Differences in Impact of Definitional Elements on Mortality Precludes International Comparisons of Sepsis Epidemiology-A Cohort Study Illustrating the Need for Standardized Reporting

The Global Burden of Sepsis and Septic Shock

A dysregulated host response to infection causes organ dysfunction in sepsis and septic shock, two potentially fatal diseases. They continue to be major worldwide health burdens with high rates of morbidity and mortality despite advancements in medical care. The goal of this thorough review was to present a thorough summary of the current body of knowledge about the prevalence of sepsis and septic shock worldwide. Using widely used computerized databases, a comprehensive search of the literature was carried out, and relevant studies were chosen in accordance with predetermined inclusion and exclusion criteria. A narrative technique was used to synthesize the data that were retrieved. The review's conclusions show how widely different locations and nations differ in terms of sepsis and septic shock's incidence, prevalence, and fatality rates. Compared to high-income countries (HICs), low- and middle-income countries (LMICs) are disproportionately burdened more heavily. We talk about risk factors, comorbidities, and difficulties in clinical management and diagnosis in a range of healthcare settings. The review highlights the need for more research, enhanced awareness, and context-specific interventions in order to successfully address the global burden of sepsis and septic shock.

Use of Immune Profiling Panel to assess the immune response of septic patients for prediction of worsening as a composite endpoint

Sepsis induces intense, dynamic and heterogeneous host response modulations. Despite improvement of patient management, the risk of mortality and healthcare-associated infections remains high. Treatments to counterbalance immune response are under evaluation, but effective biomarkers are still lacking to perform patient stratification. The design of the present study was defined to alleviate the limitations of existing literature: we selected patients who survived the initial hyperinflammatory response and are still hospitalized at day 5-7 after ICU admission. Using the Immune Profiling Panel (IPP), a fully automated RT-qPCR multiplex prototype, we optimized a machine learning model combining the IPP gene expression levels for the identification of patients at high risk of worsening, a composite endpoint defined as death or secondary infection, within one week after sampling. This was done on 332 sepsis patients selected from two retrospective studies. The IPP model identified a high-risk group comprising 30% of patients, with a significant increased proportion of worsening events at day 28 compared to the low-risk group (49% vs. 28%, respectively). These preliminary results underline the potential clinical application of IPP for sepsis patient stratification in a personalized medicine perspective, that will be confirmed in a larger prospective multicenter study.

[A Study of the Prevalence of Asthma in the General Population in Spain]

Introduction

Asthma is a disease with high prevalence, which affects all age groups and generates high health and social care costs. Studies carried out in a number of populations show great variability in its prevalence, even in geographically close populations, with data suggesting a relevant influence of socio-economic factors. At present, we do not have reliable data on the prevalence of this disease in the adult population of Spain. The objectives of this study are to estimate the prevalence of asthma in the Spanish population for those aged 18-79, to describe the variability between autonomous communities, to estimate the prevalence of under and overdiagnosis, to analyse the prevalence of uncontrolled asthma and steroid-dependent asthma, to evaluate the health care cost, to identify the most frequent phenotypes and to establish a starting point to evaluate the temporal trend with subsequent studies.

Methods

A cross-sectional, two-stage study will be carried out, including patients from 50 catchment areas. The study will be carried out in 3 phases: 1) screening and confirmation in the clinical history, in which patients with a previously correctly established diagnosis of asthma will be identified; 2) diagnosis of asthma to evaluate patients without a confirmed or excluded diagnosis; 3) characterization of asthma, where the characteristics of the asthmatic patients will be analysed, identifying the most frequent phenotypes.

Discussion

It seems necessary and feasible to carry out an epidemiological study of asthma in Spain to identify the prevalence of asthma, to optimize healthcare planning, to characterize the most frequent phenotypes of the disease, and to evaluate inaccurate diagnoses.

Toll-like receptor 4-mediated endoplasmic reticulum stress induces intestinal paneth cell damage in mice following CLP-induced sepsis

A marked elevation of TLR4 was observed in various organs of septic mice. The mechanism of TLR4 in intestinal epithelial cell damage in sepsis remains unclear. CLP mice models were used to assess the role of TLR4 in intestinal Paneth cell damage by histological, polymerase chain reaction, western-blot analyses. The ileal expression of TLR4 was increased by more than five-fold after CLP. CLP significantly increased 7-day mortality and was associated with a higher murine sepsis score (MSS), closely related with increased TLR4 expression. Histological staining revealed that a reduced number of Paneth cells, accompanied by reduced lysozyme and defensin alpha 5(DEF-5) expression as detected by PCR. Of note, the expression levels of ATF6, XBP1 and CHOP increased in the ileal of the sepsis group. Meanwhile, the uncleaved p90 ATF6 was markedly reduced and cleaved p50 ATF6 was increased in the sepsis group. Intriguingly, The TAK-242 had improved intestinal mucosal injury, reduced the expression of ATF6, XBP1 and CHOP and relieved the cleavage of ATF6. We found that increased the expression level of TLR4 in the ileal of CLP mice promoted the depletion of Paneth cell and reduced LYZ and DEF-5 expression. Furthermore, our findings suggested that TLR4-mediated the hyperactivation of ER stress, via activating the ATF6/CHOP pathway, might be one of the mechanisms associated with Paneth cells loss and dysfunction during intestinal barrier impairment of sepsis.

The impact of changes in coding on mortality reports using the example of sepsis

OBJECTIVES

NHS Digital issued new guidance on sepsis coding in April 2017 which was further modified in April 2018. During these timeframes some centres reported increased sepsis associated mortality, whilst others reported reduced mortality, in some cases coincident with specific quality improvement programmes. We hypothesised that changes in reported mortality could not be separated from changes in coding practice.

METHODS

Hospital Episode Statistics from the Admitted Patient Care dataset for NHS hospitals in England, from April 2016 to March 2020 were analysed. Admissions of adults with sepsis: an International Classification of Diseases 10 (ICD-10) code associated with the Agency for Healthcare Research and Quality Clinical Classifications Software class 'Septicaemia (except in labour)', were assessed. Patient comorbidities were defined by other ICD-10 codes recorded within the admission episode.

RESULTS

1,081,565 hospital episodes with a coded diagnosis of sepsis were studied. After April 2017 there was a significant increase in admission episodes with sepsis coded as the primary reason for admission. There were significant changes in the case-mix of patients with a primary diagnosis of sepsis after April 2017. An analysis of case-mix, hospital and year treated as random effects, defined a small reduction in sepsis associated mortality across England following the first change in coding guidance. No centre specific improvement in outcome could be separated from these random-effects.

CONCLUSION

Changes in sepsis coding practice altered case-mix and case selection, in ways that varied between centres. This was associated with changes in centre-specific sepsis associated mortality, over time. According to the direction of change these may be interpreted either as requiring local investigation for cause or as supporting coincident changes in clinical practice. A whole system analysis showed that centre specific changes in mortality cannot be separated from system-wide changes. Caution is therefore required when interpreting sepsis outcomes in England, particularly when using single centre studies to inform or support guidance or policy.

Resveratrol: Potential Application in Sepsis

Sepsis is a life-threatening organ dysfunction syndrome caused by host response disorders due to infection or infectious factors and is a common complication of patients with clinical trauma, burns, and infection. Resveratrol is a natural polyphenol compound that is a SIRT-1 activator with anti-inflammatory, antiviral, antibacterial, antifungal inhibitory abilities as well as cardiovascular and anti-tumor protective effects. In recent years, some scholars have applied resveratrol in animal models of sepsis and found that it has an organ protective effect and can improve the survival time and reduce the mortality of animals with sepsis. In this study, Medline (Pubmed), embase, and other databases were searched to retrieve literature published in 2021 using the keywords “resveratrol” and “sepsis,” and then the potential of resveratrol for the treatment of sepsis was reviewed and prospected to provide some basis for future clinical research.

Ground truth labels challenge the validity of sepsis consensus definitions in critical illness

BACKGROUND

Sepsis is the leading cause of death in the intensive care unit (ICU). Expediting its diagnosis, largely determined by clinical assessment, improves survival. Predictive and explanatory modelling of sepsis in the critically ill commonly bases both outcome definition and predictions on clinical criteria for consensus definitions of sepsis, leading to circularity. As a remedy, we collected ground truth labels for sepsis.

