Daily Sepsis Research Analysis
Analyzed 87 papers and selected 3 impactful papers.
Summary
Today’s most impactful papers span bedside and systems-level sepsis research: a multicenter prospective validation of the Epic Sepsis Model v2 clarifies real-world performance and alert burden; a large ICU cohort quantifies minute-by-minute MAP responses to initial norepinephrine dosing and links time-to-target MAP with mortality; and targeted lipidomics reveals a reproducible ceramide signature in sepsis across etiologies, informing selective therapeutic strategies.
Research Themes
- External validation and deployment of AI-based sepsis prediction
- Precision hemodynamics: initial norepinephrine dosing and time-to-target MAP
- Lipidomics-defined endotypes in sepsis guiding selective therapeutics
Selected Articles
1. Multicenter Prospective Validation of an Updated Proprietary Sepsis Prediction Model.
Across four US health systems (n=227,091 encounters; 7,401 with sepsis by Sepsis-3), ESM v2 demonstrated good discrimination (encounter-level AUROC 0.82–0.92; 12-hour prediction AUROC 0.75–0.85) but low positive predictive values (0.13–0.26), substantial site-level variability, and high alert burden. Performance decreased slightly when benchmarked against clinician recognition (antibiotics, lactate, cultures).
Impact: This is the first multicenter, prospective external validation of a widely deployed proprietary sepsis model, quantifying real-world discrimination, PPV, and alert burden across heterogeneous sites.
Clinical Implications: Adoption of ESM v2 should include local calibration, threshold tuning, and workflow integration to mitigate low PPV and alert fatigue; comparing model triggers with clinician heuristics can aid deployment decisions.
Key Findings
- Encounter-level AUROC ranged 0.82–0.92 across sites; 12-hour prediction-level AUROC 0.75–0.85.
- Positive predictive values were low (0.13–0.26), yielding high alert burden and number needed to evaluate.
- Performance decreased modestly when benchmarked against clinician recognition proxies (antibiotics, lactate, cultures).
- Substantial institutional variability indicates need for site-specific calibration and governance.
Methodological Strengths
- Prospective, multicenter external validation across four large health systems
- Large sample size with standardized Sepsis-3 outcome and multiple time horizons (4 h, 12 h, hospitalization)
Limitations
- Proprietary model limits interpretability and independent reproducibility
- Low PPV and high alert burden may constrain clinical utility without careful thresholding
Future Directions: Conduct site-specific calibration studies, prospective impact and cost-effectiveness trials, and fairness/Drift monitoring; compare model-triggered care pathways versus standard care.
IMPORTANCE: The Epic Sepsis Model version 2 (ESM v2) is a widely implemented proprietary sepsis prediction model, but no multicenter, external validation of its performance has been reported to guide adoption and use. OBJECTIVE: To conduct a multicenter validation of the ESM v2 to compare performance against the original ESM v1, outline differences across heterogenous clinical sites, and compare model performance against clinician recognition of sepsis. DESIGN, SETTING, AND PARTICIPANTS: This prognostic study included adult inpatient enc
2. Association between initial norepinephrine dose and minute by minute mean arterial pressure.
In a seven-ICU cohort (n=5,349 NE-treated; 37.5% sepsis), higher initial norepinephrine (0.100 µg/kg/min) produced larger and faster MAP increases than lower starting doses. Modeling showed that low starting doses often failed to reach MAP ≥65 mmHg within 60 minutes in severe hypotension; failure to reach target within 60 minutes independently associated with higher ICU mortality (OR 1.49). In sepsis, the initial MAP slope at 0.025 µg/kg/min was smaller than in non-sepsis.
Impact: Provides minute-resolution hemodynamic evidence linking initial NE dose, time-to-target MAP, and mortality, informing practical starting-dose strategies in shock including sepsis.
Clinical Implications: Consider higher initial NE dosing in severe hypotension to achieve MAP ≥65 mmHg within 60 minutes, with close monitoring; sepsis may require more assertive titration. Prospective trials should balance perfusion gains against ischemic risks.
