Pulmonary and Nonpulmonary Sepsis Differentially Modulate Lung Immunity toward Secondary Bacterial Pneumonia: A Critical Role for Alveolar Macrophages.

Clinical observations suggest that the source of primary infection accounts for a major determinant of further nosocomial pneumonia in critically ill patients with sepsis. Here we addressed the impact of primary nonpulmonary or pulmonary septic insults on lung immunity using relevant double-hit animal models. C57BL/6J mice were first subjected to polymicrobial peritonitis induced by cecal ligation and puncture (CLP) or bacterial pneumonia induced by intratracheal challenge with Escherichia coli. Seven days later, postseptic mice received ab intratracheal challenge with Pseudomonas aeruginosa. Compared with controls, post-CLP mice became highly susceptible to P. aeruginosa pneumonia, as demonstrated by defective lung bacterial clearance and increased mortality rate. In contrast, all postpneumonia mice survived the P. aeruginosa challenge and even exhibited improved bacterial clearance. Nonpulmonary and pulmonary sepsis differentially modulated the amounts and some important immune functions of alveolar macrophages. Additionally, we observed a Toll-like receptor 2 (TLR2)-dependent increase in regulatory T cells (Tregs) in lungs from post-CLP mice. Antibody-mediated Treg depletion restored the numbers and functions of alveolar macrophages in post-CLP mice. Furthermore, post-CLP TLR2-deficient mice were found resistant to secondary P. aeruginosa pneumonia. In conclusion, polymicrobial peritonitis and bacterial pneumonia conferred susceptibility or resistance to secondary gram-negative pulmonary infection, respectively. Immune patterns in post-CLP lungs argue for a TLR2-dependent cross-talk between Tregs and alveolar macrophages as an important regulatory mechanism in postseptic lung defense.

COVID-19 rapidly increases MDSCs and prolongs innate immune dysfunctions.

We used unsupervised immunophenotyping of blood leukocytes and measured cytokine production by innate immune cell exposed to LPS and R848. We show that COVID-19 induces a rapid, transient upregulation of myeloid-derived suppressor cells (MDSCs) accompanied by a rapid, sustained (up to 3 months) hyporesponsiveness of dendritic cells and monocytes. Blood MDSCs may represent biomarkers and targets for intervention strategies in COVID-19 patients.

Infection of lung megakaryocytes and platelets by SARS-CoV-2 anticipate fatal COVID-19.

SARS-CoV-2, although not being a circulatory virus, spread from the respiratory tract resulting in multiorgan failures and thrombotic complications, the hallmarks of fatal COVID-19. A convergent contributor could be platelets that beyond hemostatic functions can carry infectious viruses. Here, we profiled 52 patients with severe COVID-19 and demonstrated that circulating platelets of 19 out 20 non-survivor patients contain SARS-CoV-2 in robust correlation with fatal outcome. Platelets containing SARS-CoV-2 might originate from bone marrow and lung megakaryocytes (MKs), the platelet precursors, which were found infected by SARS-CoV-2 in COVID-19 autopsies. Accordingly, MKs undergoing shortened differentiation and expressing anti-viral IFITM1 and IFITM3 RNA as a sign of viral sensing were enriched in the circulation of deadly COVID-19. Infected MKs reach the lung concomitant with a specific MK-related cytokine storm rich in VEGF, PDGF and inflammatory molecules, anticipating fatal outcome. Lung macrophages capture SARS-CoV-2-containing platelets in vivo. The virus contained by platelets is infectious as capture of platelets carrying SARS-CoV-2 propagates infection to macrophages in vitro, in a process blocked by an anti-GPIIbIIIa drug. Altogether, platelets containing infectious SARS-CoV-2  alter COVID-19 pathogenesis and provide a powerful fatality marker. Clinical targeting of platelets might prevent viral spread, thrombus formation and exacerbated inflammation at once and increase survival in COVID-19.

[Alpha-2 adrenoreceptor agonists for the intensive care physician]. / Les agonistes α2-adrénergiques pour l'intensiviste.

Clonidine and dexmedetomidine are two α2-adrenoreceptors agonists available for the intensivist in the clinical practice. The affinity of dexmedetomidine is eight times greater than clonidine affinity for the α2 receptors. Their main effect is sedation. They act by inhibition of noradrenaline release in the locus coeruleus in the brainstem. α2-agonists are used primarily for sedation, analgesia, and management of delirium. Nowadays, dexmedetomidine application is increasing in critically ill patients showing a good safety. Most frequent side effects include bradycardia and hypotension.

