Surviving the first hours in sepsis: getting the basics right (an intensivist's perspective)

Assessment of implementation methods in sepsis: study protocol for a cluster-randomized hybrid type 2 trial

BACKGROUND

Sepsis is the leading cause of intensive care unit (ICU) admission and ICU death. In recognition of the burden of sepsis, the Surviving Sepsis Campaign (SSC) and the Institute for Healthcare Improvement developed sepsis "bundles" (goals to accomplish over a specific time period) to facilitate SSC guideline implementation in clinical practice. Using the SSC 3-h bundle as a base, the Centers for Medicare and Medicaid Services developed a 3-h sepsis bundle that has become the national standard for early management of sepsis. Emerging observational data, from an analysis conducted for the AIMS grant application, suggest there may be additional mortality benefit from even earlier implementation of the 3-h bundle, i.e., the 1-h bundle.

METHOD

The primary aims of this randomized controlled trial are to: (1) examine the effect on clinical outcomes of Emergency Department initiation of the elements of the 3-h bundle within the traditional 3 h versus initiating within 1 h of sepsis recognition and (2) examine the extent to which a rigorous implementation strategy will improve implementation and compliance with both the 1-h bundle and the 3-h bundle. This study will be entirely conducted in the Emergency Department at 18 sites. A secondary aim is to identify clinical sepsis phenotypes and their impact on treatment outcomes.

DISCUSSION

This cluster-randomized trial, employing implementation science methodology, is timely and important to the field. The hybrid effectiveness-implementation design is likely to have an impact on clinical practice in sepsis management by providing a rigorous evaluation of the 1- and 3-h bundles.

FUNDING

NHLBI R01HL162954.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05491941. Registered on August 8, 2022.

New Insights into the Fluid Management in Patients with Septic Shock

The importance of fluid resuscitation therapy during the early stages of sepsis management is a well-established principle. Current Surviving Sepsis Campaign (SSC) guidelines recommend the early administration of intravenous crystalloid fluids for sepsis-related hypotension or hyperlactatemia due to tissue hypoperfusion, within the first 3 h of resuscitation and suggest using balanced solutions (BSs) instead of normal saline (NS) for the management of patients with sepsis or septic shock. Studies comparing BS versus NS administration in septic patients have demonstrated that BSs are associated with better outcomes including decreased mortality. After initial resuscitation, fluid administration has to be judicious in order to avoid fluid overload, which has been associated with increased mortality, prolonged mechanical ventilation, and worsening of acute kidney injury. The "one size fits all" approach may be "convenient" but it should be avoided. Personalized fluid management, based on patient-specific hemodynamic indices, provides the foundations for better patient outcomes in the future. Although there is a consensus on the need for adequate fluid therapy in sepsis, the type, the amount of administered fluids, and the ideal fluid resuscitation strategy remain elusive. Well-designed large randomized controlled trials are certainly needed to compare fluid choices specifically in the septic patient, as there is currently limited evidence of low quality. This review aims to summarize the physiologic principles and current scientific evidence regarding fluid management in patients with sepsis, as well as to provide a comprehensive overview of the latest data on the optimal fluid administration strategy in sepsis.

Effect of a tailored sepsis treatment protocol on patient outcomes in the Tikur Anbessa Specialized Hospital, Ethiopia: results of an interrupted time series analysis

BACKGROUND

Despite improvement, sepsis mortality rates remain high, with an estimated 11 million sepsis-related deaths globally in 2017 (Rudd et. al, Lancet 395:200-211, 2020). Low- and middle-income countries (LMICs) are estimated to account for 85% of global sepsis mortality; however, evidence for improved sepsis mortality in LMICs is lacking. We aimed to improve sepsis care and outcomes through development and evaluation of a sepsis treatment protocol tailored to the Tikur Anbessa Specialized Hospital Emergency Department, Ethiopia, context.

METHODS

We employed a mixed methods design, including an interrupted times series study, pre-post knowledge testing, and process evaluation. The primary outcome was the proportion of patients receiving appropriate sepsis care (blood culture collection before antibiotics and initiation of appropriate antibiotics within 1 h of assessment). Secondary outcomes included time to antibiotic administration, 72-h sepsis mortality, and 90-day all-cause mortality. Due to poor documentation, we were unable to assess our primary outcome and time to antibiotic administration. We used segmented regression with outcomes as binomial proportions to assess the impact of the intervention on mortality. Pre-post knowledge test scores were analyzed using the Student's t-test to compare group means for percentage of scenarios with correct diagnosis.

RESULTS

A total of 113 and 300 patients were enrolled in the pre-implementation and post-implementation phases respectively. While age and gender were similar across the phases, a higher proportion (31 vs. 57%) of patients had malignancies in the post-implementation phase. We found a significant change in trend between the phases, with a trend for increasing odds of survival in the pre-implementation phase (OR 1.24, 95% CI 0.98-1.56), and a shift down, with odds of survival virtually flat (OR 0.95, 95% CI. 0.88-1.03) in the post-implementation phases for 72-h mortality, and trends for survival pre- and post-implementation are virtually flat for 90-day mortality. We found no significant difference in pre-post knowledge test scores, with interpretation limited by response rate. Implementation quality was negatively impacted by resource challenges.

CONCLUSION

We found no improvement in sepsis outcomes, with a trend for increasing odds of survival lost post-implementation and no significant change in knowledge pre- and post-implementation. Variable availability of resources was the principal barrier to implementation.

TRIAL REGISTRATION

Open Science Framework osf.io/ju4ga . Registered June 28, 2017.

Prehospital administration of broad-spectrum antibiotics for sepsis patients: A systematic review and meta-analysis

Background and Aims

Some studies have suggested that earlier initiation of antibiotics has shown positive outcomes in sepsis patients. We aimed to do a systematic review and meta-analysis to evaluate the effect of prehospital administration of antibiotics on 28 days mortality and length of stay in hospital and intensive care unit for sepsis patients.

Methods

We formulated a search strategy and used it on search databases PubMed, Scopus, Web of Science, and Embase. We then screened the records for eligibility and included controlled studies, either clinical trials or cohort studies reporting prehospital antibiotic administration for sepsis patients. We excluded duplicates, books, conferences' abstracts, case reports, editorials, letters, author responses, not English studies, and studies with nonavailable full text. Animal and lab studies were also excluded.

Results

The total number of studies identified is 1811, 19 were eligible for systematic review and 4 for meta-analysis (three cohort and one clinical trial). The total number of sepsis patients in the four included studies in the 28 days mortality outcome was 3523 (1779 took prehospital antibiotics and 1744 did not take prehospital antibiotics). Of 1779 who took the antibiotics, 190 died, and of 1744 who did not take antibiotics, 292 died (95% confidence interval 0.68-0.97, p = 0.02).

Conclusion

This meta-analysis reveals that receiving prehospital antibiotics can significantly lower mortality in sepsis patients compared to patients who do not receive prehospital antibiotics. However, more clinical trials and multicenter prospective studies with high sample sizes are needed to get strong evidence supporting our findings.

Improving sepsis care in Africa: an opportunity for change?

Sepsis is common and represents a major public health burden with significant associated morbidity and mortality. However, despite substantial advances in sepsis recognition and management in well-resourced health systems, there remains a distinct lack of research into sepsis in Africa. The lack of evidence affects all levels of healthcare delivery from individual patient management to strategic planning at health-system level. This is particular pertinent as African countries experience some of the highest global burden of sepsis. The 2017 World Health Assembly resolution on sepsis and the creation of the Africa Sepsis Alliance provided an opportunity for change. However, progress so far has been frustratingly slow. The recurrent Ebola virus disease outbreaks and the COVID-19 pandemic on the African continent further reinforce the need for urgent healthcare system strengthening. We recommend that African countries develop national action plans for sepsis which should address the needs of all critically ill patients.

