Daily Sepsis Research Analysis
Three papers stand out today: a Europe-wide modeling study projects age- and sex-specific antimicrobial resistance (AMR) burdens in bloodstream infections through 2050; a large cohort analysis finds no association between time to vasopressor initiation and 90-day mortality in septic shock; and a trajectory-based study shows that dynamic serum sodium patterns predict mortality in ICU sepsis. Together, they inform policy targets, bedside hemodynamic decisions, and risk stratification.
Summary
Three papers stand out today: a Europe-wide modeling study projects age- and sex-specific antimicrobial resistance (AMR) burdens in bloodstream infections through 2050; a large cohort analysis finds no association between time to vasopressor initiation and 90-day mortality in septic shock; and a trajectory-based study shows that dynamic serum sodium patterns predict mortality in ICU sepsis. Together, they inform policy targets, bedside hemodynamic decisions, and risk stratification.
Research Themes
- Age- and sex-stratified AMR forecasting in bloodstream infections
- Hemodynamic management timing in septic shock
- Dynamic biomarker trajectories for sepsis risk stratification
Selected Articles
1. Combining demographic shifts with age-based resistance prevalence to estimate future antimicrobial resistance burden in Europe and implications for targets: A modelling study.
Using over 12.8 million susceptibility tests and Bayesian models, the authors project that resistant bloodstream infection burden in Europe will rise disproportionately among older adults—especially men—through 2050. Notably, age/sex stratification alters projections, and achieving a 10% reduction by 2030 appears infeasible for many bacteria–antibiotic combinations even under aggressive incidence reductions.
Impact: Provides policy-relevant, age/sex-specific AMR forecasts with explicit intervention scenarios, challenging the feasibility of uniform reduction targets. It reframes how Europe should set and evaluate AMR goals.
Clinical Implications: AMR control should prioritize high-burden groups (older men) and be tailored by country, age, and sex. Uniform targets (e.g., 10% by 2030) may be unrealistic without substantial reductions in infection incidence and demographic-aware strategies.
Key Findings
- BSI incidence projected to rise more in men than women across 6/8 bacteria, with steepest increases in ages 74+.
- Excluding age/sex yields misestimation: 47% of bacteria–antibiotic combinations show fewer resistant BSIs by 2030 vs. age/sex-aware models.
- Even with −20 per 100,000/year incidence rate changes, only 26/38 combinations reach a 10% reduction by 2030; some rebound by 2050.
Methodological Strengths
- Massive surveillance dataset (12,807,473 tests) with Bayesian hierarchical modeling across 38 bacteria–antibiotic combinations.
- Explicit age/sex disaggregation linked to demographic projections and intervention scenario analysis.
Limitations
- Relies on European surveillance and extrapolation of current trends; findings may not generalize beyond Europe.
- Does not incorporate comorbidities, ethnicity, or clinical severity; projections may omit important risk modifiers.
Future Directions: Integrate comorbidity and health system variables, validate projections prospectively, and test targeted interventions in high-burden subgroups.
BACKGROUND: Antimicrobial Resistance (AMR) is a global public health crisis. Evaluating intervention impact requires accurate estimates of how the AMR burden will change over time, given likely demographic shifts. This study aimed to provide an estimate of future AMR burden in Europe, investigating resistance variation by age and sex and the impact of interventions to achieve the proposed United Nations (UN) political declaration targets. METHODS AND FINDINGS: Using data from 12,807,473 bloodstream infection (BSI) susceptibility tests from routine surveillance in Europe, we estimate age- and sex-specific rates of change in BSI incidence for the 8 bacteria included in European Antimicrobial Resistance Surveillance Network (EARS-Net) surveillance over 2015-2019. This was used to project incidence rates by age and sex for 2022-2050 and, with demographic projections, to generate estimates of BSI burden (2022-2050). Two Bayesian hierarchical models were fitted across 38 bacteria-antibiotic combinations to the 2015-2019 resistance proportion of BSI by year and at the country-level with and without age and sex disaggregation. Inputting the incidence estimates into the "agesex" and "base" model, respectively, we sampled 1,000 model estimates of resistant BSI burden by age, sex, and country to determine the importance of age and sex disaggregation. We explored Intervention scenarios consisting of a 1, 5, or 20 per 100,000 per year reduction in infection incidence rate of change or 5 per 100,000 per year reduction in those older than 64 years. Overall, in Europe, BSI incidence rates are predicted to increase more in men than women across 6 of the 8 bacteria (Pseudomonas aeruginosa and Enterococcus faecium were the exception) and are projected to increase more dramatically in older age groups (74+ years) but stabilise or decline in younger age groups.
2. Time to Vasopressor Initiation Is Not Associated With Increased Mortality in Patients With Septic Shock.
In 4,699 septic shock patients from a statewide database, the interval from first hypotension to vasopressor initiation did not predict 90-day mortality or vasopressor-free days. Severity markers (age, ventilation, SOFA labs, lactate) and comorbidities, rather than clock time to vasopressors, drove outcomes.
Impact: Challenges the emphasis on ultra-early vasopressor initiation as an independent driver of mortality, helping refocus priorities on resuscitation quality and severity-based decisions.
Clinical Implications: Prioritize timely antibiotics, source control, and hemodynamic optimization; do not escalate vasopressors solely to meet arbitrary time targets without considering patient severity and perfusion.
Key Findings
- Time to vasopressor initiation was not associated with 90-day mortality (OR 1.01; 95% CI 1.00–1.02).