Key Findings
- Initial NE 0.100 µg/kg/min yielded greater maximum MAP rise and faster 15-minute slope than 0.025 or 0.050 µg/kg/min (p<0.01).
- Lower starting doses failed to reach MAP ≥65 mmHg within 60 minutes when baseline MAP was very low (e.g., <53.9 mmHg for 0.025 µg/kg/min).
- Failure to reach MAP ≥65 mmHg within 60 minutes independently associated with increased ICU mortality (OR 1.49, 95% CI 1.27–1.76).
- In sepsis, the initial MAP slope at 0.025 µg/kg/min was significantly smaller than in non-sepsis.
Methodological Strengths
- Large multicenter cohort with high-frequency invasive arterial waveform data
- Generalized additive models adjusting for confounders to capture time-dependent effects
Limitations
- Observational design with potential residual confounding and indication bias
- Generalizability outside participating Japanese ICUs requires validation
Future Directions: Randomized trials comparing NE starting doses and titration protocols; sepsis-specific dosing algorithms; integration of real-time perfusion targets.
BACKGROUND: Neither the magnitude nor the timing of mean arterial pressure (MAP) increase after norepinephrine (NE) initiation is well defined, leaving clinicians without clear criteria for adequate starting doses. This study aimed to characterize minute-by-minute MAP responses to different initial NE doses in intensive care unit (ICU) patients with shock. METHODS: We included patients admitted to seven ICUs in Japan between 2013 and 2024 who had hypotension (MAP ≤ 65 mmHg) and initiated NE infusion more than
3. A Reproducible Ceramide Phenotype of Sepsis Across Aetiologies - A Monocenter Cohort Study.
Targeted lipidomics across two cohorts showed a consistent ceramide signature in SIRS/sepsis: increases in LC species (e.g., 16:0, 18:0, 20:0, 24:1) and decreases in VLC species (e.g., 23:0, 24:0, 26:0), irrespective of SARS-CoV-2 status. Several ceramides correlated with CRP and cholesterol, but neither individual species nor LC/VLC ratios associated with survival. Findings argue against non-selective acid sphingomyelinase inhibition and support evaluating selective ceramide synthase targeting.
Impact: Defines a reproducible, etiology-agnostic lipid signature of sepsis with therapeutic implications, while transparently showing no survival association for ceramide metrics.
Clinical Implications: Immediate prognostic use is limited, but results disfavor non-selective sphingomyelinase inhibition and prioritize selective ceramide synthase targeting for preclinical/clinical evaluation.
Key Findings
- Sepsis/SIRS increased LC ceramides (16:0, 18:0, 20:0, 24:1; p<0.001) and decreased VLC ceramides (23:0, 24:0, p=0.001; 26:0, p<0.001) versus non-septic comparators.
- Ceramide profiles were comparable between SARS-CoV-2 and non-SARS-CoV-2 sepsis (p>0.05).
- Several ceramides correlated with CRP and cholesterol, but neither individual ceramides nor LC/VLC ratios were associated with survival.
- Data argue against non-selective acid sphingomyelinase inhibition and support selective ceramide synthase targeting.
Methodological Strengths
- Two independent clinical cohorts with targeted lipidomics
- Direct comparison of COVID-19 vs non-COVID-19 sepsis and inclusion of controls
Limitations
- Monocenter design and modest sample sizes limit generalizability
- Serum vs plasma matrices and cross-sectional sampling may introduce variability; no causal inference
Future Directions: Longitudinal multi-center studies to track ceramide dynamics and interventional trials testing selective ceramide synthase modulators.
PURPOSE: Sepsis due to SARS-CoV-2 shares features with non-COVID-19 sepsis. Ceramides-bioactive sphingolipids-exist as long-chain (LC) and very-long-chain (VLC) species with opposing signaling effects. Whether LC and VLC ceramides are altered similarly in COVID-19 vs non-COVID-19 sepsis, and the therapeutic relevance of sphingomyelinase inhibition, remains uncertain. We characterised circulating ceramides in patients with systemic inflammatory response syndrome (SIRS) or sepsis with and without SARS-CoV-