The Gut in Critical Illness

PURPOSE OF REVIEW

The purpose of this narrative review is to describe the mechanisms for gut dysfunction during critical illness, outline hypotheses of gut-derived inflammation, and identify nutrition and non-nutritional therapies that have direct and indirect effects on preserving both epithelial barrier function and gut microbiota during critical illness.

RECENT FINDINGS

Clinical and animal model studies have demonstrated that critical illness pathophysiology and interventions breach epithelial barrier function and convert a normally commensal gut microbiome into a pathobiome. As a result, the gut has been postulated to be the "motor" of critical illness and numerous hypotheses have been put forward to explain how it contributes to systemic inflammation and drives multiple organ failure. Strategies to ameliorate gut dysfunction have focused on maintaining gut barrier function and promoting gut microbiota commensalism. The trajectory of critical illness may be closely related to gut epithelial barrier function, the gut microbiome and interventions that may contribute towards a deleterious pathobiome with immune dysregulation.

Norepinephrine Infusion and the Central Venous Waveform in a Porcine Model of Endotoxemic Hypotension with Resuscitation: A Large Animal Study

BACKGROUND

Venous waveform analysis is an emerging technique to estimate intravascular fluid status by fast Fourier transform deconvolution. Fluid status has been shown proportional to f0, the amplitude of the fundamental frequency of the waveform's cardiac wave upon deconvolution. Using a porcine model of distributive shock and fluid resuscitation, we sought to determine the influence of norepinephrine on f0 of the central venous waveform.

METHODS

Eight pigs were anesthetized, catheterized and treated with norepinephrine after precipitation of endotoxemic hypotension, and subsequent fluid resuscitation to mimic sepsis physiology. Hemodynamic parameters and central venous waveforms were continually transduced throughout the protocol for post-hoc analysis. Central venous waveform f0 before, during and after norepinephrine administration were determined using Fourier analysis.

RESULTS

Heart rate increased, while central venous pressure, pulmonary capillary wedge pressure and stroke volume decreased throughout norepinephrine administration (p < 0.05). Mean f0 at pre-norepinephrine, and doses 0.05, 0.10, 0.15, 0.20 and 0.25 mcg/kg/min, were 2.5, 1.4, 1.7, 1.7, 1.6 and 1.4 mmHg2, respectively (repeated measures ANOVA; p < 0.001). On post-hoc comparison to pre-norepinephrine, f0 at 0.05 mcg/kg/min was decreased (p = 0.04).

CONCLUSIONS

As the performance of f0 was previously characterized during fluid administration, these data offer novel insight into the performance of f0 during vasopressor delivery. Central venous waveform f0 is a decreased with norepinephrine, in concordance with pulmonary capillary wedge pressure. This allows contextualization of the novel, venous-derived signal f0 during vasopressor administration, a finding that must be understood prior to clinical translation.

Why should lymphocytes immune profile matter in sepsis?

The global incidence of critical illness has been steadily increasing, resulting in higher mortality rates thereby presenting substantial challenges for clinical management. Among these conditions, sepsis stands out as the leading cause of critical illness, underscoring the urgent need for continued research to enhance patient care and deepen our understanding of its complex pathophysiology. Lymphocytes play a pivotal role in both innate and adaptive immune responses, acting as key regulators of the balance between pro-inflammatory and anti-inflammatory processes to preserve immune homeostasis. In the context of sepsis, an impaired immunity has been associated with disrupted lymphocytic metabolic activity, persistent pro-inflammatory state, and subsequent immunosuppression. These disruptions not only impair pathogen clearance but also predispose patients to secondary infections and hinder recovery, highlighting the importance of targeting lymphocyte dysfunction in sepsis management. Moreover, studies have identified absolute lymphocyte counts and derived parameters as promising clinical biomarkers for prognostic assessment and therapeutic decision-making. In particular, neutrophil-to-lymphocyte ratio, and lymphopenia have gained recognition in the literature as a critical prognostic markers and therapeutic target in the management of sepsis. This review aims to elucidate the multifaceted role of lymphocytes in pathophysiology, with a focus on recent advancements in their use as biomarkers and key findings in this evolving field.

Venous excess ultrasound: A mini-review and practical guide for its application in critically ill patients

Advancements in healthcare technology have improved mortality rates and extended lifespans, resulting in a population with multiple comorbidities that complicate patient care. Traditional assessments often fall short, underscoring the need for integrated care strategies. Among these, fluid management is particularly challenging due to the difficulty in directly assessing volume status especially in critically ill patients who frequently have peripheral oedema. Effective fluid management is essential for optimal tissue oxygen delivery, which is crucial for cellular metabolism. Oxygen transport is dependent on arterial oxygen levels, haemoglobin concentration, and cardiac output, with the latter influenced by preload, afterload, and cardiac contractility. A delicate balance of these factors ensures that the cardiovascular system can respond adequately to varying physiological demands, thereby safeguarding tissue oxygenation and overall organ function during states of stress or illness. The Venous Excess Ultrasound (VExUS) Grading System is instrumental in evaluating fluid intolerance, providing detailed insights into venous congestion and fluid status. It was originally developed to assess the risk of acute kidney injury in postoperative cardiac patients, but its versatility has enabled broader applications in nephrology and critical care settings. This mini review explores VExUS’s application and its impact on fluid management and patient outcomes in critically ill patients.

Advancing extracorporeal carbon dioxide removal technology: bridging basic science and clinical practice

Recently, advancements in extracorporeal carbon dioxide removal (ECCO 2 R) technology have markedly enhanced its clinical applicability and efficacy for managing severe respiratory conditions. This review highlights critical innovations in ECCO 2 R, such as advanced catheter technologies, active mixing methods, and biochemical enhancements, which have substantially improved gas exchange efficiency and broadened the scope of ECCO 2 R applications. Integrating ECCO 2 R into acute and chronic respiratory care has led to a shift toward more mobile and less invasive modalities, promising for extending ECCO 2 R usage from intensive care units to home settings. By examining these technological advancements and their clinical impacts, this paper outlines the potential future directions of ECCO 2 R technology, emphasizing its role in transforming respiratory care practices and enhancing patient outcomes.

Effect of the aspect ratio and wall heterogeneities on the mechanical behaviour of the aneurysm wall: Experimental investigation on phantom arteries

The management of unruptured intracranial aneurysms (UIA) involves assessing the risk of rupture, which requires a thorough understanding of risk factors such as the geometric characteristics of the neck (neck size) or local structural heterogeneities. This study explores the impact of neck size on the rupture risk of the aneurysmal sac and examines how local heterogeneities, such as calcifications or variations in tissue composition, influence the mechanical response of the wall of a saccular aneurysm during the insertion of an innovative arterial wall deformation device (DDP). The results reveal that high aspect ratios (AR) are associated with increased hemodynamic stress, thereby raising the risk of rupture. Additionally, this study provides valuable insights into the complex relationship between tissue heterogeneity, especially calcifications, and the mechanical response of aneurysm walls to mechanical stimuli. It appears that local heterogeneities weaken the integrity of the arterial wall, thus increasing the potential for rupture. Finally, although the DDP is not intended to treat intracranial aneurysms (IA), it could prove to be a relevant tool for deepening the understanding of their rupture mechanisms.

Xenon gas as a potential treatment for opioid use disorder, alcohol use disorder, and related disorders

Xenon gas is considered to be a safe anesthetic and imaging agent. Research on its other potentially beneficial effects suggests that xenon may have broad efficacy for treating health disorders. A number of reviews on xenon applications have been published, but none have focused on substance use disorders. Accordingly, we review xenon effects and targets relevant to the treatment of substance use disorders, with a focus on opioid use disorder and alcohol use disorder. We report that xenon inhaled at subsedative concentrations inhibits conditioned memory reconsolidation and opioid withdrawal symptoms. We review work by others reporting on the antidepressant, anxiolytic, and analgesic properties of xenon, which could diminish negative affective states and pain. We discuss research supporting the possibility that xenon could prevent analgesic- or stress-induced opioid tolerance and, by so doing could reduce the risk of developing opioid use disorder. The rapid kinetics, favorable safety and side effect profiles, and multitargeting capability of xenon suggest that it could be used as an ambulatory on-demand treatment to rapidly attenuate maladaptive memory, physical and affective withdrawal symptoms, and pain drivers of substance use disorders when they occur. Xenon may also have human immunodeficiency virus and oncology applications because its effects relevant to substance use disorders could be exploited to target human immunodeficiency virus reservoirs, human immunodeficiency virus protein-induced abnormalities, and cancers. Although xenon is expensive, low concentrations exert beneficial effects, and gas separation, recovery, and recycling advancements will lower xenon costs, increasing the economic feasibility of its therapeutic use. More research is needed to better understand the remarkable repertoire of effects of xenon and its potential therapeutic applications.

