fat extract (CEFFE) is a kind of bioactive extraction from adipose tissues and exhibits a potent anti-inflammatory effect on wound healing and inflammatory diseases. However, the potential role of CEFFE in sepsis remains unclear.

METHODS

CEFFE was extracted from healthy donors and was intraperitoneally injected into septic mice. The septic mice models were constructed using lipopolysaccharide (LPS), E. coli, and cecal ligation and puncture (CLP). The survival of septic mice was detected for 96 h and Kaplan-Meier analysis was used to analyze the differences of survival rates. Lung tissues that were collected from septic mice were subjected to HE staining to evaluate the extent of lung injury, and the mice serum was obtained for inflammasome-related cytokines detection. Moreover, peritoneal macrophages were extracted from C57 mice and treated with CEFFE and/or inflammasome activators. The level of IL-1β, IL-18, IL-6, and TNF-α was detected by ELISA, and the activation of NLRP3 were evaluated by Western Blot. Total mtDNA and mitochondrial permeability transition pore were determined to explore the mitochondrial dysfunction in the activation of NLRP3 inflammasome with or without CEFEE. Coimmunoprecipitation (Co-IP) assays were performed to confirm the mechanism of NLRP3 activation induced by CEFFE.

RESULTS

CEFFE significantly improved the survival of sepsis mice and alleviate sepsis-induced lung injury. Moreover, CEFFE significantly decreased the level of inflammasome-cytokines (IL-1β and IL-18) but not the pro-inflammatory cytokines such as IL-6 and TNF-α. Moreover, CEFFE markedly suppressed the canonical activation of NLRP3 inflammasome without affecting inflammasomes NLRC4 and AIM2. Additionally, the non-canonical activation of NLRP3 inflammasome was significantly inhibited by CEFFE. CEFFE treatment attenuated the mtDNA outflow and the increase of mitochondrial permeability induced by both canonical and non-canonical pathway of NLRP3 inflammasome activation. The results of Co-IP assays revealed that CEFFE remarkably attenuated the oligomerization of ASC and inhibited the association between NLRP3 and ASC.

CONCLUSION

Our study revealed that CEFFE could significantly alleviate sepsis-related injuries possibly by suppressing NLRP3 inflammasome activation. CEFFE was a promising approach for sepsis treatment.

Central Nervous System Manifestations of COVID-19: A Critical Review and Proposed Research Agenda

OBJECTIVE

On March 11, 2020, the World Health Organization declared an outbreak of a new viral entity, coronavirus 2019 (COVID-19), to be a worldwide pandemic. The characteristics of this virus, as well as its short- and long-term implications, are not yet well understood. The objective of the current paper was to provide a critical review of the emerging literature on COVID-19 and its implications for neurological, neuropsychiatric, and cognitive functioning.

METHOD

A critical review of recently published empirical research, case studies, and reviews pertaining to central nervous system (CNS) complications of COVID-19 was conducted by searching PubMed, PubMed Central, Google Scholar, and bioRxiv.

RESULTS

After considering the available literature, areas thought to be most pertinent to clinical and research neuropsychologists, including CNS manifestations, neurologic symptoms/syndromes, neuroimaging, and potential long-term implications of COVID-19 infection, were reviewed.

CONCLUSION

Once thought to be merely a respiratory virus, the scientific and medical communities have realized COVID-19 to have broader effects on renal, vascular, and neurological body systems. The question of cognitive deficits is not yet well studied, but neuropsychologists will undoubtedly play an important role in the years to come.

RhANP attenuates endotoxin-derived cognitive dysfunction through subdiaphragmatic vagus nerve-mediated gut microbiota-brain axis

BACKGROUND

Atrial natriuretic peptide (ANP) secreted from atrial myocytes is shown to possess anti-inflammatory, anti-oxidant and immunomodulatory effects. The aim of this study is to assess the effect of ANP on bacterial lipopolysaccharide (LPS)-induced endotoxemia-derived neuroinflammation and cognitive impairment.

METHODS

LPS (5 mg/kg) was given intraperitoneally to mice. Recombinant human ANP (rhANP) (1.0 mg/kg) was injected intravenously 24 h before and/or 10 min after LPS injection. Subdiaphragmatic vagotomy (SDV) was performed 14 days before LPS injection or 28 days before fecal microbiota transplantation (FMT). ANA-12 (0.5 mg/kg) was administrated intraperitoneally 30 min prior to rhANP treatment.

RESULTS

LPS (5.0 mg/kg) induced remarkable splenomegaly and an increase in the plasma cytokines at 24 h after LPS injection. There were positive correlations between spleen weight and plasma cytokines levels. LPS also led to increased protein levels of ionized calcium-binding adaptor molecule (iba)-1, cytokines and inducible nitric oxide synthase (iNOS) in the hippocampus. LPS impaired the natural and learned behavior, as demonstrated by an increase in the latency to eat the food in the buried food test and a decrease in the number of entries and duration in the novel arm in the Y maze test. Combined prophylactic and therapeutic treatment with rhANP reversed LPS-induced splenomegaly, hippocampal and peripheral inflammation as well as cognitive impairment. However, rhANP could not further enhance the protective effects of SDV on hippocampal and peripheral inflammation. We further found that PGF mice transplanted with fecal bacteria from rhANP-treated endotoxemia mice alleviated the decreased protein levels of hippocampal polyclonal phosphorylated tyrosine kinase receptor B (p-TrkB), brain-derived neurotrophic factor (BDNF) and cognitive impairment, which was abolished by SDV. Moreover, TrkB/BDNF signaling inhibitor ANA-12 abolished the improving effects of rhANP on LPS-induced cognitive impairment.

