Daily Sepsis Research Analysis
Analyzed 37 papers and selected 3 impactful papers.
Summary
Across three impactful studies in sepsis, an AI-powered learning health system improved real-world outcomes, fuzzy/dynamic sepsis subtyping revealed that uncertainty modifies patient trajectories and treatment effects, and a randomized trial of fluoxetine reduced vasopressor duration and ICU stay without a mortality signal. Together, these works advance implementation, precision phenotyping, and drug repurposing in sepsis.
Research Themes
- AI-enabled sepsis detection and quality improvement
- Dynamic, probabilistic sepsis phenotyping and treatment effect modification
- Drug repurposing targeting immunometabolic pathways in sepsis
Selected Articles
1. Fuzzy classification of sepsis subtypes and implications for trajectory and treatment.
Using multi-cohort EHR and trial data, most adults with community-acquired sepsis changed clinical subtype within 48 hours, and many had uncertain (margin) subtype membership. Margin status predicted greater subtype transitions and modified randomized treatment effects on 365-day mortality in ProCESS, challenging static phenotyping for precision sepsis care.
Impact: It introduces probabilistic, dynamic subtyping and demonstrates that uncertainty meaningfully alters trajectories and treatment effects, providing a critical framework for adaptive precision trials in sepsis.
Clinical Implications: Clinicians and trialists should incorporate dynamic phenotyping and uncertainty (core vs margin) into decision-making and study designs. Adaptive protocols and real-time reclassification may better align treatments with evolving patient states.
Key Findings
- In 35,691 adults with community-acquired sepsis, 82% changed clinical subtype within 48 hours of presentation.
- Most patients belonged to subtype margin strata (α 70%, β 66%, γ 64%), except δ-type (18% margin).
- Margin strata were associated with higher odds of subtype change (e.g., δ margin vs α core: OR 7.13, 95% CI 5.16–9.85).
- Subtype margin status modified randomized treatment effects on risk-adjusted 365-day mortality in ProCESS (interaction p=0.026).
Methodological Strengths
- Large, multi-cohort analysis with integration of randomized trial data (ProCESS).
- Probabilistic membership modeling capturing uncertainty (core vs margin) with multivariable adjustments.
Limitations
- Observational design with reliance on EHR-derived variables may introduce residual confounding.
- Generalizability of subtype assignments and thresholds may vary across health systems and datasets.
Future Directions: Prospective, adaptive trials that incorporate dynamic subtype reclassification and uncertainty thresholds; evaluation of subtype-guided treatment strategies in real time.
BACKGROUND: Sepsis is common and deadly, and subtypes are proposed to guide precision treatment. However, little is known about the uncertainty in subtype classification, and its implications for trajectory and treatment response. METHODS: In multiple electronic health record and trial data of adults with sepsis, we assigned patients clinical sepsis subtypes (α, β, γ, or δ-type), and measured uncertainty by defining core (≥90%) and margin (<90%) strata for each subtype according to model-derived membership probabilities. In multivariable logistic regression models, we determined the association between subtype, core/margin strata, and two outcomes, i.) change in subtype over 48 h and ii.) 365-day mortality in the ProCESS randomised trial. FINDINGS: We included 35,691 adult patients (mean age 68 [SD 16] years; 51% male, 85% White, 5.7% in-hospital mortality) with community-acquired sepsis according to Sepsis-3. Most patients changed clinical sepsis subtype during the 48 h after presentation (82%) regardless of initial subtype. The majority of patients were in the margin stratum of the subtype (α-type: 70%, β-type: 66%, γ-type: 64%), except for those in δ-type (18% margin strata). The odds of subtype change over 48 h was increased in the margin strata (interaction p = 0.023), where, for example, patients with the margin delta subtype had significantly higher odds than patients with alpha core (ref) subtype (odds ratio, 7.13; 95% confidence interval [CI], 5.16-9.85). For risk-adjusted 365-day mortality in the ProCESS trial, the effect of randomised treatment was modified by the subtype margin strata (interaction p = 0.026). INTERPRETATION: In patients with community sepsis, clinical subtypes are dynamic. Patients on the subtype margin are more likely to change groups, and uncertainty of subtype classification modified treatment effects. FUNDING: National Institutes of Health, National Institute of General Medical Sciences (R35GM119519).
2. An artificial intelligence-powered learning health system to improve sepsis detection and quality of care: a before-and-after study.
At Lausanne University Hospital, an AI-powered sepsis learning health system (SLHS) integrating the HERACLES classifier with standardized pathways and dashboards reduced in-hospital and 90-day mortality among algorithm-flagged sepsis cases, while control wards showed no such improvement. Sepsis coding also increased in intervention wards, indicating better detection and documentation.
Impact: This real-world, clinician-integrated AI intervention demonstrates measurable outcome improvements at scale, moving beyond prediction to system-level quality enhancement in sepsis care.
Clinical Implications: Health systems can integrate AI-driven sepsis surveillance with standardized pathways and feedback dashboards to improve detection, documentation, and outcomes. Implementation should include governance, monitoring for bias, and iterative workflow co-design.
Key Findings
- SLHS integrated HERACLES to classify sepsis status every 6 hours and drive quality dashboards.