Exploring DMT: Endogenous role and therapeutic potential

N,N-Dimethyltryptamine (DMT) is a naturally occurring amine and psychedelic compound, found in plants, animals, and humans. While initial studies reported only trace amounts of DMT in mammalian brains, recent findings have identified alternative methylation pathways and DMT levels comparable to classical neurotransmitters in rodent brains, calling for a re-evaluation of its biological role and exploration of this inconsistency. This study evaluated DMT's biosynthetic pathways, focusing on indolethylamine N-methyltransferase (INMT) and its isoforms, and possible regulatory mechanisms, including alternative routes of synthesis and how physiological conditions, such as stress and hypoxia influence DMT levels. This review considers the impact of endogenous regulatory factors on DMT synthesis and degradation, particularly under conditions affecting monoamine oxidase (MAO) efficiency and activity. We also examined DMT's potential roles in various physiological processes, including neuroplasticity and neurogenesis, mitochondrial homeostasis, immunomodulation, and protection against hypoxia and oxidative stress. DMT's lipophilic properties allow it to cross cell membranes and activate intracellular 5-HT2A receptors, contributing to its role in neuroplasticity. This suggests DMT may act as an endogenous ligand for intracellular receptors, highlighting its broader biological significance beyond traditional receptor pathways. The widespread evolutionary presence of DMT's biosynthetic pathways across diverse species suggests it may play essential roles in various developmental stages and cellular adaptation to environmental challenges, highlighting the neurobiological significance of DMT and its potential clinical applications. We propose further research to explore the role of endogenous DMT, particularly as a potential neurotransmitter.

Evaluating the evidence for GM-CSF as a host-directed therapy in respiratory infections

Novel therapeutic approaches are needed to treat respiratory infections due to the rising antimicrobial resistance and the lack of effective antiviral therapies. A promising avenue to overcome treatment failure is to develop strategies that target the host immune response rather than the pathogen itself. Granulocyte-macrophage colony-stimulating factor (GM-CSF) plays a critical role in controlling homeostasis in lungs, alveolar macrophages being the most sensitive cells to GM-CSF signaling. In this review, we discuss the importance of GM-CSF secretion for lung homeostasis and its alteration during respiratory infections. We also present the pre-clinical evidence and clinical investigations evaluating GM-CSF-based treatments (administration or inhibition) as a therapeutic strategy for treating respiratory infections, highlighting both supporting and contradictory findings.

Fluoxetine mitigates hypothermia and inflammatory responses in lipopolysaccharide-induced systemic inflammation: Insights into serotonergic and hypothalamic thermoregulatory mechanisms

An abnormally elevated mortality rate is evident in cases of sepsis. To study specific mechanisms of sepsis experimentally, lipopolysaccharide (LPS) systemically administered has been used as a model, in which an exaggerated immune response, neurochemistry settings, and fever following hypothermia take place. Notably, systemic inflammation (SI) can modulate the central serotonergic pathways and being influenced by it. This influence extends to the hypothalamus, which holds a hierarchical significance in the control of body temperature (Tb). This study investigates the potential impact of orally administered fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI) given orally for 7 days before on LPS-induced SI (1.5 mg/kg, i.v.) in rats. The assessment involved monitoring Tb, heat loss index (HLI), along non-shivering thermogenesis assessed by oxygen consumption. Cytokine levels in the spleen and blood, along with nitric oxide (NO), and prostaglandins (PGs) E2 and D2, levels were also measured. The findings reveal increased plasma NO, cytokines in plasma and spleen, and hypothalamus PGE2 levels during SI. Interestingly, FLX mitigated LPS-induced hypothermia, accompanied by a reduction in plasma and splenic NO, interleukins (IL) 6, and 10. Additionally, the results align with the hypothesis that hypothermia, blunted by FLX, develops in fact in a regulated form, as an adaptive strategy.

Prickle2 regulates apical junction remodeling and tissue fluidity during vertebrate neurulation

The process of folding the flat neuroectoderm into an elongated neural tube depends on tissue fluidity, a property that allows epithelial deformation while preserving tissue integrity. Neural tube folding also requires the planar cell polarity (PCP) pathway. Here, we report that Prickle2 (Pk2), a core PCP component, increases tissue fluidity by promoting the remodeling of apical junctions (AJs) in Xenopus embryos. This Pk2 activity is mediated by the unique evolutionarily conserved Ser/Thr-rich region (STR) in the carboxyterminal half of the protein. Mechanistically, the effects of Pk2 require Rac1 and are accompanied by increased dynamics of C-cadherin and tricellular junctions, the hotspots of AJ remodeling. Notably, Pk2 depletion leads to the accumulation of mediolaterally oriented cells in the neuroectoderm, whereas the overexpression of Pk2 or Pk1 containing the Pk2-derived STR promotes cell elongation along the anteroposterior axis. We propose that Pk2-dependent regulation of tissue fluidity contributes to anteroposterior tissue elongation in response to extrinsic cues.

Recent Insights into the Evolving Role of the Gut Microbiome in Critical Care

This review explores the evolving understanding of gut microbiota's role in critical illness, focusing on how acute illness and exposures in intensive care unit (ICU) environment negatively impact the gut microbiota and the implications of these changes on host responses in critically-ill patients. Focusing on recent findings from clinical and preclinical studies, we discuss the effects of inflammation, enteral nutrient deprivation, and antibiotics on gut microbial dynamics. This review aims to enhance comprehension of microbial dynamics in the ICU and their implications for clinical outcomes and therapeutic strategies.

Baclofen modulates the immune response after spinal cord injury with locomotor benefits

BACKGROUND AND PURPOSE

Spinal cord injury (SCI) is a neurological condition that affects motor and sensory functions below the injury site. The consequences of SCI are devastating for the patients, and although significant efforts have been done in the last years, there is no effective therapy. Baclofen has emerged in the last few years as an interesting drug in the SCI field. Already used in the SCI clinical setting to control spasticity, baclofen has shown important impact on SCI recovery in animal models, such as lampreys and mice.

EXPERIMENTAL APPROACH AND KEY RESULTS

Herein, we proposed to go deeper into baclofen's mechanism of action and to study its role on the modulation of the immune response after SCI, a major process associated with the severeness of the lesion. Using a SCI compression mice model, we confirmed that baclofen leads to higher locomotor performance, but only at 1 mg·kg-1 and not in higher concentrations, as 5 mg·kg-1. Moreover, we found that baclofen at 1 mg·kg-1 can strongly modulate the immune response after SCI at local, systemic and peripheric levels. This is interesting and intriguingly at the same time, since now, additional studies should be performed to understand if the modulation of the immune response is the responsible for the locomotor outcomes observed on Baclofen treated animals.

CONCLUSION AND IMPLICATIONS

Our findings showed, for the first time, that baclofen can modulate the immune response after SCI, becoming a relevant drug in the field of the immunomodulators.

Portal vein pulsatility is associated with the cumulative fluid balance: A post hoc longitudinal analysis of a prospective, general intensive care unit cohort

BACKGROUND

Previous studies have explored tools for evaluating the effects of positive fluid balance, with recent emphasis, and controversies, on venous ultrasound parameters and composite scores. The portal vein pulsatility index and the renal venous pattern have emerged as the most promising indicators of volume-induced venous congestion. But in the general intensive care unit (ICU), numerous factors influence cardiovascular homeostasis, affecting venous function.

OBJECTIVES

This study aimed to evaluate the factors associated with portal vein pulsatility index in general ICU patients. Secondary objectives were to examine the correlations between pulsatility index and additional markers of congestion.

DESIGN

This exploratory study was a post hoc analysis of a prospective, multicentric, observational database.

SETTING

The data collection was performed in four ICUs in university-affiliated or tertiary hospitals.

PATIENTS

This study included adult patients within 24 h of general ICU admission with an expected ICU length of stay of more than 2 days.

INTERVENTION

Patients underwent clinical, biological, and echocardiographic assessments at several times: ICU admission, day 1, day 2, day 5 and the last day of ICU.

MAIN OUTCOME MEASURE

The study primary endpoint was the portal vein pulsatility index during the course of the patients' stay on the ICU.

RESULTS

One hundred forty-five patients and 514 haemodynamic evaluations were analysed. The mean age of the patients was 64 ± 15 years, 41% were women, with a median [IQR] admission simplified acute physiology score II of 46 [37 to 59]. The univariable followed by multivariable mixed-effects linear regression analyses demonstrated an association between portal vein pulsatility index, heart rate [estimate -0.002 (95% CI, -0.003 to -0.001), P  < 0.001] and the cumulative fluid balance [estimate 0.0007 (95% CI, 0.00007 to 0.001), P  = 0.024]. Portal vein pulsatility index showed no agreement with CVP of at least 12 mmHg (kappa correlation -0.008, P  = 0.811), negative passive leg raising (kappa correlation -0.036, P  = 0.430), mean inferior vena caval (IVC) diameter greater than 2 cm (kappa correlation -0.090, P  = 0.025), maximal IVC diameter greater than 2 cm (kappa correlation -0.010, P  = 0.835), hepatic vein systolic/diastolic ratio less than 1 (kappa correlation 0.043, P  = 0.276), or renal vein pulsatile pattern (kappa correlation -0.243, P  < 0.001).

CONCLUSION

The study findings emphasise the unique sensitivity of portal vein pulsatility index in assessing fluid balance in general ICU patients. The lack of correlation between portal vein pulsatility index and other parameters of venous congestion underscores its potential to provide distinctive insights into venous congestion.