METHODS

In the Ground Truth for Sepsis Questionnaire (GTSQ), senior attending physicians in the ICU documented daily their opinion on each patient's condition regarding sepsis as a five-category working diagnosis and nine related items. Working diagnosis groups were described and compared and their SOFA-scores analyzed with a generalized linear mixed model. Agreement and discriminatory performance measures for clinical criteria of sepsis and GTSQ labels as reference class were derived.

RESULTS

We analyzed 7291 questionnaires and 761 complete encounters from the first survey year. Editing rates for all items were > 90%, and responses were consistent with current understanding of critical illness pathophysiology, including sepsis pathogenesis. Interrater agreement for presence and absence of sepsis was almost perfect but only slight for suspected infection. ICU mortality was 19.5% in encounters with SIRS as the "worst" working diagnosis compared to 5.9% with sepsis and 5.9% with severe sepsis without differences in admission and maximum SOFA. Compared to sepsis, proportions of GTSQs with SIRS plus acute organ dysfunction were equal and macrocirculatory abnormalities higher (p < 0.0001). SIRS proportionally ranked above sepsis in daily assessment of illness severity (p < 0.0001). Separate analyses of neurosurgical referrals revealed similar differences. Discriminatory performance of Sepsis-1/2 and Sepsis-3 compared to GTSQ labels was similar with sensitivities around 70% and specificities 92%. Essentially no difference between the prevalence of SIRS and SOFA ≥ 2 yielded sensitivities and specificities for detecting sepsis onset close to 55% and 83%, respectively.

CONCLUSIONS

GTSQ labels are a valid measure of sepsis in the ICU. They reveal suspicion of infection as an unclear clinical concept and refute an illness severity hierarchy in the SIRS-sepsis-severe sepsis spectrum. Ground truth challenges the accuracy of Sepsis-1/2 and Sepsis-3 in detecting sepsis onset. It is an indispensable intermediate step towards advancing diagnosis and therapy in the ICU and, potentially, other health care settings.

Assessment of Metabolic Dysfunction in Sepsis in a Retrospective Single-Centre Cohort

Objective

Our primary aim was to assess selected metabolic dysfunction parameters, both independently and as a complement to the SOFA score, as predictors of short-term mortality in patients with infection admitted to the intensive care unit (ICU).

Methods

We retrospectively enrolled all consecutive adult patients admitted to the eight ICUs of Lille University Hospital, between January 2015 and September 2016, with suspected or confirmed infection. We selected seven routinely measured biological and clinical parameters of metabolic dysfunction (maximal arterial lactatemia, minimal and maximal temperature, minimal and maximal glycaemia, cholesterolemia, and triglyceridemia), in addition to age and the Charlson's comorbidity score. All parameters and SOFA scores were recorded within 24 h of admission.

Results

We included 956 patients with infection, among which 295 (30.9%) died within 90 days. Among the seven metabolic parameters investigated, only maximal lactatemia was associated with higher risk of 90-day hospital mortality in SOFA-adjusted analyses (SOFA-adjusted OR, 1.17; 95%CI, 1.10 to 1.25; p < 0.001). Age and the Charlson's comorbidity score were also statistically associated with a poor prognosis in SOFA-adjusted analyses. We were thus able to develop a metabolic failure, age, and comorbidity assessment (MACA) score based on scales of lactatemia, age, and the Charlson's score, intended for use in combination with the SOFA score.

Conclusions

The maximal lactatemia level within 24 h of ICU admission is the best predictor of short-term mortality among seven measures of metabolic dysfunction. Our combined "SOFA + MACA" score could facilitate early detection of patients likely to develop severe infections. Its accuracy requires further evaluation.

The immunology of sepsis

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to an infection. This recently implemented definition does not capture the heterogeneity or the underlying pathophysiology of the syndrome, which is characterized by concurrent unbalanced hyperinflammation and immune suppression. Here, we review current knowledge of aberrant immune responses during sepsis and recent initiatives to stratify patients with sepsis into subgroups that are more alike from a clinical and/or pathobiological perspective, which could be key for identification of patients who are more likely to benefit from specific immune interventions.

Predictive factors of in-hospital mortality in patients with laboratory-confirmed Escherichia coli, Klebsiella species or Pseudomonas aeruginosa bloodstream infections

Gram-negative bloodstream infections (GNBSI) are confirmed by the presence of gram-negative bacteria in the bloodstream and pose a significant healthcare issue as they increase the risk of sepsis and mortality. In England, the aim is to reduce GNBSI cases and further deterioration through enhanced population surveillance of patients with a laboratory-confirmed GNBSI to inform on healthcare policies. The objective of this study was to evaluate the factors associated with in-hospital mortality in patients with a laboratory-confirmed Escherichia coli, Klebsiella or Pseudomonas aeruginosa GNBSIs, with data obtained from the enhanced data capture for the surveillance of GNBSIs. All patients with a laboratory-confirmed GNBSI at a single centre, admitted between April 2017 and March 2019, were included in this retrospective observational study. Demographic and recent exposure to healthcare risk factors were collected and assessed for the association with in-hospital mortality. In 1113 patients with laboratory-confirmed GNBSIs, the in-hospital mortality rate was 13%. Multivariable analysis confirmed that patients with respiratory (OR = 3.73, 95%CI = 2.05-6.76), gastrointestinal (2.61; 1.22-5.58) or skin (3.61; 1.24-10.54) infection primary focus had a greater risk of in-hospital mortality, compared to upper urinary tract infections. Increased risk of in-hospital mortality was also observed in patients with hospital-onset GNBSIs (OR = 1.87; 1.17-2.97) compared with community-onset healthcare acquired GNBSIs, or who were on dialysis at the time of the GNBSI (3.28; 1.01-10.14), as well as in patients who had recently been discharged from hospital (1.55; 1.01-2.38), or had a vascular device recently manipulated (2.41; 1.01-5.74). Results confirm that the data obtained from the enhanced data capture for GNBSIs in England can predict in-hospital mortality in patients with a GNBSI. Several factors associated with an increased risk of in-hospital mortality have been identified. Results should be reported back to clinicians in order to identify patients at a greater risk of dying in-hospital who may benefit from further monitoring.

Energetic dysfunction in sepsis: a narrative review

Background

Growing evidence associates organ dysfunction(s) with impaired metabolism in sepsis. Recent research has increased our understanding of the role of substrate utilization and mitochondrial dysfunction in the pathophysiology of sepsis-related organ dysfunction. The purpose of this review is to present this evidence as a coherent whole and to highlight future research directions.

Main text

Sepsis is characterized by systemic and organ-specific changes in metabolism. Alterations of oxygen consumption, increased levels of circulating substrates, impaired glucose and lipid oxidation, and mitochondrial dysfunction are all associated with organ dysfunction and poor outcomes in both animal models and patients. The pathophysiological relevance of bioenergetics and metabolism in the specific examples of sepsis-related immunodeficiency, cerebral dysfunction, cardiomyopathy, acute kidney injury and diaphragmatic failure is also described.

Conclusions

Recent understandings in substrate utilization and mitochondrial dysfunction may pave the way for new diagnostic and therapeutic approaches. These findings could help physicians to identify distinct subgroups of sepsis and to develop personalized treatment strategies. Implications for their use as bioenergetic targets to identify metabolism- and mitochondria-targeted treatments need to be evaluated in future studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00893-7.

Maternal Risk Modeling in Critical Care-Development of a Multivariable Risk Prediction Model for Death and Prolonged Intensive Care

OBJECTIVES

We aimed to develop and validate an accurate risk prediction model for both mortality and a combined outcome of mortality and morbidity for maternal admissions to critical care.

DESIGN

We used data from a high-quality prospectively collected national database, supported with literature review and expert opinion. We tested univariable associations between each risk factor and outcome. We then developed two separate multivariable logistic regression models for the outcomes of acute hospital mortality and death or prolonged ICU length of stay. We validated two parsimonious risk prediction models specific for a maternal population.

