Management of severe sepsis: advances, challenges, and current status

Platelet P2Y12 signalling pathway in the dysregulated immune response during sepsis

Sepsis is a complicated pathological condition in response to severe infection. It is characterized by a strong systemic inflammatory response, where multiple components of the immune system are involved. Currently, there is no treatment for sepsis. Blood platelets are known for their role in haemostasis, but they also participate in inflammation through cell-cell interaction and the secretion of inflammatory mediators. Interestingly, an increase in platelet activation, secretion, and aggregation with other immune cells (such as monocytes, T-lymphocytes and neutrophils) has been detected in septic patients. Therefore, antiplatelet therapy in terms of P2Y12 antagonists has been evaluated as a possible treatment for sepis. It was found that blocking P2Y12 receptors decreased platelet marker expression and limited attachment to immune cells in some studies, but not in others. This review addresses the role of platelets in sepsis and discusses whether antagonizing P2Y12 signalling pathways can alter the disease outcome. Challenges in studying P2Y12 antagonists in sepsis also are discussed. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.

Molecular antimicrobial susceptibility testing in sepsis

Rapidly detecting and identifying pathogens is crucial for appropriate antimicrobial therapy in patients with sepsis. Conventional diagnostic methods have been a great asset to medicine, though they are time consuming and labor intensive. This work will enable healthcare professionals to understand the bacterial community better and enhance their diagnostic capacity by using novel molecular methods that make obtaining quicker, more precise results possible. The authors discuss and critically assess the merits and drawbacks of molecular testing and the added value of these tests, including the shift turnaround time, the implication for clinicians' decisions, gaps in knowledge, future research directions and novel insights or innovations. The field of antimicrobial molecular testing has seen several novel insights and innovations to improve the diagnosis and management of infectious diseases.

Sepsis induced cardiotoxicity by promoting cardiomyocyte cuproptosis

BACKGROUND

Currently, sepsis induced cardiotoxicity is among the major causes of sepsis-related death. The specific molecular mechanisms of sepsis induced cardiotoxicity are currently unknown. Therefore, the purpose of this paper is to identify the key molecule mechanisms for sepsis induced cardiotoxicity.

METHODS

Original data of sepsis induced cardiotoxicity was derived from Gene Expression Omnibus (GEO; GSE63920; GSE44363; GSE159309) dataset. Functional enrichment analysis was used to analysis sepsis induced cardiotoxicity related signaling pathways. Our findings also have explored the relationship of cuproptosis and N6-Methyladenosine (m6A) in sepsis induced cardiotoxicity. Mice are randomly assigned to 3 groups: saline treatment control group, LPS group administered a single 5 mg/kg dose of LPS for 24 h, LPS + CD274 inhibitor group administered 10 mg/kg CD274 inhibitor for 24 h.

RESULTS

Overall, expression of cuproptosis-related genes (CRGs) CD274, Ceruloplasmin (CP), Vascular endothelial growth factor A (VEGFA), Copper chaperone for cytochrome c oxidase 11 (COX11), chemokine C-C motif ligand 8 (CCL8), Mitogen-activated protein kinase kinase 1(MAP2K1), Amine oxidase 3 (AOC3) were significantly altered in sepsis induced cardiotoxicity. The results of spearman correlation analysis was significant relationship between differentially regulated genes (DEGs) of CRGs and the expression level of m6A methylation genes. GO and KEGG showed that these genes were enriched in response to interferon-beta, MHC class I peptide loading complex, proteasome core complex, chemokine receptor binding, TAP binding, chemokine activity, cytokine activity and many more. These findings suggest that cuproptosis is strongly associated with sepsis induced cardiotoxicity.

CONCLUSION

In the present study, we found that cuproptosis were associated with sepsis induced cardiotoxicity. The CD274, CP, VEGFA, COX11, CCL8, MAP2K1, AOC3 genes are showing a significant difference expression in sepsis induced cardiotoxicity. Our studies have found significant correlations between CRGs and m6A methylation related genes in sepsis induced cardiotoxicity. These results provide insight into mechanism for sepsis induced cardiotoxicity.

Transcriptomics reveals shared immunosuppressive landscapes in ventilator-associated lower respiratory tract infections (VA-LRTI) patients

BACKGROUND

Ventilator-associated pneumonia (VAP) represents a transitory status of immunoparalysis, and we hypothesized that ventilator-associated tracheobronchitis (VAT) could share also some degree of immune response to a respiratory infection.

RESEARCH DESIGN AND METHODS

A prospective observational study in five medical ICUs to evaluate immunological alterations of patients with VA-LRTI. Immunological gene expression profiles in the blood using whole transcriptome microarrays in the first 24 hours following diagnosis. The area under the receiver operating characteristic curve (AUROC) was used to assess the accuracy of mRNA levels to differentiate VA-LRTI and lack of infection. A principal component analysis (PCA) was employed for analyzing the impact of each genetic expression footprint variable in explaining the variance of the cohort.

RESULTS

There was overlapping between the three classes of patients encompassing gene expression levels of 8 genes (i.e. HLA, IL2RA, CD40LG, ICOS, CCR7, CD1C, CD3E). HLA-DRA was equally low among VAT and VAP patients characterizing immune depression, and significantly lower than the control group.

CONCLUSIONS

Our findings suggest that VAP and VAT are not so different regarding gene expression levels suggesting a degree of immunosuppression. Our results indicate a state of immunoparalysis in respiratory infections in critically ill patients.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

PURPOSE

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and whilst European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

METHODS

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID), and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID, and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment, and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

BACKGROUND

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and while European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

MATERIALS AND METHODOLOGY

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

Berberine Alleviates Acute Lung Injury in Septic Mice by Modulating Treg/Th17 Homeostasis and Downregulating NF-κB Signaling

Purpose

A common complication of sepsis is acute lung injury (ALI), which is associated with an acute onset, rapid disease changes, and high mortality. Regulatory T (Treg) and T helper 17 (Th17) cells comprise CD4⁺ T cell subsets, which strongly influence inflammation during ALI. In this study, we investigated the effect of berberine (BBR), an antioxidant, anti-inflammatory, and immunomodulatory drug, on the inflammatory response and immune state in mice with sepsis.

Methods

A mouse model of cecal ligation and puncture (CLP) was established. The mice were intragastrically administered 50 mg/kg BBR. We used histological techniques to evaluate inflammatory tissue injury and flow cytometry for analyzing Treg/Th17 levels. We also assessed NF-κB signaling pathways by Western blotting assays and immunofluorescence staining. Enzyme-linked immunosorbent assay (ELISA) was performed to measure the content of cytokines.

Results

Treatment with BBR considerably mitigated lung injury while improving survival, post-cecal ligation, and puncture (CLP). Treatment with BBR ameliorated pulmonary edema and hypoxemia in septic mice and inhibited the NF-κB signaling pathway. BBR also increased Treg cells and decreased Th17 proportions in the spleen and lung tissue of CLP-treated mice. Blocking Treg cells weakened the protective effect of BBR on sepsis-associated lung injury.

Conclusion

Overall, these results suggested that BBR is a potential therapeutic agent for sepsis.

Sex-related differences in the response of anti-platelet drug therapies targeting purinergic signaling pathways in sepsis

Sepsis, a complex clinical syndrome resulting from a serious infection, is a major healthcare problem associated with high mortality. Sex-related differences in the immune response to sepsis have been proposed but the mechanism is still unknown. Purinergic signaling is a sex-specific regulatory mechanism in immune cell physiology. Our studies have shown that blocking the ADP-receptor P2Y12 but not P2Y1 receptor was protective in male mice during sepsis, but not female. We now hypothesize that there are sex-related differences in modulating P2Y12 or P2Y1 signaling pathways during sepsis. Male and female wild-type (WT), P2Y12 knock-out (KO), and P2Y1 KO mice underwent sham surgery or cecal ligation and puncture (CLP) to induce sepsis. The P2Y12 antagonist ticagrelor or the P2Y1 antagonist MRS2279 were administered intra-peritoneally after surgery to septic male and female mice. Blood, lungs and kidneys were collected 24 hours post-surgery. Sepsis-induced changes in platelet activation, secretion and platelet interaction with immune cells were measured by flow cytometry. Neutrophil infiltration in the lung and kidney was determined by a myeloperoxidase (MPO) colorimetric assay kit. Sepsis-induced platelet activation, secretion and aggregate formation were reduced in male CLP P2Y12 KO and in female CLP P2Y1 KO mice compared with their CLP WT counterpart. Sepsis-induced MPO activity was reduced in male CLP P2Y12 KO and CLP P2Y1 KO female mice. CLP males treated with ticagrelor or MRS2279 showed a decrease in sepsis-induced MPO levels in lung and kidneys, aggregate formation, and platelet activation as compared to untreated male CLP mice. There were no differences in platelet activation, aggregate formation, and neutrophil infiltration in lung and kidney between female CLP mice and female CLP mice treated with ticagrelor or MRS2279. In human T lymphocytes, blocking P2Y1 or P2Y12 alters cell growth and secretion in vitro in a sex-dependent manner, supporting the data obtained in mice. In conclusion, targeting purinergic signaling represents a promising therapy for sepsis but drug targeting purinergic signaling is sex-specific and needs to be investigated to determine sex-related targeted therapies in sepsis.

