Prevalence, Underlying Causes, and Preventability of Sepsis-Associated Mortality in US Acute Care Hospitals

Discharge to Skilled Nursing Facility Is a Risk Factor for Readmission: A Nationwide Propensity-Matched Study

INTRODUCTION

General surgery procedures place stress on geriatric patients, and postdischarge care options should be evaluated. We compared the association of discharge to a skilled nursing facility (SNF) versus home on patient readmission.

METHODS

We retrospectively reviewed the Nationwide Readmission Database (2016-2019) and included patients ≥65 y who underwent a general surgery procedure between January and September. Our primary outcome was 30-d readmissions. Our secondary outcome was predictors of readmission after discharge to an SNF. We performed a 1:1 propensity-matched analysis adjusting for patient demographics and hospital course to compare patients discharged to an SNF with patients discharged home. We performed a sensitivity analysis on patients undergoing emergency procedures and a stepwise regression to identify predictors of readmission.

RESULTS

Among 140,056 included patients, 33,916 (24.2%) were discharged to an SNF. In the matched population of 19,763 pairs, 30-d readmission was higher in patients discharged to an SNF. The most common diagnosis at readmission was sepsis, and a greater proportion of patients discharged to an SNF were readmitted for sepsis. In the sensitivity analysis, emergency surgery patients discharged to an SNF had higher 30-d readmission. Higher illness severity during the index admission and living in a small or fringe county of a large metropolitan area were among the predictors of readmission in patients discharged to an SNF, while high household income was protective.

CONCLUSIONS

Discharge to an SNF compared to patients discharged home was associated with a higher readmission. Future studies need to identify the patient and facility factors responsible for this disparity.

Electrical stimulation of the dorsal motor nucleus of the vagus in male mice can regulate inflammation without affecting the heart rate

BACKGROUND

The vagus nerve plays an important role in neuroimmune interactions and in the regulation of inflammation. A major source of efferent vagus nerve fibers that contribute to the regulation of inflammation is the brainstem dorsal motor nucleus of the vagus (DMN), as recently shown using optogenetics. In contrast to optogenetics, electrical neuromodulation has broad therapeutic implications. However, the anti-inflammatory effectiveness of electrical stimulation of the DMN (eDMNS) and the possible heart rate (HR) alterations associated with this approach have not been investigated. Here, we examined the effects of eDMNS on HR and cytokine levels in mice administered with lipopolysaccharide (LPS, endotoxin) and in mice subjected to cecal ligation and puncture (CLP) sepsis.

METHODS

Anesthetized male 8-10-week-old C57BL/6 mice on a stereotaxic frame were subjected to eDMNS using a concentric bipolar electrode inserted into the left or right DMN or sham stimulation. eDMNS (500, 250 or 50 μA at 30 Hz, for 1 min) was performed and HR recorded. In endotoxemia experiments, sham or eDMNS utilizing 250 μA or 50 μA was performed for 5 mins and was followed by LPS (0.5 mg/kg) i.p. administration. eDMNS was also applied in mice with cervical unilateral vagotomy or sham operation. In CLP experiments sham or left eDMNS was performed immediately post CLP. Cytokines and corticosterone were analyzed 90 mins after LPS administration or 24 h after CLP. CLP survival was monitored for 14 days.

RESULTS

Either left or right eDMNS at 500 μA and 250 μA decreased HR, compared with baseline pre-stimulation. This effect was not observed at 50 μA. Left side eDMNS at 50 μA, compared with sham stimulation, significantly decreased serum and splenic levels of the pro-inflammatory cytokine TNF and increased serum levels of the anti-inflammatory cytokine IL-10 during endotoxemia. The anti-inflammatory effect of eDMNS was abrogated in mice with unilateral vagotomy and was not associated with serum corticosterone alterations. Right side eDMNS in endotoxemic mice suppressed serum TNF and increased serum IL-10 levels but had no effects on splenic cytokines. In mice with CLP, left side eDMNS suppressed serum IL-6, as well as splenic IL-6 and increased splenic IL-10 and significantly improved the survival rate of CLP mice.

CONCLUSIONS

For the first time we show that a regimen of eDMNS which does not cause bradycardia alleviates LPS-induced inflammation. These eDMNS anti-inflammatory effects require an intact vagus nerve and are not associated with corticosteroid alterations. eDMNS also decreases inflammation and improves survival in a model of polymicrobial sepsis. These findings are of interest for further studies exploring bioelectronic anti-inflammatory approaches targeting the brainstem DMN.

Rapid Antimicrobial Susceptibility Testing Using the MicroScan System: Performance Evaluation of a 4-Hour Bacterial Cultivation From Positive Blood Cultures

A reliable and above all, rapid antimicrobial susceptibility test (AST) is required for the diganostics of blood stream infections (BSI). In this study, resistance testing using DxM MicroScan WalkAway (MicroScan) from a 4-h subculture is compared with the standard overnight culture (18-24 h). Randomly selected positive blood cultures (PBC, n = 102) with gram-negative bacteria were included in the study. PBC were sub-cultured onto appropriate agar plates and AST by MicroScan was performed after 4 h of incubation and repeated after incubation for 18-24 h as standard. In a total of 1909 drug-strain pairs, the 4-h subculture approach showed a very high essential agreement (EA) (98.6%) and categorical agreement (CA) (97.1%) compared with the standard. The incidence of minor error (mE), major error (ME), very major error (VME), and adjusted very major error (aVME) was 1.1%, 0.4%, 12.9%, and 5.3%, respectively. In summary, the use of 4-h subcultures for resistance testing with the MicroScan offers a very reliable and easy to realize time saving when testing positive blood cultures with gram-negative bacteria.

Comparing the clinical characteristics and outcomes of septic shock children with and without malignancies: a retrospective cohort study

OBJECTIVE

There is an amelioration in mortality rates of septic shock patients with malignancies over time, but it remains uncertain in children. Therefore, the authors endeavored to compare the clinical characteristics, treatment needs, and outcomes of septic shock children with or without malignancies.

METHODS

The authors retrospectively analyzed the data of children admitted to the PICU due to septic shock from January 2015 to December 2022 in a tertiary pediatric hospital. The main outcome was in-hospital mortality.

RESULTS

A total of 508 patients were enrolled. The proportion of Gram-negative bacteria and fungal infections in children with malignancies was significantly higher than those without malignancies. Septic shock children with malignancies had a longer length of stay (LOS) in the hospital (21 vs. 11 days, p<0.001). However, there were no statistically significant differences in the LOS of PICU (5 vs. 5 days, p = 0.591), in-hospital mortality (43.0 % vs. 49.4 %, p = 0.276), and 28-day mortality (49.2 % vs. 44.7 %, p = 0.452). The 28-day survival analysis (p = 0.314) also showed no significant differences.

CONCLUSION

Although there are significant differences in the bacterial spectrum of infections, the septic shock children with or without malignancies showed a similar mortality rate. The septic shock children with malignancies had longer LOS of the hospital.

Carbon Dot-Loaded Apoptotic Vesicles Improve the Liver Kupffer Cell-Mediated Antibacterial Effect to Synergistically Alleviate Sepsis

Sepsis is a lethal systemic inflammatory disease against infection that lacks effective therapeutic approaches. Liver resident macrophage Kupffer cell (KC)-initiated bacterial clearance is crucial for the host to defend against infection. However, it remains unclear whether this process also governs the antibacterial therapy of sepsis that would be used to improve therapeutic outcomes. Here, we found that copper-doped carbon dots (Cu-CDs) exhibited superior antibacterial capabilities in vitro but displayed limited therapeutic effects in septic mice due to their limited ability to target the liver and restore KC antimicrobial capacity. Thus, we developed a composite nanodrug of copper-doped carbon dot-loaded apoVs (CC-apoVs) that combined the antibacterial ability of Cu-CDs and liver KC targeting features of apoV. Moreover, intravenous injection of CC-apoVs markedly alleviated the systemic infection and decreased the mortality of septic mice compared to Cu-CD and apoV infusion alone. Mechanistically, CC-apoV injection rescued impaired liver KCs during sepsis and enhanced their ability to capture and kill bloodborne bacteria. In addition, apoV-promoted macrophage killing of bacteria could be blocked by the inhibition of small GTPase Rab5. This study reveals a liver KC-targeted therapeutic strategy for sepsis and provides a nanodrug CC-apoV to improve the host antibacterial defense and amplify the therapeutic effect of the nanodrug.

Development and Validation of the Hospital Medicine Safety Sepsis Initiative Mortality Model

BACKGROUND

When comparing outcomes after sepsis, it is essential to account for patient case mix to make fair comparisons. We developed a model to assess risk-adjusted 30-day mortality in the Michigan Hospital Medicine Safety sepsis initiative (HMS-Sepsis).