- Independent predictors included age, mechanical ventilation, SOFA laboratory components, lactate, chronic hypertension (protective), and liver disease.
- No association between timing and vasopressor-free days.
Methodological Strengths
- Large multicenter real-world cohort with LASSO-assisted multivariable modeling and clinically relevant 90-day mortality endpoint.
- Clear inclusion criteria leveraging diagnoses, antibiotics, and hypotension, enhancing construct validity.
Limitations
- Retrospective design with potential misclassification of hypotension episodes and timing.
- Generalizability beyond the OneFlorida health systems and practice patterns may be limited.
Future Directions: Prospective, protocolized studies to test vasopressor strategies integrating perfusion targets and fluid responsiveness rather than fixed time thresholds.
STUDY OBJECTIVE: The optimal timing of vasopressor initiation in septic shock remains unclear. Our objective was to evaluate the association between time to vasopressor initiation and mortality. METHODS: This was a retrospective cohort study of patients with septic shock in the OneFlorida Data Trust, a statewide repository of health care data. We included patients if they received vasopressors during hospitalization after at least 1 episode of hypotension (systolic blood pressure ≤100 mmHg) and had either (1) an International Classification of Disease 9 or 10 code for sepsis, or (2) an International Classification of Disease code for infection and received IV antibiotics. The primary outcome was 90-day mortality. The secondary outcome was vasopressor-free days. We used multiple logistic regression with Least Absolute Shrinkage and Selection Operator for variable selection to assess associations with 90-day mortality. RESULTS: There were 4,699 patients with septic shock between 2012 and 2018 included. The primary outcome, 90-day mortality, was present in 34% (n=1,610). Time to vasopressor initiation was not found to be associated with 90-day mortality (odds ratio [OR] 1.01; 95% confidence interval [CI] 1.00 to 1.02). Independent predictors included age (OR 1.04; 95% CI 1.04 to 1.05), mechanical ventilation (OR 2.98; 95% CI 2.56 to 3.48), laboratory components of the Sequential Organ Failure Assessment score (OR 1.18; 95% CI 1.14 to 1.23), lactate level (OR 1.10; 95% CI 1.08 to 1.13), chronic hypertension (OR 0.60; 95% CI 0.52 to 0.70), and liver disease (OR 1.54; 95% CI 1.30 to 1.82). Time to vasopressor initiation was not found to be an independent predictor of vasopressor-free days. CONCLUSION: Time from first hypotensive episode to vasopressor initiation was not found to be associated with 90-day mortality or vasopressor-free days in this large cohort of septic shock patients.
3. Association between sodium level trajectories and clinical prognosis in patients with sepsis: A longitudinal retrospective cohort study.
Among 9,697 ICU patients with sepsis, four distinct sodium trajectories over the first 8 ICU days were identified. The U-shaped increase trajectory conferred the highest mortality risk (adjusted HR 1.55), and SHAP analyses highlighted class-specific feature contributions, supporting dynamic sodium monitoring for prognostication.
Impact: Introduces trajectory-based electrolyte phenotyping at scale, moving beyond single-point sodium values to dynamic risk stratification in sepsis.
Clinical Implications: Serial sodium trajectories can inform early risk stratification and guide fluid/electrolyte and vasopressor strategies, complementing scores like SOFA.
Key Findings
- Four sodium trajectory classes over the first 8 ICU days were identified: U-shaped increase, low-level stable, high-level stable, and inverted U-shaped decrease.
- The U-shaped increase class had the highest mortality risk (adjusted HR 1.55; 95% CI 1.30–1.85), followed by the inverted U-shaped decrease class.
- SHAP analysis quantified class-specific feature contributions to mortality, supporting trajectory-aware prognostication.
Methodological Strengths
- Large ICU cohort with latent class mixed modeling of time-series sodium and robust survival analyses (KM, Cox, logistic).
- Explainable ML (SHAP) to interpret feature contributions across trajectory classes.
Limitations
- Retrospective single-database study; residual confounding and selection biases possible.
- Trajectory classification depends on measurement frequency and may be affected by practice patterns.
Future Directions: Prospective validation across centers, assessment of intervention responsiveness by trajectory class, and integration with multimodal physiologic data.
ObjectiveSepsis treatment remains challenging in ICU due to patient heterogeneity. Although sodium imbalance is common and associated with poor outcomes, its longitudinal dynamics and complexity have been overlooked. This study aimed to identify sodium trajectories in ICU patients with sepsis and evaluate their prognostic value.MethodsThis retrospective study included ICU patients with sepsis from the Medical Information Mart for Intensive Care IV v3.0 database. Time-series sodium measurements were extracted for the first 8 days of ICU stay. Latent Class Mixed Model was used to identify sodium trajectory patterns. The primary outcome was 28-day mortality, and the secondary outcome was 90-day mortality. Kaplan-Meier, cox regression, and logistic regression analyses were employed to examine associations between trajectory classes and outcomes. Further SHAP analysis quantified the contribution of individual features to mortality across the different classes. Subgroup analyses assessed robustness and effect modification.ResultsA total of 9697 patients were included and divided into four trajectory groups: "U-shaped increase"; "Low-level stable"; "High-level stable"; and "Inverted U-shaped decrease". Class 1 exhibited the highest mortality risk, followed by Class 4, with adjusted hazard ratios (HRs) of 1.55 (95% CI: 1.30-1.85;