CONCLUSIONS

Our results suggest that rhANP could mitigate LPS-induced hippocampal inflammation and cognitive dysfunction through subdiaphragmatic vagus nerve-mediated gut microbiota-brain axis.

Regional changes with global brain hypometabolism indicates a physiological triage phenomenon and can explain shared pathophysiological events in Alzheimer's & small vessel diseases and delirium

While reduced global brain metabolism is known in aging, Alzheimer's disease (AD), small vessel disease (SVD) and delirium, explanation of regional brain metabolic (rBM) changes is a challenge. We hypothesized that this may be explained by "triage phenomenon", to preserve metabolic supply to vital brain areas. We studied changes in rBM in 69 patients with at least 5% decline in global brain metabolism during active lymphoma. There was significant decline in the rBM of the inferior parietal, precuneus, superior parietal, lateral occipital, primary visual cortices (P<0.001) and in the right lateral prefrontal cortex (P=0.01). Some areas showed no change; multiple areas had significantly increased rBM (e.g. medial prefrontal, anterior cingulate, pons, cerebellum and mesial temporal cortices; P<0.001). We conclude the existence of a physiological triage phenomenon and argue a new hypothetical model to explain the shared events in the pathophysiology of aging, AD, SVD and delirium.

(R)-Ketamine attenuates LPS-induced endotoxin-derived delirium through inhibition of neuroinflammation

RATIONALE

(R)-Ketamine produced beneficial effects in a variety of models of inflammatory diseases, including low dose of bacterial lipopolysaccharide (LPS) (0.5-1.0 mg/kg)-induced endotoxemia. LPS-treated mice have been used as animal model of delirium.

OBJECTIVES

We investigated the effects of (R)-ketamine in neuroinflammation and cognitive impairment in rodents after administration of high dose of LPS.

METHODS

LPS (5 mg/kg) or saline was administered intraperitoneally (i.p.) to mice. (R)-Ketamine (10 mg/kg) was administrated i.p. 24 h before and/or 10 min after LPS injection.

RESULTS

LPS (5.0 mg/kg) caused a remarkable splenomegaly and increased plasma levels of pro-inflammatory cytokines [i.e., interleukin (IL-6), IL-17A, and interferon (IFN)-γ]. There were positive correlations between spleen weight and plasma cytokines levels. Furthermore, LPS led to increased levels of pro-inflammatory cytokines in the prefrontal cortex (PFC) and hippocampus. Moreover, LPS impaired the natural and learned behaviors, as demonstrated by a decrease in the number of mice's entries and duration in the novel arm in the Y maze test and an increase in the latency of mice to eat the food in the buried food test. Interestingly, the treatment with (R)-ketamine (twice 24 h before and 10 min after LPS injection) significantly attenuated LPS-induced splenomegaly, central and systemic inflammation, and cognitive impairment.

CONCLUSION

Our results highlighted the importance of combined prophylactic and therapeutic use of (R)-ketamine in the attenuation of LPS-induced systemic inflammation, neuroinflammation, and cognitive impairment in mice. It is likely that (R)-ketamine could be a prophylactic drug for delirium.

Cognitive Impairment After COVID-19-A Review on Objective Test Data

Objective: The aim was to conduct a review on the literature on objective cognitive impairment in patients after COVID-19. Methods: We performed a literature review and searched Ovid Medline in February 2021 based on a PECO scheme. Results: Twelve articles met all inclusion criteria. Total patient sample was <1,000. All studies on global cognitive function found impairment, ranging from 15 to 80% of the sampled patients. Seven studies on attention and executive functions reported impairment, with varying results depending on sub-domain and different tests. Three out of four studies reported memory difficulties, with two studies reporting short-term memory deficits. Although results indicate possible language impairment, only one study used domain-specific language tasks. Two out of four studies on visuospatial function did not report any impairment. Conclusion: Patients with recent SARS-CoV-2 infection appear to experience global cognitive impairment, impairment in memory, attention and executive function, and in particular verbal fluency. Based on the current results, we recommend clinicians to evaluate the need for cognitive assessment of patients with a recent COVID-19 infection, regardless of the severity of the disease, treatment methods and length of ICU stay. We need studies with larger sample and control group.

Protocol for a two-arm pragmatic stepped-wedge hybrid effectiveness-implementation trial evaluating Engagement and Collaborative Management to Proactively Advance Sepsis Survivorship (ENCOMPASS)

BACKGROUND

Sepsis survivors experience high morbidity and mortality, and healthcare systems lack effective strategies to address patient needs after hospital discharge. The Sepsis Transition and Recovery (STAR) program is a navigator-led, telehealth-based multicomponent strategy to provide proactive care coordination and monitoring of high-risk patients using evidence-driven, post-sepsis care tasks. The purpose of this study is to evaluate the effectiveness of STAR to improve outcomes for sepsis patients and to examine contextual factors that influence STAR implementation.

METHODS

This study uses a hybrid type I effectiveness-implementation design to concurrently test clinical effectiveness and gather implementation data. The effectiveness evaluation is a two-arm, pragmatic, stepped-wedge cluster randomized controlled trial at eight hospitals in North Carolina comparing clinical outcomes between sepsis survivors who receive Usual Care versus care delivered through STAR. Each hospital begins in a Usual Care control phase and transitions to STAR in a randomly assigned sequence (one every 4 months). During months that a hospital is allocated to Usual Care, all eligible patients will receive usual care. Once a hospital transitions to STAR, all eligible patients will receive STAR during their hospitalization and extending through 90 days from discharge. STAR includes centrally located nurse navigators using telephonic counseling and electronic health record-based support to facilitate best-practice post-sepsis care strategies including post-discharge review of medications, evaluation for new impairments or symptoms, monitoring existing comorbidities, and palliative care referral when appropriate. Adults admitted with suspected sepsis, defined by clinical criteria for infection and organ failure, are included. Planned enrollment is 4032 patients during a 36-month period. The primary effectiveness outcome is the composite of all-cause hospital readmission or mortality within 90 days of discharge. A mixed-methods implementation evaluation will be conducted before, during, and after STAR implementation.