En pratique clinique, l'intensiviste dispose de deux α2-agonistes, à savoir la clonidine et la dexmédétomidine. L'affinité de la dexmédétomidine pour les récepteurs α2-adrénergiques est huit fois plus importante que celle de la clonidine. Leur principal effet est la sédation. Cet effet est obtenu par inhibition de la libération de noradrénaline dans le locus cœruleus du tronc cérébral. Ces molécules sont surtout utilisées pour la sédation, l'analgésie et la prise en charge du delirium chez le patient critique. Le recours à la dexmédétomidine augmente actuellement et montre une bonne sécurité de la molécule. Les effets indésirables les plus fréquents sont la bradycardie et l'hypotension.

Physiological response to prone positioning in intubated adults with COVID-19 acute respiratory distress syndrome: a retrospective study.

BACKGROUND: COVID-19 related acute respiratory distress syndrome (ARDS) has specific characteristics compared to ARDS in other populations. Proning is recommended by analogy with other forms of ARDS, but few data are available regarding its physiological effects in this population. This study aimed to assess the effects of proning on oxygenation parameters (PaO2/FiO2 and alveolo-arterial gradient (Aa-gradient)), blood gas analysis, ventilatory ratio (VR), respiratory system compliance (CRS) and estimated dead space fraction (VD/VT HB). We also looked for variables associated with treatment failure. METHODS: Retrospective monocentric study of intubated COVID-19 ARDS patients managed with an early intubation, low to moderate positive end-expiratory pressure and early proning strategy hospitalized from March 6 to April 30 2020. Blood gas analysis, PaO2/FiO2, Aa-gradient, VR, CRS and VD/VT HB were compared before and at the end of each proning session with paired t-tests or Wilcoxon tests (p < 0.05 considered as significant). Proportions were assessed using Fischer exact test or Chi square test. RESULTS: Forty-two patients were included for a total of 191 proning sessions, median duration of 16 (5-36) hours. Considering all sessions, PaO2/FiO2 increased (180 [148-210] vs 107 [90-129] mmHg, p < 0.001) and Aa-gradient decreased (127 [92-176] vs 275 [211-334] mmHg, p < 0.001) with proning. CRS (36.2 [30.0-41.8] vs 32.2 [27.5-40.9] ml/cmH2O, p = 0.003), VR (2.4 [2.0-2.9] vs 2.3 [1.9-2.8], p = 0.028) and VD/VT HB (0.72 [0.67-0.76] vs 0.71 [0.65-0.76], p = 0.022) slightly increased. Considering the first proning session, PaO2/FiO2 increased (186 [165-215] vs 104 [94-126] mmHg, p < 0.001) and Aa-gradient decreased (121 [89-160] vs 276 [238-321] mmHg, p < 0.001), while CRS, VR and VD/VT HB were unchanged. Similar variations were observed during the subsequent proning sessions. Among the patients who experienced treatment failure (defined as ICU death or need for extracorporeal membrane oxygenation), fewer expressed a positive response in terms of oxygenation (defined as increase of more than 20% in PaO2/FiO2) to the first proning (67 vs 97%, p = 0.020). CONCLUSION: Proning in COVID-19 ARDS intubated patients led to an increase in PaO2/FiO2 and a decrease in Aa-gradient if we consider all the sessions together, the first one or the 4 subsequent sessions independently. When considering all sessions, CRS increased and VR and VD/VT HB only slightly increased.

Post-cardiac arrest myoclonus and in ICU mortality: insights from the Parisian Registry of Cardiac Arrest (PROCAT).