M8OI toxicity is associated with an inhibition of ubiquinone reduction by complex I in the mitochondrial electron transport chain

Methylimidazolium ionic liquids (MILs) are solvents used in an increasing variety of industrial applications. Recent studies identified the 8C MIL (M8OI) contaminating the environment, detected exposure in humans and proposed M8OI to be a potential trigger for the autoimmune liver disease primary biliary cholangitis (PBC). To gain a better understanding of any PBC trigger mechanism(s), the interaction of M8OI with mitochondria has been examined. M8OI inhibited oxygen consumption in intact cells and induced cell death (IC50%-10 μM). Results from permeabilized cells indicated M8OI inhibits the mitochondrial electron transport chain at complex I, not complexes II, III or IV. Accordingly, succinate supported mitochondrial oxygen consumption and reduced cell death in the presence of M8OI. M8OI inhibited NADH oxidation by both mitochondrial membranes and purified complex I with IC50% values of 470 μM and 340 μM respectively. Based on direct determinations of M8OI in non-mitochondrial and mitochondrial compartments, toxic M8OI concentrations were estimated to result in mitochondrial concentrations commensurate with complex I inhibition. Mitochondrial accumulation followed by complex I inhibition is therefore a possible molecular initiating event for M8OI-dependent cell death. NADH oxidation by purified complex I in combination with a flavin-site electron acceptor was not inhibited by M8OI, indicating no interaction of M8OI at the NADH-binding active site. Modelling supported M8OI binding to the ubiquinone-binding site. By inhibiting turnover, M8OI also gave rise to increases in complex-I-linked reactive oxygen species. However, inhibitors of oxidative stress did not affect M8OI-mediated cell death. The metabolic consequences of M8OI-mediated complex I inhibition, not increased reactive oxygen species production, are therefore the likely cause of apoptotic cell death. Understanding the effects on complex I and the pathways activated and leading to cell death may be informative regarding mitochondrial stress, cell death and diseases such as PBC.

Update on traumatic brain injury in the ICU

PURPOSE OF REVIEW

This review aims to summarize recent developments for the management of severe traumatic brain injury (TBI) in the ICU. Recent advancements in TBI ICU management emphasize a progression toward more multimodal approaches and mitigating secondary brain injury by increased focus on careful systemic management.

RECENT FINDINGS

Invasive monitoring techniques such as continuous intracranial pressure (ICP) and brain tissue oxygen pressure (PbtO 2 ) monitoring are considered standard of care or may become crucial, respectively, for managing severe TBI. Technological advances in noninvasive techniques (e.g. quantitative pupillometry) are likely to advance our diagnostic and prognostic ability. Blood biomarkers, including glial fibrillary acidic protein, neurofilament light chain, and ubiquitin carboxy-terminal hydrolase L1, provide minimally invasive ways to better assess injury severity and predict outcomes. These advancements support personalized care, which will likely influence clinical management strategies in the future.

SUMMARY

ICP monitoring remains a key component of severe TBI management in ICU. Emerging evidence is slowly changing and improving intensive care and patient outcomes and include both brain-targeted therapies and careful systemic intensive care management.

Microglial activation and neuroinflammation in acute and chronic cognitive deficits in sepsis

Sepsis is characterised by dysregulated immune responses to infection, leading to multi-organ dysfunction and high rates of mortality. With increasing survival rates in recent years long-term neurological and psychiatric consequences have become more apparent in survivors. Many patients develop sepsis associated encephalopathy (SAE) which encompasses the profound but usually transient neuropsychiatric syndrome delirium but also new brain injury that emerges in the months and years post-sepsis. It is now clear that systemic inflammatory signals reach the brain during sepsis and that very significant neuroinflammation ensues. The major brain resident immune cell population, the microglia, has been implicated in acute and chronic cognitive dysfunction in animal models of sepsis based on a growing number of studies using bacterial endotoxin and in polymicrobial sepsis models such as cecal ligation and puncture. The current review explores the effects of sepsis on the brain, focussing on how systemic insults translate to microglial activation and neuroinflammation and how this disrupts neuronal function and integrity. We examine what has been demonstrated specifically with respect to microglial activation, revealing robust evidence for a role for neuroinflammation in sepsis-induced brain sequelae but less clear information on the extent of the specific microglial contribution to this, arising from findings using global knockout mice, non-selective drugs and treatments that equally target peripheral and central compartments. There is, nonetheless, clear evidence that microglia do become activated and do contribute to brain consequences of sepsis thus arguing for improved understanding of these neuroinflammatory processes toward the prevention and treatment of sepsis-induced brain dysfunction.

Hemodynamic effects of slower versus faster intravenous fluid bolus rates in critically ill patients: An observational study

PURPOSE

We compared the immediate and sustained effects of 500 mL of crystalloid administered at slow (333 mL/h) versus fast rates (999 mL/h) on mean arterial pressure (MAP) in critically ill patients.

MATERIALS AND METHODS

Hemodynamic variables were collected immediately before and every 30 min up to 60 min after the end of the infusion. The primary outcome was the adjusted difference in MAP.

RESULTS

We included 146 patients (slow rate: 71, fast rate: 75). One hour after the end of the infusion, there was no difference in the overall mean marginal effect on MAP between the groups [1.9 mmHg (95 % CI: -1.5 to 5.3 mmHg), p = 0.27] or on the perfusion parameters. Similarly, no difference was found in the immediate effect after 90 min [overall marginal effect: 1.1 mmHg (95 % CI: -2.3 to 4.6 mmHg); p = 0.52]. In patients with cardiac output (CO) monitoring, there was an increase in CO in the fast rate group (overall mean marginal effect: 1.78 L/min (95 % CI: 0.08 to 3.48 L/min); p = 0.04).

CONCLUSION

In critically ill patients, crystalloid infusion at both fast and slow rates did not lead to immediate or sustained differences in MAP. However, fast infusion may result in a greater increase in CO.

Advances in IgY antibody dosage form design and delivery strategies: Current status and future perspective

Immunoglobulin Y (IgY), a unique type of antibody found in birds, is attracting increasing attention for a broad range of biomedical applications. Rational IgY protection, dosage form design, and delivery are highly essential to transform functional IgY antibodies into desired IgY products for therapeutic and prophylactic administration. Although progress has been made in this field, it remains in the early stages, highlighting the fundamental research and development needed in this aspect of IgY technology. Hence, this article reviews the conventional and innovative IgY dosage designs and delivery strategies, emphasizes the challenges faced in various IgY delivery systems, discusses the criteria for evaluating IgY dosage form performance, and provides a comprehensive analysis of the current research status and prospects of IgY delivery strategies.

Training programmes for healthcare professionals in managing epidural analgesia: A scoping review

BACKGROUND

Epidural analgesia (EA) is widely used for postoperative and labour pain management. Systematic training of healthcare professionals, particularly nurses, is essential for the safe administration and management. This scoping review aimed to identify and map existing EA training programmes.

METHODS

A PRISMA-ScR-guided search was conducted across multiple databases and grey literature. Studies on educational interventions for healthcare professionals in EA management were included. Data extraction and categorisation were performed using Kirkpatrick's Four-Level Training Evaluation Model.

RESULTS

Eighteen studies were included, covering classroom training, workshops, self-directed learning, simulation-based training, and on-the-job training. Participants were primarily nurses. Programmes addressed epidural techniques, monitoring and assessment, spinal anatomy and pharmacology, complication management, and patient care. Most studies focused on short-term knowledge gains, with a limited assessment of long-term clinical impacts.

CONCLUSION

Limited research exists on EA training, with most programmes targeting nurses and relying on classroom-based training. Training structures varied, and evaluations primarily assessed short-term knowledge gains.

EDITORIAL COMMENT

The authors conducted a literature search to get an overview of programmes that aimed to train healthcare staff in managing epidural pain relief. Most of the identified 18 studies described classroom teaching and focused primarily on knowledge about complications. Patient contact in this type of training was not reported. The effectiveness of this type of training in a clinical context was difficult to evaluate based on the published evidence.

Dodecafluoropentane improves neuro-behavioral outcomes and return of spontaneous circulation rate in a swine model of cardiac arrest

INTRODUCTION

Dodecafluoropentane emulsion (DDFPe) administration has previously demonstrated improved gas exchange in single-organ perfusion models. This could translate to prevention of brain injury in cardiac arrest.

METHODS

We induced cardiac arrest in 12 pigs, performing CPR after 5-minute downtime. Pigs were randomly assigned to DDFPe (n = 7) or saline placebo (n = 5) groups. Neurologic injury biomarkers were measured at baseline, after return of spontaneous circulation (ROSC), and every 24 hours in survivors. Blinded Neurological Alertness Score, Neurological Dysfunction Score, and Overall Performance Score was performed in addition to histopathological scoring of parietal and hippocampal sections.

RESULTS

One placebo and four DDFPe pigs survived the 96-hour observation period. The odds ratio for ROSC was 7.2 (p = 0.22). Survival odds ratio was 4.6 (p = 0.29). All surviving animals had impaired motor responses that recovered by 72 hours. DDFPe animals showed better neuro-behavioral scores than placebo.