DISCUSSION

This pragmatic evaluation will test the effectiveness of STAR to reduce combined hospital readmissions and mortality, while identifying key implementation factors. Results will provide practical information to advance understanding of how to integrate post-sepsis management across care settings and facilitate implementation, dissemination, and sustained utilization of best-practice post-sepsis management strategies in other heterogeneous healthcare delivery systems.

TRIAL REGISTRATION

NCT04495946 . Submitted July 7, 2020; Posted August 3, 2020.

Paediatrics: how to manage septic shock

Background

Septic shock is a common critical illness associated with high morbidity and mortality in children. This article provides an updated narrative review on the management of septic shock in paediatric practice.

Methods

A PubMed search was performed using the following Medical Subject Headings: "sepsis", "septic shock" and "systemic inflammatory response syndrome". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies and reviews. The search was limited to the English literature and specific to children.

Results

Septic shock is associated with high mortality and morbidity. The outcome can be improved if the diagnosis is made promptly and treatment initiated without delay. Early treatment with antimicrobial therapy, fluid therapy and vasoactive medications, and rapid recognition of the source of sepsis and control are the key recommendations from paediatric sepsis management guidelines.

Conclusion

Most of the current paediatric sepsis guideline recommendations are based on the adult population; therefore, the research gaps in paediatric sepsis management should be addressed.

Mesenchymal Stromal Cells Protect the Blood-Brain Barrier, Reduce Astrogliosis, and Prevent Cognitive and Behavioral Alterations in Surviving Septic Mice

OBJECTIVES

Survivors of sepsis are frequently left with significant cognitive and behavioral impairments. These complications derive from nonresolving inflammation that persists following hospital discharge. To date, no study has investigated the effects of mesenchymal stromal cell therapy on the blood-brain barrier, astrocyte activation, neuroinflammation, and cognitive and behavioral alterations in experimental sepsis.

DESIGN

Prospective, randomized, controlled experimental study.

SETTING

Government-affiliated research laboratory.

SUBJECTS

Male Swiss Webster mice (n = 309).

INTERVENTIONS

Sepsis was induced by cecal ligation and puncture; sham-operated animals were used as control. All animals received volume resuscitation (1 mL saline/mouse subcutaneously) and antibiotics (meropenem 10 mg/kg intraperitoneally at 6, 24, and 48 hours). Six hours after surgery, mice were treated with mesenchymal stromal cells IV (1 × 10 cells in 0.05 mL of saline/mouse) or saline (0.05 mL IV).

MEASUREMENTS AND MAIN RESULTS

At day 1, clinical score and plasma levels of inflammatory mediators were increased in cecal ligation and puncture mice. Mesenchymal stromal cells did not alter clinical score or survival rate, but reduced levels of systemic interleukin-1β, interleukin-6, and monocyte chemoattractant protein-1. At day 15, survivor mice completed a battery of cognitive and behavioral tasks. Cecal ligation and puncture mice exhibited spatial and aversive memory deficits and anxiety-like behavior. These effects may be related to increased blood-brain barrier permeability, with altered tight-junction messenger RNA expression, increased brain levels of inflammatory mediators, and astrogliosis (induced at day 3). Mesenchymal stromal cells mitigated these cognitive and behavioral alterations, as well as reduced blood-brain barrier dysfunction, astrocyte activation, and interleukin-1β, interleukin-6, tumor necrosis factor-α, and interleukin-10 levels in vivo. In cultured primary astrocytes stimulated with lipopolysaccharide, conditioned media from mesenchymal stromal cells reduced astrogliosis, interleukin-1β, and monocyte chemoattractant protein-1, suggesting a paracrine mechanism of action.

CONCLUSIONS

In mice who survived experimental sepsis, mesenchymal stromal cell therapy protected blood-brain barrier integrity, reduced astrogliosis and neuroinflammation, as well as improved cognition and behavior.

The long-lasting effects of the acute respiratory distress syndrome

Introduction: Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury common in critically ill patients and characterized by significant morbidity and mortality. It frequently manifests long-lasting effects beyond hospitalization, from cognitive impairment to physical weakness.Areas covered: Several complications of ARDS have been identified in patients after hospital discharge. The authors conducted literature searches to identify observational studies, randomized clinical trials, systematic reviews, and guidelines. A summary of is presented here to outline the sequelae of ARDS and their risk factors with a focus on the limited but growing research into possible therapies. Long term sequelae of ARDS commonly identified in the literature include long-term cognitive impairment, psychological morbidities, neuromuscular weakness, pulmonary dysfunction, and ongoing healthcare utilization with reduced quality of life.Expert opinion: Given the public health significance of long-term complications following ARDS, the development of new therapies for prevention and treatment is of vital importance. Furthering knowledge of the pathophysiology of these impairments will provide a framework to develop new therapeutic targets to fuel future clinical trials in this area of critical care medicine.

