Daily Sepsis Research Analysis
Today’s top sepsis research advances include: a scoping review that exposes major inconsistencies in source control reporting for severe bloodstream infections and offers a standardization roadmap; a transcriptomic endotyping study that identifies a high-risk neonatal sepsis signature linked to mortality and cardiac dysfunction; and a multi-ICU cohort suggesting abrupt hydrocortisone discontinuation in septic shock may reduce ICU-related adverse events, with steroid duration driving post-discont
Summary
Today’s top sepsis research advances include: a scoping review that exposes major inconsistencies in source control reporting for severe bloodstream infections and offers a standardization roadmap; a transcriptomic endotyping study that identifies a high-risk neonatal sepsis signature linked to mortality and cardiac dysfunction; and a multi-ICU cohort suggesting abrupt hydrocortisone discontinuation in septic shock may reduce ICU-related adverse events, with steroid duration driving post-discontinuation instability.
Research Themes
- Standardizing source control research in severe bloodstream infections
- Precision endotyping in neonatal sepsis via transcriptomics
- Steroid stewardship in septic shock: discontinuation strategies and risks
Selected Articles
1. Source control in bloodstream infections in patients with sepsis, septic shock, or requiring ICU admission: a scoping review with recommendations for standardizing research.
This scoping review of 77 studies shows major heterogeneity in how source control is defined, timed, and assessed in severe bloodstream infections, with overrepresentation of catheter removal and candidemia. The authors propose standardized reporting to improve evidence quality; 65% of studies suggested source control improved outcomes with no reported harm, but adequacy was seldom assessed.
Impact: Source control is central to sepsis care but under-studied and inconsistently reported; this paper provides a much-needed framework that can harmonize future trials and observational studies.
Clinical Implications: Adopting standardized definitions, timing metrics, and adequacy assessments for source control can enhance comparability across studies and inform timely, effective interventions for critically ill patients with bloodstream infections.
Key Findings
- Among 2193 abstracts, 77 studies met inclusion; only 21% had source control as a primary objective.
- Candidemia accounted for 47% and catheter removal for 60% of studies; 34% evaluated catheter removal regardless of source.
- Definitions of source control varied widely (no definition 8%, minimal 7%, concise 17%, comprehensive 9%); timing was inconsistently reported (68%), adequacy assessed in only 3%, and 65% reported improved outcomes with source control without reported harm.
Methodological Strengths
- Comprehensive multi-database search (Medline, EMBASE, Cochrane) with predefined inclusion criteria
- Structured scoping methodology and explicit extraction of definitions, timing, and adequacy elements
Limitations
- Scoping review does not quantify effect sizes or perform meta-analysis
- Evidence base is skewed toward catheter-associated BSI and candidemia with inconsistent definitions across studies
Future Directions: Develop and validate a consensus source control reporting checklist (definitions, timing benchmarks, adequacy metrics) and prospectively apply it in multicenter BSI cohorts and trials.
BACKGROUND: Bloodstream infections (BSI) account for 15% of intensive care unit (ICU) infections, often causing sepsis with mortality rates up to 50%. Source control (SC), encompassing interventions to reduce bacterial or fungal load and prevent infection spread, is a critical yet under-investigated component of management. OBJECTIVES: This scoping review examines SC definitions, interventions, timing, adequacy, and outcomes in BSI literature in patients with sepsis, septic shock, or ICU admission, and offers a proposal for standardized reporting. METHODS: We searched Medline, EMBASE, and Cochrane Library for studies on adult BSI addressing SC in populations with ≥ 50% ICU admission, ≥ 75% sepsis, or ≥ 25% septic shock, extracted and reported data following established guidance. RESULTS: From 2193 abstracts, 77 studies were included. SC was a primary objective in 21%, with others reporting it alongside other objectives. Candidemia (47%) and catheter removal (60%) studies were predominant, with 34% evaluating catheter removal regardless of BSI source. SC definitions varied from no definition (8%), minimal (7%), concise (17%), comprehensive (9%) definitions and catheter removal (60%). Forty-seven % reported proportions receiving SC for the entire cohort rather than those requiring SC. Timing was reported by 68%, with inconsistent definitions. SC adequacy was assessed by 3%. SC improved outcomes in 65%, with no reported harm. CONCLUSION: SC research in severe BSI is limited by inconsistent definitions, poor SC efficacy assessments, and overrepresentation of catheter-source BSI and candidemia. Standardized reporting is essential to enhance evidence quality and optimize BSI management in critically ill patients.
2. Transcriptomic mortality signature defines high-risk neonatal sepsis endotype.
Secondary analyses across datasets defined three neonatal sepsis endotypes using a 100-gene mortality signature. Endotype A had markedly higher mortality (22% vs 0%) and more cardiac dysfunction, with biology dominated by neutrophil progenitors and emergency granulopoiesis.
Impact: This work advances precision medicine in neonatal sepsis by linking a transcriptomic signature to clinically meaningful outcomes, enabling risk stratification and hypothesis generation for targeted therapies.
Clinical Implications: Pending validation, transcriptomic endotyping could identify high-risk neonates for early escalation of care or enrollment in targeted immunomodulatory trials.
Key Findings
- Three neonatal sepsis endotypes were identified using a 100-gene mortality signature across datasets.
- Endotype A showed higher mortality (22% vs 0%, p=0.003) and more cardiac dysfunction (61% vs 31%, p=0.025).
- Pathobiology of Endotype A was driven by neutrophil progenitors consistent with emergency granulopoiesis.