SETTING

The Intensive Care National Audit and Research Centre Case Mix Programme is the national clinical audit for adult critical care in England, Wales, and Northern Ireland.

PATIENTS

All female admissions to adult general critical care units, for the period January 1, 2007-December 31, 2016, 16-50 years old, and admitted either while pregnant or within 42 days of delivery-a cohort of 15,480 women.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We aimed to develop and validate an accurate risk prediction model for both mortality and a combined outcome of mortality and morbidity for maternal admissions to critical care. For the primary outcome of acute hospital mortality, our parsimonious risk model consisting of eight variables had an area under the receiver operating characteristic of 0.96 (95% CI, 0.91-1.00); these variables are commonly available for all maternal admissions. For the secondary composite outcome of death or ICU length of stay greater than 48 hours, the risk model consisting of 17 variables had an area under the receiver operating characteristic of 0.80 (95% CI, 0.78-0.83).

CONCLUSIONS

We developed risk prediction models specific to the maternal critical care population. The models compare favorably against general adult ICU risk prediction models in current use within this population.

Brunkhorst* F. Long-Term Survival Following Sepsis

BACKGROUND

There have not yet been any prospective registry studies in Germany with active investigation of the long-term survival of patients with sepsis.

METHODS

The Jena Sepsis Registry (JSR) included all patients with a diagnosis of sepsis in the four intensive care units of Jena University Hospital from January 2011 to December 2015. Long-term survival 6-48 months after diagnosis was documented by asking the treating general practitioners. The survival times were studied with Kaplan-Meier estimators. Cox regressions were calculated to show associations between possible predictors and survival time.

RESULTS

1975 patients with sepsis or septic shock were included. The mean time of observation was 730 days. For 96.4% of the queries to the general practitioners, information on long-term survival was available. Mortality in the intensive care unit was 34% (95% confidence interval [32; 37]), and in-hospital mortality was 45% [42; 47]. The overall mortality six months after diagnosis was 59% [57; 62], the overall mortality 48 months after diagnosis was 74% [72; 78]. Predictors of shorter survival were age, nosocomial origin of sepsis, diabetes, cerebrovascular disease, duration of stay in the intensive care unit, and renal replacement therapy.

CONCLUSION

The nearly 75% mortality four years after diagnosis indicates that changes are needed both in the acute treatment of patients with sepsis and in their multi-sector long-term care. The applicability of these findings may be limited by their having been obtained in a single center.

The Epidemiology of Sepsis in Chinese ICUs: A National Cross-Sectional Survey

OBJECTIVES

We performed a national cross-sectional survey to determine the epidemiologic characteristics of patients with sepsis in ICU in China.

DESIGN

A cross-section survey study.

SETTING

Forty-four hospitals in mainland China from December 1, 2015, to January 31, 2016.

PATIENTS

All septic patients diagnosed according sepsis-1 criteria admitted to participating ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We recorded demographic, physiologic, and microbiological data with follow-up for 90 days or death, if sooner. The frequency of sepsis and 90-day mortality rate were computed, and the relationship with gross domestic product determined. Multivariate logistic regression analysis was used to determine risk factors for 90-day mortality in patients with sepsis. Two-thousand three-hundred twenty-two patients with sepsis were included in the analysis, of whom 786 patients (33.9%) had hospital-acquired sepsis. The most common infection site was the lung (68.2%), followed by abdomen (26.6%) and bloodstream (7.8%). The frequency of sepsis in the ICU was 20.6 cases per 100 ICU admissions (95% CI, 15.8-25.4) with a 90-day mortality of 35.5%. The proportion of sepsis, severe sepsis, and septic shock were 3.10%, 43.6%, and 53.3% with a 90-day mortality of 2.78%, 17.69%, and 51.94%, respectively. Older age, low body weight, higher Sequential Organ Failure Assessment score, the number of systemic inflammatory response syndrome criteria, comorbid with heart failure, hematologic cancer, immunosuppression, higher level of lactate, infection site (pneumonia and bloodstream) were associated with 90-day mortality.

CONCLUSIONS

Sepsis affects a fifth of patients admitted to ICUs in mainland China with a 90-day mortality rate of 35.5%. Our findings indicate that a large burden of sepsis, and we need to focus on sepsis as a quality improvement target in China given the high mortality. In addition, further studies are needed to delineate the epidemiology of sepsis outside the ICU.

Sepsis and septic shock in France: incidences, outcomes and costs of care

Background

Sepsis is one of the leading causes of death worldwide. The associated incidence, mortality and trends do not differ greatly between documented reports. The purpose of this study was to provide an in-depth description of patients with sepsis and septic shock hospitalized in France from 2010 to 2015 and to explore the temporal trends of their clinical characteristics, costs and outcomes.

Methods

Retrospective cohort study of the French hospital administrative database in which organ failure therapies and severity scores are systematically registered. All patients admitted between 2010 and 2015 for sepsis and septic shock as defined by an ICD-10 code for infection, and for organ failure or the use of organ failure supplementation were included. Incidence, outcomes and trends were analyzed. Subgroup analyses based on several coding strategies and adjusted for severity scores were performed.

Results

A total of 737,147 patients with sepsis and 492,902 patients with septic shock were included. From 2010 to 2015, the incidence of sepsis and septic shock increased, respectively, from 206 to 243 and from 135 to 171 cases per 100,000 population. Case fatality remained at 34% for sepsis, but decreased from 46 to 44% for septic shock.

Median hospital stay costs amounted to €11,400 (IQR: 5036; 24,364) for patients with sepsis and €16,439 (IQR: 7339; 29,360) for patients with septic shock.

After adjustment for case-mix and illness severity, the risk of death was stable for sepsis (0.08% [− 0.04; 0.20] per year), but decreased for sepsis patients admitted to the intensive care unit and for cases of septic shock (− 0.33%[ − 0.40; − 0.27] per year).

Conclusions

Sepsis is common, frequently fatal and expensive to treat. Its incidence has increased. Case fatality has decreased in most severely affected patients, owing partly to general improvements in care.

Impact of different consensus definition criteria on sepsis diagnosis in a cohort of critically ill patients-Insights from a new mathematical probabilistic approach to mortality-based validation of sepsis criteria

Background

Sepsis-3 definition uses SOFA score to discriminate sepsis from uncomplicated infection, replacing SIRS criteria that were criticized for being inaccurate. Eligibility of sepsis-3 criteria for sepsis diagnosis and the applied validation methodology using mortality as endpoint are topic of ongoing debate. We assessed the impact of different criteria on sepsis diagnosis in our ICU and devised a mathematical approach for mortality-based validation of sepsis criteria. As infectious status is often unclear at clinical deterioration, we integrated non-infected patients into analysis.

Methods

Suspected infection, SOFA and SIRS were captured for an ICU cohort of a university center over one year. For raw scores (SIRS/SOFA) and sepsis criteria (SIRS≥2/SOFA≥2/SOFA_change≥2) frequencies and associations with in-hospital mortality were assessed. Using a mathematical approach, we estimated the correlation between sepsis and in-hospital mortality serving as reference for evaluation of observed mortality correlations of sepsis criteria.

Results

Of 791 patients, 369 (47%) were infected and 422 (53%) non-infected, with an in-hospital mortality of 39% and 15%. SIRS≥2 indicated sepsis in 90% of infected patients, SOFA≥2 in 99% and SOFA_change≥2 in 77%. In non-infected patients, SIRS, SOFA and SOFA_change were ≥2 in 78%, 88% and 58%. In AUROC analyses neither SOFA nor SIRS displayed superior mortality discrimination in infected compared to non-infected patients. The mathematically estimated correlation of sepsis and in-hospital mortality was 0.10 in infected and 0 in non-infected patients. Among sepsis criteria, solely SIRS≥2 agreed with expected correlations in both subgroups (infected: r = 0.19; non-infected: r = 0.02).