Therapeutic drug monitoring (TDM) in real-time: a need for the present future

Therapeutic drug monitoring (TDM) represents a real need for the present days. There is a huge amount of discussion around personalised medicine and probably this is very relevant in determining the right concentration of antibiotics in some populations. Patients with the most severe spectrum of infections, sepsis and septic shock, currently have wide variations on antibiotic concentrations. This is paramount in order to adequately treat patients with severe infection. In this editorial piece, we propose tools that help to cover the need of minimally invasive monitor of antibiotic concentrations.

The Effect of Mesenchymal Stromal Cells on the Mortality of Patients with Sepsis and Septic Shock: A Promising Therapy

Purpose

Sepsis and septic shock are the major causes of death in intensive care units. This study aimed to evaluate the clinical safety and efficacy of mesenchymal stem cells (MSCs) in sepsis and septic shock patients.

Methods

Ten patients were enrolled in the study. Adipose-derived MSC infusions were given (1 × 10⁶/kg, on the 1^st, 3^rd, 5^th, 7^th, and 9^th days of therapy) together with standard therapy. Before the MSC applications, blood samples were collected for cytokine assessment (TNF-α, IFN-γ, IL-2, IL-4, IL-6, IL-10). The clinical and laboratory improvements were recorded and compared with control groups selected retrospectively. The clinical trial was registered on 16.03.2022 with the registration number NCT05283317.

Results

In the study group, the ages of patients ranged from 22 to 68 years, and APACHE II scores ranged from 14 to 42. In the control group, ages ranged from 22 to 80 years and their APACHE II scores were between 14–35. The survival rate in the study group was 100% on the 14^th day whereas it was 70% on the 28^th day. A significant decrease in the SOFA score (adjusted), clinical, and laboratory improvements were observed during the MSC administration. However, no significant cytokine level changes were observed. In the control group, the survival rate of 20 patients was 70% on the 14^th day, whereas 60% was on the 28^th day. While deaths were observed in the control group in the first week of treatment, deaths in the MSCs group were observed between the 15^th and 28^th days.

Conclusion

MSCs treatment may have a positive impact on the survival rates of sepsis during the early phase. However, further randomized controlled studies with a large group of patients are needed. Trial Registration. This trial is registered with ClinicalTrials.gov Identifier: NCT05283317.

The Effect of Mesenchymal Stromal Cells on the Mortality of Patients with Sepsis and Septic Shock: A Promising Therapy

Purpose. Sepsis and septic shock are the major causes of death in intensive care units. This study aimed to evaluate the clinical safety and efficacy of mesenchymal stem cells (MSCs) in sepsis and septic shock patients. Methods. Ten patients were enrolled in the study. Adipose-derived MSC infusions were given (1 × 106/kg, on the 1st, 3rd, 5th, 7th, and 9th days of therapy) together with standard therapy. Before the MSC applications, blood samples were collected for cytokine assessment (TNF-α, IFN-γ, IL-2, IL-4, IL-6, IL-10). The clinical and laboratory improvements were recorded and compared with control groups selected retrospectively. The clinical trial was registered on 16.03.2022 with the registration number NCT05283317. Results. In the study group, the ages of patients ranged from 22 to 68 years, and APACHE II scores ranged from 14 to 42. In the control group, ages ranged from 22 to 80 years and their APACHE II scores were between 14–35. The survival rate in the study group was 100% on the 14th day whereas it was 70% on the 28th day. A significant decrease in the SOFA score (adjusted), clinical, and laboratory improvements were observed during the MSC administration. However, no significant cytokine level changes were observed. In the control group, the survival rate of 20 patients was 70% on the 14th day, whereas 60% was on the 28th day. While deaths were observed in the control group in the first week of treatment, deaths in the MSCs group were observed between the 15th and 28th days. Conclusion. MSCs treatment may have a positive impact on the survival rates of sepsis during the early phase. However, further randomized controlled studies with a large group of patients are needed. Trial Registration. This trial is registered with ClinicalTrials.gov Identifier: NCT05283317.

Diagnostic Value and Prognostic Evaluation of Autophagy-Related Protein Expression Level in Sepsis Complicated with Acute Respiratory Distress Syndrome

Objective. To explore the diagnostic value and prognostic evaluation of the autophagy-related protein expression level among patients with sepsis comorbid with acute respiratory distress syndrome. Methods. A total of 182 sepsis patients were admitted to Naval Medical Center from March 2016 to April 2020 and divided into the acute respiratory distress syndrome and non-ARDS groups. Immunoblotting was employed to identify the expression of autophagy-associated protein from participants’ peripheral blood mononuclear cells. Multivariate linear regression analysis was used to examine the association between mortality and the protein expression in sepsis complicated with acute respiratory distress syndrome. Results. Among the 182 patients with sepsis included in this study, 82 patients had acute respiratory distress syndrome and 100 patients did not have acute respiratory distress syndrome. We observed that microtubule-related protein 1A/1B LC3II, Beclin-1, RAB7, and LAMP2 protein expression was significantly decreased in septic patients with ARDS, and p62 was significantly increased. Further receiver operating characteristic curve analysis showed that autophagy-related proteins had a high recognition ability in sepsis complicated with acute respiratory distress syndrome. LAMP2 protein was the best among them, and its specificity was up to 91.46%. In this study, 38 of the 82 patients with sepsis complicated with acute respiratory distress syndrome died, with a mortality rate of 46.34%. We found that the autophagy level was further inhibited in the patients with death, LC3II, Beclin-1, and RAB7. However, the lysosomal-associated membrane protein 2 levels in the survival patients were remarkably higher than that in the dead patients. In addition, the p62 level was lower in survival patients as well. Our results indicated age and SOFA score were the independent risk factors for mortality in septic patients with acute respiratory distress syndrome. Conclusion. The autophagy level is significantly inhibited in septic patients with acute respiratory distress syndrome, and autophagy-associated proteins LC3II, Beclin-1, RAB7, LAMP2, and p62 have good value for the diagnosis and prognosis evaluation of sepsis comorbid with acute respiratory distress syndrome.

Development of Loop-Mediated Isothermal Amplification Rapid Diagnostic Assays for the Detection of Klebsiella pneumoniae and Carbapenemase Genes in Clinical Samples

Klebsiella pneumoniae is an important pathogenic bacterium commonly associated with human healthcare and community-acquired infections. In recent years, K. pneumoniae has become a significant threat to global public and veterinary health, because of its high rates of antimicrobial resistance (AMR). Early diagnosis of K. pneumoniae infection and detection of any associated AMR would help to accelerate directed therapy and reduce the risk of the emergence of multidrug-resistant isolates. In this study, we identified three target genes (yhaI, epsL, and xcpW) common to K. pneumoniae isolates from both China and Europe and designed loop-mediated isothermal amplification (LAMP) assays for the detection of K. pneumoniae in clinical samples. We also designed LAMP assays for the detection of five AMR genes commonly associated with K. pneumoniae. The LAMP assays were validated on a total of 319 type reference strains and clinical isolates of diverse genetic backgrounds, in addition to 40 clinical human sputum samples, and were shown to be reliable, highly specific, and sensitive. For the K. pneumoniae–specific LAMP assay, the calculated sensitivity, specificity, and positive and negative predictive values (comparison with culture and matrix-assisted laser desorption/ionization–time of flight mass spectrometry) were all 100% on clinical isolates and, respectively, of 100%, 91%, and 90%, and 100% when tested on clinical sputum samples, while being significantly faster than the reference methods. For the bla_KPC and other carbapenemases’ LAMP assays, the concordance between the LAMP results and the references methods (susceptibility tests) was 100%, on both pure cultures (n = 125) and clinical samples (n = 18). In conclusion, we developed highly sensitive and specific LAMP assays for the clinical identification of K. pneumoniae and detection of carbapenem resistance.