BACKGROUND: Post-cardiac arrest myoclonus (PCAM) is a frequent finding in resuscitated patients after cardiac arrest (CA), with rather poor prognostic significance. In this study, we evaluated the association of PCAM within intensive care unit (ICU) mortality from a university hospital CA patients' registry. METHODS: Clinical data of consecutive CA survivors admitted in the intensive care unit (ICU) between January and December 2016 at the Paris Cochin University Hospital were assessed from the Parisian registry of cardiac arrest (PROCAT) and analyzed. Neurologic outcome was assessed using the Cerebral Performance Categories (CPC) scale at ICU discharge. Prevalence of PCAM and their association with mortality at ICU discharge were computed. RESULTS: One hundred thirty-two (132) patients were included (73.5% males), median age of 66 years. Among them, 37 (28%) developed PCAM during their ICU stay. Only two patients with PCAM survived (5.4%). PCAM was strongly associated with mortality at ICU discharge (odds ratio 17.5 [4.2-123.2]). Sensitivity, specificity, PPV, and NPV of PCAM for prediction of death were 41%, 96%, 95%, and 46%, respectively. CONCLUSION: PCAM was observed in nearly one-third of CA patients admitted in ICU. Patients with PCAM had a significantly higher likelihood of ICU mortality and a low likelihood of a good outcome. The prognostic value of PCAM seems rather bleak but remains nuanced and merits study in larger-scale prospective studies taking into account confounding factors.

Validation of a Protocol for Continuous Hemodiafiltration with Regional Citrate Anticoagulation with Omni®.

INTRODUCTION: Omni® (B Braun, Melsungen, Germany) is able to run continuous renal replacement therapy (CRRT) in continuous veno-venous hemofiltration (CVVH), hemodialysis (CVVHD), and hemodiafiltration (CVVHDF) modes. However, to date, there is no validated protocol to guide the use of Omni® in CVVHDF mode with regional citrate anticoagulation (RCA). METHODS: We designed a protocol for CVVHDF-RCA tailored for Omni®. This protocol was tested in patients included in an observational study conducted in our center between January and March 2021. For all study patients, we collected baseline characteristics, laboratory results, CRRT circuit lifespan as well as plasma and effluent samples at 12, 24, 48, and 72 h of CRRT circuit initiation. At each study time point, we computed urea, creatinine, and ß2-microglobulin clearance as well as effluent/blood ratios. Data from circuits in CVVHDF-RCA mode are compared with those in standard therapy (CVVHD-RCA) with the same device. RESULTS: We analyzed ten circuits (5 patients) in CVVHDF-RCA mode and 32 (13 patients) in CVVHD-RCA mode. No adverse events related to the therapy were observed. In CVVHDF-RCA mode, median circuit running time was 68 (IQR 8.1) hours versus 46 (IQR 9.0) in CVVHD mode, p = 0.053. Therapy adaptations (dialysate rate and/or blood flow) were required in one (10%) circuit (15.6% in CVVHD mode, p = 0.56). Compared to CVVHD, CVVHDF was able to achieve similar clearance and effluent/blood ratio for urea, creatinine, and ß2-microglobulin across the entire duration of circuit lifetime. CONCLUSION: The proposed protocol for CVVHDF-RCA for Omni® was associated with similar circuit lifetime, number of required adaptations and clearances to standard CVVHD-RCA. It appears to be safe and feasible.

[Monitoring respiratory mechanics in ventilated patients: a bedside approach]. / Monitorage de la mécanique respiratoire chez le patient ventilé : comment procéder au lit du malade.

In clinical practice, the term respiratory mechanics usually refers to the concept of compliance and resistance of the respiratory system. In ventilated patients, measurements of compliance and resistance can be performed at the bedside using the ventilator (end- inspiratory and end-expiratory occlusions). Those measurements allow caregivers to monitor pulmonary disorders and evaluate treatment effectiveness. In case of sudden change in compliance or resistance, the variation of flow and pressure curves displayed on the ventilator screen helps to narrow down the differential diagnosis. This article defines what are compliance and resistance and how to calculate and use them at the bedside.

Le terme « mécanique respiratoire ¼ se rapporte souvent, en pratique, aux concepts de compliance et résistance du système respiratoire. Chez un patient ventilé, les mesures de compliance et de résistance s'effectuent à l'aide du ventilateur (occlusion télé-inspiratoire et télé-expiratoire). Ces mesures permettent de suivre l'évolution d'une atteinte pulmonaire ou l'efficacité d'un traitement administré. En cas de changement brusque de compliance ou de résistance, l'analyse des variations des courbes affichées sur l'écran du ventilateur permet d'élaborer un diagnostic différentiel rapidement. Cet article de synthèse décrit les concepts de compliance et résistance du système respiratoire, la façon de les calculer et de les utiliser au lit du malade.

[Classic ventilatory modes for invasive mechanical ventilation]. / Modes ventilatoires de base en ventilation mécanique invasive.