Conclusions

SOFA≥2 yielded a more liberal sepsis diagnosis than SIRS≥2. None of the criteria showed an infection specific occurrence that would be essential for reliable sepsis detection. However, SIRS≥2 matched the mortality association pattern of a valid sepsis criterion, whereas SOFA-based criteria did not. With this study, we establish a mathematical approach to mortality-based evaluation of sepsis criteria.

Potential Lipid Signatures for Diagnosis and Prognosis of Sepsis and Systemic Inflammatory Response Syndrome

Systemic inflammatory response syndrome (SIRS) and sepsis are two conditions which are difficult to differentiate clinically and which are strongly impacted for prompt intervention. This study identified potential lipid signatures that are able to differentiate SIRS from sepsis and to predict prognosis. Forty-two patients, including 21 patients with sepsis and 21 patients with SIRS, were involved in the study. Liquid chromatography coupled to mass spectrometry and multivariate statistical methods were used to determine lipids present in patient plasma. The obtained lipid signatures revealed 355 features for the negative ion mode and 297 for the positive ion mode, which were relevant for differential diagnosis of sepsis and SIRS. These lipids were also tested as prognosis predictors. Lastly, L-octanoylcarnitine was found to be the most promising lipid signature for both the diagnosis and prognosis of critically ill patients, with accuracies of 75% for both purposes. In short, we presented the determination of lipid signatures as a potential tool for differential diagnosis of sepsis and SIRS and prognosis of these patients.

Development, Validation, and Clinical Utility Assessment of a Prognostic Score for 1-Year Unplanned Rehospitalization or Death of Adult Sepsis Survivors

IMPORTANCE

The longer-term risk of rehospitalizations and death of adult sepsis survivors is associated with index sepsis illness characteristics.

OBJECTIVE

To derive and validate a parsimonious prognostic score for unplanned rehospitalizations or death in the first year after hospital discharge of adult sepsis survivors.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the Intensive Care National Audit & Research Centre Case Mix Programme database on adult sepsis survivors identified from consecutive critical care admissions to 192 adult general critical care units in England, United Kingdom, between April 1, 2009, and March 31, 2014 (94 748 patients in the derivation cohort), and between April 1, 2014, and March 31, 2015 (24 669 patients in the validation cohort). Statistical analysis was performed from July 5 to October 31, 2019. Generic characteristics (age, sex, race/ethnicity, 2015 Index of Multiple Deprivation [IMD2015] in England quintiles, preadmission dependence, previous hospitalizations in the year preceding index sepsis admission, comorbidity, admission type, Acute Physiology and Chronic Health Evaluation II physiology score, hospital length of stay, worst blood lactate and blood hemoglobin concentrations, and type of hospital) and sepsis-specific characteristics (site of infection, numbers of organ dysfunctions, and organ support) at the index sepsis admission were used as predictors.

MAIN OUTCOMES AND MEASURES

Prognostic score derived and validated using multivariable logistic regression for the outcome of unplanned rehospitalization or death in the first year after hospital discharge of adult sepsis survivors, as well as clinical usefulness assessed using decision curve analysis. Prognostic score validation was performed for internal validation with bootstrapping and temporal cohort external validation.

RESULTS

This cohort study included 94 748 patients (51 164 men [54.0%]; mean [SD] age, 61.3 [17.0] years) in the derivation cohort and 24 669 patients (13 255 men [53.7%]; mean [SD] age, 62.1 [16.8%]) in the validation cohort. Unplanned rehospitalization or death in the first year after hospital discharge occurred for 48 594 patients (51.3%) in the derivation cohort and 13 129 patients (53.2%) in the validation cohort. Eight independent predictors were identified and weighted to generate a prognostic score for every patient: previous hospitalizations, age in 10-year increments, IMD2015 in England quintiles, preadmission dependence, comorbidities, admission type, blood hemoglobin level, and site of infection. The total prognostic score ranged from 0 to 22 points, with lower scores indicating a lower risk of the outcome. The derivation and validation cohorts had similar rates of prognostic scores of 0 to 4 points (5088 of 16 684 patients [30.5%] and 471 of 1725 patients [27.3%]) and prognostic scores of 11 points or more (15 732 of 21 641 patients [72.7%] and 5753 of 7952 patients [72.3%]). The area under the receiver operating characteristic curve for the prognostic score was 0.675 (95% CI, 0.672-0.679). The decision curve analysis highlighted an optimal score cutoff of 7 points or more.

CONCLUSIONS AND RELEVANCE

The prognostic score reported in this study uses 8 internationally feasible predictors measured during the index sepsis admission and provides clinically useful information on sepsis survivors' risk of unplanned rehospitalization or death in the first year after hospital discharge.

Association of a Care Bundle for Early Sepsis Management With Mortality Among Patients With Hospital-Onset or Community-Onset Sepsis

IMPORTANCE

The Early Management Bundle for Severe Sepsis/Septic Shock (SEP-1) is a quality metric based on a care bundle for early sepsis management. Published evidence on the association of SEP-1 with mortality is mixed and largely excludes cases of hospital-onset sepsis.

OBJECTIVE

To assess the association of the SEP-1 bundle with mortality and organ dysfunction in cohorts with hospital-onset or community-onset sepsis.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used data from 4 University of California hospitals from October 1, 2014, to October 1, 2017. Adult inpatients with a diagnosis consistent with sepsis or disseminated infection and laboratory or vital signs meeting the Sepsis-3 (Third International Consensus Definitions for Sepsis and Septic Shock) criteria were divided into community-onset sepsis and hospital-onset sepsis cohorts based on whether time 0 of sepsis occurred after arrival in the emergency department or an inpatient area. Data were analyzed from April to October 2019. Additional analyses were performed from December 2019 to January 2020.

EXPOSURES

Administration of SEP-1 and 4 individual bundle components (serum lactate level testing, blood culture, broad-spectrum intravenous antibiotic treatment, and intravenous fluid treatment).

MAIN OUTCOMES AND MEASURES

The primary outcome was in-hospital mortality. The secondary outcome was days requiring vasopressor support, measured as vasopressor days.

RESULTS

Among the 6404 patient encounters identified (3535 men [55.2%]; mean [SD] age, 64.0 [18.2] years), 2296 patients (35.9%) had hospital-onset sepsis. Among 4108 patients (64.1%) with community-onset sepsis, serum lactate level testing within 3 hours of time 0 was associated with reduced mortality (absolute difference, -7.61%; 95% CI, -14.70% to -0.54%). Blood culture (absolute difference, -1.10 days; 95% CI, -1.85 to -0.34 days) and broad-spectrum intravenous antibiotic treatment (absolute difference, -0.62 days; 95% CI, -1.02 to -0.22 days) were associated with fewer vasopressor days. Among patients with hospital-onset sepsis, broad-spectrum intravenous antibiotic treatment was the only bundle component significantly associated with any improved outcome (mortality difference, -5.20%; 95% CI, -9.84% to -0.56%). Care that was adherent to the complete SEP-1 bundle was associated with increased vasopressor days in patients with community-onset sepsis (absolute difference, 0.31 days; 95% CI, 0.11-0.51 days) but was not significantly associated with reduced mortality in either cohort (absolute difference, -0.07%; 95% CI, -3.02% to 2.88% in community-onset; absolute difference, -0.42%; 95% CI, -6.77% to 5.93% in hospital-onset).

CONCLUSIONS AND RELEVANCE

SEP-1-adherent care was not associated with improved outcomes of sepsis. Although multiple components of SEP-1 were associated with reduced mortality or decreased days of vasopressor therapy for patients who presented with sepsis in the emergency department, only broad-spectrum intravenous antibiotic treatment was associated with reduced mortality when time 0 occurred in an inpatient unit. Current sepsis quality metrics may need refinement.

Serum total carbon dioxide as a prognostic factor for 28-day mortality in patients with sepsis

OBJECTIVE

Metabolic acidosis is commonly associated with the disease severity in patients with sepsis or septic shock. This study was performed to investigate the association between serum total carbon dioxide (TCO₂₎ concentration and 28-day mortality in patients with sepsis.