Apoptotic Cells for Therapeutic Use in Cytokine Storm Associated With Sepsis- A Phase Ib Clinical Trial

Background

Sepsis has no proven specific pharmacologic treatment and reported mortality ranges from 30%–45%. The primary aim of this phase IB study was to determine the safety profile of Allocetra™-OTS (early apoptotic cell) infusion in subjects presenting to the emergency room with sepsis. The secondary aims were to measure organ dysfunction, intensive care unit (ICU) and hospital stays, and mortality. Exploratory endpoints included measuring immune modulator agents to elucidate the mechanism of action.

Methods

Ten patients presenting to the emergency room at the Hadassah Medical Center with sepsis were enrolled in this phase Ib clinical study. Enrolled patients were males and females aged 51–83 years, who had a Sequential Organ Failure Assessment (SOFA) score ≥2 above baseline and were septic due to presumed infection. Allocetra™-OTS was administered as a single dose (day +1) or in two doses of 140×10⁶ cells/kg on (day +1 and +3), following initiation of standard-of-care (SOC) treatment for septic patients. Safety was evaluated by serious adverse events (SAEs) and adverse events (AEs). Organ dysfunction, ICU and hospital stays, and mortality, were compared to historical controls. Immune modulator agents were measured using Luminex^® multiplex analysis.

Results

All 10 patients had mild-to-moderate sepsis with SOFA scores ranging from 2–6 upon entering the study. No SAEs and no related AEs were reported. All 10 study subjects survived, while matched historical controls had a mortality rate of 27%. The study subjects exhibited rapid resolution of organ dysfunction and had significantly shorter ICU stays compared to matched historical controls (p<0.0001). All patients had both elevated pro- and anti-inflammatory cytokines, chemokines, and additional immune modulators that gradually decreased following treatment.

Conclusion

Administration of apoptotic cells to patients with mild-to-moderate sepsis was safe and had a significant immuno-modulating effect, leading to early resolution of the cytokine storm.

Clinical Trial Registration

ClinicalTrials.gov Identifier: NCT03925857. (https://clinicaltrials.gov/ct2/show/study/NCT03925857).

Multifunctional and Self-Healable Intelligent Hydrogels for Cancer Drug Delivery and Promoting Tissue Regeneration In Vivo

Regenerative medicine seeks to assess how materials fundamentally affect cellular functions to improve retaining, restoring, and revitalizing damaged tissues and cancer therapy. As potential candidates in regenerative medicine, hydrogels have attracted much attention due to mimicking of native cell-extracellular matrix (ECM) in cell biology, tissue engineering, and drug screening over the past two decades. In addition, hydrogels with a high capacity for drug loading and sustained release profile are applicable in drug delivery systems. Recently, self-healing supramolecular hydrogels, as a novel class of biomaterials, are being used in preclinical trials with benefits such as biocompatibility, native tissue mimicry, and injectability via a reversible crosslink. Meanwhile, the localized therapeutics agent delivery is beneficial due to the ability to deliver more doses of therapeutic agents to the targeted site and the ability to overcome post-surgical complications, inflammation, and infections. These highly potential materials can help address the limitations of current drug delivery systems and the high clinical demand for customized drug release systems. To this aim, the current review presents the state-of-the-art progress of multifunctional and self-healable hydrogels for a broad range of applications in cancer therapy, tissue engineering, and regenerative medicine.

Diagnostic value of combined detection of IL-1β, IL-6, and TNF-α for sepsis-induced cardiomyopathy

INTRODUCTION

This study aimed to explore the diagnostic value and the correlation of the combined detection of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) with sepsis-induced cardiomyopathy (SIC).

PATIENTS AND METHODS

Admitted to our hospital from January 2017 to January 2019, 96 patients with SIC (a study group) and 90 patients with sepsis (a control group) were enrolled. The three cytokines were determined and the diagnostic value of their combined detection for SIC was analyzed.

RESULTS

The cytokines were remarkably higher in the study group (p<.001). The combined detection of the three had a better diagnostic value for SIC (p<.001). The three cytokines were independent risk factors for the death of patients with SIC.

CONCLUSION

IL-1β, IL-6, and TNF-α in SIC patients rise markedly. The combined detection of the three has a better predictive value for patients with SIC and is closely related to the patients' prognoses, so it may be crucial in diagnosing and treating the disease.

β-Sitosterol Alters the Inflammatory Response in CLP Rat Model of Sepsis by Modulation of NFκB Signaling

Purpose

Sepsis originates from the host inflammatory response, especially to bacterial infections, and is considered one of the main causes of death in intensive care units. Various agents have been developed to inhibit mediators of the inflammatory response; one prospective agent is β-sitosterol (βS), a phytosterol with a structure similar to cholesterol. This study is aimed at evaluating the effects of βS on the biomarkers of inflammation and liver function in cecal ligation and puncture- (CLP-) induced septic rats.

Methods

Thirty male Wistar rats were divided equally into six groups as follows: sham, CLP, CLP+dexamethasone (DX, 0.2 mg/kg), CLP+βS (1 mg/kg), CLP+imipenem (IMI, 20 mg/kg), and CLP+IMI (20 mg/kg)+βS (1 mg/kg). Serum levels of IL-1β, IL-6, IL-10, AST, ALT, and liver glutathione (GSH) were assessed by ELISA. Liver expression levels of TNF-α and NF-κBi mRNAs were evaluated by RT-qPCR.

Results

Serum concentrations of IL-1β, IL-6, IL-10, ALT, and AST and mRNA levels of TNF-α and NF-κBi were all significantly higher in septic rats than in normal rats (p < 0.05). Liver GSH content was markedly lower in the CLP group than that in the sham group. βS-treated rats had remarkably lower levels of IL-1β, IL-6, IL-10, TNF-α, NF-κBi, AST, and ALT (51.79%, 62.63%, 41.46%, 54.35%, 94.37%, 95.30%, 34.87%, and 46.53% lower, respectively) and greater liver GSH content (35.71% greater) compared to the CLP group (p < 0.05).

Conclusion

βS may play a protective role in the septic process by mitigating inflammation. This effect is at least partly mediated by inhibition of the NF-κB signaling pathway. Thus, βS can be considered as a supplementary treatment in septic patients.

Roflumilast as a Potential Therapeutic Agent for Cecal Ligation and Puncture-Induced Septic Lung Injury

PURPOSE/AIMS

This study focused on delineating the possible effects of roflumilast (ROF), a selective phosphodiesterase 4 (PDE4) inhibitor, in rats with cecal ligation and puncture (CLP)-induced polymicrobial sepsis, and investigated whether ROF can act as a protective agent in sepsis-induced lung damage.

MATERIAL AND METHODS

Four experimental groups were organized, each comprising eight rats: Control, Sepsis, Sepsis + ROF 0.5 mgkg^-1, and Sepsis + ROF 1 mgkg^-1 groups. A polymicrobial sepsis model was induced in the rats by cecal ligation and puncture under anesthesia. Twelve hours after sepsis induction, the lungs were obtained for biochemical, molecular, and histopathological analyses.

RESULTS

In the sepsis group's lungs, the TNF-α, IL-1β, and IL-6 mRNA expression levels peaked in the sepsis group's lung tissues, and ROF significantly decreased these levels compared with the sepsis group dose-dependently. ROF also significantly decreased MDA levels in septic lungs and increased antioxidant parameters (SOD and GSH) compared with the sepsis group. Histopathological analysis results supported biochemical and molecular results.

CONCLUSIONS

ROF, a PDE4 inhibitor, suppressed the expression levels of pro-inflammatory cytokines, alleviated lung damage (probably by blocking neutrophil infiltration), and increased the capacity of the antioxidant system.

Enhancement in Performance of Septic Shock Prediction Using National Early Warning Score, Initial Triage Information, and Machine Learning Analysis

BACKGROUND

Several studies reported that the National Early Warning Score (NEWS) has shown superiority over other screening tools in discriminating emergency department (ED) patients who are likely to progress to septic shock.