Randomised feasibility study of prehospital recognition and antibiotics for emergency patients with sepsis (PhRASe)

Severe sepsis is a time critical condition which is known to have a high mortality rate. Evidence suggests that early diagnosis and early administration of antibiotics can reduce morbidity and mortality from sepsis. The prehospital phase of emergency medical care may provide the earliest opportunity for identification of sepsis and delivery of life-saving treatment for patients. We aimed to assess the feasibility of (1) paramedics recognising and screening patients for severe sepsis, collecting blood cultures and administering intravenous antibiotics; and (2) trial methods in order to decide whether a fully-powered trial should be undertaken to determine safety and effectiveness of this intervention. Paramedics were trained in using a sepsis screening tool, aseptic blood culture collection and administration of intravenous antibiotics. If sepsis was suspected, paramedics randomly allocated patients to intervention or usual care using scratchcards. Patients were followed up at 90 days using linked anonymised data to capture length of hospital admission and mortality. We collected self-reported health-related quality of life at 90 days. We pre-specified criteria for deciding whether to progress to a fully-powered trial based on: recruitment of paramedics and patients; delivery of the intervention; retrieval of outcome data; safety; acceptability; and success of anonymised follow-up. Seventy-four of the 104 (71.2%) eligible paramedics agreed to take part and 54 completed their training (51.9%). Of 159 eligible patients, 146 (92%) were recognised as eligible by study paramedics, and 118 were randomised (74% of eligible patients, or 81% of those recognised as eligible). Four patients subsequently dissented to be included in the trial (3%), leaving 114 patients recruited to follow-up. All recruited patients were matched to routine data outcomes in the Secure Anonymised Information Linkage Databank. Ninety of the 114 (79%) recruited patients had sepsis or a likely bacterial infection recorded in ED. There was no evidence of any difference between groups in patient satisfaction, and no adverse reactions reported. There were no statistically significant differences between intervention and control groups in Serious Adverse Events (ICU admissions; deaths). This feasibility study met its pre-determined progression criteria; an application will therefore be prepared and submitted for funding for a fully-powered multi-centre randomised trial.Trial registration: ISRCTN36856873 sought 16th May 2017; https://doi.org/10.1186/ISRCTN36856873.

Monocyte Distribution Width, Neutrophil-to-Lymphocyte Ratio, and Platelet-to-Lymphocyte Ratio Improves Early Prediction for Sepsis at the Emergency

(1) Background: Sepsis is a life-threatening condition, and most patients with sepsis first present to the emergency department (ED) where early identification of sepsis is challenging due to the unavailability of an effective diagnostic model. (2) Methods: In this retrospective study, patients aged ≥20 years who presented to the ED of an academic hospital with systemic inflammatory response syndrome (SIRS) were included. The SIRS, sequential organ failure assessment (SOFA), and quick SOFA (qSOFA) scores were obtained for all patients. Routine complete blood cell testing in conjugation with the examination of new inflammatory biomarkers, namely monocyte distribution width (MDW), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), was performed at the ED. Propensity score matching was performed between patients with and without sepsis. Logistic regression was used for constructing models for early sepsis prediction. (3) Results: We included 296 patients with sepsis and 1184 without sepsis. A SIRS score of >2, a SOFA score of >2, and a qSOFA score of >1 showed low sensitivity, moderate specificity, and limited diagnostic accuracy for predicting early sepsis infection (c-statistics of 0.660, 0.576, and 0.536, respectively). MDW > 20, PLR > 9, and PLR > 210 showed higher sensitivity and moderate specificity. When we combined these biomarkers and scoring systems, we observed a significant improvement in diagnostic performance (c-statistics of 0.796 for a SIRS score of >2, 0.761 for a SOFA score of >2, and 0.757 for a qSOFA score of >1); (4) Conclusions: The new biomarkers MDW, NLR, and PLR can be used for the early detection of sepsis in the current sepsis scoring systems.

What can we learn from supermarkets? An application of the Poisson distribution (order-up-to) model to improve blood culture bottle supplies

Background

The order-up-to inventory model is a method for identifying and maintaining the optimal product level for items that that hold value over time and have recurring demand. Typically, supermarkets utilise it to manage stock-levels of non-perishable goods.

Local problem

This project aimed to improve blood culture bottle supplies following reports by junior doctors of shortages when dealing with septic/unwell patients.

Methods

Data regarding blood culture bottle use was acquired from four hospitals within one trust in London (245 wards). The mathematical 'order-up-to' inventory model (an iterative Poisson distribution) was applied to the 6 months' data.

Interventions

The model found three predictable levels of demand to stock wards with no shortages in 99.3% of circumstances (based on historical data). Wards were stocked with blood culture bottles as per their required demand.

Results

A collection method and infrastructure was designed to implement the new policy and was applied to a London tertiary centre. A review of doctors, nurses and ward-managers found significant improvements in supply with no shortages since the model was applied. Issues with the dataset were identified for intensive therapy unit / high dependency unit.

Conclusions

The 'order-up-to' inventory model provides a useful tool within hospitals for improving stock levels of blood cultures bottles and with that the satisfaction of trainees and patient safety.

Rethinking animal models of sepsis - working towards improved clinical translation whilst integrating the 3Rs

Sepsis is a major worldwide healthcare issue with unmet clinical need. Despite extensive animal research in this area, successful clinical translation has been largely unsuccessful.

We propose one reason for this is that, sometimes, the experimental question is misdirected or unrealistic expectations are being made of the animal model.

As sepsis models can lead to a rapid and substantial suffering – it is essential that we continually review experimental approaches and undertake a full harm:benefit impact assessment for each study. In some instances, this may require refinement of existing sepsis models. In other cases, it may be replacement to a different experimental system altogether, answering a mechanistic question whilst aligning with the principles of reduction, refinement and replacement (3Rs).

We discuss making better use of patient data to identify potentially useful therapeutic targets which can subsequently be validated in preclinical systems. This may be achieved through greater use of construct validity models, from which mechanistic conclusions are drawn. We argue that such models could provide equally useful scientific data as face validity models, but with an improved 3Rs impact. Indeed, construct validity models may not require sepsis to be modelled, per se. We propose that approaches that could support and refine clinical translation of research findings, whilst reducing the overall welfare burden on research animals.

The effect of red blood cell transfusion on peripheral tissue oxygen delivery and consumption in septic patients

OBJECTIVES

The impact of blood transfusion on tissue oxygen delivery (DO₂) and tissue oxygen consumption (VO₂) is a subject of current clinical studies. The primary objective of this observational study is to evaluate and measure the parameters involved in determining DO₂ and VO₂, in early phase of septic patients. A secondary objective of this study is to assess the potential benefit of blood transfusion on tissue metabolism by serial measurements of lactic acid (Ac. Lac.).

MATERIAL AND METHODS

A group of 29 patients were studied, each patient received between one to three units of fresh packed red blood cells (pRBC). Clinical and paraclinical criteria for sepsis as well as the plasma value of haemoglobin (Hb) below 10g/dL represented the inclusion criteria in this study. We evaluated Hb, haematocrit (HCT), arterial blood oxigen saturation (SAO₂), central venous oxygen saturation (SCVO₂), parameters which are involved in determination of DO₂ and VO₂, before and after the transfusion of one unit of pRBC. Values of Ac. Lac. were also assessed in order to determine the type of metabolism (aerobic or anaerobic). SCVO₂, SAO₂, Hb, HCT and Ac. Lac. were determined using Epoc blood analyser. The cardiac output (CO) and systemic vascular resistance (SVR) were monitored during blood transfusion, using Vigileo monitor (Edward's Life Science, PreSep catheter kit). SAO₂ was also monitored by pulse-oximetry.