RESEARCH QUESTION

Can HMS-Sepsis registry data adequately predict risk of 30-day mortality? Do performance assessments using adjusted vs unadjusted data differ?

STUDY DESIGN AND METHODS

Retrospective cohort of community-onset sepsis hospitalizations in the HMS-Sepsis registry (April 2022-September 2023), with split-derivation (70%) and validation (30%) cohorts. We fit a risk-adjustment model (HMS-Sepsis mortality model) incorporating acute physiologic, demographic, and baseline health data and assessed model performance using concordance (C) statistics, Brier's scores, and comparisons of predicted vs observed mortality by deciles of risk. We compared hospital performance (first quintile, middle quintiles, fifth quintile) using observed vs adjusted mortality to understand the extent to which risk adjustment impacted hospital performance assessment.

RESULTS

Among 17,514 hospitalizations from 66 hospitals during the study period, 12,260 hospitalizations (70%) were used for model derivation and 5,254 hospitalizations (30%) were used for model validation. Thirty-day mortality for the total cohort was 19.4%. The final model included 13 physiologic variables, two physiologic interactions, and 16 demographic and chronic health variables. The most significant variables were age, metastatic solid tumor, temperature, altered mental status, and platelet count. The model C statistic was 0.82 for the derivation cohort, 0.81 for the validation cohort, and ≥ 0.78 for all subgroups assessed. Overall calibration error was 0.0%, and mean calibration error across deciles of risk was 1.5%. Standardized mortality ratios yielded different assessments than observed mortality for 33.9% of hospitals.

INTERPRETATION

The HMS-Sepsis mortality model showed strong discrimination and adequate calibration and reclassified one-third of hospitals to a different performance category from unadjusted mortality. Based on its strong performance, the HMS-Sepsis mortality model can aid in fair hospital benchmarking, assessment of temporal changes, and observational causal inference analysis.

Failure to Rescue as a Quality Measure in Sepsis

This Viewpoint discusses the limitations of current tools to improve sepsis outcomes and proposes that these tools be supplemented with “failure to rescue,” a systems-level approach for recognizing and addressing complications and managing sepsis throughout the hospitalization period.

Evaluating Sepsis Bundle Compliance as a Predictor for Patient Outcomes at a Community Hospital: A Retrospective Study

BACKGROUND

Clinicians are encouraged to use the Centers for Medicare & Medicaid Services early management bundle for severe sepsis and septic shock (SEP-1); however, it is unclear whether this process measure improves patient outcomes.

PURPOSE

The purpose of this study was to evaluate whether compliance with the SEP-1 bundle is a predictor of hospital mortality, length of stay (LOS), and intensive care unit LOS at a suburban community hospital.

METHODS

A retrospective observational study was conducted.

RESULTS

A total of 577 patients were included in the analysis. Compliance with the SEP-1 bundle was not a significant predictor for patient outcomes.

CONCLUSIONS

SEP-1 compliance may not equate with quality of health care. Efforts to comply with SEP-1 may help organizations develop systems and structures that improve patient outcomes. Health care leaders should evaluate strategies beyond SEP-1 compliance to ensure continuous improvement of outcomes for patients experiencing sepsis.

Accuracy of Noninvasive Blood Pressure Monitoring in Critically Ill Adults

Background: Blood pressure (BP) is routinely invasively monitored by an arterial catheter in the intensive care unit (ICU). However, the available data comparing the accuracy of noninvasive methods to arterial catheters for measuring BP in the ICU are limited by small numbers and diverse methodologies. Purpose: To determine agreement between invasive arterial blood pressure monitoring (IABP) and noninvasive blood pressure (NIBP) in critically ill patients. Methods: This was a single center, observational study of critical ill adults in a tertiary care facility evaluating agreement (≤10% difference) between simultaneously measured IABP and NIBP. We measured clinical features at time of BP measurement inclusive of patient demographics, laboratory data, severity of illness, specific interventions (mechanical ventilation and dialysis), and vasopressor dose to identify particular clinical scenarios in which measurement agreement is more or less likely. Results: Of the 1852 critically ill adults with simultaneous IABP and NIBP readings, there was a median difference of 6 mm Hg in mean arterial pressure (MAP), interquartile range (1-12), P < .01. A logistic regression analysis identified 5 independent predictors of measurement discrepancy: increasing doses of norepinephrine (adjusted odds ratio [aOR] 1.10 [95% confidence interval, CI 1.08-1.12] P = .03 for every change in 5 µg/min), lower MAP value (aOR 0.98 [0.98-0.99] P < .01 for every change in 1 mm Hg), higher body mass index (aOR 1.04 [1.01-1.09] P = .01 for an increase in 1), increased patient age (aOR 1.31 [1.30-1.37] P < .01 for every 10 years), and radial arterial line location (aOR 1.74 [1.16-2.47] P = .04). Conclusions: There was broad agreement between IABP and NIBP in critically ill patients over a range of BPs and severity of illness. Several variables are associated with measurement discrepancy; however, their predictive capacity is modest. This may guide future study into which patients may specifically benefit from an arterial catheter.

Enhancing Sepsis Outcomes: A 7-Year Multidisciplinary Endeavor

Regulatory bodies in the United States have implemented quality metrics aimed at improving outcomes for patients with severe sepsis and septic shock. The current study was a quality improvement (QI) project in a community-based academic center aimed at improving adherence to sepsis quality metrics, time to antibiotic administration, and patient outcomes. Electronic health record systems were utilized to capture sepsis-related data. Regular audits and feedback sessions were conducted to identify areas for improvement, with a focus on the timely administration of antibiotics. Interventions included improving access to antibiotics, transitioning from intravenous piggyback to intravenous push formulations, and providing continuous staff education and training. This multidisciplinary QI initiative led to significant improvements in the mortality index, length of stay index, and direct cost index for patients with sepsis. Targeted multidisciplinary QI interventions resulted in improved quality metrics and patient outcomes.

Mortality of Patients With Sepsis Administered Piperacillin-Tazobactam vs Cefepime

Importance

Experimental and observational studies have suggested that empirical treatment for bacterial sepsis with antianaerobic antibiotics (eg, piperacillin-tazobactam) is associated with adverse outcomes compared with anaerobe-sparing antibiotics (eg, cefepime). However, a recent pragmatic clinical trial of piperacillin-tazobactam and cefepime showed no difference in short-term outcomes at 14 days. Further studies are needed to help clarify the empirical use of these agents.

Objective

To examine the use of piperacillin-tazobactam compared with cefepime in 90-day mortality in patients treated empirically for sepsis, using instrumental variable analysis of a 15-month piperacillin-tazobactam shortage.

Design, Setting, and Participants

In a retrospective cohort study, hospital admissions at the University of Michigan from July 1, 2014, to December 31, 2018, including a piperacillin-tazobactam shortage period from June 12, 2015, to September 18, 2016, were examined. Adult patients with suspected sepsis treated with vancomycin and either piperacillin-tazobactam or cefepime for conditions with presumed equipoise between piperacillin-tazobactam and cefepime were included in the study. Data analysis was conducted from December 17, 2022, to April 11, 2023.

Main Outcomes and Measures

The primary outcome was 90-day mortality. Secondary outcomes included organ failure-free, ventilator-free, and vasopressor-free days. The 15-month piperacillin-tazobactam shortage period was used as an instrumental variable for unmeasured confounding in antibiotic selection.

Results

Among 7569 patients (4174 men [55%]; median age, 63 [IQR 52-73] years) with sepsis meeting study eligibility, 4523 were treated with vancomycin and piperacillin-tazobactam and 3046 were treated with vancomycin and cefepime. Of patients who received piperacillin-tazobactam, only 152 (3%) received it during the shortage. Treatment groups did not differ significantly in age, Charlson Comorbidity Index score, Sequential Organ Failure Assessment score, or time to antibiotic administration. In an instrumental variable analysis, piperacillin-tazobactam was associated with an absolute mortality increase of 5.0% at 90 days (95% CI, 1.9%-8.1%) and 2.1 (95% CI, 1.4-2.7) fewer organ failure-free days, 1.1 (95% CI, 0.57-1.62) fewer ventilator-free days, and 1.5 (95% CI, 1.01-2.01) fewer vasopressor-free days.

Conclusions and Relevance

Among patients with suspected sepsis and no clear indication for antianaerobic coverage, administration of piperacillin-tazobactam was associated with higher mortality and increased duration of organ dysfunction compared with cefepime. These findings suggest that the widespread use of empirical antianaerobic antibiotics in sepsis may be harmful.