Invasive mechanical ventilation is part of the daily practice of the intensivist and anesthetist. The comprehensive knowledge of ventilatory modes is mandatory for managing the ventilated patients. The objective of this article is to explain the characteristics of the barometric and volumetric modes and the differences between controlled, assist-controlled, and assisted ventilation. The most common modes (volume and pressure assist-control, dual modes and pressure support) are described in detail. Parameters that must be set and those that must be monitored in each mode are also described. Finally, suggestions for initial settings are provided in order to offer the reader unfamiliar with mechanical ventilation a practical decision-making aid.

La ventilation mécanique invasive est un outil indispensable à la pratique de l'intensiviste et de l'anesthésiste. La connaissance des modes ventilatoires est nécessaire pour la prise en charge des patients ventilés. L'objectif de cet article est, d'une part, de distinguer les caractéristiques des modes barométriques et volumétriques, et de comprendre les différences entre les modes contrôlé, assisté-contrôlé et assisté et, d'autre part, de distinguer les paramètres qui doivent être réglés de ceux qui doivent être monitorés. Les modes les plus utilisés (volume contrôlé, pression contrôlée, modes mixtes et aide inspiratoire) font l'objet d'une description détaillée. Des suggestions de réglages initiaux sont proposées pour ces modes afin d'offrir au lecteur peu familier avec la ventilation mécanique une aide décisionnelle pratique.

Impact of Blood Product Transfusions on the Risk of ICU-Acquired Infections in Septic Shock.

OBJECTIVES: Transfusions of blood products are common in critically ill patients and have a potential for immunomodulation. The aim of this study is to address the impact of transfusion of blood products on the susceptibility to ICU-acquired infections in the high-risk patients with septic shock. DESIGN: A single-center retrospective study over a 10-year period (2008-2017). SETTING: A medical ICU of a tertiary-care center. PATIENTS: All consecutive patients diagnosed for septic shock within the first 48 hours of ICU admission were included. Patients who were discharged or died within the first 48 hours were excluded. INTERVENTIONS: RBC, platelet, and fresh frozen plasma transfusions collected up to 24 hours prior to the onset of ICU-acquired infection. MEASUREMENTS AND MAIN RESULTS: During the study period, 1,152 patients were admitted for septic shock, with 893 patients remaining alive in the ICU after 48 hours of management. A first episode of ICU-acquired infection occurred in 28.3% of the 48-hour survivors, with a predominance of pulmonary infections (57%). Patients with ICU-acquired infections were more likely to have received RBC, platelet, and fresh frozen plasma transfusions. In a multivariate Cox cause-specific analysis, transfusions of platelets (cause-specific hazard ratio = 1.55 [1.09-2.20]; p = 0.01) and fresh frozen plasma (cause-specific hazard ratio = 1.38 [0.98-1.92]; p = 0.05) were independently associated with the further occurrence of ICU-acquired infections. CONCLUSIONS: Transfusions of platelets and fresh frozen plasma account for risk factors of ICU-acquired infections in patients recovering from septic shock. The occurrence of ICU-acquired infections should be considered as a relevant endpoint in future studies addressing the indications of transfusions in critically ill patients.

Sepsis and Cancer: An Interplay of Friends and Foes.

Sepsis and cancer share a number of pathophysiological features, and both result from the inability of the host's immune system to cope with the initial insult (tissue invasion by pathogens and malignant cell transformation, respectively). The common coexistence of both disorders and the profound related alterations in immune homeostasis raise the question of their mutual impact on each other's course. This translational review aims to discuss the interactions between cancer and sepsis supported by clinical data and the translation to experimental models. The dramatic improvement in cancer has come at a cost of increased risks of life-threatening infectious complications. Investigating the long-term outcomes of sepsis survivors has revealed an unexpected susceptibility to cancer long after discharge from the ICU. Nonetheless, it is noteworthy that an acute septic episode may harbor antitumoral properties under particular circumstances. Relevant double-hit animal models have provided clues to whether and how bacterial sepsis may impact malignant tumor growth. In sequential sepsis-then-cancer models, postseptic mice exhibited accelerated tumor growth. When using reverse cancer-then-sepsis models, bacterial sepsis applied to mice with cancer conversely resulted in inhibition or even regression of tumor growth. Experimental models thus highlight dual effects of sepsis on tumor growth, mostly depending on the sequence of insults, and allow deciphering the immune mechanisms and their relation with microorganisms.