CONCLUSION

The findings of this novel study provide a proof of concept and early signal toward efficacy of intravenous DDFPe in cardiac arrest. The trend toward improved ROSC and functional survival may reflect improved microcirculatory gas exchange in DDFPe animals. Improving gas exchange in brain microcirculation during resuscitation from cardiac arrest may provide a significant therapeutic benefit.

Ventilation-induced acute kidney injury in acute respiratory failure: Do PEEP levels matter?

Acute Respiratory Distress Syndrome (ARDS) is a leading cause of morbidity and mortality among critically ill patients, and mechanical ventilation (MV) plays a critical role in its management. One of the key parameters of MV is the level of positive end-expiratory pressure (PEEP), which helps to maintain an adequate lung functional volume. However, the optimal level of PEEP remains controversial. The classical approach in clinical trials for identifying the optimal PEEP has been to compare "high" and "low" levels in a dichotomous manner. High PEEP can improve lung compliance and significantly enhance oxygenation but has been inconclusive in hard clinical outcomes such as mortality and duration of MV. This discrepancy could be related to the fact that inappropriately high or low PEEP levels may adversely affect other organs, such as the heart, brain, and kidneys, which could counteract its potential beneficial effects on the lung. Patients with ARDS often develop acute kidney injury, which is an independent marker of mortality. Three primary mechanisms have been proposed to explain lung-kidney crosstalk during MV: gas exchange abnormalities, such as hypoxemia and hypercapnia; remote biotrauma; and hemodynamic changes, including reduced venous return and cardiac output. As PEEP levels increase, lung volume expands to a variable extent depending on mechanical response. This dynamic underlies two potential mechanisms that could impair venous return, potentially leading to splanchnic and renal congestion. First, increasing PEEP may enhance lung aeration, particularly in highly recruitable lungs, where previously collapsed alveoli reopen, increasing lung volume and pleural pressure, leading to vena cava compression, which can contribute to systemic venous congestion and abdominal organ impairment function. Second, in lungs with low recruitability, PEEP elevation may induce minimal changes in lung volume while increasing airway pressure, resulting in alveolar overdistension, vascular compression, and increased pulmonary vascular resistance. Therefore, we propose that high PEEP settings can contribute to renal congestion, potentially impairing renal function. This review underscores the need for further rigorous research to validate these perspectives and explore strategies for optimizing PEEP settings while minimizing adverse renal effects.

Haemoadsorption to remove inflammatory mediators in sepsis: past, present, and future

While a dysregulated immune response is at the center of the sepsis definition, standard care is still solely focussed on prompt administration of antimicrobial therapy, source control, resuscitation and organ supportive therapies. Extracorporeal blood purification therapies, such as haemoadsorption, have been proposed as a possible adjunctive therapy to standard care in sepsis. These adsorption devices aim to rebalance the dysregulated immune response by removal of excessive amounts of circulating inflammatory mediators, including cytokines and endotoxins. Thus far, the effects of haemoadsorption on clinical outcomes have been insufficiently studied and although its routine use is not justified based on the current evidence, multiple centers use these devices in patients with severe septic shock. This narrative review describes the most well-studied adsorption devices as well as a novel selective adsorption device called the 'IL-6-Sieve', including in vitro data showing its capturing potential. Finally, it addresses important considerations for future trials on haemoadsorption in septic patients.

Treatment of severe traumatic brain injury with human bone marrow mesenchymal stem cell extracellular vesicles: a case report

OBJECTIVE

Extracellular vesicles (EVs) derived from regenerative mesenchymal stem cells might safely treat traumatic brain injury (TBI). We evaluated the safety and efficacy of a human bone marrow derived mesenchymal stem cell EVs (hBM-MSC EV) investigational product (IP) in a patient with severe TBI.

DESIGN

A single case study employing an IP with a strong safety profile in over 200 patients.

METHOD

The patient was dosed intravenously three times/week in the first week of six successive months. Functional Independence Measure (FIM) and Functional Assessment Measure (FAM) were performed to quantify effects. Safety monitoring was performed every week for nine months.

RESULTS

No adverse events occurred. Within eight weeks FIM and FAM scores improved by 48-55% and were sustained for the entire 36 weeks. All specific outcome items assessed by FIM and FAM that were initially low showed sustained improvements ranging from 41% to 233%, with the greatest improvements seen in locomotion, mobility and cognitive function.

CONCLUSION

After moderate improvement with conventional therapy, the substantial improvement observed following introduction of the IP suggests that hBM-MSC EVs may offer a novel and safe means to improve TBI patient outcomes. Appropriate randomized, controlled clinical trials to conclusively evaluate this therapeutic option are indicated.

Establishment of rat model for aspiration pneumonia and potential mechanisms

BACKGROUND

Aspiration pneumonia is a severe health concern, particularly for ICU patients with impaired airway defenses. Current animal models fail to fully replicate the condition, focusing solely on chemical lung injury from gastric acid while neglecting pathogen-induced inflammation. This gap hinders research on pathogenesis and treatment, creating an urgent need for a clinically relevant model. This study aimed to develop an improved rat model of aspiration pneumonia by combining hydrochloric acid (HCl) and lipopolysaccharide (LPS) administration.

METHODS

Specific pathogen-free Sprague Dawley rats underwent intratracheal instillation of HCl and LPS. Techniques included rat weight measurement, tracheal intubation, pulmonary function monitoring, lung tissue sampling with HE staining and scoring, bronchoalveolar lavage fluid (BALF) sampling, protein and inflammatory cytokine analysis via BCA and ELISA, BALF pH determination, Evans Blue dye assessment, blood gas analysis, FITC-dextran leakage, Western blotting, electron microscopy, survival analysis, and transcriptome sequencing with bioinformatics. Statistical analysis was performed using GraphPad Prism.

RESULTS

The optimal model involved instillation of 1.5 μL/g.wt HCl (pH = 1) followed by 20 μg/g.wt LPS after 1 h. This model reproduced acute lung injury, including tissue damage, pulmonary microvascular dysfunction, inflammatory responses, hypoxemia, and impaired pulmonary ventilation, with recovery observed at 72 h. PANoptosis was confirmed, characterized by increased markers. Concentration-dependent effects of HCl and LPS on lung damage were identified, alongside cytokine elevation and microvascular dysfunction.

CONCLUSIONS

This optimized model closely mimics clinical aspiration pneumonia, providing a valuable tool for studying pathophysiology and therapeutic strategies.

Sublethal systemic LPS in mice enables gut-luminal pathogens to bloom through oxygen species-mediated microbiota inhibition

Endotoxin-driven systemic immune activation is a common hallmark across various clinical conditions. During acute critical illness, elevated plasma lipopolysaccharide triggers non-specific systemic immune activation. In addition, a compositional shift in the gut microbiota, including an increase in gut-luminal opportunistic pathogens, is observed. Whether a causal link exists between acute endotoxemia and abundance of gut-luminal opportunistic pathogens is incompletely understood. Here, we model acute, pathophysiological lipopolysaccharide concentrations in mice and show that systemic exposure promotes a 100-10'000-fold expansion of Klebsiella pneumoniae, Escherichia coli, Enterococcus faecium and Salmonella Typhimurium in the gut within one day, without overt enteropathy. Mechanistically, this is driven by a Toll-like receptor 4-dependent increase in gut-luminal oxygen species levels, which transiently halts microbiota fermentation and fuels growth of gut-luminal facultative anaerobic pathogens through oxidative respiration. Thus, systemic immune activation transiently perturbs microbiota homeostasis and favours opportunistic pathogens, potentially increasing the risk of infection in critically ill patients.

Enhanced glomerular thrombosis in pronated animals with ARDS

BACKGROUND

Prone positioning is part of the management of acute respiratory distress syndrome (ARDS) and has been demonstrated to successfully improve the ventilation-perfusion match and reduce mortality in patients with severe respiratory failure. However, the effect of pronation on other organs than the lungs has not been widely studied. This study aimed to compare abdominal edema, perfusion and inflammation in supine and prone positioning in a porcine ARDS model.

METHODS

Seventeen piglets were randomized into two groups: a supine group (n = 9) and a prone group (n = 8). Both groups received endotoxemic infusion and were observed for 6 h. Three animals per group underwent positron emission tomography-magnetic resonance imaging (PET-MRI) for imaging acquisition. Hemodynamic and respiratory parameters were recorded throughout the protocol. Inflammation was assessed by measuring cytokine concentrations in blood, ascites and the abdominal organs' tissue. The edema in abdominal organs was assessed by wet-dry ratio and pathophysiological analysis of tissue samples and by MRI and PET measurements from volumes of interest (VOIs) delineated in abdominal organ in MRI and PET images. The abdominal organs' perfusion was also assessed by MRI and PET measurements.

RESULTS

The prone group had a faster CO2 washout and needed a lower positive end-expiratory pressure to maintain the desired oxygenation. In the prone group duodenal edema was lower (measured with wet-dry ratio) and renal perfusion, by both MRI and PET measurements, was lower than half compared to the supine group (MRI, perfusion fraction, f: supine group 0.13; prone group 0.03; p-value 0.002. PET Flow: supine group 1.7; prone group 0.4 ml/cm3/min; p-value 0.002). In addition, the histopathological samples of the kidneys showed a higher incidence and extent of glomerular thrombosis in the prone group.