Methodological Strengths
- Multi-dataset secondary analysis with unsupervised clustering (t-SNE)
- Use of a predefined 100-gene mortality signature to stratify risk
Limitations
- Small number of non-survivors (n=5) and retrospective nature limit generalizability
- Lack of prospective validation and potential batch effects across datasets
Future Directions: Prospectively validate the endotypes, integrate with clinical biomarkers, and test tailored immunomodulatory strategies in stratified neonatal sepsis trials.
INTRODUCTION: Neonatal sepsis remains a leading cause of global childhood mortality, yet treatment options are limited. Clinical and biological heterogeneity hinders the development of targeted therapies. Gene-expression profiling offers a potential strategy to identify neonatal sepsis subtypes and guide targeted intervention. METHODS: We performed secondary analyses of publicly available gene-expression datasets. Differential gene expression analysis and T-distributed Stochastic Neighbor Embedding (t-SNE) identified biologically relevant patient clusters. Mortality and organ dysfunction were compared across clusters to determine clinical relevance. RESULTS: We identified three endotypes of neonatal sepsis based on the 100 gene expression mortality signature, distinguishing five non-survivors from 72 survivors across datasets. Compared with other endotypes, Endotype A was associated with high mortality (22% vs. 0%, p=0.003) and cardiac dysfunction (61% vs. 31%, p=0.025). Pathobiology among endotype A patients was primarily driven by neutrophil progenitors. CONCLUSIONS: Gene-expression profiling can be used to disentangle neonatal sepsis heterogeneity. Dysregulated hyperinflammatory response with emergency granulopoiesis was pathognomonic of high-risk endotype A. Pending further validation, gene-expression-based subclassification may be used to identify at-risk neonates and inform the selection of targeted sepsis therapies.
3. Evaluation of Hydrocortisone Discontinuation Strategies in Septic Shock: A Retrospective Cohort Study.
In 414 septic shock patients on stress-dose hydrocortisone, gradual tapering was associated with higher hemodynamic instability, more dysglycemia, and longer ventilation and ICU stays than abrupt discontinuation. Total steroid duration independently predicted post-discontinuation instability.
Impact: Addresses a common yet understudied decision in septic shock management, suggesting practice-relevant advantages of abrupt discontinuation and emphasizing the importance of minimizing steroid exposure.
Clinical Implications: Consider abrupt cessation once stable and avoid unnecessary prolongation of hydrocortisone; prioritize prospective trials to confirm causality and refine discontinuation protocols.
Key Findings
- Gradual tapering had higher hemodynamic instability than abrupt stop (29.2% vs 12.9%; p<0.001).
- More dysglycemia with tapering (59.4% vs 43.1%; p<0.001) and longer steroid exposure (9.9 vs 4.1 days; p<0.001).
- Longer mechanical ventilation (20 vs 15 days; p=0.014) and ICU stay (23 vs 17 days; p=0.008) with tapering; total hydrocortisone duration independently predicted instability (aOR 1.083; 95% CI 1.025-1.145; p=0.004).
Methodological Strengths
- Multi-ICU single-center cohort with a sizable sample (n=414)
- Adjusted analyses identifying independent predictors of instability
Limitations
- Retrospective design with potential confounding by indication and selection bias
- Single tertiary center limits generalizability; non-random allocation of discontinuation strategies
Future Directions: Conduct randomized or pragmatic prospective studies comparing abrupt vs tapered discontinuation and test steroid-sparing protocols to minimize exposure while maintaining hemodynamic stability.
IMPORTANCE: While corticosteroid administration in septic shock has been shown to reduce vasopressor requirements and accelerate shock reversal, the optimal discontinuation strategy remains unexplored. OBJECTIVES: The purpose of this study was to assess whether rates of hemodynamic instability differ among patients with septic shock undergoing abrupt hydrocortisone discontinuation compared with gradual tapering. DESIGN, SETTING, AND PARTICIPANTS: A retrospective cohort study conducted in five medical and surgical ICUs at a tertiary care hospital, involving adult patients (≥ 18 yr) with septic shock who received at least 48 hours of stress-dose hydrocortisone (≥ 200 mg/d). MAIN OUTCOMES AND MEASURES: The primary outcome was hemodynamic instability, defined as vasopressor reinitiation during tapering or within 72 hours of hydrocortisone discontinuation. Secondary outcomes included dysglycemia, duration of mechanical ventilation, ICU and hospital length of stay, and mortality. RESULTS: Patients were grouped based on their hydrocortisone discontinuation strategy into abrupt and gradual tapering groups. A total of 414 patients were included in this evaluation. Gradual tapering was associated with higher rates of hemodynamic instability (29.2% vs. 12.9%; p < 0.001), more frequent dysglycemia (59.4% vs. 43.1%; p < 0.001), longer hydrocortisone use (9.9 vs. 4.1 d; p < 0.001), and extended mechanical ventilation (20 vs. 15 d; p = 0.014) and ICU stay (23 vs. 17 d; p = 0.008). Total hydrocortisone duration was the strongest independent predictor of post-discontinuation hemodynamic instability, regardless of strategy (adjusted odds ratio, 1.083; 95% CI, 1.025-1.145; p = 0.004). CONCLUSIONS AND RELEVANCE: While abrupt hydrocortisone discontinuation was associated with fewer ICU-related adverse events, hydrocortisone duration was the primary factor influencing hemodynamic instability post-discontinuation among patients with septic shock. Prospective studies are needed to determine the optimal discontinuation strategy in septic shock.