Post-transfusion platelet responses in critically ill cancer patients with hypoproliferative thrombocytopenia.

BACKGROUND: Platelet transfusion is aimed at increasing platelet counts to prevent or treat bleeding. Critically ill cancer patients with hypoproliferative thrombocytopenia are high consumers of blood products. We herein described their post-transfusion platelet responses in the intensive care unit (ICU) and analyzed the determinants of poor post-transfusion increments. STUDY DESIGN AND METHODS: This was a single-center 9-year (2009-2017) retrospective observational study. Patients with malignancies and presumed or proven hypoproliferative thrombocytopenia who had received at least one platelet transfusion in the ICU were included. Poor post-transfusion platelet increments were defined as body surface-adjusted corrected count increment (CCI) <7, or alternatively as weight-adjusted platelet transfusion recovery (PTR) <0.2. Patients were deemed refractory to platelet transfusions when two consecutive ABO-compatible transfusions resulted in poor platelet increments. RESULTS: A total of 1470 platelet transfusions received by 326 patients were analyzed. Indications for platelet transfusions were distributed into prophylactic (44.5%), peri-procedural (18.1%) and therapeutic (37.4%). Regardless of indications, 54.6% and 55.4% of transfusion episodes were associated with a CCI <7 or a PTR <0.2. Factors independently associated with poor post-transfusion increments were lower body mass index, spleen enlargement, concurrent severity of clinical condition, fever ≥39°C, antibiotic therapy and increased storage duration of platelet concentrates. Eventually, 48 patients developed refractoriness to platelet transfusion, which was associated increased incidence of bleeding events. CONCLUSION: Platelet transfusions are often associated with poor increments in critically ill cancer patients with hypoproliferative thrombocytopenia. The findings suggest amenable interventions to improve the platelet transfusion practices in this setting.

Methodological challenges in European ethics approvals for a genetic epidemiology study in critically ill patients: the GenOSept experience.

BACKGROUND: During the set-up phase of an international study of genetic influences on outcomes from sepsis, we aimed to characterise potential differences in ethics approval processes and outcomes in participating European countries. METHODS: Between 2005 and 2007 of the FP6-funded international Genetics Of Sepsis and Septic Shock (GenOSept) project, we asked national coordinators to complete a structured survey of research ethic committee (REC) approval structures and processes in their countries, and linked these data to outcomes. Survey findings were reconfirmed or modified in 2017. RESULTS: Eighteen countries participated in the study, recruiting 2257 patients from 160 ICUs. National practices differed widely in terms of composition of RECs, procedures and duration of the ethics approval process. Eight (44.4%) countries used a single centralised process for approval, seven (38.9%) required approval by an ethics committee in each participating hospital, and three (16.7%) required both. Outcomes of the application process differed widely between countries because of differences in national legislation, and differed within countries because of interpretation of the ethics of conducting research in patients lacking capacity. The RECs in four countries had no lay representation. The median time from submission to final decision was 1.5 (interquartile range 1-7) months; in nine (50%) approval was received within 1 month; six took over 6 months, and in one 24 months; had all countries been able to match the most efficient approvals processes, an additional 74 months of country or institution-level recruitment would have been available. In three countries, rejection of the application by some local RECs resulted in loss of centres; and one country rejected the application outright. CONCLUSIONS: The potential benefits of the single application portal offered by the European Clinical Trials Regulation will not be realised without harmonisation of research ethics committee practices as well as national legislation.

A Multicenter Randomized Trial Assessing the Efficacy of Helium/Oxygen in Severe Exacerbations of Chronic Obstructive Pulmonary Disease.