RESULTS

Changes in Hb, HCT and SCVO₂ before and after pRBC transfusion (which further determine VO₂) were statistically significant (P<0.001). A statistically significant increase (P<0.001) was obtained in Ac. Lac. values, before and after pRBC transfusion. SAO₂ and CO directly involved in producing DO₂, were clinically monitored during blood transfusion and the results remained constant.

CONCLUSION

Results obtained in this clinical study show an increase in DO2 in critically ill septic patients and also an increase in oxygen tissue uptake which is similar to VO2, clearly pointing out the benefit of pRBC transfusion. The benefits of pRBC transfusion on tissue metabolism in critically ill septic patients remain elusive because of lactic acid values increase during and after transfusion. Based on our findings we recommend that Hb values used as a single trigger for pRBC transfusion should be further studied and that additional parameters such as SCVO₂ and lactic acid should be considered as possible triggers for transfusion. Values of Hb and HCT should never be neglected.

CD28 Agonism Improves Survival in Immunologically Experienced Septic Mice via IL-10 Released by Foxp3+ Regulatory T Cells

Immune dysregulation during sepsis is mediated by an imbalance of T cell costimulatory and coinhibitory signaling. CD28 is downregulated during sepsis and is significantly altered on memory versus naive T cells. Thus, to study the role of CD28 during sepsis in a more physiologically relevant context, we developed a "memory mouse" model in which animals are subjected to pathogen infections to generate immunologic memory, followed by sepsis induction via cecal ligation and puncture. Using this system, we show that agonistic anti-CD28 treatment resulted in worsened survival in naive septic animals but conferred a significant survival advantage in immunologically experienced septic animals. Mechanistically, this differential response was driven by the ability of CD28 agonism to elicit IL-10 production from regulatory T cells uniquely in memory but not naive mice. Moreover, elevated IL-10 released by activated regulatory T cells in memory mice inhibited sepsis-induced T cell apoptosis via the antiapoptotic protein Bcl-xL. Together, these data demonstrate that immunologic experience is an important parameter that affects sepsis pathophysiology and can fundamentally change the outcome of modulating the CD28 pathway during sepsis. This study suggests that testing therapeutic strategies in immunologically experienced hosts may be one way to increase the physiologic relevance of rodent models in sepsis research.

The challenge of recognising sepsis: Future nanotechnology solutions

The urgent need to start anti-infective therapeutic interventions in suspected sepsis, and the lack of specific time-critical diagnostic information often lead to the widespread administration of broad-spectrum antimicrobial therapies, increasing the risk of unwanted patient harms and contributing to rising pathogen antimicrobial resistance. Nanotechnology, which involves engineering at the nanoscale, allows for the bespoke development of diagnostic solutions with multi-functionality and high sensitivity that has the potential to help provide time-critical information to make more accurate diagnoses and treatment decisions for sepsis. Nanotechnologies also have the potential to improve upon the current strategies used for novel biomarker discovery. Here we describe some of the current limitations to identifying sepsis and explore the potential role for nanotechnology solutions.

Antibiotic treatment with one single dose of gentamicin at admittance in addition to a β-lactam antibiotic in the treatment of community-acquired bloodstream infection with sepsis

Background

Combination therapy in the treatment of sepsis, especially the value of combining a β-Lactam antibiotic with an aminoglycoside, has been discussed. This retrospective cohort study including patients with sepsis or septic shock aimed to investigate whether one single dose of gentamicin at admittance (SGA) added to β-Lactam antibiotic could result in a lower risk of mortality than β-Lactam monotherapy, without exposing the patient to the risk of nephrotoxicity.

Methods and findings

All patients with positive blood cultures were evaluated for participation (n = 1318). After retrospective medical chart review, a group of patients with community-acquired sepsis with positive blood cultures who received β-Lactam antibiotic with or without the addition of SGA (n = 399) were included for the analysis. Mean age was 74.6 yrs. (range 19–98) with 216 (54%) males. Sequential Organ Failure Assessment score (SOFA score) median was 3 (interquartile range [IQR] 2–5) and the median Charlson Comorbidity Index for the whole group was 2 (IQR 1–3). Sixty-seven (67) patients (17%) had septic shock. The 28-day mortality in the combination therapy group was 10% (20 of 197) and in the monotherapy group 22% (45 of 202), adjusted HR 3.5 (95% CI (1.9–6.2), p = < 0.001. No significant difference in incidence of acute kidney injury (AKI) was detected.

Conclusion

This retrospective observational study including patients with community-acquired sepsis or septic shock and positive blood cultures, who meet Sepsis-3 criteria, shows that the addition of one single dose of gentamicin to β-lactam treatment at admittance was associated with a decreased risk of mortality and was not associated with AKI. This antibiotic regime may be an alternative to broad-spectrum antibiotic treatment of community-acquired sepsis. Further prospective studies are warranted to confirm these results.

Microfluidic systems for rapid antibiotic susceptibility tests (ASTs) at the single-cell level

Infectious diseases caused by multidrug resistant (MDR) bacterial pathogens are impending threats to global health. Since delays in identifying drug resistance would significantly increase mortality, fast and accurate antibiotic susceptibility tests (ASTs) are critical for addressing the antibiotic resistance issue. However, the conventional methods for ASTs are always labor-intensive, imprecise, complex and slow (taking 2-3 days). To address these issues, some advanced microfluidic systems have been designed for rapid phenotypic and genotypic analysis of antibiotic resistance. This review highlights the recent development of microfluidics-based ASTs at the single-cell or single-molecule level for guiding antibiotic treatment decisions and predicting therapeutic outcomes.

Gravity-driven microfluidic assay for digital enumeration of bacteria and for antibiotic susceptibility testing

The alarming dynamics of antibiotic-resistant infections calls for the development of rapid and point-of-care (POC) antibiotic susceptibility testing (AST) methods. Here, we demonstrated the first completely stand-alone microfluidic system that allowed the execution of digital enumeration of bacteria and digital antibiograms without any specialized microfluidic instrumentation. A four-chamber gravity-driven step emulsification device generated ∼2000 monodisperse 2 nanoliter droplets with a coefficient of variation of 8.9% of volumes for 95% of droplets within less than 10 minutes. The manual workload required for droplet generation was limited to the sample preparation, the deposition into the sample inlet of the chip and subsequent orientation of the chip vertically without an additional pumping system. The use of shallow chambers imposing a 2D droplet arrangement provided superior stability of the droplets against coalescence and minimized the leakage of the reporter viability dye between adjacent droplets during long-term culture. By using resazurin as an indicator of the growth of bacteria, we were also able to reduce the assay time to ∼5 hours compared to 20 hours using the standard culture-based test.

