Daily Sepsis Research Analysis
Analyzed 57 papers and selected 3 impactful papers.
Summary
A nationwide matched cohort shows bloodstream infection is associated with a substantial long-term excess risk of dementia beyond hospitalization effects. A 10-year multicenter Brazilian cohort in very low birth weight preterm infants reveals rising Gram-negative late-onset sepsis and persistently high mortality. A population pharmacokinetic sub-study of the LOVIT trial demonstrates highly variable vitamin C exposure in septic adults and no independent association between exposure and mortality.
Research Themes
- Infection-associated neurodegeneration risk after bloodstream infection
- Neonatal late-onset sepsis epidemiology and microbiological shifts in LMICs
- Pharmacokinetics and safety interpretation of adjunctive vitamin C in sepsis
Selected Articles
1. Risk of dementia after bloodstream infection-a nationwide propensity score matched cohort study.
In a nationwide matched cohort from Wales, microbiologically confirmed bloodstream infection was associated with a substantial excess hazard of dementia over 10 years. Negative-control analyses using uncomplicated total knee replacement and a lung cancer outcome suggest the association exceeds hospitalization effects and residual confounding.
Impact: This study strengthens the causal inference between severe infection and later dementia by leveraging negative-control designs at population scale, highlighting infection prevention as a potential dementia risk-reduction strategy.
Clinical Implications: Intensified prevention and optimal management of severe infections (including timely sepsis care and vaccination strategies) may reduce long-term dementia risk; survivors of BSI may warrant cognitive monitoring and risk modification.
Key Findings
- Bloodstream infection was associated with 160 (128–182) additional dementia cases per 1000 person-years at 10 years.
- Uncomplicated total knee replacement (negative-control exposure) was not associated with dementia, arguing against hospitalization bias.
- A small excess hazard of lung cancer after BSI suggests limited residual confounding that does not explain the dementia signal.
Methodological Strengths
- Nationwide population-scale EHR with propensity score matching.
- Use of negative-control exposure and outcome to address confounding.
Limitations
- Observational design cannot definitively prove causality.
- Dementia ascertainment from routine records may be prone to misclassification and diagnostic delay.
Future Directions: Evaluate whether targeted infection-prevention and optimized sepsis care reduce incident dementia; elucidate mechanisms linking systemic infection/inflammation to neurodegeneration; extend analyses across diverse populations.
BACKGROUND: Dementia is a global public health threat. Current treatments have limited efficacy, making identification of modifiable risk factors of paramount importance. Observational studies link severe infections to increased dementia risk but often suffer confounding. Here, we address this by determining dementia risk following bloodstream infection (BSI) in a nationwide study. METHODS: We conducted a cohort study within the Secure Anonymised Information Linkage Databank, containing anonymised population-scale electronic health record data for the population of Wales, UK. Patients with microbiologically confirmed BSI were propensity score matched 1:1 to controls (n = 2.5 million without dementia at baseline). We created two comparative models to estimate the true effect of BSI on dementia risk: modelling hospitalisation with sterile inflammation, uncomplicated total knee replacement (TKR) replaced BSI as the exposure; assessing residual confounding, lung cancer replaced dementia as outcome. RESULTS: We included 26 792 people with BSI and 26 792 matched controls, all without dementia at cohort entry. BSI was associated with an increased cumulative hazard of dementia corresponding to 160 (128-182) additional cases per 1000 person-years 10 years after exposure. TKR was not associated with an increased risk of dementia. BSI was potentially associated with a small excess hazard of lung cancer [12.4 (5.4-19.5) additional cases per 1000 person-years 10 years after exposure]. CONCLUSIONS: BSI was associated with incident dementia in excess of that expected by hospitalisation or residual confounding. These findings suggest that treatment of BSI and other severe infections merits further investigation as a potentially modifiable risk factor for dementia.
2. Trends in Late-onset Sepsis in Very Low Birth Weight Preterm Infants in the Brazilian Network on Neonatal Research: A 10-year Cohort Study.
In 13,439 very low birth weight preterm infants across 18 Brazilian NICUs, proven late-onset sepsis occurred in 24.6% with a decade-long increase in Gram-negative infections and no decline in mortality. Coagulase-negative staphylococci dominated Gram-positive isolates, while fungal infections decreased over time.
Impact: This large multicenter cohort from a middle-income setting provides critical trend data showing rising Gram-negative LOS and stagnant mortality, informing priority targets for infection control and antimicrobial stewardship.
Clinical Implications: Strengthen prevention bundles (line care, hand hygiene), Gram-negative-targeted stewardship, and context-specific quality improvement to reduce LOS burden and mortality in VLBW infants.
Key Findings
- Proven LOS incidence was 24.6% and clinical LOS 19.2% among 13,439 VLBW infants.
- Gram-positive bacteria (64.1%) predominated, with 49.4% coagulase-negative staphylococci; Gram-negatives accounted for 27.2%, fungi 8.8%.
- Over 2010–2020, fungal infections decreased, but Gram-negative infections and proven LOS incidence increased; in-hospital mortality remained high at 24.8% without reduction.
Methodological Strengths
- Large, multicenter level-3 NICU network with over a decade of surveillance.
- Clear case definitions distinguishing proven vs clinical LOS and organism profiling.
Limitations
- Observational design limits causal inference and may be affected by center-level practice variation.
- Lacks detailed antimicrobial resistance patterns and standardized treatment protocols across sites.
Future Directions: Implement and evaluate targeted bundles against Gram-negative LOS, incorporate AMR surveillance, and assess impact of stewardship and catheter-care QI on mortality in VLBW infants.