Provider-to-provider telemedicine for sepsis is used less frequently in communities with high social vulnerability

PURPOSE

Sepsis disproportionately affects patients in rural and socially vulnerable communities. A promising strategy to address this disparity is provider-to-provider emergency department (ED)-based telehealth consultation (tele-ED). The objective of this study was to determine if county-level social vulnerability index (SVI) was associated with tele-ED use for sepsis and, if so, which SVI elements were most strongly associated.

METHODS

We used data from the TELEmedicine as a Virtual Intervention for Sepsis in Rural Emergency Department study. The primary exposures were SVI aggregate and component scores. We used multivariable generalized estimating equations to model the association between SVI and tele-ED use.

FINDINGS

Our study cohort included 1191 patients treated in 23 Midwestern rural EDs between August 2016 and June 2019, of whom 326 (27.4%) were treated with tele-ED. Providers in counties with a high SVI were less likely to use tele-ED (adjusted odds ratio [aOR] = 0.51, 95% confidence interval [CI] 0.31‒0.87), an effect principally attributable to the housing type and transportation component of SVI (aOR = 0.44, 95% CI 0.22-0.89). Providers who treated fewer sepsis patients (1‒10 vs. 31+ over study period) and therefore may have been less experienced in sepsis care, were more likely to activate tele-ED (aOR = 3.91, 95% CI 2.08‒7.38).

CONCLUSIONS

Tele-ED use for sepsis was lower in socially vulnerable counties and higher among providers who treated fewer sepsis patients. These findings suggest that while tele-ED increases access to specialized care, it may not completely ameliorate sepsis disparities due to its less frequent use in socially vulnerable communities.

Sepsis Order Set Use Associated With Increased Care Value

BACKGROUND

Sepsis is common and expensive, and evidence suggests that sepsis order sets may help to improve care. Very incomplete evidence exists regarding the effects of sepsis order sets on the value of care produced by hospitals or the societal costs of sepsis care.

RESEARCH QUESTION

In patients hospitalized for sepsis, is the receipt a of a sepsis order set vs no order set associated with improved value of care, defined as decreased hospital mortality, decreased hospital direct variable costs, and decreased societal spending on hospitalizations?

STUDY DESIGN AND METHODS

This retrospective cohort study included patients discharged with sepsis International Classification of Diseases, Tenth Revision, codes over 2 years from a large integrated delivery system. Using a propensity score, sepsis order set users were matched to nonusers to study the association between sepsis order set use and the value of care from the hospital and societal perspective. The association between order set receipt and hospital mortality, direct variable cost, and hospital revenue also were examined in a priori defined subgroups of sepsis severity and hospital mortality.

RESULTS

The study included 97,249 patients, with 52,793 patients (54%) receiving the sepsis order set. The propensity score match analysis included 55,542 patients, with 27,771 patients in each group. Recipients of the sepsis order set showed a 3.3% lower hospital mortality rate and a $1,487 lower median direct variable total cost (P < .01 for both). Median payer-neutral reimbursement (PNR), a proxy for hospital revenue and thus societal costs, was $465 lower for sepsis order set users (P < .01). Receipt of the sepsis order set was associated with a $1,022 increase in contribution margin, the difference between direct variable costs and PNR per patient.

INTERPRETATION

Receipt of the sepsis order set was associated with improved value of care, from both a hospital and societal perspective.

Gut microbes improve prognosis of Klebsiella pneumoniae pulmonary infection through the lung-gut axis

Background

The gut microbiota plays a vital role in the development of sepsis and in protecting against pneumonia. Previous studies have demonstrated the existence of the gut-lung axis and the interaction between the gut and the lung, which is related to the prognosis of critically ill patients; however, most of these studies focused on chronic lung diseases and influenza virus infections. The purpose of this study was to investigate the effect of faecal microbiota transplantation (FMT) on Klebsiella pneumoniae-related pulmonary infection via the gut-lung axis and to compare the effects of FMT with those of traditional antibiotics to identify new therapeutic strategies.

Methods

We divided the mice into six groups: the blank control (PBS), pneumonia-derived sepsis (KP), pneumonia-derived sepsis + antibiotic (KP + PIP), pneumonia-derived sepsis + faecal microbiota transplantation(KP + FMT), antibiotic treatment control (KP+PIP+PBS), and pneumonia-derived sepsis+ antibiotic + faecal microbiota transplantation (KP + PIP + FMT) groups to compare the survival of mice, lung injury, inflammation response, airway barrier function and the intestinal flora, metabolites and drug resistance genes in each group.

Results

Alterations in specific intestinal flora can occur in the gut of patients with pneumonia-derived sepsis caused by Klebsiella pneumoniae. Compared with those in the faecal microbiota transplantation group, the antibiotic treatment group had lower levels of proinflammatory factors and higher levels of anti-inflammatory factors but less amelioration of lung pathology and improvement of airway epithelial barrier function. Additionally, the increase in opportunistic pathogens and drug resistance-related genes in the gut of mice was accompanied by decreased production of favourable fatty acids such as acetic acid, propionic acid, butyric acid, decanoic acid, and secondary bile acids such as chenodeoxycholic acid 3-sulfate, isodeoxycholic acid, taurodeoxycholic acid, and 3-dehydrocholic acid; the levels of these metabolites were restored by faecal microbiota transplantation. Faecal microbiota transplantation after antibiotic treatment can gradually ameliorate gut microbiota disorder caused by antibiotic treatment and reduce the number of drug resistance genes induced by antibiotics.

Conclusion

In contrast to direct antibiotic treatment, faecal microbiota transplantation improves the prognosis of mice with pneumonia-derived sepsis caused by Klebsiella pneumoniae by improving the structure of the intestinal flora and increasing the level of beneficial metabolites, fatty acids and secondary bile acids, thereby reducing systemic inflammation, repairing the barrier function of alveolar epithelial cells, and alleviating pathological damage to the lungs. The combination of antibiotics with faecal microbiota transplantation significantly alleviates intestinal microbiota disorder, reduces the selection for drug resistance genes caused by antibiotics, and mitigates lung lesions; these effects are superior to those following antibiotic monotherapy.

Preventable deaths involving sepsis in England and Wales, 2013-2022: a systematic case series of coroners' reports

PURPOSE

Coroners' Prevention of Future Death (PFDs) reports are an under-utilized resource to learn about preventable deaths in England and Wales. We aimed to identify sepsis-related PFDs and explore the causes and concerns in this subset of preventable sepsis deaths.

METHODS

Four thousand three hundred five reports were acquired from the Courts and Tribunals Judiciary website between July 2013 and November 2022, which were screened for sepsis. Demographic information, coroners concerns and responses to these reports were extracted and analyzed, including a detailed paediatric subgroup analysis.

RESULTS

Two hundred sixty-five reports (6% of total PFDs) involved sepsis-related deaths. The most common cause of death in these reports was "sepsis without septic shock" (42%) and the most common site of infection was the respiratory system (18%) followed by gastrointestinal (16%) and skin (13%) infections. Specific pathogens were named in few reports (27%). Many deaths involved multimorbid patients (49%) or those with recent surgery (26%). Coroners named 773 individual concerns, the most frequent were: a failure to keep accurate records or notes (28%), failure in communication or handover (27%) or failure to recognize risk factors or comorbidities (20%). Paediatric cases frequently reported issues with sepsis screening tools (26%). Sepsis PFDs resulted in 421 individual reports being sent, of which 45% received no response. Most organisations who did respond acknowledged concerns and initiated a new change (74%).

CONCLUSION

Sepsis-related PFDs provide valuable insights into preventable causes of sepsis and identify important sources of improvement in sepsis care. Wider dissemination of findings is vital to learn from these reports.

Physical Activity and the incidence of sepsis: A 10-year observational study among 4 million adults

BACKGROUND

As the group at high risk for sepsis is increasing with the aging of the population, physical activity (PA), which has beneficial effects on various diseases, needs to be considered as a personalized prevention strategy for sepsis without direct anti-sepsis drug.

PURPOSE

To examine the association between the amount of PA (based on intensity, duration, and frequency) and the incidence rates of sepsis and mortality after sepsis.

METHODS

This was a large-scale, retrospective, longitudinal cohort study using data from the Korean National Health Insurance Service and the biennial general health screening program. The amount of PA self-reported at the time of the health screening was categorized as non-PA, mild (<500 metabolic equivalents [METs]-Min/Week), moderate (500-1000), severe (1000-1500), and extreme (≥1500). The multivariable regression model was adjusted for age, sex, income, body mass index, smoking, alcohol consumption, diabetes, hypertension, dyslipidemia, and chronic diseases.