O-GlcNAc stimulation: A new metabolic approach to treat septic shock

Septic shock is a systemic inflammation associated with cell metabolism disorders and cardiovascular dysfunction. Increases in O-GlcNAcylation have shown beneficial cardiovascular effects in acute pathologies. We used two different rat models to evaluate the beneficial effects of O-GlcNAc stimulation at the early phase of septic shock. Rats received lipopolysaccharide (LPS) to induce endotoxemic shock or saline (control) and fluid resuscitation (R) with or without O-GlcNAc stimulation (NButGT-10 mg/kg) 1 hour after shock induction. For the second model, rats received cecal ligature and puncture (CLP) surgery and fluid therapy with or without NButGT. Cardiovascular function was evaluated and heart and blood samples were collected and analysed. NButGT treatment efficiently increased total O-GlcNAc without modification of HBP enzyme expression.Treatment improved circulating parameters and cardiovascular function in both models, and restored SERCA2a expression levels. NButGT treatment also reduced animal mortality. In this study, we demonstrate that in septic shock O-GlcNAc stimulation improves global animal and cardiovascular function outcomes associated with a restoration of SERCA2a levels. This pre-clinical study opens avenues for a potential therapy of early-stage septic shock.

Bruton's Tyrosine Kinase Inhibition Attenuates the Cardiac Dysfunction Caused by Cecal Ligation and Puncture in Mice

Sepsis is one of the most prevalent diseases in the world. The development of cardiac dysfunction in sepsis results in an increase of mortality. It is known that Bruton's tyrosine kinase (BTK) plays a role in toll-like receptor signaling and NLRP3 inflammasome activation, two key components in the pathophysiology of sepsis and sepsis-associated cardiac dysfunction. In this study we investigated whether pharmacological inhibition of BTK (ibrutinib 30 mg/kg and acalabrutinib 3 mg/kg) attenuates sepsis associated cardiac dysfunction in mice. 10-week old male C57BL/6 mice underwent CLP or sham surgery. One hour after surgery mice received either vehicle (5% DMSO + 30% cyclodextrin i.v.), ibrutinib (30 mg/kg i.v.), or acalabrutinib (3 mg/kg i.v.). Mice also received antibiotics and an analgesic at 6 and 18 h. After 24 h, cardiac function was assessed by echocardiography in vivo. Cardiac tissue underwent western blot analysis to determine the activation of BTK, NLRP3 inflammasome and NF-κB pathway. Serum analysis of 33 cytokines was conducted by a multiplex assay. When compared to sham-operated animals, mice subjected to CLP demonstrated a significant reduction in ejection fraction (EF), fractional shortening (FS), and fractional area change (FAC). The cardiac tissue from CLP mice showed significant increases of BTK, NF-κB, and NLRP3 inflammasome activation. CLP animals resulted in a significant increase of serum cytokines and chemokines (TNF-α, IL-6, IFN-γ, KC, eotaxin-1, eotaxin-2, IL-10, IL-4, CXCL10, and CXCL11). Delayed administration of ibrutinib and acalabrutinib attenuated the decline of EF, FS, and FAC caused by CLP and also reduced the activation of BTK, NF-κB, and NLRP3 inflammasome. Both ibrutinib and acalabrutinib significantly suppressed the release of cytokines and chemokines. Our study revealed that delayed intravenous administration of ibrutinib or acalabrutinib attenuated the cardiac dysfunction associated with sepsis by inhibiting BTK, reducing NF-κB activation and the activation of the inflammasome. Cytokines associated with sepsis were significantly reduced by both BTK inhibitors. Acalabrutinib is found to be more potent than ibrutinib and could potentially prove to be a novel therapeutic in sepsis. Thus, the FDA-approved BTK inhibitors ibrutinib and acalabrutinib may be repurposed for the use in sepsis.

Biomarker-guided antibiotic cessation in sepsis: evidence and future challenges

Sepsis is a medical emergency, which requires the initiation of broad-spectrum antimicrobial agents as early as possible. In the absence of positive microbiological cultures providing targeted antimicrobial advice, broad-spectrum antibiotics are commonly continued until there is clinical evidence of infection resolution. With an absence of robust evidence to inform when it is safe to stop antimicrobial agents in sepsis, the duration of antimicrobial courses may be longer than is required. Prolonged courses of potent broad-spectrum antimicrobials increase the risk of adverse drug events and contribute to the growing emergence of multidrug resistant pathogens, which is a global public health emergency. The protocolised use of protein biomarkers to guide clinical decision making can be used to help combat excessive durations of antimicrobials in patients with sepsis. This article reviews the current evidence for biomarker-guided antimicrobial discontinuation protocols in sepsis, identifies related evidence gaps and examines future innovation challenges in this field.

TLR9 signaling in fibroblastic reticular cells regulates peritoneal immunity

Fibroblastic reticular cells (FRCs), a subpopulation of stromal cells in lymphoid organs and fat-associated lymphoid clusters (FALCs) in adipose tissue, play immune-regulatory roles in the host response to infection and may be useful as a form of cell therapy in sepsis. Here, we found an unexpected major role of TLR9 in controlling peritoneal immune cell recruitment and FALC formation at baseline and after sepsis induced by cecal ligation and puncture (CLP). TLR9 regulated peritoneal immunity via suppression of chemokine production by FRCs. Adoptive transfer of TLR9-deficient FRCs more effectively decreased mortality, bacterial load, and systemic inflammation after CLP than WT FRCs. Importantly, we found that activation of TLR9 signaling suppressed chemokine production by human adipose tissue-derived FRCs. Together, our results indicate that TLR9 plays critical roles in regulating peritoneal immunity via suppression of chemokine production by FRCs. These data form a knowledge basis upon which to design new therapeutic strategies to improve the therapeutic efficacy of FRC-based treatments for sepsis and immune dysregulation diseases.

Recognition, response and outcomes of sepsis: A dual site retrospective observational study

OBJECTIVES

To describe clinical recognition, response and outcomes of patients with sepsis.

METHODS

A retrospective, observational study was undertaken at two hospitals. Inclusion criteria were: adult patients admitted via the Emergency Department (ED) between 1 January and 30 April 2014 allocated a primary ICD-10-AM discharge from hospital code related to sepsis. Recognition of sepsis was considered based on the presence of clinical documentation that reflects the Sepsis Kills criteria being met. Response to sepsis was considered based on the presence of clinical documentation where the patient received a response consistent with the 'Sepsis Six' strategies. Outcomes pertained to response to sepsis (e.g. time to antibiotics) and ED measures (e.g. time to be seen, ED length of stay). Sub-group analysis considered location where sepsis was recognised (ED/ward).

RESULT

In total, 96 patients met the inclusion criteria; most were admitted under general medicine (37%) followed by intensive care (18%). Sepsis was recognised in the ED for most patients (n = 64), with a history of fevers/rigors the most common (60%) indication of infection. Regarding response and ED outcomes for this group, the median time from triage nurse assessment i) to being seen by the treating clinician was 19 min; ii) to sepsis recognition was 27 min; and iii) to antibiotics was 181 min; 35% received antibiotics within 60 min from recognition. Those recognised in the ED had a longer ED stay than those where sepsis was recognised on the ward (336 min vs. 225 min, p = 0.013).

CONCLUSIONS

Sepsis can develop at various stages throughout the patient's journey. In this small sample, ED recognition was associated with longer ED stay, likely due to more interventions. Whilst guidelines recommend antibiotics be administered within 60 min of triage, this was not achieved for most patients. Given the dynamic nature of sepsis, future indicators may focus on time from recognition rather than time from triage.

A 'culture' shift: Application of molecular techniques for diagnosing polymicrobial infections

With the advancement of microbiological discovery, it is evident that many infections, particularly bloodstream infections, are polymicrobial in nature. Consequently, new challenges have emerged in identifying the numerous etiologic organisms in an accurate and timely manner using the current diagnostic standard. Various molecular diagnostic methods have been utilized as an effort to provide a fast and reliable identification in lieu or parallel to the conventional culture-based methods. These technologies are mostly based on nucleic acid, proteins, or physical properties of the pathogens with differing advantages and limitations. This review evaluates the different molecular methods and technologies currently available to diagnose polymicrobial infections, which will help determine the most appropriate option for future diagnosis.