NADPH oxidase 2 as a potential therapeutic target for protection against cognitive deficits following systemic inflammation in mice

BACKGROUND

Research indicates that sepsis increases the risk of developing cognitive impairment. After systemic inflammation, a corresponding activation of microglia is rapidly induced in the brain, and multiple neurotoxic factors, including inflammatory mediators (e.g., cytokines) and reactive oxygen species (e.g., superoxide), are also released that contribute to neuronal injury. NADPH oxidase (NOX) enzymes play a vital role in microglial activation through the generation of superoxide anions. We hypothesized that NOX isoforms, particularly NOX2, could exhibit remarkable abilities in developing cognitive deficits induced by systemic inflammation.

METHODS

Mice with deficits of NOX2 organizer p47phox (p47^phox-/-) and wild-type (WT) mice treated with the NOX inhibitor diphenyleneiodonium (DPI) were used in this study. Intraperitoneal lipopolysaccharide (LPS) injection was used to induce systemic inflammation. Spatial learning and memory were compared among treatment groups using the radial arm maze task. Brain tissues were collected for evaluating the transcript levels of proinflammatory cytokines, whereas immunofluorescence staining and immunoblotting were conducted to determine the percentage of activated glia (microglia and astroglia) and damaged neurons and the expression of synaptic proteins and BDNF.

RESULTS

Cognitive impairment induced by systemic inflammation was significantly attenuated in the p47^phox-/- mice compared to that in the WT mice. The p47^phox-/- mice exhibited reduced microglial and astroglial activation and neuronal damage and attenuated the induction of multiple proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and CCL2. Similar to that observed in the p47^phox-/- mice, the administration of DPI significantly attenuated the cognitive impairment, reduced the glial activation and brain cytokine concentrations, and restored the expression of postsynaptic proteins (PSD-95) and BDNF in neurons and astrocytes, compared to those in the vehicle-treated controls within 10 days after LPS injection.

CONCLUSIONS

This study clearly demonstrates that NOX2 contributes to glial activation with subsequent reduction in the expression of BDNF, synaptic dysfunction, and cognitive deficits after systemic inflammation in an LPS-injected mouse model. Our results provide evidence that NOX2 might be a promising pharmacological target that could be used to protect against synaptic dysregulation and cognitive impairment following systemic inflammation.

Complications and Outcomes of Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a disease associated with both short- and long-term complications. Acute complications include refractory respiratory failure requiring prolonged dependence on mechanical ventilation and the subsequent need for tracheostomy and gastrostomy tubes, protracted immobilization, and lengthy stays in the intensive care unit resulting in delirium, critical illness myopathy, and polyneuropathy, as well as secondary nosocomial infections. Chronic adverse outcomes of ARDS include irreversible changes such as fibrosis, tracheal stenosis from prolonged tracheostomy tube placement, pulmonary function decline, cognitive impairment and memory loss, posttraumatic stress disorder, depression, anxiety, muscle weakness, ambulatory dysfunction, and an overall poor quality of life. The degree of disability in ARDS survivors is heterogeneous and can be evident even years after hospitalization. Although survival rates have improved over the past 4 decades, mortality remains significant with rates reported as high as 40%. Despite advancements in management, the causes of death in ARDS have remained relatively unchanged since the 1980s with sepsis/septic shock and multiorgan failure at the top of the list.

Structured, proactive care coordination versus usual care for Improving Morbidity during Post-Acute Care Transitions for Sepsis (IMPACTS): a pragmatic, randomized controlled trial

Background

Hospital mortality for patients with sepsis has recently declined, but sepsis survivors still suffer from significant long-term mortality and morbidity. There are limited data that support effective strategies to address post-discharge management of patients hospitalized with sepsis.

Methods

The Improving Morbidity during Post-Acute Care Transitions for Sepsis (IMPACTS) study is a pragmatic, randomized controlled trial at three hospitals within a single healthcare delivery system comparing clinical outcomes between sepsis survivors who receive usual care versus care delivered through the Sepsis Transition and Recovery (STAR) program. The STAR program includes a centrally located nurse navigator using telephone counseling and electronic health record-based support to facilitate best-practice post-sepsis care strategies for patients during hospitalization and the 30 days after hospital discharge, including post-discharge review of medications, evaluation for new impairments or symptoms, monitoring existing comorbidities, and palliative care referral when appropriate. Adults admitted through the Emergency Department with suspected infection (i.e., antibiotics initiated, bacterial cultures drawn) and deemed, by previously developed risk-stratification models, high risk for readmission or death are included. Eligible patients are randomly allocated 1:1 to either Arm 1, usual care or Arm 2, STAR. Planned enrollment is 708 patients during a 6-month period. The primary outcome is the composite of all-cause hospital readmissions and mortality assessed 30 days post discharge. Secondary outcomes include 30- and 90-day hospital readmissions, mortality, emergency department visits, acute care-free days alive, and acute care and total costs.

Discussion

This pragmatic evaluation provides the most comprehensive assessment to date of a strategy to improve delivery of recommended post-sepsis care.

Trial registration

ClinicalTrials.gov, NCT03865602. Registered retrospectively on 6 March 2019.

Effect of atorvastatin on delirium status of patients in the intensive care unit: a randomized controlled trial

INTRODUCTION

Delirium is one of the most prevalent complications in intensive care unit (ICU) patients, which is related to worse clinical outcomes including a longer ICU stay, longer duration of mechanical ventilation, higher mortality rates and increased risk of cognitive impairment. Observational studies have suggested that statins might have a positive effect on delirium status of hospitalized patients. To date, there has been no trial assessing the effect of atorvastatin on delirium status in critically ill patients. Thus, the aim of the current study was to determine the efficacy of atorvastatin on delirium status of patients in the ICU.