OBJECTIVES

To improve the performance of the NEWS for septic shock prediction by adding variables collected during ED triage, and to implement a machine-learning algorithm.

METHODS

The study population comprised adult ED patients with suspected infection. To detect septic shock within 24 h after ED arrival, the Sepsis-3 clinical criteria and nine variables were used: NEWS, age, gender, systolic blood pressure, diastolic blood pressure, pulse rate, respiratory rate, body temperature, and oxygen saturation. The model was developed using logistic regression (LR), extreme gradient boosting (XGB), and artificial neural network (ANN) algorithms. The evaluations were performed using an area under the receiver operating characteristic curve (AUROC), Hosmer-Lemeshow test, and net reclassification index (NRI).

RESULTS

Overall, 41,687 patients were enrolled. The AUROC of the model with NEWS, age, gender, and the six vital signs (0.835-0.845) was better than that of the baseline model (0.804). The XGB model (AUROC 0.845) was the most accurate, compared with LR (0.844) and ANN (0.835). The LR and XGB models were well calibrated; however, the ANN showed poor calibration power. The LR and XGB models showed better reclassification than the baseline model with positive NRI.

CONCLUSION

The discrimination power of the model for screening septic shock using NEWS, age, gender, and the six vital signs collected at ED triage outperformed the baseline NEWS model.

Advances in sepsis diagnosis and management: a paradigm shift towards nanotechnology

Sepsis, a dysregulated immune response due to life-threatening organ dysfunction, caused by drug-resistant pathogens, is a major global health threat contributing to high disease burden. Clinical outcomes in sepsis depend on timely diagnosis and appropriate early therapeutic intervention. There is a growing interest in the evaluation of nanotechnology-based solutions for sepsis management due to the inherent and unique properties of these nano-sized systems. This review presents recent advancements in nanotechnology-based solutions for sepsis diagnosis and management. Development of nanosensors based on electrochemical, immunological or magnetic principals provide highly sensitive, selective and rapid detection of sepsis biomarkers such as procalcitonin and C-reactive protein and are reviewed extensively. Nanoparticle-based drug delivery of antibiotics in sepsis models have shown promising results in combating drug resistance. Surface functionalization with antimicrobial peptides further enhances efficacy by targeting pathogens or specific microenvironments. Various strategies in nanoformulations have demonstrated the ability to deliver antibiotics and anti-inflammatory agents, simultaneously, have been reviewed. The critical role of nanoformulations of other adjuvant therapies including antioxidant, antitoxins and extracorporeal blood purification in sepsis management are also highlighted. Nanodiagnostics and nanotherapeutics in sepsis have enormous potential and provide new perspectives in sepsis management, supported by promising future biomedical applications included in the review.

P2Y12 antagonism results in altered interactions between platelets and regulatory T cells during sepsis

Sepsis is a complex clinical condition resulting from a serious bloodstream infection. With mortality rates as high as 50%, improved treatments are needed. Regulatory T cells (Tregs), a subset of T lymphocytes, promote the resolution of inflammation. Septic patients have elevated levels of circulating Tregs. Platelets influence the proliferation and activation of Tregs in vitro. However, modulating platelet-Tregs interaction during sepsis may restraing Treg proliferation, leading to the restoration of immunologic homeostasis. P2Y₁₂ is a purinergic receptor present on platelets and T lymphocytes. Blocking P2Y₁₂ improves the outcome of sepsis. We investigated whether blocking P2Y₁₂ alters platelet-Treg interaction in vivo. We used the murine model of sepsis, cecal ligation, and puncture (CLP) and we blocked P2Y₁₂ using the P2Y₁₂ antagonist, clopidogrel. Twenty-four hours after surgery, we measured Treg population sizes in the spleens of the Sham, CLP, and CLP + clopidogrel groups. We investigated the effect of blocking P2Y₁₂ in vitro using cocultures of human platelets and T cells with or without anti-CD3/CD28. P2Y₁₂ was blocked using AR-C69931MX. Treg population sizes were reduced in the septic mice treated with clopidogrel compared with untreated septic mice. Aggregation of platelets and CD4⁺ T cells was reduced in treated CLP mice compared with untreated CLP mice. P2Y₁₂ antagonism changes how platelets influence T cells in vitro, depending on T-cell activation. In conclusion, blockade of the P2Y₁₂ signaling pathway restrains Treg proliferation in vivo and in vitro. Targeting platelets to control Treg proliferation and activity may be a promising strategy for treating sepsis.

Bakuchiol from Psoralea corylifolia L. Ameliorates acute kidney injury and improves survival in experimental polymicrobial sepsis

Bakuchiol (BAK) is a prenylated phenolic mono-terpene extracted from the fruit of Psoralea corylifolia L., which exerts a protective effect on organs. However, whether BAK has a protective effect on sepsis-induced acute kidney injury (S-AKI) is not clear. In our study we have demonstrated for the first time that pretreatment with BAK significantly reduced bacterial load, inflammation and renal oxidative stress in caecal ligation and puncture (CLP)-induced sepsis. Moreover, CLP-induced renal histological damage, mortality and clinical signs were markedly attenuated by BAK. Additionally, BAK inhibited sepsis-induced activation of NF-κB and p38 MAPK signaling in the kidneys. The evidence presented here has confirmed that BAK exerts multifunctional activity in protection against S-AKI. This action of BAK is probably due to the blockade of the NF-κB and p38 MAPK signaling pathways. Our findings offer a novel potential for BAK in protection against sepsis and S-AKI.

Spectral clustering of risk score trajectories stratifies sepsis patients by clinical outcome and interventions received

Sepsis is not a monolithic disease, but a loose collection of symptoms with diverse outcomes. Thus, stratification and subtyping of sepsis patients is of great importance. We examine the temporal evolution of patient state using our previously-published method for computing risk of transition from sepsis into septic shock. Risk trajectories diverge into four clusters following early prediction of septic shock, stratifying by outcome: the highest-risk and lowest-risk groups have a 76.5% and 10.4% prevalence of septic shock, and 43% and 18% mortality, respectively. These clusters differ also in treatments received and median time to shock onset. Analyses reveal the existence of a rapid (30–60 min) transition in risk at the time of threshold crossing. We hypothesize that this transition occurs as a result of the failure of compensatory biological systems to cope with infection, resulting in a bifurcation of low to high risk. Such a collapse, we believe, represents the true onset of septic shock. Thus, this rapid elevation in risk represents a potential new data-driven definition of septic shock.

Studies on the effects of bone marrow stem cells on mitochondrial function and the alleviation of ARDS

Mesenchymal stem cells (MSCs) can alleviate acute respiratory distress syndrome (ARDS), but the mechanisms involved are unclear, especially about their specific effects on cellular mitochondrial respiratory function. Thirty mice were allocated into the Control, LPS, and LPS + Bone marrow mesenchymal stem cell (BMSC) group (n = 10/group). Mouse alveolar epithelial cells (MLE-12) and macrophage cells (RAW264.7) were divided into the same groups. Pathological variation, inflammation-related factors, reactive oxygen species (ROS), ATP levels, and oxygen consumption rate (OCR) were analyzed. Pathologic features of ARDS were observed in the LPS group and were significantly alleviated by BMSCs. The trend in inflammation-related factors among the three groups was the LPS group > LPS + BMSC group > Control group. In the MLE-12 co-culture system, IL-6 was increased in the LPS group but not significantly reduced in the LPS + BMSC group. In the RAW264.7 co-culture system, IL-1β, TNF-α, and IL-10 levels were all increased in the LPS group, IL-1β and TNF-α levels were reduced by BMSCs, while IL-10 level kept increasing. ROS and ATP levels were increased and decreased respectively in both MLE-12 and RAW264.7 cells in the LPS groups but reversed by BMSCs. Basal OCR, ATP-linked OCR, and maximal OCR were lower in the LPS groups. Impaired basal OCR and ATP-linked OCR in MLE-12 cells were partially restored by BMSCs, while impaired basal OCR and maximal OCR in RAW264.7 cells were restored by BMSCs. BMSCs improved the mitochondrial respiration dysfunction of macrophages and alveolar epithelial cells induced by LPS, alleviated lung tissue injury, and inflammatory response in a mouse model of ARDS.