CONCLUSIONS

In a porcine ARDS model, prone positioning was associated with enhanced glomerular thrombosis and low renal perfusion.

Accelerometer-based estimation of respiratory rate using principal component analysis and autocorrelation

Objective.Respiratory rate (RR) is an important vital sign but is often neglected. Multiple technologies exist for RR monitoring but are either expensive or impractical. Tri-axial accelerometry represents a minimally intrusive solution for continuous RR monitoring, however, the method has not been validated in a wide RR range. Therefore, the aim of this study was to investigate the agreement between RR estimation from a tri-axial accelerometer and a reference method in a wide RR range.Approach.Twenty-five healthy participants were recruited. For accelerometer RR estimation, the accelerometer was placed on the abdomen for optimal breathing movement detection. The acquired accelerometry data were processed using a lowpass filter, principal component analysis (PCA), and autocorrelation. The subjects were instructed to breathe at slow, normal, and fast paces in segments of 60 s. A flow meter was used as reference. Furthermore, the PCA-autocorrelation method was compared with a similar single axis method.Main results.The PCA-autocorrelation method resulted in a bias of 0.0 breaths per minute (bpm) and limits of agreement (LOA) = [-1.9; 1.9 bpm] compared to the reference. Overall, 99% of the RRs estimated by the PCA-autocorrelation method were within ±2 bpm of the reference. A Pearson correlation indicated a very strong correlation withr = 0.99 (p<0.001). The single axis method resulted in a bias of 3.7 bpm, LOA = [-14.9; 22.3 bpm], andr = 0.44 (p<0.001).Significance.The results indicate a strong agreement between the PCA-autocorrelation method and the reference. Furthermore, the PCA-autocorrelation method outperformed the single axis method.

The adverse impact of cytomegalovirus infection on intensive care units outcomes in critically ill COVID-19 patients: a single-center prospective observational study

PURPOSE

To assess the incidence and clinical impact of CMV infection in critically ill COVID-19 patients, examining ICU and hospital mortality, and length of hospital stay.

METHODS

In this single-center, prospective observational study (March 2020 - September 2022), 431 patients with COVID-19 pneumonia and moderate to severe ARDS were included. An active CMV surveillance protocol was implemented, analyzing CMV DNA in plasma and bronchoalveolar lavage (BAL). Clinical characteristics and outcomes were compared between CMV-COVID co-infected patients and those without CMV reactivation.

RESULTS

CMV-COVID co-infection was detected in 14.8% (64/431) of the cohort. Patients with CMV-COVID co-infection exhibited significantly higher ICU mortality (43.8% vs. 13.6%; p < 0.001) and hospital mortality (48.4% vs. 13.6%; p < 0.001) compared to patients without CMV. CMV infection was an independent predictor of hospital mortality (OR 4.91; 95% CI 2.76-8.75; p = 0.019). Earlier CMV reactivation was associated with an increased risk of hospital mortality (HR = 0.94; 95% CI: 0.90-0.98; p = 0.003). Additionally, CMV-COVID patients had a higher incidence of ICU-acquired infections and a prolonged hospital stay.

CONCLUSIONS

In critically ill patients with SARS-CoV-2 pneumonia, CMV infection was frequently observed, and associated with increased ICU and hospital mortality. CMV co-infection correlated with a higher incidence of ICU-acquired bacterial and fungal infections and prolonged hospital stays. This emphasizes the importance of early CMV monitoring upon ICU admission, as timely detection and intervention could potentially mitigate its impact on patient outcomes.

Cecal slurry-induced sepsis in mice impairs cognition and decreases SUMO-2/3 conjugation

Sepsis is characterized by multiple organ dysfunction, dysregulation of the response to the infection process, and a high mortality rate in intensive care units. In addition, individuals who overcome sepsis often manifest cognitive deficits associated with neuroinflammation resulting from the entry of pro-inflammatory cytokines into the brain. Post-translational protein modifications, such as SUMOylation, can regulate the expression of pro-inflammatory genes during sepsis. Since SUMO-2/3 can play a role in pathological conditions, our aim was to investigate a potential link between sepsis-induced cognitive decline and SUMOylation by this isoform. Firstly, the cecal slurry model was induced by intraperitoneally injecting male Swiss mice with different volumes of a cecal solution. Following assessment of body temperature, mass and septic scores, the groups that received 300μL and 350μL of the cecal solution were selected for the behavioural tests, as they presented signs of sepsis without excessive mortality. Surviving animals were evaluated for cognition/memory and anxious/depressive-like behaviours through the open-field, object recognition, Y-maze, and tail suspension tests. Subsequently, SUMO-2/3 conjugation was determined in samples from the hippocampus and prefrontal cortex by Western blotting. Mice in the septic groups showed decreased locomotor activity, anxious-and depressive-like behaviours, as well as impaired memory. These deficits were accompanied by a decrease in SUMO-2/3 conjugation in the hippocampus and prefrontal cortex at 24hours and 10 days after the induction of the cecal slurry model. Taken together, our findings suggest that SUMOylation is impaired in septic animals and this could be related to the behavioural deficits seen in the surviving mice.

Cytosolic nucleic acid sensing as driver of critical illness: mechanisms and advances in therapy

Nucleic acids from both self- and non-self-sources act as vital danger signals that trigger immune responses. Critical illnesses such as acute respiratory distress syndrome, sepsis, trauma and ischemia lead to the aberrant cytosolic accumulation and massive release of nucleic acids that are detected by antiviral innate immune receptors in the endosome or cytosol. Activation of receptors for deoxyribonucleic acids and ribonucleic acids triggers inflammation, a major contributor to morbidity and mortality in critically ill patients. In the past decade, there has been growing recognition of the therapeutic potential of targeting nucleic acid sensing in critical care. This review summarizes current knowledge of nucleic acid sensing in acute respiratory distress syndrome, sepsis, trauma and ischemia. Given the extensive research on nucleic acid sensing in common pathological conditions like cancer, autoimmune disorders, metabolic disorders and aging, we provide a comprehensive summary of nucleic acid sensing beyond critical illness to offer insights that may inform its role in critical conditions. Additionally, we discuss potential therapeutic strategies that specifically target nucleic acid sensing. By examining nucleic acid sources, sensor activation and function, as well as the impact of regulating these pathways across various acute diseases, we highlight the driving role of nucleic acid sensing in critical illness.

mRNA vaccine-induced SARS-CoV-2 spike-specific IFN-γ and IL-2 T-cell responses are predictive of serological neutralization and are transiently enhanced by pre-existing cross-reactive immunity

The contributions of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cells to vaccine efficacy and durability are unclear. We investigated relationships between mRNA vaccine-induced spike-specific interferon- gamma (IFN-γ) and interleukin-2 (IL-2) T-cell responses and neutralizing antibody development in long-term care home staff doubly vaccinated with BNT162b2 or mRNA-1273. The impacts of pre-existing cross-reactive T-cell immunity on cellular and humoral responses to vaccination were additionally assessed. Mathematical modeling of the kinetics of spike-specific IFN-γ and IL-2 T-cell responses over 6 months post-second dose was bifurcated into recipients who exhibited gradual increases with doubling times of 155 and 167 days or decreases with half-lives of 165 and 132 days, respectively. Differences in kinetics did not correlate with clinical phenotypes. Serological anti-spike IgG, anti-receptor binding domain (RBD) IgG, anti-spike IgA, and anti-RBD IgA antibody levels otherwise decayed in all participants with half-lives of 63, 57, 79, and 46 days, respectively, alongside waning neutralizing capacity (t1/2 = 408 days). Spike-specific T-cell responses induced at 2-6 weeks positively correlated with live viral neutralization at 6 months post-second dose, especially in hybrid immune individuals. Participants with pre-existing cross-reactive T-cell immunity to SARS-CoV-2 exhibited greater spike-specific T-cell responses, reduced anti-RBD IgA antibody levels, and a trending increase in neutralization at 2-6 weeks post-second dose. Non-spike-specific T-cells predominantly targeted SARS-CoV-2 non-structural protein at 6 months post-second dose in cross-reactive participants. mRNA vaccination was lastly shown to induce off-target T-cell responses against unrelated antigens. In summary, vaccine-induced spike-specific T-cell immunity appeared to influence serological neutralizing capacity, with only a modest effect induced by pre-existing cross-reactivity.

IMPORTANCE

Our findings provide valuable insights into the potential contributions of mRNA vaccine-induced spike-specific T-cell responses to the durability of neutralizing antibody levels in both uninfected and hybrid immune recipients. Our study additionally sheds light on the precise impacts of pre-existing cross-reactive T-cell immunity to severe acute respiratory syndrome coronavirus 2 on the magnitude and kinetics of cellular and humoral responses to vaccination. Accordingly, our data will help optimize the development of next-generation T cell-based coronavirus vaccines and vaccine regimens to maximize efficacy and durability.