RESULTS

From 4,234,415 individuals who underwent a health screening in 2009, 3,929,165 subjects were selected after exclusion for wash-out period and a 1-year lag period, and then observed for the event of sepsis or all-cause death until December 2020. During a median 10.3 years of follow-up, 83,011 incidents of sepsis were detected. The moderate-PA group showed the lowest incidence (1.56/1000 person-years) and risk for sepsis, with an adjusted hazard ratio (aHR) of 0.73 (95% CI, 0.72-0.75, P < 0.001) compared with the non-PA group. The occurrence of sepsis among people aged ≥65 years and ex-smokers were significantly lower in the moderate-PA group (aHR; 0.77, 95% CI; 0.74-0.79; and 0.68, 0.64-0.71, respectively, Ps < 0.001). The long-term all-cause mortality after sepsis was significantly lower in the PA group than in the non-PA group (overall P = 0.003).

CONCLUSIONS

Physical activity is associated with a lower risk of sepsis, especially in elderly people who have the highest incidence of sepsis. The protective effects of aerobic PA on sepsis might need to be incorporated with other interventions in sepsis guidelines through the accumulation of future studies.

Platelet Bioenergetics and Associations With Delirium and Coma in Patients With Sepsis: A Prospective Cohort Study

BACKGROUND

Acute brain dysfunction during sepsis, which manifests as delirium or coma, is common and is associated with multiple adverse outcomes, including longer periods of mechanical ventilation, prolonged hospital stays, and increased mortality. Delirium and coma during sepsis may be manifestations of alteration in systemic metabolism. Because access to brain mitochondria is a limiting factor, measurement of peripheral platelet bioenergetics offers a potential opportunity to understand metabolic changes associated with acute brain dysfunction during sepsis.

RESEARCH QUESTION

Are altered platelet mitochondrial bioenergetics associated with acute brain dysfunction during sepsis?

STUDY DESIGN AND METHODS

We assessed participants with critical illness in the ICU for the presence of delirium or coma via validated assessment measures. Blood samples were collected and processed to isolate and measure platelet mitochondrial oxygen consumption. We used Seahorse extracellular flux to measure directly baseline, proton leak, maximal oxygen consumption rate, and extracellular acidification rate. We calculated adenosine triphosphate-linked, spare respiratory capacity, and nonmitochondrial oxygen consumption rate from the measured values.

RESULTS

Maximum oxygen consumption was highest in patients with coma, as was spare respiratory capacity and extracellular acidification rate in unadjusted analysis. After adjusting for age, sedation, modified Sequential Organ Failure Assessment score without the neurologic component, and preexisting cognitive function, increased spare respiratory capacity remained associated with coma. Delirium was not associated with any platelet mitochondrial bioenergetics.

INTERPRETATION

In this single-center exploratory prospective cohort study, we found that increased platelet mitochondrial spare respiratory capacity was associated with coma in patients with sepsis. Future studies powered to determine any relationship between delirium and mitochondrial respiration bioenergetics are needed.

Prussian Blue Analogues-Derived Molecularly Imprinted Nanozyme Array for Septicemia Detection

Septicemia, a severe bacterial infection, poses significant risks to human health. Early detection of septicemia by tracking specific biomarkers is crucial for a timely intervention. Herein, we developed a molecularly imprinted (MI) TiO2-Fe-CeO2 nanozyme array derived from Ce[Fe(CN)6] Prussian blue analogues (PBA), specifically targeting valine, leucine, and isoleucine, as potential indicators of septicemia. The synthesized nanozyme arrays were thoroughly characterized using various analytical techniques, including Fourier transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscope, and energy-dispersive X-ray. The results confirmed their desirable physical and chemical properties, indicating their suitability for the oxidation of 3,3',5,5'-tetramethylbenzidine serving as a colorimetric probe in the presence of a persulfate oxidizing agent, further highlighting the potential of these arrays for sensitive and accurate detection applications. The MITiO2 shell selectively captures valine, leucine, and isoleucine, partially blocking the cavities for substrate access and thereby hindering the catalyzed TMB chromogenic reaction. The nanozyme array demonstrated excellent performance with linear detection ranges of 5 μM to 1 mM, 10-450 μM, and 10-450 μM for valine, leucine, and isoleucine, respectively. Notably, the corresponding limit of detection values were 0.69, 1.46, and 2.76 μM, respectively. The colorimetric assay exhibited outstanding selectivity, reproducibility, and performance in the detection of analytes in blood samples, including C-reactive protein at a concentration of 61 mg/L, procalcitonin at 870 ng/dL, and the presence of Pseudomonas aeruginosa bacteria. The utilization of Ce[Fe(CN)6]-derived MITiO2-Fe-CeO2 nanozyme arrays holds considerable potential in the field of septicemia detection. This approach offers a sensitive and specific method for early diagnosis and intervention, thereby contributing to improved patient outcomes.

Development and external validation of deep learning clinical prediction models using variable-length time series data

OBJECTIVES

To compare and externally validate popular deep learning model architectures and data transformation methods for variable-length time series data in 3 clinical tasks (clinical deterioration, severe acute kidney injury [AKI], and suspected infection).

MATERIALS AND METHODS

This multicenter retrospective study included admissions at 2 medical centers that spanned 2007-2022. Distinct datasets were created for each clinical task, with 1 site used for training and the other for testing. Three feature engineering methods (normalization, standardization, and piece-wise linear encoding with decision trees [PLE-DTs]) and 3 architectures (long short-term memory/gated recurrent unit [LSTM/GRU], temporal convolutional network, and time-distributed wrapper with convolutional neural network [TDW-CNN]) were compared in each clinical task. Model discrimination was evaluated using the area under the precision-recall curve (AUPRC) and the area under the receiver operating characteristic curve (AUROC).

RESULTS

The study comprised 373 825 admissions for training and 256 128 admissions for testing. LSTM/GRU models tied with TDW-CNN models with both obtaining the highest mean AUPRC in 2 tasks, and LSTM/GRU had the highest mean AUROC across all tasks (deterioration: 0.81, AKI: 0.92, infection: 0.87). PLE-DT with LSTM/GRU achieved the highest AUPRC in all tasks.

DISCUSSION

When externally validated in 3 clinical tasks, the LSTM/GRU model architecture with PLE-DT transformed data demonstrated the highest AUPRC in all tasks. Multiple models achieved similar performance when evaluated using AUROC.

CONCLUSION

The LSTM architecture performs as well or better than some newer architectures, and PLE-DT may enhance the AUPRC in variable-length time series data for predicting clinical outcomes during external validation.

2024 Focused Update: Guidelines on Use of Corticosteroids in Sepsis, Acute Respiratory Distress Syndrome, and Community-Acquired Pneumonia

RATIONALE

New evidence is available examining the use of corticosteroids in sepsis, acute respiratory distress syndrome (ARDS) and community-acquired pneumonia (CAP), warranting a focused update of the 2017 guideline on critical illness-related corticosteroid insufficiency.

OBJECTIVES

To develop evidence-based recommendations for use of corticosteroids in hospitalized adults and children with sepsis, ARDS, and CAP.

PANEL DESIGN

The 22-member panel included diverse representation from medicine, including adult and pediatric intensivists, pulmonologists, endocrinologists, nurses, pharmacists, and clinician-methodologists with expertise in developing evidence-based Clinical Practice Guidelines. We followed Society of Critical Care Medicine conflict of interest policies in all phases of the guideline development, including task force selection and voting.

METHODS

After development of five focused Population, Intervention, Control, and Outcomes (PICO) questions, we conducted systematic reviews to identify the best available evidence addressing each question. We evaluated the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach and formulated recommendations using the evidence-to-decision framework.

RESULTS

In response to the five PICOs, the panel issued four recommendations addressing the use of corticosteroids in patients with sepsis, ARDS, and CAP. These included a conditional recommendation to administer corticosteroids for patients with septic shock and critically ill patients with ARDS and a strong recommendation for use in hospitalized patients with severe CAP. The panel also recommended against high dose/short duration administration of corticosteroids for septic shock. In response to the final PICO regarding type of corticosteroid molecule in ARDS, the panel was unable to provide specific recommendations addressing corticosteroid molecule, dose, and duration of therapy, based on currently available evidence.

CONCLUSIONS

The panel provided updated recommendations based on current evidence to inform clinicians, patients, and other stakeholders on the use of corticosteroids for sepsis, ARDS, and CAP.

The Role of Soluble Urokinase Plasminogen Activator Receptor (suPAR) as an Early Indicator of Mortality in Pediatric Septic Shock

BACKGROUND

Despite advancements in antibiotic therapy and resuscitation protocols, sepsis and septic shock remain major contributors to morbidity and mortality in children. We aimed to investigate the utility of soluble urokinase plasminogen activator receptor (suPAR) for the early detection of septic shock and to evaluate its accuracy in predicting mortality.