METHODS

In this randomized, double-blind and controlled trial, a total of 90 patients in the general ICU who had delirium for at least 2 days were randomly divided into atorvastatin (40 mg/day) (n = 40) and control (n = 50) groups. Delirium status of the patients was determined twice a day at 10:00 a.m. and 18:00 p.m. using the Richmond Agitation-Sedation Scale (RASS).

RESULTS

Administration 40 mg/day of atorvastatin significantly reduced the mean RASS score and increased delirium-free days at both morning and afternoon time points compared to the control group (p < 0.05).

CONCLUSIONS

Administration of atorvastatin had a significant positive effect on delirium status in patients admitted to the ICU.

Targeting the Blood-Brain Barrier to Prevent Sepsis-Associated Cognitive Impairment

Sepsis is a systemic inflammatory disease resulting from an infection. This disorder affects 750 000 people annually in the United States and has a 62% rehospitalization rate. Septic symptoms range from typical flu-like symptoms (eg, headache, fever) to a multifactorial syndrome known as sepsis-associated encephalopathy (SAE). Patients with SAE exhibit an acute altered mental status and often have higher mortality and morbidity. In addition, many sepsis survivors are also burdened with long-term cognitive impairment. The mechanisms through which sepsis initiates SAE and promotes long-term cognitive impairment in septic survivors are poorly understood. Due to its unique role as an interface between the brain and the periphery, numerous studies support a regulatory role for the blood-brain barrier (BBB) in the progression of acute and chronic brain dysfunction. In this review, we discuss the current body of literature which supports the BBB as a nexus which integrates signals from the brain and the periphery in sepsis. We highlight key insights on the mechanisms that contribute to the BBB's role in sepsis which include neuroinflammation, increased barrier permeability, immune cell infiltration, mitochondrial dysfunction, and a potential barrier role for tissue non-specific alkaline phosphatase (TNAP). Finally, we address current drug treatments (eg, antimicrobials and intravenous immunoglobulins) for sepsis and their potential outcomes on brain function. A comprehensive understanding of these mechanisms may enable clinicians to target specific aspects of BBB function as a therapeutic tool to limit long-term cognitive impairment in sepsis survivors.

Long-Term Cognitive Outcomes After Sepsis: a Translational Systematic Review

Sepsis is systemic inflammatory response syndrome with a life-threatening organ dysfunction that is caused by an unbalanced host immune response in an attempt to eliminate invasive microorganisms. We posed questions, "Does sepsis survivor patients have increased risk of neuropsychiatric manifestations?" and "What is the mechanism by which sepsis induces long-term neurological sequelae, particularly substantial cognitive function decline in survivor patients and in pre-clinical sepsis models?" The studies were identified by searching PubMed/MEDLINE (National Library of Medicine), PsycINFO, EMBASE (Ovid), LILACS (Latin American and Caribbean Health Sciences Literature), IBECS (Bibliographical Index in Spanish in Health Sciences), and Web of Science databases for peer-reviewed journals that were published until January 2018. A total of 3555 papers were included in the primary screening. After that, 130 articles were selected for the study. A number of pre-clinical studies have shown an auto amplification of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6 in the first few hours after sepsis induction, also increased blood-brain barrier permeability, elevated levels of matrix metalloproteinases, increased levels of damage-associated molecular patterns were demonstrated. In addition, the rodents presented long-term cognitive impairment in different behavioral tasks that were prevented by blocking the mechanism of action of these inflammatory mediators. Clinical studies have showed that sepsis survivors presented increased bodily symptoms such as fatigue, pain, visual disturbances, gastrointestinal problems, and neuropsychiatric problems compared to before sepsis. Sepsis leaves the survivors with an aftermath of physiological, neuropsychiatric, and functional impairment. Systematic review registration: CRD42017071755.

A Systematic Review of Risk Factors Associated With Cognitive Impairment After Pediatric Critical Illness

OBJECTIVES

To identify risk factors associated with cognitive impairment as assessed by neuropsychologic tests in neurotypical children after critical illness.

DATA SOURCES

For this systematic review, we searched the Cochrane Library, Scopus, PubMed, Ovid, Embase, and CINAHL databases from January 1960 to March 2017.

STUDY SELECTION

Included were studies with subjects 3-18 years old at the time of post PICU follow-up evaluation and use of an objective standardized neuropsychologic test with at least one cognitive functioning dimension. Excluded were studies featuring patients with a history of cardiac arrest, traumatic brain injury, or genetic anomalies associated with neurocognitive impairment.

DATA EXTRACTION

Twelve studies met the sampling criteria and were rated using the Newcastle-Ottawa Quality Assessment Scale.

DATA SYNTHESIS

Ten studies reported significantly lower scores in at least one cognitive domain as compared to healthy controls or normed population data; seven of these-four case-control and three prospective cohort studies-reported significant lower scores in more than one cognitive domain. Risk factors associated with post critical illness cognitive impairment included younger age at critical illness and/or older age at follow-up, low socioeconomic status, high oxygen requirements, and use of mechanical ventilation, sedation, and pain medications.

CONCLUSIONS

Identifying risk factors for poor cognitive outcomes post critical illness may help healthcare teams modify patient risk and/or provide follow-up services to improve long-term cognitive outcomes in high-risk children.

Enhancing Recovery From Sepsis: A Review

Importance

Survival from sepsis has improved in recent years, resulting in an increasing number of patients who have survived sepsis treatment. Current sepsis guidelines do not provide guidance on posthospital care or recovery.