METHODS

This study was a multicenter retrospective cohort study of patients with sepsis or septic shock. The relationships between serum TCO₂ and 28-day mortality, bicarbonate, pH, lactate, and anion gap were determined with cubic spline curves. The patients were divided into four groups according to their serum TCO₂ concentration: Group I (TCO₂ > 20 mmol/l), Group II (15 < TCO₂ ≤ 20 mg/dl), Group III (10 < TCO₂ ≤ 15 mmol/l), and Group IV (TCO₂ ≤ 10 mmol/l).

RESULTS

A total of 3168 patients were included in the analysis, and the overall mortality rate was 24.1%. Serum TCO₂ concentrations below 20 mmol/l showed an almost linear correlation with mortality as well as with lactate, bicarbonate, and pH. The 28-day mortality rates of Group I, II, III, and IV were 18.3%, 23.6%, 32.6%, and 50.0%, respectively (p < .001). In Multivariable Cox proportional hazard regression analysis, the groups with lower serum TCO₂ concentrations had a higher risk of 28-day mortality compared with Group I: Group II (Hazard ratio (HR), 1.35; 95% confidence interval (CI), 1.11-1.64), Group III (HR, 1.74; 95% CI, 1.37-2.21), and Group IV (HR, 2.72; 95% CI, 2.03-3.64).

CONCLUSIONS

Serum TCO₂ concentrations of 20 mmol/l or less were associated with 28-day mortality in patients with sepsis.

Goodbye SIRS? Innate, trained and adaptive immunity and pathogenesis of organ dysfunction

The novel concepts within Sepsis‑3 criteria include a focus on dysregulated host responses, removal of the systemic inflammation response syndrome (SIRS) criteria from sepsis diagnosis, the use of Sepsis-related (Sequential) Organ Failure Assessment (SOFA) scores to define organ dysfunction, and the explicit recognition of the septic shock as a subset of sepsis. Protection against infection requires a surveillance system, an effector response against "perceived" pathogens, a method for regaining immune homeostasis following an immune response, and generation of immunological memory. In comparison to normally regulated responses to infection, the innate immune system shows profoundly abnormal neutrophil and macrophage function. Similarly, the adaptive immune system is typically depleted numerically of lymphocytes and functionally with T and B cell exhaustion. Although there are numerous proposed mechanisms by which these dysregulated immune responses may be associated with organ failure, it is unclear what the unifying organ failure mechanisms in sepsis are. Furthermore, in sepsis survivors, the epigenetic changes on immune cells and widespread changes to lymphocyte populations may increase the risk of adverse events such as rehospitalisation and mortality. Finally, our current gaps in understanding of the immune response trajectory and the associated modifiable mechanisms in sepsis leave us a long way from successful immunomodulation for these patients. This article is freely available.

Adherence to the SEP-1 Sepsis Bundle in Hospital-Onset v. Community-Onset Sepsis: a Multicenter Retrospective Cohort Study

BACKGROUND

Sepsis is the leading cause of in-hospital death. The SEP-1 sepsis bundle is a protocol for early sepsis care that requires providers to diagnose and treat sepsis quickly. Limited evidence suggests that adherence to the sepsis bundle is lower in cases of hospital-onset sepsis.

OBJECTIVE

To compare sepsis bundle adherence in hospital-onset vs. community-onset sepsis.

DESIGN

Retrospective cohort study using multivariable analysis of clinical data.

PARTICIPANTS

A total of 4658 inpatients age 18 or older were identified by diagnosis codes consistent with sepsis or disseminated infection.

SETTING

Four university hospitals in California between 2014 and 2016.

MAIN OUTCOMES AND MEASURES

The primary outcome was adherence to key components of the sepsis bundle defined by the Centers for Medicare and Medicaid Services in their core measure, SEP-1. Covariates included clinical characteristics related to the patient, infection, and pathogen.

KEY RESULTS

Compared with community-onset, cases of hospital-onset sepsis were less likely to receive SEP-1 adherent care (relative risk 0.33, 95% confidence interval 0.29-0.38, p < 0.001). With the exception of vasopressors (RR 1.11, p = 0.002), each component of SEP-1 evaluated-blood cultures (RR 0.76, p < 0.001), serum lactate (RR 0.51, p < 0001), broad-spectrum antibiotics (RR 0.62, p < 0.001), intravenous fluids (0.47, p < 0.001), and follow-up lactate (RR 0.71, p < 0.001)-was less likely to be performed within the recommended time frame in hospital-onset sepsis. Within the hospital, cases of hospital-onset sepsis arising on the ward were less likely to receive SEP-1-adherent care than were cases arising in the intensive care unit (RR 0.68, p = 0.004).

CONCLUSIONS

Inpatients with hospital-onset sepsis receive different management than individuals with community-onset sepsis. It remains to be determined whether system-level factors, provider-level factors, or factors related to measurement explain the observed variation in care or whether variation in care affects outcomes.

Defining persistent critical illness based on growth trajectories in patients with sepsis

BACKGROUND

Persistent critical illness is common in critically ill patients and is associated with vast medical resource use and poor clinical outcomes. This study aimed to define when patients with sepsis would be stabilized and transitioned to persistent critical illness, and whether such transition time varies between latent classes of patients.

METHODS

This was a retrospective cohort study involving sepsis patients in the eICU Collaborative Research Database. Persistent critical illness was defined at the time when acute physiological characteristics were no longer more predictive of in-hospital mortality (i.e., vital status at hospital discharge) than antecedent characteristics. Latent growth mixture modeling was used to identify distinct trajectory classes by using Sequential Organ Failure Assessment score measured during intensive care unit stay as the outcome, and persistent critical illness transition time was explored in each latent class.

RESULTS

The mortality was 16.7% (3828/22,868) in the study cohort. Acute physiological model was no longer more predictive of in-hospital mortality than antecedent characteristics at 15 days after intensive care unit admission in the overall population. Only a minority of the study subjects (n = 643, 2.8%) developed persistent critical illness, but they accounted for 19% (15,834/83,125) and 10% (19,975/198,833) of the total intensive care unit and hospital bed-days, respectively. Five latent classes were identified. Classes 1 and 2 showed increasing Sequential Organ Failure Assessment score over time and transition to persistent critical illness occurred at 16 and 27 days, respectively. The remaining classes showed a steady decline in Sequential Organ Failure Assessment scores and the transition to persistent critical illness occurred between 6 and 8 days. Elevated urea-to-creatinine ratio was a good biochemical signature of persistent critical illness.

CONCLUSIONS

While persistent critical illness occurred in a minority of patients with sepsis, it consumed vast medical resources. The transition time differs substantially across latent classes, indicating that the allocation of medical resources should be tailored to different classes of patients.

Early noncardiovascular organ failure and mortality in the cardiac intensive care unit

Background

Noncardiac organ failure has been associated with worse outcomes among a cardiac intensive care unit (CICU) population.

Hypothesis

We hypothesized that early organ failure based on the sequential organ failure assessment (SOFA) score would be associated with mortality in CICU patients.

Methods

Adult CICU patients from 2007 to 2015 were reviewed. Organ failure was defined as any SOFA organ subscore ≥3 on the first CICU day. Organ failure was evaluated as a predictor of hospital mortality and postdischarge survival after adjustment for illness severity and comorbidities.

Results

We included 10 004 patients with a mean age of 67 ± 15 years (37% female). Admission diagnoses included acute coronary syndrome in 43%, heart failure in 46%, cardiac arrest in 12%, and cardiogenic shock in 11%. Organ failure was present in 31%, including multiorgan failure in 12%. Hospital mortality was higher in patients with organ failure (22% vs 3%, adjusted OR 3.0, 95% CI 2.5‐3.7, P < .001). After adjustment, each failing organ system predicted twofold higher odds of hospital mortality (adjusted OR 1.9, 95% CI 1.1‐2.1, P < .001). Mortality risk was highest with cardiovascular, coagulation and liver failure. Among hospital survivors, organ failure was associated with higher adjusted postdischarge mortality risk (P < .001); multiorgan failure did not confer added long‐term mortality risk.

Conclusions

Early noncardiovascular organ failure, especially multiorgan failure, is associated with increased hospital mortality in CICU patients, and this risk continues after hospital discharge, emphasizing the need to promote early recognition of organ failure in CICU patients.