METHODS

A prospective study was conducted in a tertiary pediatric emergency department (ED), enrolling patients diagnosed with the sepsis, severe sepsis, or septic shock. In addition to assessing infection biomarkers such as C-reactive protein and procalcitonin, suPAR levels were quantified upon admission using enzyme-linked immunosorbent assay. The primary outcome measure was 30-day mortality.

RESULTS

Overall 72 patients and 80 healthy children included. Plasma suPAR levels demonstrated a statistically significant elevation in the sepsis, severe sepsis, and septic shock groups compared with the control group (p < 0.001 for all). The septic shock group exhibited the highest suPAR levels upon admission, surpassing both the sepsis and severe sepsis groups (p = 0.009 and 0.042). ROC analysis underscored the promising potential of suPAR with an AUC of 0.832 for septic shock. Analysis of mortality prediction revealed significantly higher suPAR levels in nonsurvivors than survivors (9.7 ng/mL vs. 4.2 ng/mL; p < 0.001). Employing plasma suPAR levels to discriminate between mortality and survival, a threshold of ≥7.0 ng/mL demonstrated a sensitivity of 90.9% and specificity of 71.0%.

CONCLUSION

Plasma suPAR levels have the potential as a biomarker for predicting mortality in children with septic shock. In pediatric septic shock, the presence of plasma suPAR ≥7 ng/mL along with an underlying disease significantly increases the risk of mortality.

Using the Kirkpatrick model to evaluate a sepsis escape room for advanced pharmacy learners

BACKGROUND AND PURPOSE

The purpose of this study was to use the first three levels of the Kirkpatrick Model to evaluate the effectiveness of a simulation center-based escape room activity designed to positively influence student learning.

EDUCATIONAL ACTIVITY AND SETTING

In this simulation, learners solve puzzles related to care of a critically ill patient. This activity was assessed via an assessment questionnaire (Kirkpatrick level 1), a pre/post learner knowledge quiz and learner self-assessment of skills and attitudes (Kirkpatrick level 2), and unstructured observation of learners upon return to the clinical environment (Kirkpatrick level 3).

FINDINGS

Average learner knowledge assessment scores (Kirkpatrick level 2) improved from 80% (pre-) to 90.5% (post-) and learners identified an increased confidence in disease state diagnosis and expression of recommendations (Kirkpatrick level 2). Learner perception of the activity (Kirkpatrick level 1) was positive but also included areas for improvement. Anecdotal reporting supports learners transfer of the knowledge and skills reviewed in the session to practice (Kirkpatrick level 3), but no formal data collection or analysis was completed.

SUMMARY

This study provides quantitative and qualitative evidence to support effectiveness of the activity according to Kirkpatrick's Levels 1 and 2, and anecdotal evidence to support effectiveness according to Kirkpatrick's Level 3. Learners had positive perspectives of this activity and demonstrated evidence of increased knowledge and self-reported confidence in skills and attitudes, suggesting this activity has a positive impact on learners in the short-term; however, the data is not robust enough to support conclusions that this activity influences learner practice.

Sorbent functionalization with vancomycin enhances bacteria killing in extracorporeal hemoadsorption

BACKGROUND

The level of bacteremia in patients with sepsis and septic shock is a predictor of complications and mortality, regardless of the type of bacteria. Devices for bacteria, endotoxin and cytokines removal by adsorption have been recently developed. Thus, extracorporeal blood purification therapies have been proposed as adjunctive therapy in sepsis in combination with drugs. Some potentially useful drugs, however, are precluded due to their organ or metabolic toxicity. The present study represents a preliminary report on the in vitro effect of a sorbent device (minimodule with HA380 beads, Jafron medical, Zhuhai, China) in which the particles have been functionalized with vancomycin on the surface. The impact of the surface-modified beads on circulating bacteria (Staphylococcus aureus) has been tested in a simulated in vitro circulation.

METHODS

In vitro experiments were carried out with 800 mL of blood enriched with S. aureus species. Blood was circulated in the vancomycin-functionalized and non-functionalized mini-module cartridges in hemoadsorption setup (300 mL each) and the bactericidal effect was assessed. Also, 200 mL of blood was used as a control.

RESULTS

A significant increase in the time to positivity of blood cultures was observed after 60 min and also after 120 min of therapy with the mini-module functionalized with vancomycin as opposed to the non-functionalized cartridge.

CONCLUSIONS

These results suggest a possible way of treating sepsis by using drug- or antibiotic-functionalized cartridges without worrying about pharmacological toxicity. The prolongation of the time to bacterial culture positivity to S. aureus after a passage through a column packed with beads functionalized with vancomycin represents a proof of concept.

Sepsis during short bowel syndrome hospitalizations: Identifying trends, disparities, and clinical outcomes in the United States

BACKGROUND

Short bowel syndrome (SBS) hospitalizations are often complicated with sepsis. There is a significant paucity of data on adult SBS hospitalizations in the United States and across the globe.

AIM

To assess trends and outcomes of SBS hospitalizations complicated by sepsis in the United States.

METHODS

The National Inpatient Sample was utilized to identify all adult SBS hospitalizations between 2005-2014. The study cohort was further divided based on the presence or absence of sepsis. Trends were identified, and hospitalization characteristics and clinical outcomes were compared. Predictors of mortality for SBS hospitalizations complicated with sepsis were assessed.

RESULTS

Of 247097 SBS hospitalizations, 21.7% were complicated by sepsis. Septic SBS hospitalizations had a rising trend of hospitalizations from 20.8% in 2005 to 23.5% in 2014 (P trend < 0.0001). Compared to non-septic SBS hospitalizations, septic SBS hospitalizations had a higher proportion of males (32.8% vs 29.3%, P < 0.0001), patients in the 35-49 (45.9% vs 42.5%, P < 0.0001) and 50-64 (32.1% vs 31.1%, P < 0.0001) age groups, and ethnic minorities, i.e., Blacks (12.4% vs 11.3%, P < 0.0001) and Hispanics (6.7% vs 5.5%, P < 0.0001). Furthermore, septic SBS hospitalizations had a higher proportion of patients with intestinal transplantation (0.33% vs 0.22%, P < 0.0001), inpatient mortality (8.5% vs 1.4%, P < 0.0001), and mean length of stay (16.1 d vs 7.7 d, P < 0.0001) compared to the non-sepsis cohort. A younger age, female gender, White race, and presence of comorbidities such as anemia and depression were identified to be independent predictors of inpatient mortality for septic SBS hospitalizations.

CONCLUSION

Septic SBS hospitalizations had a rising trend between 2005-2014 and were associated with higher inpatient mortality compared to non-septic SBS hospitalizations.

Application of AI in Sepsis: Citation Network Analysis and Evidence Synthesis

BACKGROUND

Artificial intelligence (AI) has garnered considerable attention in the context of sepsis research, particularly in personalized diagnosis and treatment. Conducting a bibliometric analysis of existing publications can offer a broad overview of the field and identify current research trends and future research directions.

OBJECTIVE

The objective of this study is to leverage bibliometric data to provide a comprehensive overview of the application of AI in sepsis.

METHODS

We conducted a search in the Web of Science Core Collection database to identify relevant articles published in English until August 31, 2023. A predefined search strategy was used, evaluating titles, abstracts, and full texts as needed. We used the Bibliometrix and VOSviewer tools to visualize networks showcasing the co-occurrence of authors, research institutions, countries, citations, and keywords.

RESULTS

A total of 259 relevant articles published between 2014 and 2023 (until August) were identified. Over the past decade, the annual publication count has consistently risen. Leading journals in this domain include Critical Care Medicine (17/259, 6.6%), Frontiers in Medicine (17/259, 6.6%), and Scientific Reports (11/259, 4.2%). The United States (103/259, 39.8%), China (83/259, 32%), United Kingdom (14/259, 5.4%), and Taiwan (12/259, 4.6%) emerged as the most prolific countries in terms of publications. Notable institutions in this field include the University of California System, Emory University, and Harvard University. The key researchers working in this area include Ritankar Das, Chris Barton, and Rishikesan Kamaleswaran. Although the initial period witnessed a relatively low number of articles focused on AI applications for sepsis, there has been a significant surge in research within this area in recent years (2014-2023).

CONCLUSIONS

This comprehensive analysis provides valuable insights into AI-related research conducted in the field of sepsis, aiding health care policy makers and researchers in understanding the potential of AI and formulating effective research plans. Such analysis serves as a valuable resource for determining the advantages, sustainability, scope, and potential impact of AI models in sepsis.