Overexpression of TGFβ1 in murine mesenchymal stem cells improves lung inflammation by impacting the Th17/Treg balance in LPS-induced ARDS mice

Background

T helper 17 cells (Th17)/regulatory T cells (Treg), as subtypes of CD4⁺ T cells, play an important role in the inflammatory response of acute respiratory distress syndrome (ARDS). However, there is still a lack of effective methods to regulate the differentiation balance of Th17/Treg. It was proven that mesenchymal stem cells (MSCs) could regulate the differentiation of CD4⁺ T cells, but the mechanism is still unclear. TGFβ1, a paracrine cytokine of MSCs, could also regulate the differentiation of Th17/Treg but is lowly expressed in MSCs. Therefore, mouse MSCs (mMSCs) overexpressing TGFβ1 were constructed by lentivirus transduction and intratracheally transplanted into LPS-induced ARDS mice in our study. The aim of this study was to evaluate the therapeutic effects of mMSCs overexpressing TGFβ1 on inflammation and immunoregulation by impacting the Th17/Treg balance in LPS-induced ARDS mice.

Methods

mMSCs overexpressing TGFβ1 were constructed using lentiviral vectors. Then, mouse bone-marrow-derived MSCs (mBM-MSC) and mBM-MSC-TGFβ1 (mBM-MSC overexpressing TGFβ1) were transplanted intratracheally into ARDS mice induced by lipopolysaccharide. At 3 and 7 days after transplantation, the mice were sacrificed, and the homing of the mMSCs was assayed by ex vivo optical imaging. The relative numbers of Th17 and Treg in the lungs and spleens of mice were detected by FCM. IL-17A and IL-10 levels in the lungs of mice were analysed by western blot. Permeability and inflammatory cytokines were evaluated by analysing the protein concentration of BALF using ELISA. Histopathology of the lungs was assessed by haematoxylin and eosin staining and lung injury scoring. Alveolar lung fibrosis was assessed by Masson’s trichrome staining and Ashcroft scoring. The mortality of ARDS mice was followed until 7 days after transplantation.

Results

The transduction efficiencies mediated by the lentiviral vectors ranged from 82.3 to 88.6%. Overexpressing TGFβ1 inhibited the proliferation of mMSCs during days 5–7 (p < 0.05) but had no effect on mMSC differentiation or migration (p > 0.05). Compared to that in the LPS + mBM-MSC-NC group mice, engraftment of mMSCs overexpressing TGFβ1 led to much more differentiation of T cells into Th17 or Treg (p < 0.05), improved permeability of injured lungs (p < 0.05) and ameliorative histopathology of lung tissue in ARDS mice (p < 0.05). Moreover, IL-17A content was also decreased while IL-10 content was increased in the LPS + mBM-MSC-TGFβ1 group compared with those in the LPS + mBM-MSC-NC group (p < 0.05). Finally, mMSCs overexpressing TGFβ1 did not aggravate lung fibrosis in ARDS mice (p > 0.05).

Conclusion

MSCs overexpressing TGFβ1 could regulate lung inflammation and attenuate lung injuries by modulating the imbalance of Th17/Treg in the lungs of ARDS mice.

Apoptotic cell therapy for cytokine storm associated with acute severe sepsis

Sepsis has no proven pharmacologic treatment other than appropriate antibiotic agents, fluids, vasopressors as needed, and possibly corticosteroids. It is generally initiated mainly by the simultaneous recognition by various components of the innate immune system of either pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs). In the current study, we employed the murine cecal ligation and puncture (CLP) model for sepsis to evaluate the effect of post-CLP infusion of apoptotic cells (Allocetra-OTS) on a CLP severe sepsis model. Cardiovascular evaluation, acute kidney injury (AKI), acute liver injury (ALI), and hematological and metabolic function were evaluated. Cytokine and chemokine profiles were measured by Multiplex ELISA and mitochondrial function, and glycolysis by Seahorse. The Murine Sepsis Score (MSS) was used for disease severity definition. CLP mice had low blood pressure, poor cardiac output, and lung dysfunction, as well as AKI, ALI, and thrombocytopenia, which correlated with the MSS and corresponded to a cytokine/chemokine storm. Apoptotic cell administration markedly improved the cytokine and chemokine storm and restored the impaired mitochondrial and glycolytic function in white blood cells leading to increased survival, from 6 to 60% (P < 0.0001), together with a significant improvement in organ dysfunction. We conclude that the deleterious immune response in CLP-induced sepsis can be successfully modified by apoptotic cell infusion.

Epidemiology, management and costs of sepsis in Spain (2008-2017): a retrospective multicentre study

Objective: To update the profile of patients attended with sepsis in specialised care centres in Spain, to analyse in-hospital mortality, disease management and costs between 2008 and 2017.Methods: Admission records registered between 1 January 2008 and 31 December 2017 obtained from a Spanish National hospital discharge database for public and private hospitals. Centres are responsible for data codification, evaluation and confidentiality. The database is validated internally and is subjected to periodic audits. Files corresponding to patients with sepsis and septic shock were selected by means of the International Statistical Classification of Diseases and Related Health Problems, 9th version and 10th version codes. These criteria claimed 311,674 records of 288,211 patients. Direct medical costs of secondary healthcare include expenses derived from the admission: examination, medication, treatment and costs of nutrition, personnel, medical equipment and resources.Results: More than 53% of all patients were males, with a mean age of 73.0 years. Fifty-one percent of the identified admissions were due to a sepsis without organ dysfunction, 21.5% to sepsis with organ dysfunction, and 27.3% registered a septic shock. The incidence of sepsis increased 2.7 times between 2008 and 2017, reaching a hospital incidence of 5.7 per 10,000 inhabitants in 2017. Case fatality rate (CFR) was 23.2% and 35.0% in patients without and with organ dysfunction in 2017, respectively, and 42.9% in patient with septic shock, decreasing over time. Mean annual direct medical costs of specialised care over the study period were €6664 and €8084 per patient in patients with sepsis without and with organ dysfunction, respectively, and €11,359 per patient in those with septic shock.Conclusions: The social and economic burden of sepsis in Spain continues to grow (incidence, total costs). Despite its general decreasing trend, CFR remains elevated, thus, patients could benefit from further research and protocol revision.

Natural Language Processing of Clinical Notes for Improved Early Prediction of Septic Shock in the ICU

Sepsis and septic shock are major concerns in public health as the leading contributors to hospital mortality and cost of treatment in the United States. Early treatment is instrumental for improving patient outcome; to this end, algorithmic methods for early prediction of septic shock have been developed using electronic health record data, with the goal of decreasing treatment delay. We extend a previously-developed method, using a gradient boosting algorithm (XG-Boost) to compute a time-evolving risk of impending transition into septic shock, by combining physiological data from the electronic health record with features obtained from natural language processing of clinical note data. We compare two different methods for generating natural language processing features, with the best method obtaining improved performance of 0.92 AUC, 84% sensitivity, 82% specificity, 49% positive predictive value, and a median early warning time of 7.0 hours. This degree of early warning is sufficient to enable intervention many hours in advance of septic shock onset, with the improved prediction performance of this method resulting in fewer false alarms and thus more actionable predictions.

Quality improvement model (IHI) as a strategy to implement a sepsis protocol in a public hospital in Brazil

A major challenge for hospitals in low-income and middle-income countries is to improve management of patients diagnosed with sepsis. The objective of the present study was to evaluate the Institute for Healthcare Improvement (IHI) Model as a strategy to implement a managed sepsis protocol aimed at reducing sepsis mortality. We performed a longitudinal, prospective, non-randomised study using PDSA cycles for translating and implementing improvement actions and tools. Baseline case mortality/case fatality data were collected, and compliance rates were evaluated according to the Surviving Sepsis Campaign guidelines (3-hour care-bundle). Sepsis multidisciplinary work teams were designated and were responsible to develop Driver Diagrams and implement process changes in the intensive care unit, wards and emergency department. Satisfaction levels of healthcare professionals were assessed (balance variables). The study was carried out in a public quaternary hospital, in São Paulo city, Brazil (Hospital Municipal da Vila Santa Catarina). The number of patients with sepsis studied was 416 who were followed over a 15-month period. The data analyses were carried out by statistical process control. Case fatality rates were kept below a prespecified target of 25% (15.9%) during the period. Satisfaction level of the participating staff was high (95.2%) and 71% of participants reported no work overload. The IHI model was found to be a feasible and useful strategy for implementing a sepsis management clinical protocol.