BACKGROUND: Late-onset sepsis (LOS) remains a leading cause of morbidity and mortality in preterm infants, with decreasing incidence in high-income countries but persistent challenges in low- and middle-income countries. This study aimed to evaluate the epidemiology, microbiological profile, and short-term outcomes of LOS in very low birth weight (VLBW) preterm infants in Brazil. METHODS: A multicenter cohort study across 18 level 3 neonatal units of the Brazilian Network on Neonatal Research included 13,439 VLBW infants (400-1499 g birth weight, 22-36 weeks gestation) admitted between 2010 and 2020, excluding those with major malformations, congenital infections or death before 72 hours. Main outcomes included incidence of proven and clinical LOS, in-hospital mortality, and associated short-term morbidities. RESULTS: The cohort had a mean gestational age of 29 ± 3 weeks and birth weight of 1079 ± 275 g. The incidence of proven LOS was 24.6%, and clinical LOS was 19.2%. Gram-positive bacteria predominated (64.1%, with 49.4% coagulase-negative staphylococci), followed by Gram-negative bacteria (27.2%) and fungi (8.8%). Over the decade, fungal infections decreased, while Gram-negative bacterial infections and proven LOS incidence increased. In-hospital mortality was 24.8%, showing no reduction. LOS was associated with an increased risk of death and severe morbidities. CONCLUSIONS: This comprehensive 10-year cohort in Brazil reveals a concerning epidemiological shift, characterized by a significant increase in Gram-negative infections and a persistent, high LOS incidence and mortality among VLBW infants. These findings, particularly the lack of improvement in prognosis, underscore the urgent need for targeted and effective preventive and control interventions tailored for resource-limited settings.
3. Population Pharmacokinetics of Intravenous Vitamin C in Adults with Sepsis: A Sub-study of the LOVIT Trial.
In septic adults randomized to high-dose IV vitamin C in LOVIT, population PK modeling showed a one-compartment model with clearance strongly influenced by eGFR and illness severity. Despite higher vitamin C exposure among non-survivors, exposure was not independently associated with 28-day mortality.
Impact: This rigorously modeled PK study clarifies why fixed dosing yields heterogeneous exposures in sepsis and supports the interpretation that higher exposure is a severity marker rather than a causal driver of harm.
Clinical Implications: High interindividual variability suggests that empiric high-dose vitamin C is unlikely to provide consistent pharmacologic effects; dosing should consider renal function and severity, and clinical use should remain cautious given LOVIT harms.
Key Findings
- A one-compartment model fit the data with population mean clearance 3.37 L/h and volume of distribution 45.06 L.
- Clearance was significantly influenced by CKD-EPI eGFR and APACHE II score, indicating illness severity and renal function drive variability.
- Non-survivors had higher vitamin C exposure, but exposure was not an independent predictor of 28-day mortality; age and APACHE II were.
Methodological Strengths
- Embedded within a large international RCT with standardized dosing and sampling.
- Robust population PK modeling with internal bootstrap validation and covariate analysis.
Limitations
- PK analysis limited to the vitamin C arm; no external validation cohort.
- Sampling at fixed days may miss early distribution phases; observational associations within the trial cannot establish causality.
Future Directions: Explore adaptive or personalized dosing guided by renal function and severity; evaluate PK-PD relationships for clinically meaningful endpoints; conduct external validation and modeling of toxicity thresholds.
BACKGROUND AND OBJECTIVES: High-dose intravenous vitamin C was associated with increased harm in adults with sepsis requiring vasopressors in the large international LOVIT trial. This population pharmacokinetic sub-study of LOVIT aimed to characterise the pharmacokinetics of vitamin C and explore associations with patient characteristics and outcomes. METHODS: Patients who enrolled in the LOVIT trial were randomized to receive 50 mg/kg vitamin C every 6 hours for 96 hours or placebo. Blood samples were collected on study Days 1, 3, and 7 for plasma vitamin C quantification. Population pharmacokinetic modeling was performed, with relevant patient and treatment-related factors tested as covariates. Internal validation was conducted using bootstrap resampling (n = 1000). Univariable and multivariable analyses explored associations between 28-day mortality and patient characteristics, as well as the relationship between vitamin C exposure and severity of illness. RESULTS: A total of 464 samples from 161 patients who were randomized to vitamin C were analysed. The median age was 64 (interquartile range [IQR] 56-72) years, weight 82 (IQR, 70-94) kg, and APACHE II score 24 (IQR, 18-29); 65.2% were male. A one-compartment model best described the data, with clearance (CL) significantly influenced by CKD-EPI eGFR and APACHE II score. Population mean estimates for clearance and volume of distribution were 3.37 L/h and 45.06 L, respectively. The model was internally validated and demonstrated to be robust and stable. Although greater vitamin C exposure was observed among non-survivors versus survivors (median 1900.5 [IQR 1191.8-2548.2] vs 1017.8 [IQR 630-1836.7] mg·h/L; p < 0.001), only age (odds ratio [OR] 1.063; 95% confidence interval [CI] 1.024-1.104, p = 0.001) and APACHE II score (OR 1.079; 95% CI 1.005-1.158, p = 0.036) were independently associated with 28-day mortality. Severity of illness was also predictive of vitamin C exposure. CONCLUSIONS: Vitamin C pharmacokinetics are highly variable between individuals. Some of this variability can be explained by changes in glomerular filtration and APACHE II score as a measure of illness severity. Although non-survivors had greater vitamin C exposure than survivors, exposure was not independently associated with mortality.