Sepsis in Patients Hospitalized in Sicily, Italy, over the Period of 2016-2020: A Retrospective Study

Background: Epidemiological data regarding the incidence and mortality of sepsis are scarcely available. The present study aimed to delineate the epidemiology of sepsis and related mortality among patients hospitalized in Sicily, Italy. Methods: Data on the discharge forms of all patients with sepsis in all Sicilian hospitals from January 2016 to December 2020 were retrospectively collected. Results: In Sicily, 15,373 hospitalizations associated with sepsis occurred from 2016 to 2020, with an overall in-hospital mortality rate of 36.3%. The percentage of hospitalizations associated with sepsis represented 0.65% of all admissions, with an increase over the years. Most patients were admitted to non-surgical and non-infectious disease units, accounting for 50.3% of total admissions. Stratification of patients according to age, intensive care unit (ICU) admission, and presence of septic shock revealed variations in in-hospital mortality rates. Among adult ICU-admitted patients with septic shock, mortality was highest at 81.0%, followed by non-ICU adult patients with septic shock (63.5%), ICU pediatric patients with septic shock (56.7%), ICU adult patients without septic shock (43.9%), non-ICU pediatric patients with septic shock (37.9%), non-ICU adult patients without septic shock (17.9%), ICU pediatric patients without septic shock (10.4%), and non-ICU pediatric patients without septic shock (1%).

Thrombocytopenia Independently Leads to Changes in Monocyte Immune Function

BACKGROUND

While platelets have well-studied hemostatic functions, platelets are immune cells that circulate at the interface between the vascular wall and white blood cells. The physiological implications of these constant transient interactions are poorly understood. Activated platelets induce and amplify immune responses, but platelets may also maintain immune homeostasis in healthy conditions, including maintaining vascular integrity and T helper cell differentiation, meaning that platelets are central to both immune responses and immune quiescence. Clinical data have shown an association between low platelet counts (thrombocytopenia) and immune dysfunction in patients with sepsis and extracorporeal membrane oxygenation, further implicating platelets as more holistic immune regulators, but studies of platelet immune functions in nondisease contexts have had limited study.

METHODS

We used in vivo models of thrombocytopenia and in vitro models of platelet and monocyte interactions, as well as RNA-seq and ATAC-seq (assay for transposase-accessible chromatin with sequencing), to mechanistically determine how resting platelet and monocyte interactions immune program monocytes.

RESULTS

Circulating platelets and monocytes interact in a CD47-dependent manner to regulate monocyte metabolism, histone methylation, and gene expression. Resting platelet-monocyte interactions limit TLR (toll-like receptor) signaling responses in healthy conditions in an innate immune training-like manner. In both human patients with sepsis and mouse sepsis models, thrombocytopenia exacerbated monocyte immune dysfunction, including increased cytokine production.

CONCLUSIONS

Thrombocytopenia immune programs monocytes in a manner that may lead to immune dysfunction in the context of sepsis. This is the first demonstration that sterile, endogenous cell interactions between resting platelets and monocytes regulate monocyte metabolism and pathogen responses, demonstrating platelets to be immune rheostats in both health and disease.

Understanding How Clinicians Personalize Fluid and Vasopressor Decisions in Early Sepsis Management

Importance

Recent sepsis trials suggest that fluid-liberal vs fluid-restrictive resuscitation has similar outcomes. These trials used generalized approaches to resuscitation, and little is known about how clinicians personalize fluid and vasopressor administration in practice.

Objective

To understand how clinicians personalize decisions about resuscitation in practice.

Design, Setting, and Participants

This survey study of US clinicians in the Society of Critical Care Medicine membership roster was conducted from November 2022 to January 2023. Surveys contained 10 vignettes of patients with sepsis where pertinent clinical factors (eg, fluid received and volume status) were randomized. Respondents selected the next steps in management. Data analysis was conducted from February to September 2023.

Exposure

Online Qualtrics clinical vignette survey.

Main Outcomes and Measures

Using multivariable logistic regression, the associations of clinical factors with decisions about fluid administration, vasopressor initiation, and vasopressor route were tested. Results are presented as adjusted proportions with 95% CIs.

Results

Among 11 203 invited clinicians, 550 (4.9%; 261 men [47.5%] and 192 women [34.9%]; 173 with >15 years of practice [31.5%]) completed at least 1 vignette and were included. A majority were physicians (337 respondents [61.3%]) and critical care trained (369 respondents [67.1%]). Fluid volume already received by a patient was associated with resuscitation decisions. After 1 L of fluid, an adjusted 82.5% (95% CI, 80.2%-84.8%) of respondents prescribed additional fluid and an adjusted 55.0% (95% CI, 51.9%-58.1%) initiated vasopressors. After 5 L of fluid, an adjusted 17.5% (95% CI, 15.1%-19.9%) of respondents prescribed more fluid while an adjusted 92.7% (95% CI, 91.1%-94.3%) initiated vasopressors. More respondents prescribed fluid when the patient examination found dry vs wet (ie, overloaded) volume status (adjusted proportion, 66.9% [95% CI, 62.5%-71.2%] vs adjusted proportion, 26.5% [95% CI, 22.3%-30.6%]). Medical history, respiratory status, lactate trend, and acute kidney injury had small associations with fluid and vasopressor decisions. In 1023 of 1127 vignettes (90.8%) where the patient did not have central access, respondents were willing to start vasopressors through a peripheral intravenous catheter. In cases where patients were already receiving peripheral norepinephrine, respondents were more likely to place a central line at higher norepinephrine doses of 0.5 µg/kg/min (adjusted proportion, 78.0%; 95% CI, 74.7%-81.2%) vs 0.08 µg/kg/min (adjusted proportion, 25.2%; 95% CI, 21.8%-28.5%) and after 24 hours (adjusted proportion, 59.5%; 95% CI, 56.6%-62.5%) vs 8 hours (adjusted proportion, 47.1%; 95% CI, 44.0%-50.1%).

Conclusions and Relevance

These findings suggest that fluid volume received is the predominant factor associated with ongoing fluid and vasopressor decisions, outweighing many other clinical factors. Peripheral vasopressor use is common. Future studies aimed at personalizing resuscitation must account for fluid volumes and should incorporate specific tools to help clinicians personalize resuscitation.

Association between blood culture turnaround time and clinical prognosis in emergency department patients with community acquired bloodstream infection: A retrospective study based on electronic medical records

Importance

Previous investigations have found that time to positive blood culture (TTP) is a prognostic factor for clinical outcomes. In fact, what the emergency physician sees from the medical information system is TAT (turnaround time) defined as time required to post a bacterial culture report. We propose a definition of blood culture TAT that more closely aligns with clinical considerations by measuring the time from starting specimen culture to the release of an official blood culture report.We were curious to know whether the duration of TAT is as intricately linked to the prognosis of bacteremia as TTP.

Objectives

To examine the association between TAT and outcomes of adult patients who present to the ED with community acquired bacteremia.

Design

Setting, and Participants: This retrospective study utilized electronic medical records from Kaohsiung Veterans General Hospital (KVGH), a 1000-bed tertiary medical center in Taiwan. Patients were adults aged 18 years and older who presented to ED (Emergency department) for initial diagnosis of community acquired bacteremia from January 1, 2016 to March 31, 2021. Data analysis was performed from December 2022 to January 2023.Main outcomes and measures.The primary outcomes included mortality in the ED, all-cause in-hospital mortality, length of hospital stay, and all-cause 30-day mortality in relation to the individual first report of positive blood culture TAT.

Results

A total of 4011 eligible patients with bacteremia were evaluated, of which 207 patients had a blood culture TAT of ≤48 h. The overall 30-day all-cause mortality rate was 13%. Contrary to expectation, no statistically significant differences were observed in clinical prognosis between the TAT groups (≤48 versus >48 h). Subgroup analyses indicated that the length of TAT did not have a significant effect on clinical prognosis in patients who underwent lactate level assessment. Furthermore, no difference in clinical outcome was noted between TAT groups (≤48 versus >48 h) in terms of Gram-negative bacilli or Gram-positive cocci bacteremia. However, in patients with delayed antibiotic treatment (>3 h), a shorter TAT was significantly associated with a fatal outcome.

Conclusion

In adults with community-acquired bacteremia, this study did not observe a significant association between blood culture TAT and clinical prognosis, except in cases of delayed antibiotic treatment.

Single-cell RNA sequencing reveals Immune Education promotes T cell survival in mice subjected to the cecal ligation and puncture sepsis model

Background

Individual T cell responses vary significantly based on the microenvironment present at the time of immune response and on prior induced T cell memory. While the cecal ligation and puncture (CLP) model is the most commonly used murine sepsis model, the contribution of diverse T cell responses has not been explored. We defined T cell subset responses to CLP using single-cell RNA sequencing and examined the effects of prior induced T cell memory (Immune Education) on these responses. We hypothesized that Immune Education prior to CLP would alter T cell responses at the single cell level at a single, early post-CLP time point.