Subduing the killer - sepsis; through simulation

Few pathophysiological processes have a higher morbidity and mortality than sepsis. Implementing effective strategies to improve these poor outcomes remains a challenge. Previous work has shown improvements using single and multifaceted approaches, many with inclusion of sepsis training for doctors and nurses. However, previous work has not necessarily trained all those involved in the recognition and treatment of sepsis. After sepsis simulation training using cognitive-constructivist teaching methods, reaudit demonstrated highly significant improvement in 'sepsis-six' delivery. This study found inclusion of healthcare assistants in sepsis training is of great importance. This training should be tailored to personnel's current knowledge base and level of experience.

Evaluation of Antibiotic Use Among Sepsis Patients in an Intensive Care Unit: A cross-sectional study at a referral hospital in Indonesia

Objectives

This study aimed to evaluate the appropriateness of antibiotic use and factors associated with outcomes among sepsis patients in an intensive care unit (ICU).

Methods

This cross-sectional study was carried out from February to May 2017 and included all adult patients with sepsis or septic shock admitted to the ICU of Dharmais Cancer Hospital, Jakarta, Indonesia. Data were collected from the patients' medical records.

Results

A total of 60 patients with sepsis or septic shock were admitted to the ICU during the study period. The most common source of infection was hospital-acquired pneumonia (61.7%) and the majority had two or more comorbidities (93.3%). There were 115 antibiotic regimens prescribed. Overall, 33.3% of patients were prescribed inappropriate types of antibiotics and 51.7% were given an inappropriate dosage. The mortality rate was 68.3%. There was a statistically significant association between patient outcome and inappropriate doses of antibiotics (P = 0.034), although not inappropriate types of antibiotics (P = 0.050). A multivariate analysis indicated that the main factors influencing patient outcome were septic shock and the presence of at least two comorbidities (P <0.050 each).

Conclusion

Inappropriate doses of antibiotics, a diagnosis of septic shock and the presence of at least two comorbidities were found to significantly increase the mortality rate of sepsis patients admitted to an ICU in Indonesia.

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.

Multivariate computational analysis of biosensor's data for improved CD64 quantification for sepsis diagnosis

Sepsis, as a leading cause of death worldwide, relies on systemic inflammatory response syndrome (SIRS) criteria for its diagnosis. SIRS is highly non-specific as it relies on monitoring of patients' vitals for sepsis diagnosis, which are known to change with many confounding factors. Changes in leukocyte counts and CD64 expression levels are known specific biomarkers of pro-inflammatory host response at the onset of sepsis. Recently, we have developed a biosensor chip that can enumerate the leukocyte counts and quantify the neutrophil CD64 expression levels from a drop of blood. We were able to show improved sepsis diagnosis and prognosis in clinical studies by measuring these parameters during different times of the patients' stay in hospital. In this paper, we investigated the rate of cell capture with CD64 expression levels and used this in a multivariate computational model using artificial neural networks (ANNs) and showed improved accuracy of quantifying CD64 expression levels from the biosensor (n = 106 whole blood experiments). We found a high coefficient of determination and low error between biosensor- and flow cytometry-based neutrophil CD64 expression levels using multiple ANN training methods in comparison to those of univariate regression commonly employed. This approach can find many applications in biosensor data analytics by utilizing multiple features of the biosensor's data for output determination.

Development of a Physiologically Based Pharmacokinetic Modelling Approach to Predict the Pharmacokinetics of Vancomycin in Critically Ill Septic Patients

BACKGROUND AND OBJECTIVES

Sepsis is characterised by an excessive release of inflammatory mediators substantially affecting body composition and physiology, which can be further affected by intensive care management. Consequently, drug pharmacokinetics can be substantially altered. This study aimed to extend a whole-body physiologically based pharmacokinetic (PBPK) model for healthy adults based on disease-related physiological changes of critically ill septic patients and to evaluate the accuracy of this PBPK model using vancomycin as a clinically relevant drug.

METHODS

The literature was searched for relevant information on physiological changes in critically ill patients with sepsis, severe sepsis and septic shock. Consolidated information was incorporated into a validated PBPK vancomycin model for healthy adults. In addition, the model was further individualised based on patient data from a study including ten septic patients treated with intravenous vancomycin. Models were evaluated comparing predicted concentrations with observed patient concentration-time data.

RESULTS

The literature-based PBPK model correctly predicted pharmacokinetic changes and observed plasma concentrations especially for the distribution phase as a result of a consideration of interstitial water accumulation. Incorporation of disease-related changes improved the model prediction from 55 to 88% within a threshold of 30% variability of predicted vs. observed concentrations. In particular, the consideration of individualised creatinine clearance data, which were highly variable in this patient population, had an influence on model performance.

CONCLUSION

PBPK modelling incorporating literature data and individual patient data is able to correctly predict vancomycin pharmacokinetics in septic patients. This study therefore provides essential key parameters for further development of PBPK models and dose optimisation strategies in critically ill patients with sepsis.

Prehospital recognition and antibiotics for 999 patients with sepsis: protocol for a feasibility study

Background

Sepsis is a common condition which kills between 36,000 and 64,000 people every year in the UK. Early recognition and management of sepsis has been shown to reduce mortality and improve the health and well-being of people with sepsis. Paramedics frequently come into contact with patients with sepsis and are well placed to provide early diagnosis and treatment.

We aim to determine the feasibility of undertaking a fully powered randomised controlled trial (RCT) to test the clinical and cost-effectiveness of paramedics obtaining blood cultures from and administering IV antibiotics to patients with sepsis, so we can make a decision about whether to proceed to a fully powered randomised controlled trial, which will answer questions regarding safety and effectiveness for patients and benefit to the National Health Service (NHS).

Methods/design

This is an individually randomised, two-arm feasibility study for a randomised controlled trial with a 1:1 ratio. Sixty paramedics will receive training to assist them to recognise sepsis using a screening tool, obtain blood cultures, and provide IV antibiotics. If sepsis is suspected, paramedics will randomly allocate patients to intervention or usual care using their next sequential individually issued scratch card. Patients will be followed up at 90 days using linked anonymised data to capture length of hospital admission and mortality. We will also collect self-reported health-related quality of life (using SF-12) at this time. We will interview ten patients by telephone and hold a focus group with paramedics, to find out what they think about the intervention.

Discussion

At the end of this study, we will make a recommendation about whether a full randomised controlled trial of paramedics obtaining blood cultures and administering IV antibiotics for sepsis is warranted, and if so, we will develop a proposal for research funding in order to take the work forward.

Trial registration

ISRCTN, ISRCTN36856873

Electronic supplementary material

The online version of this article (10.1186/s40814-018-0258-8) contains supplementary material, which is available to authorized users.

The feasibility of paramedics delivering antibiotic treatment pre-hospital to 'red flag' sepsis patients: a service evaluation

Background:

Sepsis is associated with a 36% mortality rate, rising to 50% for septic shock. Currently, when an East Midlands Ambulance Service clinician recognises ‘red flag’ sepsis, only the oxygen and fluid elements of the ‘Sepsis Six’ care bundle are delivered, omitting the antibiotic therapy. For a patient in septic shock, every hour’s delay in antibiotic therapy is associated with a 7.6% increase in mortality. Ambulance clinicians are therefore appropriately placed to assess and commence treatment at the earliest point of recognition. The aim of this evaluation was to assess the feasibility of training paramedics to recognise ‘red flag’ sepsis, obtain blood cultures and administer a broad spectrum antibiotic, meropenem, to patients in the pre-hospital environment.