Therapeutic potential of fecal microbiota transplantation in colorectal cancer based on gut microbiota regulation: from pathogenesis to efficacy

Colorectal cancer (CRC) remains a leading cause of cancer-related deaths worldwide, with its progression intricately linked to gut microbiota dysbiosis. Disruptions in microbial homeostasis contribute to tumor initiation, immune suppression, and inflammation, establishing the microbiota as a key therapeutic target. Fecal microbiota transplantation (FMT) has emerged as a transformative approach to restore microbial balance, enhance immune responses, and reshape the tumor microenvironment. This review explores the mechanisms underlying FMT's therapeutic potential, evaluates its advantages over other microbiota-based interventions, and addresses challenges such as donor selection, safety concerns, and treatment standardization. Looking forward, the integration of FMT into personalized CRC therapies requires robust clinical trials and the identification of predictive biomarkers to optimize its efficacy and safety.

The Neurochemical Signature of Cardiac Arrest: A Multianalyte Online Microdialysis Study

This work describes the use of high resolution online microdialysis coupled with a wireless microfluidic electrochemical sensing platform for continuous monitoring of the effect of cardiac arrest and resuscitation methods on brain glucose and other key neurochemicals in a porcine model. The integrated portable device incorporates low-volume three-dimensional (3D) printed microfluidic flow cells containing enzyme-based biosensors for glucose, lactate and glutamate measurement and a complementary metal-oxide semiconductor (CMOS)-based ion-sensitive field effect transistor (ISFET) for potassium measurement. Both analysis systems incorporate wireless electronics forming a complete compact system that is ideal for use in a crowded clinical environment. Using this integrated system we were able to build a signature of the neurochemical impact of cardiac arrest and resuscitation. Our results demonstrate the almost complete depletion of brain glucose following cardiac arrest and the subsequent increase in lactate, highlighting the vulnerability of the brain while the blood flow is compromised. Following a return of spontaneous circulation, glucose levels increased again and remained higher than baseline levels. These trends were correlated with simultaneous blood measurements to provide further explanation of the metabolic changes occurring in the brain. In addition, the onset of cardiac arrest corresponded to a transient increase in potassium. In most cases glutamate levels remained unchanged after cardiac arrest, while in some cases a transient increase was detected. We were also able to validate the trends seen using online microdialysis with traditional discontinuous methods; the two methods showed good agreement although online microdialysis was able to capture dynamic changes that were not seen in the discontinuous data.

Role of inflammasomes in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is present in >10% of all people admitted to critical care and is associated with severe morbidity and mortality. Despite more than half a century since its first description, no efficacious pharmacological therapies have been developed, and little progress has been made in improving clinical outcomes. Neutrophils are the principal drivers of ARDS, with their priming and subsequent aberrant downstream functions, including interleukin (IL) 1β and IL-18 secretion, central to the disease pathogenesis. The dominant pathways through which IL-1β and IL-18 are believed to be elaborated are multimeric protein structures called inflammasomes that consist of sensor proteins, adaptor proteins and an effector enzyme. The inflammasome's initial activation depends on one of a variety of damage-associated (DAMP) or pathogen-associated (PAMP) molecular patterns. However, once activated, a common downstream inflammatory pathway is initiated regardless of the specific DAMP or PAMP involved. Several inflammasomes exist in humans. The nucleotide-binding domain leucine-rich repeat (NLR) family, pyrin domain-containing 3 (NLRP3), inflammasome is the best described in the context of ARDS and is known to be activated in both infective and sterile cases. The NLR family, caspase activation and recruitment domain-containing 4 (NLRC4) and absent in melanoma 2 (AIM2) inflammasomes have also been implicated in various ARDS settings, as have inflammasome-independent pathways. Further work is required to understand human biology as much of our knowledge is extrapolated from rodent experimental models. Experimental lung injury models have demonstrated beneficial responses to inflammasome, IL-1β and IL-18 blockade. However, findings have yet to be successfully translated into humans with ARDS, likely due to an underappreciation of the central role of the neutrophil inflammasome. A thorough understanding of inflammasome pathways is vital for critical care clinicians and researchers and for the development of beneficial therapies. In this review, we describe the central role of the inflammasome in the development of ARDS and its potential for immunomodulation, highlighting key areas for future research.

Advances in Renal Replacement Therapy: The Role of Polymethyl Methacrylate Membranes in Acute Critically Ill Patients

BACKGROUND

Polymethyl methacrylate (PMMA) membranes are increasingly recognized for their effectiveness in treating acute kidney injury (AKI) due to their strong adsorption capabilities, particularly for inflammatory mediators like β2-microglobulin and IL-6. These membranes ensure mechanical stability and chemical inertness, minimizing adverse reactions during blood filtration.

SUMMARY

In acute conditions such as sepsis and acute respiratory distress syndrome (ARDS), PMMA membranes show promising findings. In sepsis, they may help reduce multiorgan failure by modulating immune responses, although further research is needed to confirm their routine use. For ARDS, PMMA membranes could mitigate "cytokine storms" by adsorbing key cytokines, improving oxygenation and hemodynamic stability, which may reduce ICU stays and reliance on mechanical ventilation. Monitoring biomarkers like IL-6, TNF-α is critical for tracking efficacy and tailoring therapy to individual needs. In chronic conditions, such as hemodialysis for chronic kidney disease, PMMA membranes help lower oxidative stress and β2-microglobulin levels, reducing complications such as amyloidosis. By decreasing oxidative damage, they provide long-term protective benefits for dialysis patients.

KEY MESSAGE

While these advantages are notable, large-scale studies are needed to establish PMMA's efficacy, refine treatment protocols, and confirm its broader role in acute and chronic disease management. The potential of PMMA membranes highlights their value, but standardized clinical evidence is necessary for widespread adoption.

A scoping review on the integration of artificial intelligence in point-of-care ultrasound: Current clinical applications

BACKGROUND

Artificial intelligence (AI) is used increasingly in point-of-care ultrasound (POCUS). However, the true role, utility, advantages, and limitations of AI tools in POCUS have been poorly understood.

AIM

to conduct a scoping review on the current literature of AI in POCUS to identify (1) how AI is being applied in POCUS, and (2) how AI in POCUS could be utilized in clinical settings.

METHODS

The review followed the JBI scoping review methodology. A search strategy was conducted in Medline, Embase, Emcare, Scopus, Web of Science, Google Scholar, and AI POCUS manufacturer websites. Selection criteria, evidence screening, and selection were performed in Covidence. Data extraction and analysis were performed on Microsoft Excel by the primary investigator and confirmed by the secondary investigators.

RESULTS

Thirty-three papers were included. AI POCUS on the cardiopulmonary region was the most prominent in the literature. AI was most frequently used to automatically measure biometry using POCUS images. AI POCUS was most used in acute settings. However, novel applications in non-acute and low-resource settings were also explored. AI had the potential to increase POCUS accessibility and usability, expedited care and management, and had a reasonably high diagnostic accuracy in limited applications such as measurement of Left Ventricular Ejection Fraction, Inferior Vena Cava Collapsibility Index, Left-Ventricular Outflow Tract Velocity Time Integral and identifying B-lines of the lung. However, AI could not interpret poor images, underperformed compared to standard-of-care diagnostic methods, and was less effective in patients with specific disease states, such as severe illnesses that limit POCUS image acquisition.

CONCLUSION

This review uncovered the applications of AI in POCUS and the advantages and limitations of AI POCUS in different clinical settings. Future research in the field must first establish the diagnostic accuracy of AI POCUS tools and explore their clinical utility through clinical trials.

Inhibitory Immune Checkpoints Predict 7-Day, In-Hospital, and 1-Year Mortality of Internal Medicine Patients Admitted With Bacterial Sepsis

BACKGROUND

Sepsis is a life-threatening syndrome with complex pathophysiology and great clinical heterogeneity, which complicates the delivery of personalized therapies. Our goal was to demonstrate that some biomarkers identified as regulatory immune checkpoints in preclinical studies could guide the stratification of patients with sepsis into subgroups with shared characteristics of immune response or survival outcomes.

METHODS

We assayed the soluble counterparts of 12 biomarkers of immune response in 113 internal medicine patients with bacterial sepsis.

RESULTS

IL-1 receptor-associated kinase M (IRAK-M) exhibited the highest hazard ratios (HRs) for increased 7-day (1.94; 95% confidence interval [CI], 1.17-3.20) and 30-day mortality (1.61; 95% CI, 1.14-2.28). HRs of IRAK-M and galectin-1 for predicting 1-year mortality were 1.52 (95% CI, 1.20-1.92) and 1.64 (95% CI, 1.13-2.36), respectively. Patients with elevated serum levels of IRAK-M and galectin-1 had clinical traits of immune suppression and low survival rates.

CONCLUSIONS

Two inhibitory immune checkpoint biomarkers (IRAK-M and galectin-1) helped identify 3 distinct sepsis phenotypes with distinct prognoses. These biomarkers shed light on the interplay between immune dysfunction and prognosis in patients with bacterial sepsis and may prove to be useful prognostic markers, therapeutic targets, and biochemical markers for targeted enrollment in therapeutic trials.