Methods

Splenic T cells were isolated from C57BL/6 mice. Four cohorts were studied: Control, Immune-Educated, CLP, and Immune-Educated CLP. At age 8 weeks, Immune-Educated and Immune-Educated CLP mice received anti-CD3ϵ antibody; Control and CLP mice were administered an isotype control. CLP (two punctures with a 22-gauge needle) was performed at 12-13 weeks of life. Mice were sacrificed at baseline or 24-hours post-CLP. Unsupervised clustering of the transcriptome library identified six distinct T cell subsets: quiescent naïve CD4+, primed naïve CD4+, memory CD4+, naïve CD8+, activated CD8+, and CD8+ cytotoxic T cell subsets. T cell subset specific gene set enrichment analysis and Hurdle analysis for differentially expressed genes (DEGs) were performed.

Results

T cell responses to CLP were not uniform - subsets of activated and suppressed T cells were identified. Immune Education augmented specific T cell subsets and led to genomic signatures favoring T cell survival in unoperated and CLP mice. Additionally, the combination of Immune Education and CLP effected the expression of genes related to T cell activity in ways that differed from CLP alone. Validating our finding that IL7R pathway markers were upregulated in Immune-Educated CLP mice, we found that Immune Education increased T cell surface IL7R expression in post-CLP mice.

Conclusion

Immune Education enhanced the expression of genes associated with T cell survival in unoperated and CLP mice. Induction of memory T cell compartments via Immune Education combined with CLP may increase the model's concordance to human sepsis.

Culture-independent identification of bloodstream infections from whole blood: prospective evaluation in specimens of known infection status

Sepsis caused by bloodstream infection (BSI) is a major healthcare burden and a leading cause of morbidity and mortality worldwide. Timely diagnosis is critical to optimize clinical outcome, as mortality rates rise every hour treatment is delayed. Blood culture remains the "gold standard" for diagnosis but is limited by its long turnaround time (1-7 days depending on the organism) and its potential to provide false-negative results due to interference by antimicrobial therapy or the presence of mixed (i.e., polymicrobial) infections. In this paper, we evaluated the performance of resistance and pathogen ID/BSI, a direct-from-specimen molecular assay. To reduce the false-positivity rate common with molecular methods, this assay isolates and detects genomic material only from viable microorganisms in the blood by incorporating a novel precursor step to selectively lyse host and non-viable microbial cells and remove cell-free genomic material prior to lysis and analysis of microbial cells. Here, we demonstrate that the assay is free of interference from host immune cells and common antimicrobial agents at elevated concentrations. We also demonstrate the accuracy of this technology in a prospective cohort pilot study of individuals with known sepsis/BSI status, including samples from both positive and negative individuals.

IMPORTANCE

Blood culture remains the "gold standard" for the diagnosis of sepsis/bloodstream infection (BSI) but has many limitations which may lead to a delay in appropriate and accurate treatment in patients. Molecular diagnostic methods have the potential for markedly improving the management of such patients through faster turnaround times and increased accuracy. But molecular diagnostic methods have not been widely adopted for the identification of BSIs. By incorporating a precursor step of selective lysis of host and non-viable microorganisms, our resistance and pathogen ID (RaPID)/BSI molecular assay addresses many limitations of blood culture and other molecular assay. The RaPID/BSI assay has an approximate turnaround time of 4 hours, thereby significantly reducing the time to appropriate and accurate diagnosis of causative microorganisms in such patients. The short turnaround time also allows for close to real-time tracking of pathogenic clearance of microorganisms from the blood of these patients or if a change of antimicrobial regimen is required. Thus, the RaPID/BSI molecular assay helps with optimization of antimicrobial stewardship; prompt and accurate diagnosis of sepsis/BSI could help target timely treatment and reduce mortality and morbidity in such patients.

Corticosteroids for infectious critical illness: A multicenter target trial emulation stratified by predicted organ dysfunction trajectory

Corticosteroids decrease the duration of organ dysfunction in a range of infectious critical illnesses, but their risk and benefit are not fully defined using this construct. This retrospective multicenter study aimed to evaluate the association between usage of corticosteroids and mortality of patients with infectious critical illness by emulating a target trial framework. The study employed a novel stratification method with predictive machine learning (ML) subphenotyping based on organ dysfunction trajectory. Our analysis revealed that corticosteroids' effectiveness varied depending on the stratification method. The ML-based approach identified four distinct subphenotypes, two of which had a large enough sample size in our patient cohorts for further evaluation: "Rapidly Improving" (RI) and "Rapidly Worsening," (RW) which showed divergent responses to corticosteroid treatment. Specifically, the RW group either benefited or were not harmed from corticosteroids, whereas the RI group appeared to derive harm. In the development cohort, which comprised of a combination of patients from the eICU and MIMIC-IV datasets, hazard ratio estimates for the primary outcome, 28-day mortality, in the RW group was 1.05 (95% CI: 0.96 - 1.04) whereas for the RW group, it was 1.40 (95% CI: 1.28 - 1.54). For the validation cohort, which comprised of patients from the Critical carE Database for Advanced Research, estimates for 28-day mortality for the RW and RI groups were 1.24 (95% CI: 1.05 - 1.46) and 1.34 (95% CI: 1.14 - 1.59), respectively. For secondary outcomes, the RW group had a shorter time to ICU discharge and time to cessation of mechanical ventilation with corticosteroid treatment, where the RI group again demonstrated harm. The findings support matching treatment strategies to empirically observed pathobiology and offer a more nuanced understanding of corticosteroid utility. Our results have implications for the design and interpretation of both observational studies and randomized controlled trials (RCTs), suggesting the need for stratification methods that account for the differential response to standard of care.

Exploring the role of antioxidants in sepsis-associated oxidative stress: a comprehensive review

Sepsis is a potentially fatal condition characterized by organ dysfunction caused by an imbalanced immune response to infection. Although an increased inflammatory response significantly contributes to the pathogenesis of sepsis, several molecular mechanisms underlying the progression of sepsis are associated with increased cellular reactive oxygen species (ROS) generation and exhausted antioxidant pathways. This review article provides a comprehensive overview of the involvement of ROS in the pathophysiology of sepsis and the potential application of antioxidants with antimicrobial properties as an adjunct to primary therapies (fluid and antibiotic therapies) against sepsis. This article delves into the advantages and disadvantages associated with the utilization of antioxidants in the therapeutic approach to sepsis, which has been explored in a variety of animal models and clinical trials. While the application of antioxidants has been suggested as a potential therapy to suppress the immune response in cases where an intensified inflammatory reaction occurs, the use of multiple antioxidant agents can be beneficial as they can act additively or synergistically on different pathways, thereby enhancing the antioxidant defense. Furthermore, the utilization of immunoadjuvant therapy, specifically in septic patients displaying immunosuppressive tendencies, represents a promising advancement in sepsis therapy.

Novel and Rapid Diagnostics for Common Infections in the Critically Ill Patient

There are several novel platforms that enhance detection of pathogens that cause common infections in the intensive care unit. These platforms have a sample to answer time of a few hours, are often higher yield than culture, and have the potential to improve antibiotic stewardship.

Identifying Barriers to The Implementation of Communicating Narrative Concerns Entered by Registered Nurses, An Early Warning System SmartApp

BACKGROUND

 Nurses are at the frontline of detecting patient deterioration. We developed Communicating Narrative Concerns Entered by Registered Nurses (CONCERN), an early warning system for clinical deterioration that generates a risk prediction score utilizing nursing data. CONCERN was implemented as a randomized clinical trial at two health systems in the Northeastern United States. Following the implementation of CONCERN, our team sought to develop the CONCERN Implementation Toolkit to enable other hospital systems to adopt CONCERN.

OBJECTIVE

 The aim of this study was to identify the optimal resources needed to implement CONCERN and package these resources into the CONCERN Implementation Toolkit to enable the spread of CONCERN to other hospital sites.

METHODS

 To accomplish this aim, we conducted qualitative interviews with nurses, prescribing providers, and information technology experts in two health systems. We recruited participants from July 2022 to January 2023. We conducted thematic analysis guided by the Donabedian model. Based on the results of the thematic analysis, we updated the α version of the CONCERN Implementation Toolkit.

RESULTS

 There was a total of 32 participants included in our study. In total, 12 themes were identified, with four themes mapping to each domain in Donabedian's model (i.e., structure, process, and outcome). Eight new resources were added to the CONCERN Implementation Toolkit.

CONCLUSIONS

 This study validated the α version of the CONCERN Implementation Toolkit. Future studies will focus on returning the results of the Toolkit to the hospital sites to validate the β version of the CONCERN Implementation Toolkit. As the development of early warning systems continues to increase and clinician workflows evolve, the results of this study will provide considerations for research teams interested in implementing early warning systems in the acute care setting.