Observations

Each year, more than 19 million individuals develop sepsis, defined as a life-threatening acute organ dysfunction secondary to infection. Approximately 14 million survive to hospital discharge and their prognosis varies. Half of patients recover, one-third die during the following year, and one-sixth have severe persistent impairments. Impairments include development of an average of 1 to 2 new functional limitations (eg, inability to bathe or dress independently), a 3-fold increase in prevalence of moderate to severe cognitive impairment (from 6.1% before hospitalization to 16.7% after hospitalization), and a high prevalence of mental health problems, including anxiety (32% of patients who survive), depression (29%), or posttraumatic stress disorder (44%). About 40% of patients are rehospitalized within 90 days of discharge, often for conditions that are potentially treatable in the outpatient setting, such as infection (11.9%) and exacerbation of heart failure (5.5%). Compared with patients hospitalized for other diagnoses, those who survive sepsis (11.9%) are at increased risk of recurrent infection than matched patients (8.0%) matched patients (P < .001), acute renal failure (3.3% vs 1.2%, P < .001), and new cardiovascular events (adjusted hazard ratio [HR] range, 1.1-1.4). Reasons for deterioration of health after sepsis are multifactorial and include accelerated progression of preexisting chronic conditions, residual organ damage, and impaired immune function. Characteristics associated with complications after hospital discharge for sepsis treatment are not fully understood but include both poorer presepsis health status, characteristics of the acute septic episode (eg, severity of infection, host response to infection), and quality of hospital treatment (eg, timeliness of initial sepsis care, avoidance of treatment-related harms). Although there is a paucity of clinical trial evidence to support specific postdischarge rehabilitation treatment, experts recommend referral to physical therapy to improve exercise capacity, strength, and independent completion of activities of daily living. This recommendation is supported by an observational study involving 30 000 sepsis survivors that found that referral to rehabilitation within 90 days was associated with lower risk of 10-year mortality compared with propensity-matched controls (adjusted HR, 0.94; 95% CI, 0.92-0.97, P < .001).

Conclusions and Relevance

In the months after hospital discharge for sepsis, management should focus on (1) identifying new physical, mental, and cognitive problems and referring for appropriate treatment, (2) reviewing and adjusting long-term medications, and (3) evaluating for treatable conditions that commonly result in hospitalization, such as infection, heart failure, renal failure, and aspiration. For patients with poor or declining health prior to sepsis who experience further deterioration after sepsis, it may be appropriate to focus on palliation of symptoms.

Five-Year Mortality and Hospital Costs Associated with Surviving Intensive Care

RATIONALE

Survivors of critical illness experience significant morbidity, but the impact of surviving the intensive care unit (ICU) has not been quantified comprehensively at a population level.

OBJECTIVES

To identify factors associated with increased hospital resource use and to ascertain whether ICU admission was associated with increased mortality and resource use.

METHODS

Matched cohort study and pre/post-analysis using national linked data registries with complete population coverage. The population consisted of patients admitted to all adult general ICUs during 2005 and surviving to hospital discharge, identified from the Scottish Intensive Care Society Audit Group registry, matched (1:1) with similar hospital control subjects. Five-year outcomes included mortality and hospital resource use. Confounder adjustment was based on multivariable regression and pre/post within-individual analyses.

MEASUREMENTS AND MAIN RESULTS

Of 7,656 ICU patients, 5,259 survived to hospital discharge (5,215 [99.2%] matched to hospital control subjects). Factors present before ICU admission (comorbidities/pre-ICU hospitalizations) were stronger predictors of hospital resource use than acute illness factors. In the 5 years after the initial hospital discharge, compared with hospital control subjects, the ICU cohort had higher mortality (32.3% vs. 22.7%; hazard ratio, 1.33; 95% confidence interval, 1.22-1.46; P < 0.001), used more hospital resources (mean hospital admission rate, 4.8 vs. 3.3/person/5 yr), and had 51% higher mean 5-year hospital costs ($25,608 vs. $16,913/patient). Increased resource use persisted after confounder adjustment (P < 0.001) and using pre/post-analyses (P < 0.001). Excess resource use and mortality were greatest for younger patients without significant comorbidity.

CONCLUSIONS

This complete, national study demonstrates that ICU survivorship is associated with higher 5-year mortality and hospital resource use than hospital control subjects, representing a substantial burden on individuals, caregivers, and society.

Neurologic complications of sepsis

Over the past decades, the incidence of sepsis and resultant neurologic sequelae has increased, both in industrialized and low- or middle-income countries, by approximately 5% per year. Up to 300 patients per 100 000 population per year are reported to suffer from sepsis, severe sepsis, and septic shock. Mortality is up to 30%, depending on the precision of diagnostic criteria. The increasing incidence of sepsis is partially explained by demographic changes in society, with aging, increasing numbers of immunocompromised patients, dissemination of multiresistant pathogens, and greater availability of supportive medical care in both industrialized and middle-income countries. This results in more septic patients being admitted to intensive care units. Septic encephalopathy is a manifestation especially of severe sepsis and septic shock where the neurologist plays a crucial role in diagnosis and management. It is well known that timely treatment of sepsis improves outcome and that septic encephalopathy may precede other signs and symptoms. Particularly in the elderly and immunocompromised patient, the brain may be the first organ to show signs of failure. The neurologist diagnosing early septic encephalopathy may therefore contribute to the optimal management of septic patients. The brain is not only an organ failing in sepsis (a "sepsis victim" - as with other organs), but it also overwhelmingly influences all inflammatory processes on a variety of pathophysiologic levels, thus contributing to the initiation and propagation of septic processes. Therefore, the best possible pathophysiologic understanding of septic encephalopathy is essential for its management, and the earliest possible therapy is crucial to prevent the evolution of septic encephalopathy, brain failure, and poor prognosis.