Methods:

A prospective six-month feasibility pilot evaluation was conducted in May 2016. Paramedics were trained and given access to a broad spectrum antibiotic, meropenem, along with a patient group direction to administer the antibiotic to ‘red flag’ sepsis patients. Training included sepsis recognition, taking of blood cultures and patient group direction compliance.

Results:

Twenty paramedics volunteered and successfully completed the training. Of the 113 patients that were identified as ‘red flag’ sepsis, 107 (94.6%) were confirmed as infected by the receiving hospital. Ninety-eight blood samples were successfully drawn by study paramedics, with only seven (7.1%) reported as contaminated samples, compared with 8.5% of samples taken by staff in the receiving ED during the same time period. Ninety patients (80%) assessed by paramedics as meeting the criteria were treated with meropenem, and patient group direction compliance was 100%.

Conclusion:

Paramedics can safely deliver pre-hospital antibiotics to patients with ‘red flag’ sepsis and obtain blood cultures prior to administration, with a contamination rate comparable with local hospitals, following a short training course.

Predicting 30-day mortality in patients with sepsis: An exploratory analysis of process of care and patient characteristics

Background

Sepsis represents a significant public health burden, costing the NHS £2.5 billion annually, with 35% mortality in 2006. The aim of this exploratory study was to investigate risk factors predictive of 30-day mortality amongst patients with sepsis in Nottingham.

Methods

Data were collected prospectively from adult patients with sepsis in Nottingham University Hospitals NHS Trust as part of an on-going quality improvement project between November 2011 and March 2014. Patients admitted to critical care with the diagnosis of sepsis were included in the study. In all, 97 separate variables were investigated for their association with 30-day mortality. Variables included patient demographics, symptoms of systemic inflammatory response syndrome, organ dysfunction or tissue hypoperfusion, locations of early care, source of sepsis and time to interventions.

Results

A total of 455 patients were included in the study. Increased age (adjOR = 1.05 95%CI = 1.03-1.07 p < 0.001), thrombocytopenia (adjOR = 3.10 95%CI = 1.23-7.82 p = 0.016), hospital-acquired sepsis (adjOR = 3.34 95%CI = 1.78-6.27 p < 0.001), increased lactate concentration (adjOR = 1.16 95%CI = 1.06-1.27 p = 0.001), remaining hypotensive after vasopressors (adjOR = 3.89 95%CI = 1.26-11.95 p = 0.02) and mottling (adjOR = 3.80 95%CI = 1.06-13.55 p = 0.04) increased 30-day mortality odds. Conversely, fever (adjOR = 0.46 95%CI = 0.28-0.75 p = 0.002), fluid refractory hypotension (adjOR = 0.29 95%CI = 0.10-0.87 p = 0.027) and being diagnosed in surgical wards (adjOR = 0.35 95%CI = 0.15-0.81 p = 0.015) were protective. Treatment timeliness were not significant factors.

Conclusion

Several important predictors of 30-day mortality were found by this research. Retrospective analysis of our sepsis data has revealed mortality predictors that appear to be more patient-related than intervention-specific. With this information, care can be improved for those identified most at risk of death.

Sepsis: the LightCycler SeptiFast Test MGRADE®, SepsiTest™ and IRIDICA BAC BSI assay for rapidly identifying bloodstream bacteria and fungi - a systematic review and economic evaluation

BACKGROUND

Sepsis can lead to multiple organ failure and death. Timely and appropriate treatment can reduce in-hospital mortality and morbidity.

OBJECTIVES

To determine the clinical effectiveness and cost-effectiveness of three tests [LightCycler SeptiFast Test MGRADE(®) (Roche Diagnostics, Risch-Rotkreuz, Switzerland); SepsiTest(TM) (Molzym Molecular Diagnostics, Bremen, Germany); and the IRIDICA BAC BSI assay (Abbott Diagnostics, Lake Forest, IL, USA)] for the rapid identification of bloodstream bacteria and fungi in patients with suspected sepsis compared with standard practice (blood culture with or without matrix-absorbed laser desorption/ionisation time-of-flight mass spectrometry).

DATA SOURCES

Thirteen electronic databases (including MEDLINE, EMBASE and The Cochrane Library) were searched from January 2006 to May 2015 and supplemented by hand-searching relevant articles.

REVIEW METHODS

A systematic review and meta-analysis of effectiveness studies were conducted. A review of published economic analyses was undertaken and a de novo health economic model was constructed. A decision tree was used to estimate the costs and quality-adjusted life-years (QALYs) associated with each test; all other parameters were estimated from published sources. The model was populated with evidence from the systematic review or individual studies, if this was considered more appropriate (base case 1). In a secondary analysis, estimates (based on experience and opinion) from seven clinicians regarding the benefits of earlier test results were sought (base case 2). A NHS and Personal Social Services perspective was taken, and costs and benefits were discounted at 3.5% per annum. Scenario analyses were used to assess uncertainty.

RESULTS

For the review of diagnostic test accuracy, 62 studies of varying methodological quality were included. A meta-analysis of 54 studies comparing SeptiFast with blood culture found that SeptiFast had an estimated summary specificity of 0.86 [95% credible interval (CrI) 0.84 to 0.89] and sensitivity of 0.65 (95% CrI 0.60 to 0.71). Four studies comparing SepsiTest with blood culture found that SepsiTest had an estimated summary specificity of 0.86 (95% CrI 0.78 to 0.92) and sensitivity of 0.48 (95% CrI 0.21 to 0.74), and four studies comparing IRIDICA with blood culture found that IRIDICA had an estimated summary specificity of 0.84 (95% CrI 0.71 to 0.92) and sensitivity of 0.81 (95% CrI 0.69 to 0.90). Owing to the deficiencies in study quality for all interventions, diagnostic accuracy data should be treated with caution. No randomised clinical trial evidence was identified that indicated that any of the tests significantly improved key patient outcomes, such as mortality or duration in an intensive care unit or hospital. Base case 1 estimated that none of the three tests provided a benefit to patients compared with standard practice and thus all tests were dominated. In contrast, in base case 2 it was estimated that all cost per QALY-gained values were below £20,000; the IRIDICA BAC BSI assay had the highest estimated incremental net benefit, but results from base case 2 should be treated with caution as these are not evidence based.

LIMITATIONS

Robust data to accurately assess the clinical effectiveness and cost-effectiveness of the interventions are currently unavailable.

CONCLUSIONS

The clinical effectiveness and cost-effectiveness of the interventions cannot be reliably determined with the current evidence base. Appropriate studies, which allow information from the tests to be implemented in clinical practice, are required.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015016724.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

An Ovine Model of Hyperdynamic Endotoxemia and Vital Organ Metabolism

BACKGROUND

Animal models of endotoxemia are frequently used to understand the pathophysiology of sepsis and test new therapies. However, important differences exist between commonly used experimental models of endotoxemia and clinical sepsis. Animal models of endotoxemia frequently produce hypodynamic shock in contrast to clinical hyperdynamic shock. This difference may exaggerate the importance of hypoperfusion as a causative factor in organ dysfunction. This study sought to develop an ovine model of hyperdynamic endotoxemia and assess if there is evidence of impaired oxidative metabolism in the vital organs.

METHODS

Eight sheep had microdialysis catheters implanted into the brain, heart, liver, kidney, and arterial circulation. Shock was induced with a 4 h escalating dose infusion of endotoxin. After 3 h vasopressor support was initiated with noradrenaline and vasopressin. Animals were monitored for 12 h after endotoxemia. Blood samples were recovered for hemoglobin, white blood cell count, creatinine, and proinflammatory cytokines (IL-1Beta, IL-6, and IL-8).