Hemofiltration in Patients with Severe Acute Pancreatitis (Review)

Questions regarding the application of extracorporeal detoxification to patients with severe acute pancreatitis have been considered. Hemodialysis, the historically first method of extracorporeal detoxification for such patients, has been also described in the review. Appropriateness of using renal replacement therapy methods and among them continued renal replacement therapy has been shown. Hemofiltration and hemodiafiltration technologies are described in detail including different modes of their application and the possibility of using various types of filters. Available data on hemofiltration for patients with severe acute pancreatitis have been analyzed. Great attention is paid to the unsolved aspects of hemofiltration in severe acute pancreatitis such as determining renal and extrarenal indices; time of starting hemofiltration; selection of volume replacement modes and a buffer system; procedure duration; anticoagulation measures, defining criteria to assess the adequacy of hemofiltration, state severity, and organ dysfunction degree. Further multicenter investigations are necessary to be able to assess the efficacy of the hemofiltration procedures on the basis of the thoroughly worked out and pathogenically grounded protocol using adequate control methods taking into consideration endogenic intoxication phases and intensity of the multiple organ failure syndrome.

Sepsis in the Context of Nonventilator Hospital-Acquired Pneumonia

BACKGROUND

Sepsis is a leading cause of mortality among hospitalized patients and is the most expensive condition affecting the US health care system. Pneumonia is associated with about half of sepsis cases, yet limited research has described the incidence of sepsis in the context of nonventilator hospital-acquired pneumonia (NV-HAP). Persons with NV-HAP who are at risk for sepsis must be identified so that interventions to reduce the burden of NV-HAP and improve outcomes among patients with sepsis can be designed.

OBJECTIVE

To determine the proportion of persons with NV-HAP in whom sepsis develops and to describe the demographic and clinical characteristics of persons with NV-HAP in whom sepsis develops.

METHODS

In this retrospective, population-based study, data were extracted from the National Inpatient Sample from the 2012 Healthcare Cost and Utilization Project dataset. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify adult patients at least 18 years of age who had a stay of at least 48 hours, had no documented diagnosis of ventilator-associated pneumonia, and had secondary diagnoses of both NV-HAP and sepsis, neither of which was present on admission.

RESULTS

In the 2012 calendar year, 119 075 adults had NV-HAP develop; sepsis developed in 36.3% of these cases. Male and black patients were overrepresented in the sample, and patients had a mean of 7 comorbid conditions (SD, 3.3).

CONCLUSIONS

Sepsis in the context of NV-HAP is a key concern. Additional research is needed to identify factors associated with the development of sepsis among patients with NV-HAP.

Prediction of presepsin concentrations through commensurate decline in kidney function in the elderly

BACKGROUND

Presepsin is a useful biomarker to diagnose sepsis. However, the correlation between plasma presepsin concentrations and kidney function in the elderly with chronic kidney disease (CKD) remains to be elucidated. We determined whether plasma presepsin concentrations were influenced by kidney function decline in the elderly.

METHODS

One hundred seventy outpatients with CKD aged ≥65 y were enrolled. Plasma presepsin concentrations were measured using immunoassay analysis. The relationship between plasma presepsin concentration and kidney function was assessed.

RESULTS

The median age of patients of this cohort was 778 (72-85) y and the mean estimated glomerular filtration rate was 51.8 ± 28.1 ml/min/1.73 m². Plasma presepsin concentrations in those with CKD G4-G5 (362 pg/ml [273-553]) were significantly higher than in those with CKD G1-G2 (111 pg/ml [91-113]) and CKD G3 (145 pg/ml [124-205]) (p < 0.001, p < 0.001, respectively). A high correlation between plasma presepsin concentrations and kidney function was observed (R² = 0.733, p < 0.001). Even after adjusting for confounders, plasma presepsin concentrations were independently associated with kidney function.

CONCLUSIONS

Increases in plasma presepsin concentrations were exponentially correlated to kidney function decline in the elderly with CKD.

Ventilator-Associated Pneumonia and PaO2/FIO2 Diagnostic Accuracy: Changing the Paradigm?

Background: Ventilator-associated pneumonia (VAP) is associated to longer stay and poor outcomes. Lacking definitive diagnostic criteria, worsening gas exchange assessed by PaO₂/F_IO₂ ≤ 240 in mmHg has been proposed as one of the diagnostic criteria for VAP. We aim to assess the adequacy of PaO₂/F_IO₂ ≤ 240 to diagnose VAP. Methods: Prospective observational study in 255 consecutive patients with suspected VAP, clustered according to PaO₂/F_IO₂ ≤ 240 vs. > 240 at pneumonia onset. The primary analysis was the association between PaO₂/F_IO₂ ≤ 240 and quantitative microbiologic confirmation of pneumonia, the most reliable diagnostic gold-standard. Results: Mean PaO₂/F_IO₂ at VAP onset was 195 ± 82; 171 (67%) cases had PaO₂/F_IO₂ ≤ 240. Patients with PaO₂/F_IO₂ ≤ 240 had a lower APACHE-II score at ICU admission; however, at pneumonia onset they had higher CPIS, SOFA score, acute respiratory distress syndrome criteria and incidence of shock, and less microbiological confirmation of pneumonia (117, 69% vs. 71, 85%, p = 0.008), compared to patients with PaO₂/FIO₂ > 240. In multivariate logistic regression, PaO₂/FIO₂ ≤ 240 was independently associated with less microbiological confirmation (adjusted odds-ratio 0.37, 95% confidence interval 0.15–0.89, p = 0.027). The association between PaO₂/F_IO₂ and microbiological confirmation of VAP was poor, with an area under the ROC curve 0.645. Initial non-response to treatment and length of stay were similar between both groups, while hospital mortality was higher in patients with PaO₂/F_IO₂ ≤ 240. Conclusion: Adding PaO₂/F_IO₂ ratio ≤ 240 to the clinical and radiographic criteria does not help in the diagnosis of VAP. PaO₂/F_IO₂ ratio > 240 does not exclude this infection. Using this threshold may underestimate the incidence of VAP.

Influenza and associated co-infections in critically ill immunosuppressed patients

BACKGROUND

It is unclear whether influenza infection and associated co-infection are associated with patient-important outcomes in critically ill immunocompromised patients with acute respiratory failure.

METHODS

Preplanned secondary analysis of EFRAIM, a prospective cohort study of 68 hospitals in 16 countries. We included 1611 patients aged 18 years or older with non-AIDS-related immunocompromise, who were admitted to the ICU with acute hypoxemic respiratory failure. The main exposure of interest was influenza infection status. The primary outcome of interest was all-cause hospital mortality, and secondary outcomes ICU length of stay (LOS) and 90-day mortality.

RESULTS

Influenza infection status was categorized into four groups: patients with influenza alone (n = 95, 5.8%), patients with influenza plus pulmonary co-infection (n = 58, 3.6%), patients with non-influenza pulmonary infection (n = 820, 50.9%), and patients without pulmonary infection (n = 638, 39.6%). Influenza infection status was associated with a requirement for intubation and with LOS in ICU (P < 0.001). Patients with influenza plus co-infection had the highest rates of intubation and longest ICU LOS. On crude analysis, influenza infection status was associated with ICU mortality (P < 0.001) but not hospital mortality (P = 0.09). Patients with influenza plus co-infection and patients with non-influenza infection alone had similar ICU mortality (41% and 37% respectively) that was higher than patients with influenza alone or those without infection (33% and 26% respectively). A propensity score-matched analysis did not show a difference in hospital mortality attributable to influenza infection (OR = 1.01, 95%CI 0.90-1.13, P = 0.85). Age, severity scores, ARDS, and performance status were all associated with ICU, hospital, and 90-day mortality.

CONCLUSIONS

Category of infectious etiology of respiratory failure (influenza, non-influenza, influenza plus co-infection, and non-infectious) was associated with ICU but not hospital mortality. In a propensity score-matched analysis, influenza infection was not associated with the primary outcome of hospital mortality. Overall, influenza infection alone may not be an independent risk factor for hospital mortality in immunosuppressed patients.