Critical Illness Brain Injury

A growing body of literature has shown that survivors of critical illness often struggle with cognitive impairment that persists months to years after hospital discharge. We describe the epidemiology of this form of cognitive impairment-which we refer to as critical illness brain injury-and review the history and maturation of the investigation of this previously unrecognized, yet common problem. We then review the characteristics of critical illness brain injury, which can vary in severity and typically affects multiple domains of cognition. Finally, we examine known risk factors for critical illness brain injury and, based on these data, suggest approaches to patient management.

Recovery and outcomes after the acute respiratory distress syndrome (ARDS) in patients and their family caregivers

Outcomes after acute respiratory distress syndrome (ARDS) are similar to those of other survivors of critical illness and largely affect the nerve, muscle, and central nervous system but also include a constellation of varied physical devastations ranging from contractures and frozen joints to tooth loss and cosmesis. Compromised quality of life is related to a spectrum of impairment of physical, social, emotional, and neurocognitive function and to a much lesser extent discrete pulmonary disability. Intensive care unit-acquired weakness (ICUAW) is ubiquitous and includes contributions from both critical illness polyneuropathy and myopathy, and recovery from these lesions may be incomplete at 5 years after ICU discharge. Cognitive impairment in ARDS survivors ranges from 70 to 100 % at hospital discharge, 46 to 80 % at 1 year, and 20 % at 5 years, and mood disorders including depression and post-traumatic stress disorder (PTSD) are also sustained and prevalent. Robust multidisciplinary and longitudinal interventions that improve these outcomes are still uncertain and data in our literature are conflicting. Studies are needed in family members of ARDS survivors to better understand long-term outcomes of the post-ICU family syndrome and to evaluate how it affects patient recovery.

The Pattern of Brain Microhemorrhages After Severe Lung Failure Resembles the One Seen in High-Altitude Cerebral Edema

OBJECTIVES

After suffering from severe acute respiratory distress syndrome, several patients show generalized brain alterations and atrophy. A distinctive morphologic pattern of cerebral injury, however, has not been found so far.

DATA SOURCES

We present the history of three patients who survived severe acute respiratory distress syndrome. In these patients, MRI of the brain showed multiple microhemorrhages predominantly in the splenium of the corpus callosum. An identical pattern of microhemorrhages has previously been described in mountaineers who suffered from high-altitude cerebral edema.

CONCLUSIONS

This report demonstrates that patients after treatment for acute respiratory distress syndrome and high-altitude cerebral edema show congruent cerebral injuries. Further investigation into the similarities of the causative conditions and neurologic consequences might reveal underlying pathophysiologic mechanisms and clinical implications of this observation.

Bioenergetics, mitochondrial dysfunction, and oxidative stress in the pathophysiology of septic encephalopathy

Sepsis is a major cause of mortality and morbidity in intensive care units. Acute and long-term brain dysfunctions have been demonstrated both in experimental models and septic patients. Sepsis-associated encephalopathy is an early and frequent manifestation but is underdiagnosed, because of the absence of specific biomarkers and of confounding factors such as sedatives used in the intensive care unit. Sepsis-associated encephalopathy may have acute and long-term consequences including development of autonomic dysfunction, delirium, and cognitive impairment. The mechanisms of sepsis-associated encephalopathy involve mitochondrial and vascular dysfunctions, oxidative stress, neurotransmission disturbances, inflammation, and cell death. Here we review specific evidence that links bioenergetics, mitochondrial dysfunction, and oxidative stress in the setting of brain dysfunctions associated to sepsis.

Imaging in sepsis-associated encephalopathy--insights and opportunities

Sepsis-associated encephalopathy (SAE) refers to a clinical spectrum of acute neurological dysfunction that arises in the context of sepsis. Although the pathophysiology of SAE is incompletely understood, it is thought to involve endothelial activation, blood-brain barrier leakage, inflammatory cell migration, and neuronal loss with neurotransmitter imbalance. SAE is associated with a high risk of mortality. Imaging studies using MRI and CT have demonstrated changes in the brains of patients with SAE that are also seen in disorders such as stroke. Next-generation imaging techniques such as magnetic resonance spectroscopy, diffusion tensor imaging and PET, as well as experimental imaging modalities, provide options for early identification of patients with SAE, and could aid in identification of pathophysiological processes that represent possible therapeutic targets. In this Review, we explore the recent literature on imaging in SAE, relating the findings of these studies to pathological data and experimental studies to obtain insights into the pathophysiology of sepsis-associated neurological dysfunction. Furthermore, we suggest how novel imaging technologies can be used for early-stage proof-of-concept and proof-of-mechanism translational studies, which may help to improve diagnosis in SAE.

Neuroimaging after critical illness: implications for neurorehabilitation outcome

Survivors of critical illness frequently have severe and long-lasting cognitive impairments and psychiatric disorders, which adversely affect functional outcomes including return to work, and quality of life. While data regarding cognitive outcomes has increased over the last 15 years, neuroimaging data in medical and surgical critical populations is extremely limited. The abrupt development of new significant cognitive impairments after critical illness along with abnormalities on neuroimaging suggest that critical illness results in new acquired brain injury, similar to that observed in other acquired brain injuries. Abnormalities on neuroimaging including cortical and subcortical lesions, brain atrophy, and white matter hyperintensities (WMH) which occur in widely distributed brain regions. Patients admitted to neurorehabilitation who received critical care related to their primary diagnosis may have sustained neurological injury from the nonspecific effects of their critical illness and as demonstrated in this review, generalized, non-specific neuroimaging findings may be observed and quantified. Given the high prevalence rate of cognitive impairments in this population, neuroimaging is important to help elucidate neuropathology of critical illness acquired brain injury and may be beneficial in guiding rehabilitation outcomes in this population.