RATIONALE: During noninvasive ventilation (NIV) for chronic obstructive pulmonary disease (COPD) exacerbations, helium/oxygen (heliox) reduces the work of breathing and hypercapnia more than air/O2, but its impact on clinical outcomes remains unknown. OBJECTIVES: To determine whether continuous administration of heliox for 72 hours, during and in-between NIV sessions, was superior to air/O2 in reducing NIV failure (25-15%) in severe hypercapnic COPD exacerbations. METHODS: This was a prospective, randomized, open-label trial in 16 intensive care units (ICUs) and 6 countries. Inclusion criteria were COPD exacerbations with PaCO2 ≥ 45 mm Hg, pH ≤ 7.35, and at least one of the following: respiratory rate ≥ 25/min, PaO2 ≤ 50 mm Hg, and oxygen saturation (arterial [SaO2] or measured by pulse oximetry [SpO2]) ≤ 90%. A 6-month follow-up was performed. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was NIV failure (intubation or death without intubation in the ICU). The secondary endpoints were physiological parameters, duration of ventilation, duration of ICU and hospital stay, 6-month recurrence, and rehospitalization rates. The trial was stopped prematurely (445 randomized patients) because of a low global failure rate (NIV failure: air/O2 14.5% [n = 32]; heliox 14.7% [n = 33]; P = 0.97, and time to NIV failure: heliox group 93 hours [n = 33], air/O2 group 52 hours [n = 32]; P = 0.12). Respiratory rate, pH, PaCO2, and encephalopathy score improved significantly faster with heliox. ICU stay was comparable between the groups. In patients intubated after NIV failed, patients on heliox had a shorter ventilation duration (7.4 ± 7.6 d vs. 13.6 ± 12.6 d; P = 0.02) and a shorter ICU stay (15.8 ± 10.9 d vs. 26.7 ± 21.0 d; P = 0.01). No difference was observed in ICU and 6-month mortality. CONCLUSIONS: Heliox improves respiratory acidosis, encephalopathy, and the respiratory rate more quickly than air/O2 but does not prevent NIV failure. Overall, the rate of NIV failure was low. Clinical trial registered with www.clinicaltrials.gov (NCT 01155310).

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016.

OBJECTIVE: To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012." DESIGN: A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development. METHODS: The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable. RESULTS: The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions. CONCLUSIONS: Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

Sepsis-induced expansion of granulocytic myeloid-derived suppressor cells promotes tumour growth through Toll-like receptor 4.

Severe sepsis remains a frequent and dreaded complication in cancer patients. Beyond the often fatal short-term outcome, the long-term sequelae of severe sepsis may also impact directly on the prognosis of the underlying malignancy in survivors. The immune system is involved in all stages of tumour development, in the detection of transforming and dying cells and in the prevention of tumour growth and dissemination. In fact, the profound and sustained immune defects induced by sepsis may constitute a privileged environment likely to favour tumour growth. We investigated the impact of sepsis on malignant tumour growth in a double-hit animal model of polymicrobial peritonitis, followed by subcutaneous inoculation of MCA205 fibrosarcoma cells. As compared to their sham-operated counterparts, post-septic mice exhibited accelerated tumour growth. This was associated with intratumoural accumulation of CD11b(+) Ly6G(high) polymorphonuclear cells (PMNs) that could be characterized as granulocytic myeloid-derived suppressor cells (G-MDSCs). Depletion of granulocytic cells in post-septic mice inhibited the sepsis-enhanced tumour growth. Toll-like receptor (TLR)-4 (Tlr4) and Myd88 deficiencies prevented sepsis-induced expansion of G-MDSCs and tumour growth. Our results demonstrate that the myelosuppressive environment induced by severe bacterial infections promotes malignant tumour growth, and highlight a critical role of CD11b(+) Ly6G(high) G-MDSCs under the control of TLR-dependent signalling. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3).