- Across 97,559 SLHS-ward stays vs 25,851 control-ward stays, in-hospital and 90-day mortality decreased for HERACLES-flagged sepsis in SLHS wards, but not in controls.
- Sepsis coding rates increased in SLHS wards, indicating improved detection and documentation.
Methodological Strengths
- Large-scale, real-world implementation with concurrent control wards.
- Closed-loop integration of AI predictions with standardized care pathways and feedback dashboards.
Limitations
- Nonrandomized before-and-after design susceptible to residual confounding and secular trends.
- Single health system; external generalizability requires validation.
Future Directions: Prospective stepped-wedge or cluster-randomized evaluations across diverse hospitals; audits for algorithmic fairness; integration with antimicrobial stewardship and rapid diagnostics.
Sepsis is a major global health crisis where early recognition and effective management remain significant challenges for healthcare systems. As part of the Lausanne University Hospital sepsis quality of care program, we developed and validated an Artificial Intelligence (AI)-powered Sepsis Learning Health System (SLHS) to enhance sepsis care. The SLHS combines a standardized clinical pathway with HERACLES, an AI algorithm that retrospectively classifies patient data into confirmed, possible, or invalidated sepsis cases every 6 h. Predictions inform dynamic dashboards displaying quality-of-care indicators to guide clinical interventions. Analysis of 97,559 stays in wards using the SLHS and 25,851 stays in control wards showed that in-hospital and 90-day mortality decreased for HERACLES-flagged sepsis in SLHS wards, while control wards did not. Further, sepsis coding increased in SLHS wards but did not change in control wards. This real-world example demonstrates how clinician-integrated AI systems can improve sepsis detection and outcomes.
3. Effect of fluoxetine on organ dysfunction and mortality in severe sepsis.
In a double-blind randomized trial (n=46), adjunctive fluoxetine (40 mg/day) in severe sepsis reduced vasopressor duration, ICU length of stay, and inflammatory biomarkers, with lower SOFA/APACHE II scores at days 7 and 10. No significant difference in 28-day mortality was observed, suggesting potential physiologic benefit without proven survival effect.
Impact: A rigorously designed RCT suggests immunometabolic repurposing with fluoxetine can improve physiologic endpoints in severe sepsis, motivating larger multicenter trials.
Clinical Implications: Fluoxetine may be considered investigational as an adjunct to standard sepsis care to reduce vasopressor dependence and ICU stay, pending confirmation of safety and mortality effects in adequately powered trials.
Key Findings
- Primary endpoint met: vasopressor duration reduced with fluoxetine (6.2±0.4 vs 7.9±0.8 days; p<0.001).
- ICU length of stay decreased (15.9±1.6 vs 17.1±1.1 days; p=0.005).
- Inflammatory biomarkers (TNF-α, IL-1, CRP, procalcitonin) were lower by day 7 (all p<0.05).
- Lower SOFA and APACHE II scores at days 7 and 10 in the fluoxetine group.
- No significant difference in 28-day mortality (8.7% vs 17.4%; p=0.381).
Methodological Strengths
- Randomized, double-blind, placebo-controlled design with standardized dosing.
- Multiple clinically relevant endpoints including organ dysfunction scores and biomarkers.
Limitations
- Small, single-center sample limits power, particularly for mortality.
- Short follow-up (28 days) and lack of multicenter validation.
Future Directions: Conduct multicenter, adequately powered RCTs to assess mortality and safety; explore mechanistic immunometabolic biomarkers for enrichment and response prediction.
INTRODUCTION: Sepsis is a leading cause of morbidity and mortality in intensive care units, characterized by a dysregulated host response to infection. Recent evidence suggests fluoxetine, a selective serotonin reuptake inhibitor, may exert immunometabolic effects beneficial in sepsis. The aim of this study is to evaluate the effect of fluoxetine on vasopressor duration, organ dysfunction, inflammatory markers, and mortality in adult patients with severe sepsis. MATERIALS AND METHODS: In this single-center, randomized, double-blind, placebo-controlled trial conducted at Ain Shams University Hospitals (December 2024-June 2025), 46 patients with severe sepsis were randomized 1:1 to receive either fluoxetine (40 mg/day) or placebo in addition to standard sepsis care. The primary outcome was vasopressor duration. Secondary outcomes included Sequential Organ Failure Assessment (SOFA) scores, inflammatory biomarkers (CRP, TNF-α, IL-1, procalcitonin), lactate levels, ICU length of stay, and 28-day mortality. RESULTS: Fluoxetine significantly reduced vasopressor duration (6.2 ± 0.4 vs. 7.9 ± 0.8 days; p < 0.001), ICU stay (15.9 ± 1.6 vs. 17.1 ± 1.1 days; p = 0.005), and inflammatory markers by day 7, including TNF-α, IL-1, CRP, and procalcitonin (all p < 0.05). SOFA and APACHE II scores were also lower in the fluoxetine group on days 7 and 10. No significant difference in 28-day mortality was observed (8.7% vs. 17.4%; p = 0.381). CONCLUSIONS: Fluoxetine as adjunctive therapy in severe sepsis may reduce vasopressor dependence, attenuate inflammation, and shorten ICU stay without increasing adverse effects. Its mortality benefit remains uncertain and warrants further investigation.