Copper-Based Metal-Organic Framework as a Potential Therapeutic Gas Carrier: Optimization, Synthesis, Characterization, and Computational Studies

The broad spectrum of health conditions and the global pandemic, leading to inadequate medical oxygen supply and management, has driven interest in developing porous nanocarriers for effective oxygenation strategies. We aim to develop an injectable oxygen carrier with regard to biocompatibility, safety, prehospital availability, and universal applicability. In this study, we have tried to identify important functional sites on metal-organic frameworks (MOFs) for gas binding with the help of Grand canonical Monte Carlo simulation. We have synthesized a copper-based MOF (Cu-BTC) with a 1,3,5-benzenetricarboxylic acid linker through a solvothermal approach as a competent porous adsorbent for oxygen storage and delivery. To optimize process variables, we performed statistical analysis using response surface methodology. A quadratic model was developed to study the interaction between independent variables and the response (i.e., maximizing surface area), whose adequacy is validated by the correlation between experimental and predicted values using the ANOVA method. The synthesized Cu-BTC, before and after oxygen loading, was characterized using X-ray diffraction, surface area, along with pore distribution measurement, particle size analysis, scanning electron microscopy, transmission electron microscopy, and gas adsorption studies. The Cu-BTC MOF exhibited an oxygen uptake of 4.6 mmol g-1, the highest among all the oxygen carriers reported in the literature under the same operating conditions. Overall, our findings suggest that this synthesized Cu-BTC with high surface area (1389 m2 g-1), high porosity, optimum oxygen uptake, and good biocompatibility would show potential toward efficient storage and delivery (direct to the targeted site) of medical oxygen to raise the blood oxygen saturation level.

Cystic fibrosis-related kidney disease-emerging morbidity and disease modifier

Cystic fibrosis (CF) is a life-shortening multisystem disease resulting from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, causing the most devastating phenotypes in the airway and pancreas. Significant advances in treatment for CF lung disease, including the expanded use of high-efficiency modulator therapies (HEMT) such as Trikafta, have dramatically increased both quality of life and life expectancy for people with CF (PwCF). With these advances, long-term extrapulmonary manifestations are more frequently recognized. Pseudo-Barter syndrome, acute kidney injury (AKI) induced by medications or dehydration, amyloidosis, nephrolithiasis, and IgA and diabetic nephropathies have been previously reported in PwCF. Newer data suggest that chronic kidney disease (CKD) is a new morbidity in the aging CF population, affecting 19% of people over age 55. CKD carries a high risk of premature death from cardiovascular complications. Studies suggest that CFTR dysfunction increases kidneys' vulnerability to injury caused by the downstream effects of CF. Improving the mutant CFTR function by HEMT may help to tease apart the kidney responses resulting from extrinsic factors and those intrinsically related to the CFTR gene mutations. Additionally, given the novelty of HEMT approaches, the potential off-target effects of their long-term use are currently unknown. We review the evolving kidney complications in PwCF and propose the term CF-related kidney disease. We hope this review will increase awareness about the changing phenotype of kidney dysfunction in PwCF and help prevent morbidity related to this condition.

Early suPAR levels as a predictor of COVID-19 severity: A new tool for efficient patient triage

BACKGROUND

Following several waves of the COVID-19 pandemic, we are now facing a lower but persistent rate of SARS-CoV-2 infections, with seasonal resurgences often coinciding with other respiratory tract infections.

OBJECTIVE

We aimed to identify early clinico-biological variables predictive of an unfavorable outcome in patients with primary SARS-CoV-2 infection. We also evaluated the role of suPAR, an innovative biomarker, in predicting disease severity.

METHODS

We included 255 patients with PCR-confirmed primary SARS-CoV-2 infection and with a 30-day follow-up minimum. Blood samples were collected within the first 24 h of hospitalization to measure suPAR levels. Comprehensive data from medical records were analyzed to assess their predictive value in stratifying patients into seven severity groups, with groups 1 to 3 representing severe COVID-19 (death, intubation, ECMO, or non-invasive ventilation).

RESULTS

Early plasma suPAR levels were significantly associated with severe disease progression, as evidenced by ANOVA and logistic regression models, highlighting suPAR as a persistent predictive factor for unfavorable outcomes.

CONCLUSION

Our findings suggest that a single suPAR measurement, performed early after a positive PCR test for SARS-CoV-2, holds strong predictive value for patient outcomes. This biomarker, alongside pulse oximetry and CT scan results, could be instrumental in early patient triage during seasonal COVID-19 resurgences.

Mortality time frame variability in septic shock clinical trials: A systematic review

OBJECTIVE

We sought to delineate the mortality outcome time frames reported in septic shock randomized control trials (RCTs).

DESIGN

Systematic review of PubMed, EMBASE, and the Cochrane Database of Systematic Reviews.

SETTING

Intensive care units.

PARTICIPANTS

Studies that included adult patients with septic shock.

INTERVENTIONS

Any type of intervention.

MAIN VARIABLES OF INTEREST

Information about the study, specific patient population, type of study intervention, specific intervention, and number of patients. Mortality time frames were analyzed for geographical differences and changes over time.

RESULTS

The search yielded 2660 unique citations. After screening, 132 eligible studies were identified. A total of 234 mortality time frames were collected from the included studies, of which 15 timeframes were unique. The most frequently reported time frame was 28-day mortality (n = 98, 74% of trials), followed by hospital mortality (n = 35, 27%), ICU mortality (n = 30, 23%), and 90-day mortality (n = 29, 22%). The most reported mortality time frame was 28 days in studies from every continent except Africa. The studies published between 2008 and 2013 (25%) more frequently reported hospital and ICU mortality combination than studies published between 2014 and 2019 (11.4%) (P = 0.043).

CONCLUSIONS

There was considerable variability in the mortality time frames reported in ICU-based septic shock trials. This variability may lead to under or overestimation of the problem, overlooking the effectiveness of the interventions studied, and further limiting the application of trials and their pooling in meta-analyses. A consensus regarding time frame reporting in septic shock trials is long overdue.

NOD-like receptor protein 3 inhibition by MCC950 improves the cognitive function of rats with sepsis-associated encephalopathy

This study aimed to investigate the effects of MCC950 in a rat model of sepsis-associated encephalopathy (SAE). Adult male rats were randomly assigned to 12 groups according to the surgery or treatment received and evaluation times. The SAE model was established using the cecal ligation and puncture (CLP) method. Intraperitoneal injections of normal saline (10 mL/kg) or MCC950 (10 mg/kg) were administered 30 min pre-surgery and daily post-surgery. Changes in survival rates, weight loss, and heart rate were assessed at four time points, and neurobehavioral changes were evaluated using the composite neural reflex function scores, light/dark box test, and open-field test (OFT). Compared with the SAE group, the SAE + MCC950 group had significantly higher survival rates (P < 0.05), lower postoperative weight loss rates (P < 0.05), and higher neurological function scores (P < 0.05); the SAE + MCC950 group also traveled further and crossed the central area more frequently in the OFT (P < 0.05), spent more time in the light compartment at different time points (P < 0.05), and exhibited a lower heart rate at different time points (P < 0.05). MCC950 treatment significantly improved cognitive function and related indices in the SAE rats.

Embracing a Penta helix hub framework for co-creating sustaining and potentially disruptive sterilization innovation that enables artificial intelligence and sustainability: A scoping review

The supply of safe pipeline medical devices is of paramount importance. Opportunities exist to transform reusable medical devices for improved processing that meets diverse patient needs. There is increased interest in multi-actor hub frameworks to meet innovation challenges globally. The purpose of this scoping paper was to identify critical decontamination and sterilization needs for the medtech and pharmaceutical sectors with a focus on understanding how to effectively use the Penta helix hub framework that combines academia, industry, healthcare, policy-makers/regulators and patients/society. A PRISMA scoping review of PubMed publications was conducted over the period 2010 to January 2025. Thirty of the 124 'helix hub' papers addressed innovation where only 3 of 16 healthcare-focused helices used or mentioned the need for key performance indicators (KPIs). Early-phase helix innovation ecosystems are mainly supported by qualitative or non-empirical data. This review explores multi-actor needs along with describing quantifiable KPIs at micro (end-user), meso (innovation hub) and macro (regional, national and international) levels. This integrated Penta hub approach will help to effectively plan, co-create, manage, analyse and utilize voluminous data, for example there are ca. 60,000 and 56,000 publications per year on artificial intelligence (AI) and medical devices respectively along, with some 35,000 adverse reports on devices submitted to the US FDA. This review addresses sustaining and potentially disruptive opportunities for decontamination and sterilization that includes the use of AI-enabled devices, bespoke training and sustainability.

Subphenotyping prone position responders with machine learning

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a heterogeneous condition with varying response to prone positioning. We aimed to identify subphenotypes of ARDS patients undergoing prone positioning using machine learning and assess their association with mortality and response to prone positioning.

METHODS

In this retrospective observational study, we enrolled 353 mechanically ventilated ARDS patients who underwent at least one prone positioning cycle. Unsupervised machine learning was used to identify subphenotypes based on respiratory mechanics, oxygenation parameters, and demographic variables collected in supine position. The primary outcome was 28-day mortality. Secondary outcomes included response to prone positioning in terms of respiratory system compliance, driving pressure, PaO2/FiO2 ratio, ventilatory ratio, and mechanical power.