Data-driven discovery of a novel sepsis pre-shock state predicts impending septic shock in the ICU

Septic shock is a life-threatening condition in which timely treatment substantially reduces mortality. Reliable identification of patients with sepsis who are at elevated risk of developing septic shock therefore has the potential to save lives by opening an early window of intervention. We hypothesize the existence of a novel clinical state of sepsis referred to as the "pre-shock" state, and that patients with sepsis who enter this state are highly likely to develop septic shock at some future time. We apply three different machine learning techniques to the electronic health record data of 15,930 patients in the MIMIC-III database to test this hypothesis. This novel paradigm yields improved performance in identifying patients with sepsis who will progress to septic shock, as defined by Sepsis- 3 criteria, with the best method achieving a 0.93 area under the receiver operating curve, 88% sensitivity, 84% specificity, and median early warning time of 7 hours. Additionally, we introduce the notion of patient-specific positive predictive value, assigning confidence to individual predictions, and achieving values as high as 91%. This study demonstrates that early prediction of impending septic shock, and thus early intervention, is possible many hours in advance.

Dexmedetomidine Attenuates Lung Injury by Promoting Mitochondrial Fission and Oxygen Consumption

BACKGROUND Sepsis is among the major antecedents of lung injury characterized by mitochondrial dysfunction. The functional integrity of the cell is influenced by mitochondrial dynamics. The present investigation evaluated the protective effects of dexmedetomidine against lung injury and speculates on the possible mechanism underlying its effects on mitochondrial function. MATERIAL AND METHODS Lung injury was induced by cecal ligation and puncture (CLP) in mice treated with 0.1, 0.3, or 0.5 mg/kg intravenous dexmedetomidine after a 30-minute surgery. The effects of dexmedetomidine were determined by the oxygenation index and the wet/dry weight ratio of the lung. The expression of mitochondrial protein was assessed by western blot analyses and real-time polymerase chain reaction, to determine the effects of dexmedetomidine on mitochondrial dynamics. The histopathology of the lung tissue was determined by hematoxylin and eosin staining, and TUNEL-positive cells were counted in TUNEL assays. Activity of caspase-3, caspase-8, and caspase-9 enzymes were determined by colorimetric assay. RESULTS Treatment with dexmedetomidine significantly attenuated changes in the oxygenation index and the wet/dry weight ratio in mice with CLP-induced lung injury. There was a significant decrease in pro-inflammatory mediators and markers of oxidative stress in the lung tissue of the dexmedetomidine-treated group compared to the negative control group. Moreover, treatment with dexmedetomidine attenuated the altered gene expression caused by mitochondrial fusion and fission in the lung tissue of mice with CLP-induced lung injury. The number of TUNEL-positive cells was significantly reduced in the dexmedetomidine-treated group compared to the negative control group. Moreover, dexmedetomidine ameliorated the altered activity of caspase-3, caspase-8, and caspase-9 enzyme in the lung tissues of CLP-induced lung injure mice. CONCLUSIONS Dexmedetomidine protected mice against CLP-induced lung injury by attenuating changes in mitochondrial fusion and fission.

Acetic acid alleviates the inflammatory response and liver injury in septic mice by increasing the expression of TRIM40

Sepsis remains a significant health care issue in clinical practice due to its high mortality rate and healthcare cost, despite extensive efforts to better understand the pathophysiology of sepsis. The systemic inflammatory response often leads to severe liver injury, even acute liver dysfunction and failure. Acetic acid, as a type of chemical compound, has been reported to be an emerging drug for improving metabolic syndrome and inhibiting inflammation in rats and human. To verify the effects of acetic acid in protecting the liver and reducing the inflammatory response, a septic mouse model was established by cecal ligation and puncture (CLP), and then the CLP-model mice were treated with acetic acid or PBS. Following the treatment, it was determined that, in CLP-model mice, acetic acid could alleviate the inflammatory response by decreasing the expression of cytokines including interleukin-6 and tumor necrosis factor-α. Additionally, acetic acid also alleviated the liver injury, and the levels of alanine aminotransaminase, aspartate aminotransferase, Toll-like receptor (TLR)4 and nuclear factor-κB (NF-κB) were decreased. The expression of tripartite motif-containing protein (TRIM)40 was also upregulated significantly. Therefore, the authors of the current study hypothesized that acetic acid could decrease the inflammatory response by increasing the expression of TRIM40 and TRIM40 may regulate the activity of the TLR4 signaling pathway. To further illustrate the interaction between TRIM40 and the TLR4 signaling pathway, the authors collected macrophages from the peritoneal cavity by intraperitoneally administering mice with 5 ml ice-cold normal saline. Following the collection, peritoneal macrophages were treated with acetic acid, TRIM40 small interfering RNA or PBS. It was demonstrated that acetic acid upregulated the expression of TRIM40. When TRIM40 was silenced, the protective effect of acetic acid would be reversed as well. The results suggested that TRIM40 could act on and downregulate the activity of the TLR4 signaling pathway. TRIM40 is possibly the major target for acetic acid, which may function as a protective factor in septic mice.

Efficacy and safety of antimicrobial de-escalation as a clinical strategy

INTRODUCTION

De-escalation is a widely recommended strategy in regard to guidelines, with an associated adherence to guidelines being around 50%. This review discusses data supporting de-escalation and possible obstacles for its implementation. Areas covered: Although it does not have a consensual definition, de-escalation consists of reducing the spectrum of empirical antimicrobial treatment based on the microbiological findings. Many observational studies have suggested that this strategy is likely safe and efficient for treating various types of infection. However, randomized controlled trials published as of now have not shown any improvement on the outcomes. Regarding the adverse effects of de-escalation on ecological pressure and multidrug resistance emergence, the data are contradictory. The implementation of new techniques, such as rapid diagnosis, can help guide clinicians. Expert opinion: De-escalation should be included as part of a large antibiotic stewardship program to balance the risk and benefit of each administration, and each physician prescribing antibiotics should be challenged for the quality of her/his prescription on a daily basis. In the future, one of our duties will involve determining whether a delay of antimicrobial treatment - making it possible to improve diagnostic performance and obtain the first laboratory results - is either safe or unsafe for our patients.

Protective effect of ginsenoside Rg1 on LPS-induced apoptosis of lung epithelial cells

Sepsis-induced acute lung injury (ALI) is a life-threatening medical condition with high mortality and morbidity in the critical care units. Though, it was commonly accepted that inflammation and apoptosis of lung epithelial cells played an essential role in the pathogenesis of ALI, the underlying mechanism remain unknown. In our study, we found that LPS-induced cell apoptosis could be counteracted by elevated cell autophagy. In LPS-treated MLE-12 cells, suppression of autophagy via 3-MA could aggravate LPS-induced apoptosis, while activation of autophagy via Rapamycin could effectively impair the apoptosis of MLE-12 cells induced by LPS. In order to further discover the molecular regulation mechanism between apoptosis and autophagy in LPS-treated MLE-12 cells, we demonstrated that autophagy could induced the expression of Nrf2, followed with the decrease of p-p65. Targeted inhibition of Nrf2 could induce enlarged cell apoptosis via increasing the level of p-p65. In addition, we demonstrated that ginsenoside Rg1 protected MLE-12 cells from LPS-induced apoptosis via augmenting autophagy and inducing the expression of Nrf2. Our data implicates that activation of autophagy and Nrf2 by ginsenoside Rg1 may provide a preventive and therapeutic strategy for ALI.

LINCS L1000 dataset-based repositioning of CGP-60474 as a highly potent anti-endotoxemic agent

Sepsis is one of the most common clinical syndromes that causes death and disability. Although many studies have developed drugs for sepsis treatment, none have decreased the mortality rate. The aim of this study was to identify a novel treatment option for sepsis using the library of integrated network-based cellular signatures (LINCS) L1000 perturbation dataset based on an in vitro and in vivo sepsis model. Sepsis-related microarray studies of early-stage inflammatory processes in patients and innate immune cells were collected from the Gene Expression Omnibus (GEO) data repository and used for candidate drug selection based on the LINCS L1000 perturbation dataset. The anti-inflammatory effects of the selected candidate drugs were analyzed using activated macrophage cell lines. CGP-60474, an inhibitor of cyclin-dependent kinase, was the most potent drug. It alleviated tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in activated macrophages by downregulating the NF-κB activity, and it reduced the mortality rate in LPS induced endotoxemia mice. This study shows that CGP-60474 could be a potential therapeutic candidate to attenuate the endotoxemic process. Additionally, the virtual screening strategy using the LINCS L1000 perturbation dataset could be a cost and time effective tool in the early stages of drug development.