IMPORTANCE: Definitions of sepsis and septic shock were last revised in 2001. Considerable advances have since been made into the pathobiology (changes in organ function, morphology, cell biology, biochemistry, immunology, and circulation), management, and epidemiology of sepsis, suggesting the need for reexamination. OBJECTIVE: To evaluate and, as needed, update definitions for sepsis and septic shock. PROCESS: A task force (n = 19) with expertise in sepsis pathobiology, clinical trials, and epidemiology was convened by the Society of Critical Care Medicine and the European Society of Intensive Care Medicine. Definitions and clinical criteria were generated through meetings, Delphi processes, analysis of electronic health record databases, and voting, followed by circulation to international professional societies, requesting peer review and endorsement (by 31 societies listed in the Acknowledgment). KEY FINDINGS FROM EVIDENCE SYNTHESIS: Limitations of previous definitions included an excessive focus on inflammation, the misleading model that sepsis follows a continuum through severe sepsis to shock, and inadequate specificity and sensitivity of the systemic inflammatory response syndrome (SIRS) criteria. Multiple definitions and terminologies are currently in use for sepsis, septic shock, and organ dysfunction, leading to discrepancies in reported incidence and observed mortality. The task force concluded the term severe sepsis was redundant. RECOMMENDATIONS: Sepsis should be defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. For clinical operationalization, organ dysfunction can be represented by an increase in the Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score of 2 points or more, which is associated with an in-hospital mortality greater than 10%. Septic shock should be defined as a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone. Patients with septic shock can be clinically identified by a vasopressor requirement to maintain a mean arterial pressure of 65 mm Hg or greater and serum lactate level greater than 2 mmol/L (>18 mg/dL) in the absence of hypovolemia. This combination is associated with hospital mortality rates greater than 40%. In out-of-hospital, emergency department, or general hospital ward settings, adult patients with suspected infection can be rapidly identified as being more likely to have poor outcomes typical of sepsis if they have at least 2 of the following clinical criteria that together constitute a new bedside clinical score termed quickSOFA (qSOFA): respiratory rate of 22/min or greater, altered mentation, or systolic blood pressure of 100 mm Hg or less. CONCLUSIONS AND RELEVANCE: These updated definitions and clinical criteria should replace previous definitions, offer greater consistency for epidemiologic studies and clinical trials, and facilitate earlier recognition and more timely management of patients with sepsis or at risk of developing sepsis.

Variants in the Mannose-binding Lectin Gene MBL2 do not Associate With Sepsis Susceptibility or Survival in a Large European Cohort.

BACKGROUND: Sepsis is an increasingly common condition, which continues to be associated with unacceptably high mortality. A large number of association studies have investigated susceptibility to, or mortality from, sepsis for variants in the functionally important immune-related gene MBL2. These studies have largely been underpowered and contradictory. METHODS: We genotyped and analyzed 4 important MBL2 single nucleotide polymorphisms (SNPs; rs5030737, rs1800450, rs1800451, and rs7096206) in 1839 European community-acquired pneumonia (CAP) and peritonitis sepsis cases, and 477 controls from the United Kingdom. We analyzed the following predefined subgroups and outcomes: 28-day and 6 month mortality from sepsis due to CAP or peritonitis combined, 28-day mortality from CAP sepsis, peritonitis sepsis, pneumococcal sepsis or sepsis in younger patients, and susceptibility to CAP sepsis or pneumococcal sepsis in the United Kingdom. RESULTS: There were no significant associations (all P-values were greater than .05 after correction for multiple testing) between MBL2 genotypes and any of our predefined analyses. CONCLUSIONS: In this large, well-defined cohort of immune competent adult patients, no associations between MBL2 genotype and sepsis susceptibility or outcome were identified.

Surviving Sepsis Campaign: association between performance metrics and outcomes in a 7.5-year study.

PURPOSE: To determine the association between compliance with the Surviving Sepsis Campaign (SSC) performance bundles and mortality. DESIGN: Compliance with the SSC performance bundles, which are based on the 2004 SSC guidelines, was measured in 29,470 subjects entered into the SSC database from January 1, 2005, through June 30, 2012. Compliance was defined as evidence that all bundle elements were achieved. SETTING: Two hundred eighteen community, academic, and tertiary care hospitals in the United States, South America, and Europe. PATIENTS: Patients from the emergency department, medical and surgical wards, and ICU who met diagnosis criteria for severe sepsis and septic shock. METHODS: A multifaceted, collaborative change intervention aimed at facilitating adoption of the SSC resuscitation and management bundles was introduced. Compliance with the SSC bundles and associated mortality rate was the primary outcome variable. RESULTS: Overall lower mortality was observed in high (29.0%) versus low (38.6%) resuscitation bundle compliance sites (p < 0.001) and between high (33.4%) and low (32.3%) management bundle compliance sites (p = 0.039). Hospital mortality rates dropped 0.7% per site for every three months (quarter) of participation (p < 0.001). Hospital and intensive care unit length of stay decreased 4% (95% CI: 1% - 7%; p = 0.012) for every 10% increase in site compliance with the resuscitation bundle. CONCLUSIONS: This analysis demonstrates that increased compliance with sepsis performance bundles was associated with a 25% relative risk reduction in mortality rate. Every 10% increase in compliance and additional quarter of participation in the SSC initiative was associated with a significant decrease in the odds ratio for hospital mortality. These results demonstrate that performance metrics can drive change in clinical behavior, improve quality of care, and may decrease mortality in patients with severe sepsis and septic shock.