RESULTS

The endotoxin infusion was successful in producing distributive shock with the mean arterial pressure decreasing from 84.5 ± 12.8 mm Hg to 49 ± 8.03 mm Hg (P < 0.001). Cardiac index remained within the normal range decreasing from 3.33 ± 0.56 L/min/m to 2.89l ± 0.36 L/min/m (P = 0.0845). Lactate/pyruvate ratios were not significantly abnormal in the heart, brain, kidney, or arterial circulation. Liver microdialysis samples demonstrated persistently high lactate/pyruvate ratios (mean 37.9 ± 3.3).

CONCLUSIONS

An escalating dose endotoxin infusion was successful in producing hyperdynamic shock. There was evidence of impaired oxidative metabolism in the liver suggesting impaired splanchnic perfusion. This may be a modifiable factor in the progression to multiple organ dysfunction and death.

Rapid Antibiotic Susceptibility Testing of Uropathogenic E. coli by Tracking Submicron Scale Motion of Single Bacterial Cells

To combat antibiotic resistance, a rapid antibiotic susceptibility testing (AST) technology that can identify resistant infections at disease onset is required. Current clinical AST technologies take 1-3 days, which is often too slow for accurate treatment. Here we demonstrate a rapid AST method by tracking sub-μm scale bacterial motion with an optical imaging and tracking technique. We apply the method to clinically relevant bacterial pathogens, Escherichia coli O157: H7 and uropathogenic E. coli (UPEC) loosely tethered to a glass surface. By analyzing dose-dependent sub-μm motion changes in a population of bacterial cells, we obtain the minimum bactericidal concentration within 2 h using human urine samples spiked with UPEC. We validate the AST method using the standard culture-based AST methods. In addition to population studies, the method allows single cell analysis, which can identify subpopulations of resistance strains within a sample.

Treatment of sepsis: What is the antibiotic choice in bacteremia due to carbapenem resistant Enterobacteriaceae?

Sepsis is one of the major challenges of today. Although gram-positive bacteria related infections are more prevalent in hospital setting, the highest mortality rate is associated with gram-negative microorganisms especially Enterobacteriaceae. Enterobacteriaceae, including Escherichia coli, Klebsiella spp., Proteus spp., Enterobacter spp. and Serratia spp. Resistance to β-lactams in Enterobacteriaceae is primarily attributed to the production of B-lactamase enzymes with subsequent antibiotic hydrolysis and to a lesser extent by alteration of efflux pump or porins expression. Carbapenem resistant Enterobacteriaceae (CRE) and Acinetobacter baumannii are the most notorious pathogens due to the high incidence of morbidity and mortality especially in the immunocompromised patients in the intensive care unit. The most appropriate antimicrobial therapy to treat CRE is still controversial. Combination therapy is preferred over monotherapy due to its broad-spectrum coverage of micro-organisms, due to its synergetic effect and to prevent development of further resistance. Current suggested therapies for CRE resistance as well as promising antibiotics that are currently under investigation for winning the war against the emerging CRE resistance are reviewed and discussed.

WNT ligands contribute to the immune response during septic shock and amplify endotoxemia-driven inflammation in mice

Improved understanding of the molecular mechanisms underlying dysregulated inflammatory responses in severe infection and septic shock is urgently needed to improve patient management and identify new therapeutic opportunities. The WNT signaling pathway has been implicated as a novel constituent of the immune response to infection, but its contribution to the host response in septic shock is unknown. Although individual WNT proteins have been ascribed pro- or anti-inflammatory functions, their concerted contributions to inflammation in vivo remain to be clearly defined. Here we report differential expression of multiple WNT ligands in whole blood of patients with septic shock and reveal significant correlations with inflammatory cytokines. Systemic challenge of mice with lipopolysaccharide (LPS) similarly elicited differential expression of multiple WNT ligands with correlations between WNT and cytokine expression that partially overlap with the findings in human blood. Molecular regulators of WNT expression during microbial encounter in vivo are largely unexplored. Analyses in gene-deficient mice revealed differential contributions of Toll-like receptor signaling adaptors, a positive role for tumor necrosis factor, but a negative regulatory role for interleukin (IL)-12/23p40 in the LPS-induced expression of Wnt5b, Wnt10a, Wnt10b, and Wnt11. Pharmacologic targeting of bottlenecks of the WNT network, WNT acylation and β-catenin activity, diminished IL-6, tumor necrosis factor, and IL-12/23p40 in serum of LPS-challenged mice and cultured splenocytes, whereas IL-10 production remained largely unaffected. Taken together, our data support the conclusion that the concerted action of WNT proteins during severe infection and septic shock promotes inflammation, and that this is, at least in part, mediated by WNT/β-catenin signaling.

A point-of-care microfluidic biochip for quantification of CD64 expression from whole blood for sepsis stratification

Sepsis, a potentially life-threatening complication of an infection, has the highest burden of death and medical expenses in hospitals worldwide. Leukocyte count and CD64 expression on neutrophils (nCD64) are known to correlate strongly with improved sensitivity and specificity of sepsis diagnosis at its onset. A major challenge is the lack of a rapid and accurate point-of-care (PoC) device that can perform these measurements from a minute blood sample. Here, we report a PoC microfluidic biochip to enumerate leukocytes and quantify nCD64 levels from 10 μl of whole blood without any manual processing. Biochip measurements have shown excellent correlation with the results from flow cytometer. In clinical studies, we have used PoC biochip to monitor leukocyte counts and nCD64 levels from patients’ blood at different times of their stay in the hospital. Furthermore, we have shown the biochip’s utility for improved sepsis diagnosis by combining these measurements with electronic medical record (EMR).

Sepsis is a potentially life–threatening complication of infection and diagnosis depends on rapid assessment of leukocyte count and CD64 expression. Here the authors present a microfluidic chip that can quantify these parameters from minimal amounts of whole blood with no manual processing.

The Effect of High-dose Parenteral Sodium Selenite in Critically Ill Patients following Sepsis: A Clinical and Mechanistic Study

INTRODUCTION

Severe sepsis and septic shock is characterized by inflammation and oxidative stress. Selenium levels have been reported to be low due to loss or increased requirements during severe sepsis and septic shock. We investigated the effect of high-dose parenteral selenium administration in septic patients.

METHODS

A prospective, randomized control clinical trial was performed in septic patients. After randomization, patients in selenium group received high-dose parenteral sodium selenite (2 mg intravenous [IV] bolus followed by 1.5 mg IV continuous infusion daily for 14 days) plus standard therapy and the control group received standard therapy. The primary endpoint was mortality at 28 days. Changes in the mean levels of high mobility group box-1 (HMGB-1) protein and superoxide dismutase (SOD), duration of vasopressor therapy, incidence of acute renal failure, and 60 days' mortality were secondary endpoints.

RESULTS

Fifty-four patients were randomized into selenium group (n = 29) and control group (n = 25). There was no significant difference in 28-day mortality. No significant difference between the two groups with respect to the average levels of HMGB-1 protein and SOD at any point in time over the course of 14 days had observed.

CONCLUSION

In early administration within the first 6 h of sepsis diagnosis, our study demonstrated that high-dose parenteral selenium administration had no significant effect either on 28-day mortality or the mean levels of HMGB-1 and SOD (Trial Registration: IRCT201212082887N4 at WHO Clinical Trial Registry, August 29, 2014).