The Impact of Acute Organ Dysfunction on Long-Term Survival in Sepsis

OBJECTIVES

To estimate the impact of each of six types of acute organ dysfunction (hepatic, renal, coagulation, neurologic, cardiac, and respiratory) on long-term mortality after surviving sepsis hospitalization.

DESIGN

Multicenter, retrospective study.

SETTINGS

Twenty-one hospitals within an integrated healthcare delivery system in Northern California.

PATIENTS

Thirty thousand one hundred sixty-three sepsis patients admitted through the emergency department between 2010 and 2013, with mortality follow-up through April 2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Acute organ dysfunction was quantified using modified Sequential Organ Failure Assessment scores. The main outcome was long-term mortality among sepsis patients who survived hospitalization. The estimates of the impact of each type of acute organ dysfunction on long-term mortality were based on adjusted Cox proportional hazards models. Sensitivity analyses were conducted based on propensity score-matching and adjusted logistic regression. Hospital mortality was 9.4% and mortality was 31.7% at 1 year. Median follow-up time among sepsis survivors was 797 days (interquartile range: 384-1,219 d). Acute neurologic (odds ratio, 1.86; p < 0.001), respiratory (odds ratio, 1.43; p < 0.001), and cardiac (odds ratio, 1.31; p < 0.001) dysfunction were most strongly associated with short-term hospital mortality, compared with sepsis patients without these organ dysfunctions. Evaluating only patients surviving their sepsis hospitalization, acute neurologic dysfunction was also most strongly associated with long-term mortality (odds ratio, 1.52; p < 0.001) corresponding to a marginal increase in predicted 1-year mortality of 6.0% for the presence of any neurologic dysfunction (p < 0.001). Liver dysfunction was also associated with long-term mortality in all models, whereas the association for other organ dysfunction subtypes was inconsistent between models.

CONCLUSIONS

Acute sepsis-related neurologic dysfunction was the organ dysfunction most strongly associated with short- and long-term mortality and represents a key mediator of long-term adverse outcomes following sepsis.

Robustness of sepsis-3 criteria in critically ill patients

Background

Early recognition of sepsis is challenging, and diagnostic criteria have changed repeatedly. We assessed the robustness of sepsis-3 criteria in intensive care unit (ICU) patients.

Methods

We studied the apparent incidence and associated mortality of sepsis-3 among patients who were prospectively enrolled in the Molecular Diagnosis and Risk Stratification of Sepsis (MARS) cohort in the Netherlands, and explored the effects of minor variations in the precise definition and timing of diagnostic criteria for organ failure.

Results

Among 1081 patients with suspected infection upon ICU admission, 648 (60%) were considered to have sepsis according to prospective adjudication in the MARS study, whereas 976 (90%) met sepsis-3 criteria, yielding only 64% agreement at the individual patient level. Among 501 subjects developing ICU-acquired infection, these rates were 270 (54%) and 260 (52%), respectively (yielding 58% agreement). Hospital mortality was 234 (36%) vs 277 (28%) for those meeting MARS-sepsis or sepsis-3 criteria upon presentation (p < 0.001), and 121 (45%) vs 103 (40%) for those having sepsis onset in the ICU (p < 0.001). Minor variations in timing and interpretation of organ failure criteria had a considerable effect on the apparent prevalence of sepsis-3, which ranged from 68 to 96% among those with infection at admission, and from 22 to 99% among ICU-acquired cases.

Conclusion

The sepsis-3 definition lacks robustness as well as discriminatory ability, since nearly all patients presenting to ICU with suspected infection fulfill its criteria. These should therefore be specified in greater detail, and applied more consistently, during future sepsis studies.

Trial registration

The MARS study is registered at ClinicalTrials.gov (identifier NCT 01905033).

Electronic supplementary material

The online version of this article (10.1186/s40560-019-0400-6) contains supplementary material, which is available to authorized users.

Risk Factors at Index Hospitalization Associated With Longer-term Mortality in Adult Sepsis Survivors

IMPORTANCE

Sepsis survivors, defined as adult patients who survived to hospital discharge following a critical care unit admission for sepsis, are at increased risk of long-term mortality. Identifying factors independently associated with long-term mortality, known during critical care admission for sepsis, could inform targeted strategies to reduce this risk.

OBJECTIVE

To assess, in adult sepsis survivors, factors independently associated with long-term mortality, known during their index critical care admission for sepsis, meeting Third International Consensus Definitions for Sepsis and Septic Shock criteria.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included a nationally representative sample of 94 748 adult sepsis survivors from 192 critical care units in England. Participants were identified from consecutive critical care admissions between April 1, 2009, and March 31, 2014, with survival status ascertained as of March 31, 2015. Statistical analyses were completed in June 2017.

EXPOSURES

Generic patient characteristics (age, sex, ethnicity, severe comorbidities [defined using the Acute Physiology and Chronic Health Evaluation II method], dependency, surgical status, and acute illness severity [scored using the Acute Physiology and Chronic Health Evaluation II acute physiology component]) and sepsis-specific patient characteristics (site of infection, number of organ dysfunctions, and septic shock status) known during index critical care admission for sepsis.

MAIN OUTCOMES AND MEASURES

Long-term mortality in adult sepsis survivors with maximum follow-up of 6 years. Adjusted hazard ratios (HRs) were estimated using Cox regression for both generic and sepsis-specific patient characteristics.

RESULTS

Sepsis survivors had a mean (SD) age of 61.3 (17.0) years, 43 584 (46.0%) were female, and 86 056 (90.8%) were white. A total of 46.3% had respiratory site of infection. By 1 year from hospital discharge, 15% of sepsis survivors had died, with 6% to 8% dying per year over the subsequent 5 years. Age, sex, race/ethnicity, severe comorbidities, dependency, nonsurgical status, and site of infection were independently associated with long-term mortality. Compared with single-organ dysfunction, having 2 or 3 organ dysfunctions was associated with increased risk of long-term mortality (adjusted HR, 1.07; 95% CI, 1.01-1.13; and adjusted HR, 1.18; 95% CI, 1.03-1.14, respectively), while having 4 organ dysfunctions or more was not associated with increased risk. Unexpectedly, the Acute Physiology and Chronic Health Evaluation acute physiology component score had an incremental association with long-term mortality (adjusted HR, 1.11 for every 5-point increase; 95% CI, 1.08-1.13). The adjusted HR for septic shock was 0.89 (95% CI, 0.85-0.92).

CONCLUSIONS AND RELEVANCE

This study suggests that generic and sepsis-specific risk factors, known during index critical care admission for sepsis, could identify a high-risk sepsis survivor population for biological characterization and designing interventions to reduce long-term mortality.

Early PREdiction of sepsis using leukocyte surface biomarkers: the ExPRES-sepsis cohort study

PURPOSE

Reliable biomarkers for predicting subsequent sepsis among patients with suspected acute infection are lacking. In patients presenting to emergency departments (EDs) with suspected acute infection, we aimed to evaluate the reliability and discriminant ability of 47 leukocyte biomarkers as predictors of sepsis (Sequential Organ Failure Assessment score ≥ 2 at 24 h and/or 72 h following ED presentation).

METHODS

In a multi-centre cohort study in four EDs and intensive care units (ICUs), we standardised flow-cytometric leukocyte biomarker measurement and compared patients with suspected acute infection (cohort-1) with two comparator cohorts: ICU patients with established sepsis (cohort-2), and ED patients without infection or systemic inflammation but requiring hospitalization (cohort-3).

RESULTS

Between January 2014 and February 2016, we recruited 272, 59 and 75 patients to cohorts 1, 2, and 3, respectively. Of 47 leukocyte biomarkers, 14 were non-reliable, and 17 did not discriminate between the three cohorts. Discriminant analyses for predicting sepsis within cohort-1 were undertaken for eight neutrophil (cluster of differentiation antigens (CD) CD15; CD24; CD35; CD64; CD312; CD11b; CD274; CD279), seven monocyte (CD35; CD64; CD312; CD11b; HLA-DR; CD274; CD279) and a CD8 T-lymphocyte biomarker (CD279). Individually, only higher neutrophil CD279 [OR 1.78 (95% CI 1.23-2.57); P = 0.002], higher monocyte CD279 [1.32 (1.03-1.70); P = 0.03], and lower monocyte HLA-DR [0.73 (0.55-0.97); P = 0.03] expression were associated with subsequent sepsis. With logistic regression the optimum biomarker combination was increased neutrophil CD24 and neutrophil CD279, and reduced monocyte HLA-DR expression, but no combination had clinically relevant predictive validity.