Antibiotic therapy in the critically ill - expert opinion of the Intensive Care Medicine Scientific Subcommittee of the European Society of Anaesthesiology

Antimicrobial treatment is the cornerstone of infection treatment, and the selection of appropriate antibiotic treatment for critically ill patients is challenging. Clinicians working with critically ill patients usually feel a greater obligation towards their patient than towards maintenance of the delicate ecological balance of prevalent microbiological threats and their resistance patterns. Although antibiotic overtreatment is a frequent phenomenon, patient outcomes need not be compromised when antibiotic treatment is driven by informed decision-making.At the 2016 Euro Anaesthesia Conference (London, UK), the European Society of Anaesthesia Intensive Care Scientific Subcommittee convened an expert panel on antibiotic therapy. This article summarises the main conclusions of the panel, namely the principles of antibiotic therapy that all physicians working with critically ill patients must know.

Cell therapy in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is driven by a severe pro-inflammatory response resulting in lung damage, impaired gas exchange and severe respiratory failure. There is no specific treatment that effectively improves outcome in ARDS. However, in recent years, cell therapy has shown great promise in preclinical ARDS studies. A wide range of cells have been identified as potential candidates for use, among these are mesenchymal stromal cells (MSCs), which are adult multi-lineage cells that can modulate the immune response and enhance repair of damaged tissue. The therapeutic potential of MSC therapy for sepsis and ARDS has been demonstrated in multiple in vivo models. The therapeutic effect of these cells seems to be due to two different mechanisms; direct cellular interaction, and paracrine release of different soluble products such as extracellular vesicles (EVs)/exosomes. Different approaches have also been studied to enhance the therapeutic effect of these cells, such as the over-expression of anti-inflammatory or pro-reparative molecules. Several clinical trials (phase I and II) have already shown safety of MSCs in ARDS and other diseases. However, several translational issues still need to be addressed, such as the large-scale production of cells, and their potentiality and variability, before the therapeutic potential of stem cells therapies can be realized.

Current aspects in sepsis approach. Turning things around

The incidence and prevalence of sepsis depend on the definitions and records that we use and we may be underestimating their impact. Up to 60% of the cases come from the community and in 30-60% we obtain microbiological information. Sometimes its presentation is ambiguous and there may be a delay in its detection, especially in the fragile population. Procalcitonin is the most validated biomarker for bacterial sepsis and the one that best discriminates the non-infectious cause. Presepsin and pro-adrenomedullin are useful for early diagnosis, risk stratification and prognosis in septic patients. The combination of biomarkers is even more useful to clarify an infectious cause than any isolated biomarker. Resuscitation with artificial colloids has worse results than crystalloids, especially in patients with renal insufficiency. The combination of saline solution and balanced crystalloids is associated with a better prognosis. Albumin is only recommended in patients who require a large volume of fluids. The modern molecular methods on the direct sample or the identification by MALDI-TOF on positive blood culture have helped to shorten the response times in diagnosis, to optimize the antibiotic treatment and to facilitate stewardship programs. The hemodynamic response in neonates and children is different from that in adults. In neonatal sepsis, persistent pulmonary hypertension leads to an increase in right ventricular afterload and heart failure with hepatomegaly. Hypotension, poor cardiac output with elevated systemic vascular resistance (cold shock) is often a terminal sign in septic shock. Developing ultra-fast Point-of-Care tests (less than 30 minutes), implementing technologies based on omics, big data or massive sequencing or restoring "healthy" microbiomes in critical patients after treatment are the main focuses of research in sepsis. The main benefits of establishing a sepsis code are to decrease the time to achieve diagnosis and treatment, improve organization, unify criteria, promote teamwork to achieve common goals, increase participation, motivation and satisfaction among team members, and reduce costs.

ARDS: challenges in patient care and frontiers in research

This review discusses the clinical challenges associated with ventilatory support and pharmacological interventions in patients with acute respiratory distress syndrome (ARDS). In addition, it discusses current scientific challenges facing researchers when planning and performing trials of ventilatory support or pharmacological interventions in these patients.

Noninvasive mechanical ventilation is used in some patients with ARDS. When intubated and mechanically ventilated, ARDS patients should be ventilated with low tidal volumes. A plateau pressure <30 cmH₂O is recommended in all patients. It is suggested that a plateau pressure <15 cmH₂O should be considered safe. Patient with moderate and severe ARDS should receive higher levels of positive end-expiratory pressure (PEEP). Rescue therapies include prone position and neuromuscular blocking agents. Extracorporeal support for decapneisation and oxygenation should only be considered when lung-protective ventilation is no longer possible, or in cases of refractory hypoxaemia, respectively. Tracheotomy is only recommended when prolonged mechanical ventilation is expected.

Of all tested pharmacological interventions for ARDS, only treatment with steroids is considered to have benefit.

Proper identification of phenotypes, known to respond differently to specific interventions, is increasingly considered important for clinical trials of interventions for ARDS. Such phenotypes could be defined based on clinical parameters, such as the arterial oxygen tension/inspiratory oxygen fraction ratio, but biological marker profiles could be more promising.

Treatment of ARDS is mainly through the prevention of ventilation-induced lung injuryhttp://ow.ly/DeJC30hGWfi

Mesenchymal stem cells decrease lung inflammation during sepsis, acting through inhibition of the MAPK pathway

Background

Sepsis is a severe medical condition that ranks among the top 10 causes of death worldwide and which has permanently high incidence rates. Mesenchymal stem cells (MSCs) have been found to be potent modulators of immune responses. More importantly, there is evidence that MSCs have a beneficial effect on preclinical models of polymicrobial sepsis. However, the changes caused by the MSCs in the effector cells of the host immune system remain unclear.

Methods

A mouse model of sepsis (male C57BL/6 mice) with three experimental groups was used for experiments in vivo: a control group, an untreated septic group, and a septic group treated with MSCs. In vitro experiments were performed using a cell line of pulmonary macrophages (RAW 264.7) co-cultured with MSCs and stimulated with lipopolysaccharide (LPS).

Results

In vivo we demonstrated that treatment with MSCs was able to reduce the expression of cyclooxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB), and thereby decrease the production of inflammatory cytokines. In vitro experiments using a co-culture of macrophages with MSCs showed a decrease in COX-2 and NF-κB, and showed that this reduction was directly related to the ability of MSCs to inhibit phosphorylation of ERK, RSK, and p38, enzymes that belong to the family of mitogen-activated protein kinases (MAPKs).

Conclusions

This study demonstrated that MSCs are able to inhibit the MAPK pathway activation, modulating the inflammatory response during sepsis. This understanding that MSCs can remodel the response of host cells and improve the course of sepsis is essential for developing new treatments for this pathology.

Obeticholic acid protects mice against lipopolysaccharide-induced liver injury and inflammation

BACKGROUND

Cholestasis, as a main manifestation, induces liver injury during sepsis. The farnesoid X receptor (FXR) plays an important role in regulating bile acid homeostasis. Whether FXR activation by its agonist obeticholic acid (OCA) is contributed to improve sepsis-induced liver injury remains unknown.

OBJECTIVE

The aim of the present study was to investigate the effect of OCA on lipopolysaccharide (LPS)-induced acute liver injury in mice.

RESULTS

8-week old male C57BL/6J mice were randomly divided into control group, LPS group, oral OCA group and LPS plus oral OCA (LPS + OCA) group. The serum and livers were collected for further analysis. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bile acid (TBA) and total bilirubin (TBIL) were measured at indicated time after LPS administration. Liver sections were stained with hematoxylin & eosin (H&E). Orally OCA pretreatment stimulated the expression of FXR and BSEP in livers and protected mice from LPS-induced hepatocyte apoptosis and inflammatory infiltration. Consistently, LPS-induced higher serum levels of ALT, AST, TBA and TBIL were significantly reversed by OCA administration. Meanwhile, the mRNA levels of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α) and IL-6 were decreased in livers of mice in LPS + OCA group compared with LPS group. Further investigation indicated that the higher expression of ATF4 and LC3II/I were associated with the protective effect of OCA on LPS-induced liver injury.

CONCLUSION

Orally OCA pretreatment protects mice from LPS-induced liver injury possibly contributed by improved bile acid homeostasis, decreased inflammatory factors and ATF4-mediated autophagy activity in hepatocytes.