RESULTS

Three distinct subphenotypes were identified. Cluster 1 (22.9% of whole cohort) had a higher PaO2/FiO2 ratio and lower Positive End-Expiratory Pressure (PEEP). Cluster 2 (51.3%) had a higher proportion of COVID-19 patients, lower driving pressure, higher PEEP, and higher respiratory system compliance. Cluster 3 (25.8%) had a lower pH, higher PaCO2, and higher ventilatory ratio. Mortality differed significantly across clusters (p = 0.03), with Cluster 3 having the highest mortality (56%). There were no significant differences in the proportions of responders to prone positioning for any of the studied parameters. Transpulmonary pressure measurements in a subcohort did not improve subphenotype characterization.

CONCLUSIONS

Distinct ARDS subphenotypes with varying mortality were identified in patients undergoing prone positioning; however, predicting which patients benefited from this intervention based on available data was not possible. These findings underscore the need for continued efforts in phenotyping ARDS through multimodal data to better understand the heterogeneity of this population.

Inferior Vena Cava Filter Placed in Neurologic Intensive Care Unit: Effectiveness, Retrieval Rate, and Mortality

PURPOSE

Patients in neurologic intensive care unit (NICU) often undergo inferior vena cava filter (IVCF) placement for venous thrombotic events. This study aims to determine the effectiveness of IVCF, filter retrieval, and mortality among patients that received IVCF in NICU.

MATERIALS AND METHODS

In this single institutional, noncomparative, retrospective study, all patients who were admitted to NICU and underwent IVCF placement from April 2015 to December 2020 were reviewed. IVCF was successfully deployed in all 175 patients [100%; median age 68 years, female 84/175 (48.0%)]. The 3 most common causes for NICU admission were intracranial hemorrhage (66/175, 37.7%), ischemic stroke (62/175, 35.4%), and traumatic brain injury (16/175, 9.1%). Deep vein thrombosis and pulmonary embolism (PE) were confirmed in 155 (88.6%) and 35 (20.0%) patients at the time of filter placement, respectively. Primary outcomes of interest were postfilter placement PE, filter retrieval, and inhospital mortality. Baseline characteristics were analyzed using t-tests and chi-squared test for continuous and noncontinuous variables, respectively. Factors associated with primary outcomes were analyzed with a logistic regression model.

RESULTS

Post-IVCF PE occurred in 3 patients (1.7%) with a median follow-up of 3 months. Excluding 26 inhospital deaths (14.9%, none was related to PE), filters were retrieved in 31 discharged patients (20.8%) with a median filter dwelling time of 9 months. Advanced filter retrieval required a higher fluoroscopy time (median 3.3 minutes vs 8.3 minutes, p = 0.016) and contrast volume use (median 35.0 ml vs 57.5 ml, p = 0.0028) than standard technique. No procedure-related complication occurred during filter placement and retrieval. Sequential Organ Failure Assessment (SOFA, p = 0.012) and Simplified Acute Physiology Scores (SAPS, p = 0.016) were independently associated with inhospital mortality. Modified Rankin Score (mRS) at discharge was an independent predictor for filter retrieval (p < 0.001).

CONCLUSION

Despite safety and effectiveness, IVCF retrieval rate for NICU patients was low, particularly those with worse mRS at time of hospital discharge. Worse SOFA and SAPS scores were associated with inhospital mortality.Clinical ImpactInferior vena cava filter (IVCF) is effective preventing post-filter pulmonary embolism (PE) in neurologic intensive care unit (NICU) patients, with only 1.7% experiencing PE post-placement, underscoring its role in managing venous thrombotic events in this high-risk population; however, the low retrieval rate of IVCFs, particularly in patients with poorer functional outcomes (worse mRS at discharge), and the association of higher SOFA and SAPS scores with increased inhospital mortality, emphasize the need for improved strategies to optimize filter retrieval and patient selection in critically ill neurologic patients.

Chronic, Shunt-Dependent Hydrocephalus in Aneurysmal Subarachnoid Hemorrhage: Incidence, Risk Factors, Clinical Phenotypes, and Outcome

OBJECTIVE

The main aim was to determine the incidence, risk factors, clinical phenotypes, and response to shunt surgery in chronic, shunt-dependent hydrocephalus (SDHC) after aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

In this observational, single-center study, 849 aSAH patients treated at Uppsala University Hospital between 2008-2018 were included. Variables on demography, injury severity, treatments, chronic hydrocephalus presentation, and outcome were evaluated.

RESULTS

In total, 107 (13%) patients were treated with a shunt due to SDHC. In multivariate logistic regressions, risk factors for SDHC were worse neurologic (World Federation of Neurosurgical Societies) grade, larger ventricles (Evans index) at admission, the need to insert an external ventricular drain (EVD), decompressive craniectomy, and complications with meningitis. Six different SDHC phenotypes were identified: impeded neurological recovery (55%), Hakim-Adams syndrome (17%), high-pressure symptoms (13%), failed EVD removal (8%), external brain herniation after decompressive craniectomy (DC; 6%), and subdural hygroma (1%). The former 3 groups significantly improved in modified Rankin Scale (mRS) and 87%-100% exhibited subjective symptomatic relief. There was no significant change in mRS for the latter 3 groups, but 60%-100% experienced some subjective relief postoperatively.

CONCLUSIONS

Chronic SDHC was a common complication after aSAH, particularly in patients with severe primary brain injury, acute hydrocephalus, and treatment-related factors. The condition presents with distinct clinical phenotypes, which may influence treatment response. Recognizing these phenotypes could aid in optimizing patient selection and expectations for shunt surgery outcomes.

Total bilirubin as a marker for hemolysis and outcome in patients with severe ARDS treated with veno-venous ECMO

BACKGROUND

Hemolysis is a common complication in critically ill patients with sepsis, acute respiratory distress syndrome (ARDS) or therapy with extracorporeal membrane oxygenation (ECMO). Heme degradation product bilirubin might accumulate in conditions of significant hemolysis. In patients with ARDS and therapy with veno-venous ECMO (vvECMO), the prognostic potential of elevated initial total bilirubin (tBili) was investigated.

METHODS

Retrospective analysis of patients with ARDS and vvECMO-therapy (n = 327) admitted to a tertiary ARDS center. A tBili cut-off value was determined by binary recursive partitioning. Baseline characteristics were compared and relevant variables were included in a multivariate logistic regression model with backward variable selection. Primary endpoint was survival within 28 days analyzed with Kaplan-Meier-curves and cox regression. Secondary endpoints included failure free composites for organ dysfunction, renal replacement therapy (RRT), vasopressor therapy and ECMO within 28 days and were compared using competing risk regression analysis.

RESULTS

A cut-off value of 3.6mg/dl divided the cohort for ICU mortality (tBili ≤ 3.6mg/dl: 46% (n = 273) vs. tBili > 3.6mg/dl: 78% (n = 54), p < 0.001). The group with tBili > 3.6mg/dl showed a higher 28-day mortality (HR 3.03 [95%CI 2.07-4.43], p < 0.001) and significantly lower chances of successful recovery from organ dysfunction (subdistribution hazard ratio (SHR) 0.29 [0.13-0.66], p < 0.001), RRT (SHR 0.34 [0.14-0.85], p = 0.02), and ECMO (SHR 0.46 [0.25-0.86], p = 0.015) compared to the group with tBili ≤ 3.6mg/dl. Recovery from vasopressor therapy did not differ between groups (SHR 0.63 [0.32-1.24], p = 0.18).

CONCLUSION

Patients with ARDS, vvECMO-therapy and tBili > 3.6mg/dl had a higher mortality and lower chances for recovery from organ dysfunction, RRT, and ECMO within 28 days. The tBili-cut-off value may be useful to identify patients at risk for unfavorable outcomes.

Comparative Analysis of 5 cmH₂O Versus 10 cmH₂O PEEP on Cerebral Oxygen Saturation in Brain Tumor Surgery: A Randomized Controlled Clinical Study

BACKGROUND The main concern regarding lung-protective ventilation strategies during neurosurgery is the reduction in venous return and increase in cerebral blood flow when using high positive end-expiratory pressure (PEEP). This study aimed to evaluate and compare the changes in regional cerebral oxygen saturations (rSO2) during the use of 5 cmH₂O and 10 cmH₂O PEEP in patients undergoing craniotomy for tumor resection. MATERIAL AND METHODS The study was designed as a prospective, single-blind randomized controlled study. Patients aged between 18 and 70 years, scheduled for an elective craniotomy for tumor resection, were divided into 2 groups: 5 cmH₂O PEEP (Group Low PEEP) and 10 cmH₂O PEEP (Group High PEEP). The PEEP was applied during general anesthesia, for controlled mechanical ventilation. The main outcome was the measurement of rSO2 before dura opening. Changes in rSO₂, hemodynamic parameters, and peripheral oxygen saturation (SpO₂) during different periods of surgery were compared between the groups. RESULTS Sixty-four patients were included. There were no significant differences between the 2 groups regarding demographic data. Mean arterial blood pressure and changes in SpO₂ were statistically similar in all periods between the groups (P=0.141 and P=0.081). When compared with the baseline value, SpO₂ increased significantly at all measurement times (P<0.05). No difference was observed in rSO₂ values compared with baseline rSO₂ values between the groups (P=0.218). CONCLUSIONS PEEP at the level of 10 cmH₂O can be safely applied during craniotomy without altering hemodynamics, and without causing a decrease in rSO₂.