CONCLUSIONS

From a large panel of leukocyte biomarkers, immunosuppression biomarkers were associated with subsequent sepsis in ED patients with suspected acute infection.

CLINICAL TRIAL REGISTRATION

NCT02188992.

Challenges in assessing the burden of sepsis and understanding the inequalities of sepsis outcomes between National Health Systems: secular trends in sepsis and infection incidence and mortality in Germany

Purpose

Sepsis contributes considerably to global morbidity and mortality, while reasons for its increasing incidence remain unclear. We assessed risk adjusted secular trends in sepsis and infection epidemiology in Germany.

Methods

Retrospective cohort study using nationwide German hospital discharge data. We assessed incidence, outcomes and trends of hospital-treated sepsis and infections between 2010 and 2015. Sepsis was identified by explicit ICD-10 sepsis codes. As sensitivity analysis, results were compared with sepsis cases identified by implicit sepsis coding (combined infection and organ dysfunction codes).

Results

Among 18 664 877 hospital admissions in 2015, 4 213 116 (22.6%) patients had at least one infection code. There were 320 198 patients that had explicit sepsis codes including 136 542 patients with severe sepsis and septic shock; 183 656 patients were coded as sepsis without organ dysfunction. For patients with explicitly coded sepsis (including severe sepsis), or with severe sepsis alone, mortality rates over the period 2010–2015 decreased from 26.6 to 23.5%, and from 47.8 to 41.7%, respectively.

Conclusions

Sepsis and infection remain significant causes of hospital admission and death in Germany. Sepsis-related mortality is higher and has declined to a lesser degree than in other high-income countries. Although infection rates steadily increased, the observed annual increase of sepsis cases seems to result, to a considerable degree, from improved coding of sepsis.

Electronic supplementary material

The online version of this article (10.1007/s00134-018-5377-4) contains supplementary material, which is available to authorized users.

Relationship between Anaemia, Haemolysis, Inflammation and Haem Oxygenase-1 at Admission with Sepsis: a pilot study

Upregulation of haem oxygenase-1 (HO-1), due to haemolysis and/or inflammation, can lead to impaired immune function. Anaemia is common among sepsis patients, but the consequences of sepsis-associated anaemia are poorly understood. Here, our objective was to determine the prevalence and extent of anaemia, haemolysis, inflammation, and HO-1 induction after early hospital admission. We hypothesised that inflammation- or infection-induced haemolysis contributes to sepsis-associated anaemia and that this will lead to expression of HO-1. In this study, plasma obtained from seventy adult patients within 12 hours of admission to intensive care due to sepsis were analysed for anaemia, haemolysis and inflammatory markers by ELISA and microbead array. The majority (82.6%) of patients were anaemic with evidence of haemolysis (raised haem, haptoglobin, haemopexin, and HO-1 concentrations). Interestingly, concentrations of both haemoglobin and IL-10 were moderately positively correlated with HO-1 concentration (Hb: r = 0.32, p = 0.007; IL-10 r = 0.39, p = 0.0008) whereas HO-1 concentration was weakly negatively correlated with haemopexin (r = −0.23, p = 0.055). Anaemia, while common, was not associated with HO-1 concentration. After adjusting for confounding, HO-1 induction appears to be associated primarily with IL-10 concentration rather than haemolysis. Disease severity at diagnosis was correlated with early plasma IL-10 (r = 0.35, p = 0.003) and HO-1 (r = 0.24, p = 0.048) concentrations. Notably, admission levels of haem, HO-1, and IL-10 were indicators of survival.

Lymphocyte subset expression and serum concentrations of PD-1/PD-L1 in sepsis - pilot study

Background

Sepsis remains a major cause of mortality in critical care, for which specific treatments are lacking. The dysregulated response to infection seen in sepsis includes features of lymphocyte dysfunction and exhaustion, suggesting that immune-stimulatory therapy may improve outcomes in certain patient groups. Monoclonal antibodies targeting checkpoint molecules, such as programmed-death 1 protein (PD-1) and its ligand PD-L1, have shown success in stimulating the immune response in patients with cancer, and are being considered for future sepsis trials. The aims of this pilot study were to compare lymphocyte subset expression of PD-1 and its ligands between patients with sepsis and controls; to characterize serum levels of PD-1 and PD-L1 in patients with sepsis and controls, and determine if serum concentrations correlated with cell surface expression.

Methods

Expression levels of PD-1, PD-L1 and PD-L2 on four lymphocyte subsets (CD27 + CD19+ B cells, CD27-CD19+ B cells, CD27 + CD4+ T cells and CD27-CD4+ T cells) were compared between 22 patients with sepsis (including 11 survivors and 11 non-survivors) and 11 healthy controls using flow cytometry. Levels of soluble PD-1 and PD-L1 were also compared using commercially available ELISA kits.

Results

Expression of PD-1 and PD-L1 was higher on all lymphocyte subsets in patients with sepsis compared to controls (p < 0.05). PD-L2 expression on CD27+ B cells was also higher in patients with sepsis (p = 0.0317). There was differential expression of PD-1 by CD27 status, with expression being higher in the B and T cell subsets associated with memory status (CD27+ and CD27-, respectively; p < 0.001). Higher PD-1 and PD-L1 expression was not associated with mortality or with a higher risk of nosocomial infection. There were no differences in levels of soluble PD-1 or PD-L1 between patients with sepsis and controls.

Conclusions

Higher expression of PD-1 by memory subpopulations of B cells and CD4+ T cells, with normal soluble PD-1 and PD-L1 in patients with sepsis, are novel findings. This information may be useful to enrich sepsis populations for trials of PD-1/PD-L1 blockade.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2020-2) contains supplementary material, which is available to authorized users.

A risk-model for hospital mortality among patients with severe sepsis or septic shock based on German national administrative claims data

BACKGROUND

Sepsis is a major cause of preventable deaths in hospitals. Feasible and valid methods for comparing quality of sepsis care between hospitals are needed. The aim of this study was to develop a risk-adjustment model suitable for comparing sepsis-related mortality between German hospitals.

METHODS

We developed a risk-model using national German claims data. Since these data are available with a time-lag of 1.5 years only, the stability of the model across time was investigated. The model was derived from inpatient cases with severe sepsis or septic shock treated in 2013 using logistic regression with backward selection and generalized estimating equations to correct for clustering. It was validated among cases treated in 2015. Finally, the model development was repeated in 2015. To investigate secular changes, the risk-adjusted trajectory of mortality across the years 2010-2015 was analyzed.

RESULTS

The 2013 deviation sample consisted of 113,750 cases; the 2015 validation sample consisted of 134,851 cases. The model developed in 2013 showed good validity regarding discrimination (AUC = 0.74), calibration (observed mortality in 1st and 10th risk-decile: 11%-78%), and fit (R2 = 0.16). Validity remained stable when the model was applied to 2015 (AUC = 0.74, 1st and 10th risk-decile: 10%-77%, R2 = 0.17). There was no indication of overfitting of the model. The final model developed in year 2015 contained 40 risk-factors. Between 2010 and 2015 hospital mortality in sepsis decreased from 48% to 42%. Adjusted for risk-factors the trajectory of decrease was still significant.

CONCLUSIONS

The risk-model shows good predictive validity and stability across time. The model is suitable to be used as an external algorithm for comparing risk-adjusted sepsis mortality among German hospitals or regions based on administrative claims data, but secular changes need to be taken into account when interpreting risk-adjusted mortality.