A combined early cognitive and physical rehabilitation program for people who are critically ill: the activity and cognitive therapy in the intensive care unit (ACT-ICU) trial

BACKGROUND

In the coming years, the number of survivors of critical illness is expected to increase. These survivors frequently develop newly acquired physical and cognitive impairments. Long-term cognitive impairment is common following critical illness and has dramatic effects on patients' abilities to function autonomously. Neuromuscular weakness affects similar proportions of patients and leads to equally profound life alterations. As knowledge of these short-term and long-term consequences of critical illness has come to light, interventions to prevent and rehabilitate these devastating consequences have been sought. Physical rehabilitation has been shown to improve functional outcomes in people who are critically ill, but subsequent studies of physical rehabilitation after hospital discharge have not. Post-hospital discharge cognitive rehabilitation is feasible in survivors of critical illness and is commonly used in people with other forms of acquired brain injury. The feasibility of early cognitive therapy in people who are critically ill remains unknown.

OBJECTIVE

The purpose of this novel protocol trial will be to determine the feasibility of early and sustained cognitive rehabilitation paired with physical rehabilitation in patients who are critically ill from medical and surgical intensive care units.

DESIGN

This is a randomized controlled trial.

SETTING

The setting for this trial will be medical and surgical intensive care units of a large tertiary care referral center.

PATIENTS

The participants will be patients who are critically ill with respiratory failure or shock.

INTERVENTION

Patients will be randomized to groups receiving usual care, physical rehabilitation, or cognitive rehabilitation plus physical rehabilitation. Twice-daily cognitive rehabilitation sessions will be performed with patients who are noncomatose and will consist of orientation, memory, and attention exercises (eg, forward and reverse digit spans, matrix puzzles, letter-number sequences, pattern recognition). Daily physical rehabilitation sessions will advance patients from passive range of motion exercises through ambulation. Patients with cognitive or physical impairment at discharge will undergo a 12-week, in-home cognitive rehabilitation program.

MEASUREMENTS

A battery of neurocognitive and functional outcomes will be measured 3 and 12 months after hospital discharge.

CONCLUSIONS

If feasible, these interventions will lay the groundwork for a larger, multicenter trial to determine their efficacy.

Neurological outcome after experimental lung injury

We examined the influences of acute lung injury and hypoxia on neurological outcome. Functional performance was assessed using a neurocognitive test and a neurologic deficit score (NDS) five days before. On experimental day, mechanically ventilated pigs were randomized to hypoxia only (HO group, n=5) or to acute lung injury (ALI group, n=5). Hemodynamics, respiratory mechanics, systemic cytokines and further physiologic variables were obtained at baseline, at the time of ALI, 2, 4 and 8h thereafter. Subsequently, injured lungs were recruited and animals weaned from the ventilator. Neurocognitive testing was re-examined for five days. Then, brains were harvested for neurohistopathology. After the experiment, neurocognitive performance was significantly worsened and the NDS increased in the ALI group. Histopathology revealed no significant differences. Oxygenation was comparable between groups although significantly higher inspiratory pressures occured after ALI. Cytokines showed a trend towards higher levels after ALI. Neurocognitive compromise after ALI seems due to a more pronounced inflammatory response and complex mechanical ventilation.

Cognitive impairment in common, noncentral nervous system medical conditions of adults and the elderly

Common, noncentral nervous system medical conditions linked with cognitive impairment in adults and the elderly include: acute respiratory distress syndrome; cancer; chronic kidney disease; chronic obstructive pulmonary disease; coronary heart disease; hypertension; obesity (bariatric surgical candidates); obstructive sleep apnea; and type 2 diabetes. Cross-condition comparison of the nature and frequency of cognitive impairment is difficult as these conditions often coexist, and there exists no consensus as to the definition of cognitive impairment, nor the optimal number and type of neuropsychological tests required for evaluation. There is as yet no clear evidence for condition-specific profiles of cognitive impairment. Rather, a generalized profile consisting of subclinical levels of impairment in attention, processing speed, executive, and memory functions from bilateral frontal-subcortical ischemia fits across all conditions. This profile: occurs only in subgroups of patients; is inconsistently related to measures of illness severity; is unrelated to patient self-report or level of functional independence; is exacerbated by very high levels of emotional distress; and is reversible in some cases but can also progress to frank neurological disease (dementia) in others, especially the elderly, when multiple conditions coexist, and/or when medical condition severity progresses.

Neurologic changes during critical illness: brain imaging findings and neurobehavioral outcomes

Encephalopathy and other neurologic morbidities are common in critical illness, sepsis, and prolonged mechanical ventilation. We assessed structural changes on brain imaging and neuropsychological outcomes in critically ill patients who developed neurological changes during their intensive care unit (ICU) stay. Patients who underwent brain imaging for neurological changes were included in the study. Medical, neuroradiological, and outcome data were obtained from patient medical records. Sixty-four patients underwent brain imaging for neurological changes. Forty-one (64%) patients had abnormalities on brain imaging. There were no differences for age, hospital length of stay, ICU length of stay, duration of mechanical ventilation or APACHE II scores for patients with normal compared to abnormal brain imaging. Cognitive impairments occurred in 48% of survivors and 6% developed psychiatric disorders. Our study demonstrates that abnormalities on brain imaging are common in critically ill patients. We also confirm previous findings that survivors of critical illness have cognitive impairments post-ICU discharge. This study further illustrates the adverse effects of critical illness on the brain and highlights the need for additional research in this emerging area.