Current and emerging techniques for antibiotic susceptibility tests

Infectious diseases caused by bacterial pathogens are a worldwide burden. Serious bacterial infection-related complications, such as sepsis, affect over a million people every year with mortality rates ranging from 30% to 50%. Crucial clinical microbiology laboratory responsibilities associated with patient management and treatment include isolating and identifying the causative bacterium and performing antibiotic susceptibility tests (ASTs), which are labor-intensive, complex, imprecise, and slow (taking days, depending on the growth rate of the pathogen). Considering the life-threatening condition of a septic patient and the increasing prevalence of antibiotic-resistant bacteria in hospitals, rapid and automated diagnostic tools are needed. This review summarizes the existing commercial AST methods and discusses some of the promising emerging AST tools that will empower humans to win the evolutionary war between microbial genes and human wits.

New Consensus Definitions for Sepsis and Septic Shock: Implications for Treatment Strategies and Drug Development?

Sepsis continues to escape a precise diagnostic definition. The most recent consensus definition, termed Sepsis-3, highlights the importance of the maladaptive and potentially life-threatening host response to infection. After briefly reviewing the history and epidemiology of sepsis, we go on to describe some of the challenges encountered when classifying such a heterogenous disease state. In the context of these new definitions for sepsis and septic shock, we explore current and potentially novel therapies, and conclude by mentioning some of the controversies of this most recent framework.

Assessment and management of the septic patient: part 2

Sepsis has gained increasing publicity in recent years, and there is now a strong focus of clinical education and training following the Surviving Sepsis Campaign. The assessment and management of a septic patients is far from simple and requires a systematic approach in both identifying and managing the condition. This second part explores sepsis care bundles and the research that underpins each of the interventions. These discussions will enable nurses to understand why each component of the sepsis care bundle is important and thus enable them to rapidly prioritise care, as early effective interventions have been shown to optimise patient outcomes.

Fluid resuscitation in human sepsis: Time to rewrite history?

Fluid resuscitation continues to be recommended as the first-line resuscitative therapy for all patients with severe sepsis and septic shock. The current acceptance of the therapy is based in part on long history and familiarity with its use in the resuscitation of other forms of shock, as well as on an incomplete and incorrect understanding of the pathophysiology of sepsis. Recently, the safety of intravenous fluids in patients with sepsis has been called into question with both prospective and observational data suggesting improved outcomes with less fluid or no fluid. The current evidence for the continued use of fluid resuscitation for sepsis remains contentious with no prospective evidence demonstrating benefit to fluid resuscitation as a therapy in isolation. This article reviews the historical and physiological rationale for the introduction of fluid resuscitation as treatment for sepsis and highlights a number of significant concerns based on current experimental and clinical evidence. The research agenda should focus on the development of hyperdynamic animal sepsis models which more closely mimic human sepsis and on experimental and clinical studies designed to evaluate minimal or no fluid strategies in the resuscitation phase of sepsis.

Changes in B-type Natriuretic Peptide and Related Hemodynamic Parameters Following a Fluid Challenge in Critically Ill Patients with Severe Sepsis or Septic Shock

CONTEXT

Severe sepsis or septic shock.

AIMS

The aim of this study is to examine the effect of a fluid challenge on the B-type natriuretic peptide (BNP) and the hemodynamic state.

SETTINGS AND DESIGN

This observational study was conducted in an intensivist-led academic, mixed medical-surgical Intensive Care Unit.

SUBJECTS AND METHODS

Focused transthoracic echocardiogram, plasma BNP, and hemodynamic measurements were recorded at baseline and following a 500 ml fluid challenge in thirty patients. Independent predictors of the percentage (%) change in stroke volume (SV) were sought. Next, these independent predictors were assessed for a relationship with the percentage change in BNP.

STATISTICAL ANALYSIS USED

Multiple linear regressions, Wilcoxon rank-sum test, t-test, and Pearson's correlation were used. Data analysis was carried out using SAS. The 5% significance level was used.

RESULTS

Using a multiple regression models, the percentage increase in SV was independently predicted by the percentage increase in mean arterial pressure, left ventricular end-diastolic volume/dimension (LVEDV/LVEDd), ejection fraction, and a decrease in Acute Physiology and Chronic Health Evaluation II score (P < 0.0001). Preload, measured using LVEDV1 (before the fluid challenge) was significantly larger in the fluid nonresponders (%SV increase <15%) vs. the responders (%SV increase ≥15%). Finally, the percentage change in BNP was positively correlated with left ventricular size at end diastole LVEDd, r = 0.4, P < 0.035).

CONCLUSIONS

An increase in BNP soon after a fluid challenge may have some predictive utility of a large LVEDd, which in turn can be used to independently predict the SV response to a fluid challenge.

Improving multidisciplinary severe sepsis management using the Sepsis Six

Each year in the UK, it is estimated that more than 100,000 people are admitted to hospital with sepsis and around 37,000 people will die as a result of the condition. We present an audit, re-audit and the implications these have had on the management of severe sepsis using the Sepsis Six, ultimately through actively promoting teamwork to initiate the protocol. This led to a significant improvement in management, decreasing admissions to the intensive care unit (ITU), length of stay in hospital and the number of patient deaths.The initial audit and re-audit were done over 2-month periods. All clerking notes of patients with a medical consultant diagnosis of 'sepsis' on post-take ward round were analysed and further screened for presence of severe sepsis according to national guidelines.There was significant improvement from only 1% of patients being appropriately managed (according to the existing guidelines) to 67% of eligible subjects adhering to the protocol (p<0.0001). Initially, 19% were admitted to the ITU (6% died), improving to 7% on re-audit (with no deaths). Length of hospital stay reduced from 10 to 7 days (p<0.0001).There was a complete change in the management of severe sepsis with trust-wide updated protocols, resulting in a decrease in hospital morbidity and mortality.

Incidence and predictive risk factors of postoperative sepsis in orthopedic trauma patients

Background

Postoperative sepsis is associated with high mortality and the national costs of septicemia exceed those of any other diagnosis. While numerous studies in the basic orthopedic science literature suggest that traumatic injuries facilitate the development of sepsis, it is currently unclear whether orthopedic trauma patients are at increased risk. The purpose of this study was thus to assess the incidence of sepsis and determine the risk factors that significantly predicted septicemia following orthopedic trauma surgery.

Materials and methods

56,336 orthopedic trauma patients treated between 2006 and 2013 were identified in the ACS-NSQIP database. Documentation of postoperative sepsis/septic shock, demographics, surgical variables, and preoperative comorbidities was collected. Chi-squared analyses were used to assess differences in the rates of sepsis between trauma and nontrauma groups. Binary multivariable regressions identified risk factors that significantly predicted the development of postoperative septicemia in orthopedic trauma patients.

Results

There was a significant difference in the overall rates of both sepsis and septic shock between orthopedic trauma (1.6%) and nontrauma (0.5%) patients (p < 0.001). For orthopedic trauma patients, ventilator use (OR = 15.1, p = 0.002), history of pain at rest (OR = 2.8, p = 0.036), and prior sepsis (OR = 2.6, p < 0.001) were significantly associated with septicemia. Statistically predictive, modifiable comorbidities included hypertension (OR = 2.1, p = 0.003) and the use of corticosteroids (OR = 2.1, p = 0.016).

Conclusions

There is a significantly greater incidence of postoperative sepsis in the trauma cohort. Clinicians should be aware of these predictive characteristics, may seek to counsel at-risk patients, and should consider addressing modifiable risk factors such as hypertension and corticosteroid use preoperatively.

Level of evidence Level III.