Unexplained mortality differences between septic shock trials: a systematic analysis of population characteristics and control-group mortality rates

Purpose

Although the definition of septic shock has been standardized, some variation in mortality rates among clinical trials is expected. Insights into the sources of heterogeneity may influence the design and interpretation of septic shock studies. We set out to identify inclusion criteria and baseline characteristics associated with between-trial differences in control group mortality rates.

Methods

We conducted a systematic review of RCTs published between 2006 and 2018 that included patients with septic shock. The percentage of variance in control-group mortality attributable to study heterogeneity rather than chance was measured by I². The association between control-group mortality and population characteristics was estimated using linear mixed models and a recursive partitioning algorithm.

Results

Sixty-five septic shock RCTs were included. Overall control-group mortality was 38.6%, with significant heterogeneity (I² = 93%, P < 0.0001) and a 95% prediction interval of 13.5–71.7%. The mean mortality rate did not differ between trials with different definitions of hypotension, infection or vasopressor or mechanical ventilation inclusion criteria. Population characteristics univariately associated with mortality rates were mean Sequential Organ Failure Assessment score (standardized regression coefficient (β) = 0.57, P = 0.007), mean serum creatinine (β = 0.48, P = 0.007), the proportion of patients on mechanical ventilation (β = 0.61, P < 0.001), and the proportion with vasopressors (β = 0.57, P = 0.002). Combinations of population characteristics selected with a linear model and recursive partitioning explained 41 and 42%, respectively, of the heterogeneity in mortality rates.

Conclusions

Among 65 septic shock trials, there was a clinically relevant amount of heterogeneity in control group mortality rates which was explained only partly by differences in inclusion criteria and reported baseline characteristics.

Electronic supplementary material

The online version of this article (10.1007/s00134-018-5134-8) contains supplementary material, which is available to authorized users.

The German Quality Network Sepsis: study protocol for the evaluation of a quality collaborative on decreasing sepsis-related mortality in a quasi-experimental difference-in-differences design

BACKGROUND

While sepsis-related mortality decreased substantially in other developed countries, mortality of severe sepsis remained as high as 44% in Germany. A recent German cluster randomized trial was not able to improve guideline adherence and decrease sepsis-related mortality within the participating hospitals, partly based on lacking support by hospital management and lacking resources for documentation of prospective data. Thus, more pragmatic approaches are needed to improve quality of sepsis care in Germany. The primary objective of the study is to decrease sepsis-related hospital mortality within a quality collaborative relying on claims data.

METHOD

The German Quality Network Sepsis (GQNS) is a quality collaborative involving 75 hospitals. This study protocol describes the conduction and evaluation of the start-up period of the GQNS running from March 2016 to August 2018. Democratic structures assure participatory action, a study coordination bureau provides central support and resources, and local interdisciplinary quality improvement teams implement changes within the participating hospitals. Quarterly quality reports focusing on risk-adjusted hospital mortality in cases with sepsis based on claims data are provided. Hospitals committed to publish their individual risk-adjusted mortality compared to the German average. A complex risk-model is used to control for differences in patient-related risk factors. Hospitals are encouraged to implement a bundle of interventions, e.g., interdisciplinary case analyses, external peer-reviews, hospital-wide staff education, and implementation of rapid response teams. The effectiveness of the GQNS is evaluated in a quasi-experimental difference-in-differences design by comparing the change of hospital mortality of cases with sepsis with organ dysfunction from a retrospective baseline period (January 2014 to December 2015) and the intervention period (April 2016 to March 2018) between the participating hospitals and all other German hospitals. Structural and process quality indicators of sepsis care as well as efforts for quality improvement are monitored regularly.

DISCUSSION

The GQNS is a large-scale quality collaborative using a pragmatic approach based on claims data. A complex risk-adjustment model allows valid quality comparisons between hospitals and with the German average. If this study finds the approach to be useful for improving quality of sepsis care, it may also be applied to other diseases.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02820675.

Epidemiology and Outcomes

Sepsis is a global public health concern. Internationally it contributes to more than 5 million deaths annually. Although rates are variable between countries, over the past 40 years reported incidence has continued to increase. Aside from potential differences in patient populations, the variation in reported rates also reflects differences in identification strategies, access to health care, and awareness of the diagnosis. Factors such as age, sex, socioeconomic status, comorbid disease, and type and site of infection impact the development of and outcomes from sepsis. Although advances have been made in treatment, its impact remains substantial.

The influence of a change in septic shock definitions on intensive care epidemiology and outcome: comparison of sepsis-2 and sepsis-3 definitions

BACKGROUND

Clear definitions for septic shock assist clinicians regarding recognition, treatment and standardized reporting of characteristics and outcome of this entity. Sepsis-3 definition of septic shock incorporates a new criterion, a lactate level >2 mmol/L. Differences in epidemiology and outcome of septic shock based upon both definitions were studied in an intensive care (ICU) population of septic patients.

METHODS

We analyzed a prospectively collected cohort of data in the ICU of the Maastricht University Medical Centre. 632 septic patients were included. ICU mortality was compared between the patient group fulfilling Sepsis-3 definition for septic shock and those that met Sepsis-2 definition. Furthermore, association between lactate levels and ICU mortality was studied.

RESULTS

Of 632 septic patients, 482 (76.3%) had septic shock according to Sepsis-2 and 300 patients (48.4%) according to Sepsis-3 definition, respectively. Patients meeting Sepsis-3 definition had a higher mortality than patients meeting Sepsis-2 definition (38.9 vs. 34.0%). Serum lactate levels between 2 and 4 mmol/L (25.0 vs. 26.2%, OR 0.94 (0.5-1.5)) and between 4 and 6 mmol/L (23.8 vs. 26.2%, OR 0.88 (0.4-1.7)) compared to levels ≤2 mmol/L were not associated with significantly higher ICU mortality. Serum lactate values ≥6 mmol/L, were significantly associated with increased ICU mortality.

CONCLUSION

Patients classified according to Sepsis-3 criteria had a higher ICU mortality compared with Sepsis-2 criteria. Lactate levels <6 mmol/L were not able to identify patients with increased ICU mortality. Lactate threshold of 2 mmol/L may be too low to point out patients with actual increased ICU mortality.

Early, Goal-Directed Therapy for Septic Shock - A Patient-Level Meta-Analysis

BACKGROUND

After a single-center trial and observational studies suggesting that early, goal-directed therapy (EGDT) reduced mortality from septic shock, three multicenter trials (ProCESS, ARISE, and ProMISe) showed no benefit. This meta-analysis of individual patient data from the three recent trials was designed prospectively to improve statistical power and explore heterogeneity of treatment effect of EGDT.

METHODS

We harmonized entry criteria, intervention protocols, outcomes, resource-use measures, and data collection across the trials and specified all analyses before unblinding. After completion of the trials, we pooled data, excluding the protocol-based standard-therapy group from the ProCESS trial, and resolved residual differences. The primary outcome was 90-day mortality. Secondary outcomes included 1-year survival, organ support, and hospitalization costs. We tested for treatment-by-subgroup interactions for 16 patient characteristics and 6 care-delivery characteristics.

RESULTS

We studied 3723 patients at 138 hospitals in seven countries. Mortality at 90 days was similar for EGDT (462 of 1852 patients [24.9%]) and usual care (475 of 1871 patients [25.4%]); the adjusted odds ratio was 0.97 (95% confidence interval, 0.82 to 1.14; P=0.68). EGDT was associated with greater mean (±SD) use of intensive care (5.3±7.1 vs. 4.9±7.0 days, P=0.04) and cardiovascular support (1.9±3.7 vs. 1.6±2.9 days, P=0.01) than was usual care; other outcomes did not differ significantly, although average costs were higher with EGDT. Subgroup analyses showed no benefit from EGDT for patients with worse shock (higher serum lactate level, combined hypotension and hyperlactatemia, or higher predicted risk of death) or for hospitals with a lower propensity to use vasopressors or fluids during usual resuscitation.

CONCLUSIONS

In this meta-analysis of individual patient data, EGDT did not result in better outcomes than usual care and was associated with higher hospitalization costs across a broad range of patient and hospital characteristics. (Funded by the National Institute of General Medical Sciences and others; PRISM ClinicalTrials.gov number, NCT02030158 .).