Investigation of exosomal tetraspanin profile in sepsis patients as a promising diagnostic biomarker

INTRODUCTION

Sepsis, a leading cause of mortality globally, has a complex and multifaceted pathophysiology which still requires elucidation. Therefore, this study aimed to analyze and quantify the number of exosomes in sepsis patients from a South African cohort using the ExoView (NanoView Biosciences, Boston, MA) platform.

METHODS

Blood samples were collected from black South African patients attending the local Intensive Care Unit (ICU) hospital. Exosomes were isolated and characterize via TEM and CD63 ELISA kits. ExoView was used to determine particle count, particle size distribution and colocalization of different tetraspanin markers.

RESULTS

Exosomal levels in sepsis patients were significantly higher compared to the control group (p < 0.05). Sepsis exosomes showed a homogenous size distribution ranging from 55 to 70 nm. Tetraspanin colocalization analysis revealed that sepsis exosomes have significantly higher CD63/CD9, CD63/CD81 and CD63/CD9/CD81 colocalization percentages than the control group.

CONCLUSION

This unique tetraspanin colocalization pattern of sepsis exosomes could serve as a potential sepsis biomarker. Further investigations are required to identify sepsis exosomal cargo signatures for further understanding of sepsis pathophysiology in order to develop effective diagnostics and treatments.

DIAGNOSTIC PERFORMANCE OF CENTRAL NERVOUS SYSTEM INFECTIONS IN PATIENTS WITH NEUROSURGICAL INTENSIVE CARE USING METAGENOMIC NEXT-GENERATION SEQUENCING: A PROSPECTIVE OBSERVATIONAL STUDY

ABSTRACT

Background. Identifying the causative pathogens of central nervous system infections (CNSIs) is crucial, but the low detection rate of traditional culture methods in cerebrospinal fluid (CSF) has made the pathogenic diagnosis of CNSIs a longstanding challenge. Patients with CNSIs after neurosurgery often overlap with inflammatory and bleeding. Metagenomic next-generation sequencing (mNGS) has shown some benefits in pathogen detection. This study aimed to investigate the diagnostic performance of mNGS in the etiological diagnosis of CNSIs in patients after neurosurgery. Methods. In this prospective observational study, we enrolled patients with suspected CNSIs after neurosurgical operations who were admitted to the intensive care unit of Beijing Tiantan Hospital. All enrolled patients' CSF was tested using mNGS and pathogen culture. According to comprehensive clinical diagnosis, the enrolled patients were divided into CNSIs group and non-CNSIs group to compare the diagnostic efficiency of mNGS and pathogen culture. Results. From December 2021 to March 2023, 139 patients were enrolled while 66 in CNSIs group and 73 in non-CNSIs. The mNGS exceeded culture in the variety and quantity of pathogens detected. The mNGS outperformed traditional pathogen culture in terms of positive percent agreement (63.63%), accuracy (82.01%), and negative predictive value (75.00%), with statistically significant differences ( P < 0.05) for traditional pathogen culture. The mNGS also detected bacterial spectrum and antimicrobial resistance genes. Conclusions. Metagenomics has the potential to assist in the diagnosis of patients with CNSIs who have a negative culture.

Sepsis and underlying comorbidities in intensive care unit patients : Analysis of the cause of death by different clinicians-a pilot study

BACKGROUND

There is an ongoing debate as to whether death with sepsis is primarily caused by sepsis or, more often, by the underlying disease. There are no data on the influence of a researcher's background on such an assessment. Therefore, the aim of this analysis was to assess the cause of death in sepsis and the influence of an investigator's professional background on such an assessment.

MATERIALS AND METHODS

We performed a retrospective observational cohort study of sepsis patients treated in the medical intensive care unit (ICU) of a tertiary care center. For deceased patients, comorbidities and severity of illness were documented. The cause of death (sepsis or comorbidities or both combined) was independently assessed by four assessors with different professional backgrounds (medical student, senior physician in the medical ICU, anesthesiological intensivist, and senior physician specialized in the predominant comorbidity).

RESULTS

In all, 78 of 235 patients died in hospital. Agreement between assessors about cause of death was low (κ 0.37, 95% confidence interval 0.29-0.44). Depending on the assessor, sepsis was the sole cause of death in 6-12% of cases, sepsis and comorbidities in 54-76%, and comorbidities alone in 18-40%.

CONCLUSIONS

In a relevant proportion of patients with sepsis treated in the medical ICU, comorbidities contribute significantly to mortality, and death from sepsis without relevant comorbidities is a rare event. Designation of the cause of death in sepsis patients is highly subjective and may be influenced by the professional background of the assessor.

Prehospital early warning scores for adults with suspected sepsis: the PHEWS observational cohort and decision-analytic modelling study

Background

Guidelines for sepsis recommend treating those at highest risk within 1 hour. The emergency care system can only achieve this if sepsis is recognised and prioritised. Ambulance services can use prehospital early warning scores alongside paramedic diagnostic impression to prioritise patients for treatment or early assessment in the emergency department.

Objectives

To determine the accuracy, impact and cost-effectiveness of using early warning scores alongside paramedic diagnostic impression to identify sepsis requiring urgent treatment.

Design

Retrospective diagnostic cohort study and decision-analytic modelling of operational consequences and cost-effectiveness.

Setting

Two ambulance services and four acute hospitals in England.

Participants

Adults transported to hospital by emergency ambulance, excluding episodes with injury, mental health problems, cardiac arrest, direct transfer to specialist services, or no vital signs recorded.

Interventions

Twenty-one early warning scores used alongside paramedic diagnostic impression, categorised as sepsis, infection, non-specific presentation, or other specific presentation.

Main outcome measures

Proportion of cases prioritised at the four hospitals; diagnostic accuracy for the sepsis-3 definition of sepsis and receiving urgent treatment (primary reference standard); daily number of cases with and without sepsis prioritised at a large and a small hospital; the minimum treatment effect associated with prioritisation at which each strategy would be cost-effective, compared to no prioritisation, assuming willingness to pay £20,000 per quality-adjusted life-year gained.

Results

Data from 95,022 episodes involving 71,204 patients across four hospitals showed that most early warning scores operating at their pre-specified thresholds would prioritise more than 10% of cases when applied to non-specific attendances or all attendances. Data from 12,870 episodes at one hospital identified 348 (2.7%) with the primary reference standard. The National Early Warning Score, version 2 (NEWS2), had the highest area under the receiver operating characteristic curve when applied only to patients with a paramedic diagnostic impression of sepsis or infection (0.756, 95% confidence interval 0.729 to 0.783) or sepsis alone (0.655, 95% confidence interval 0.63 to 0.68). None of the strategies provided high sensitivity (> 0.8) with acceptable positive predictive value (> 0.15). NEWS2 provided combinations of sensitivity and specificity that were similar or superior to all other early warning scores. Applying NEWS2 to paramedic diagnostic impression of sepsis or infection with thresholds of > 4, > 6 and > 8 respectively provided sensitivities and positive predictive values (95% confidence interval) of 0.522 (0.469 to 0.574) and 0.216 (0.189 to 0.245), 0.447 (0.395 to 0.499) and 0.274 (0.239 to 0.313), and 0.314 (0.268 to 0.365) and 0.333 (confidence interval 0.284 to 0.386). The mortality relative risk reduction from prioritisation at which each strategy would be cost-effective exceeded 0.975 for all strategies analysed.

Limitations

We estimated accuracy using a sample of older patients at one hospital. Reliable evidence was not available to estimate the effectiveness of prioritisation in the decision-analytic modelling.

Conclusions

No strategy is ideal but using NEWS2, in patients with a paramedic diagnostic impression of infection or sepsis could identify one-third to half of sepsis cases without prioritising unmanageable numbers. No other score provided clearly superior accuracy to NEWS2. Research is needed to develop better definition, diagnosis and treatments for sepsis.

Study registration

This study is registered as Research Registry (reference: researchregistry5268).

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/136/10) and is published in full in Health Technology Assessment; Vol. 28, No. 16. See the NIHR Funding and Awards website for further award information.

Critical roles of S100A12, MMP9, and PRTN3 in sepsis diagnosis: Insights from multiple microarray data analyses

BACKGROUND

Sepsis, characterized by systemic inflammatory response syndrome and life-threatening organ dysfunction, remains a significant global cause of disability and death. Despite its impact, reliable biomarkers for sepsis diagnosis are yet to be identified.

OBJECTIVE

This study aims to investigate and identify key genes and pathways in sepsis through the analysis of multiple microarray datasets, providing potential treatment targets for future clinical trials.

METHODS

Two independent gene expression profiles (GSE54514 and GSE69528) were downloaded from the Gene Expression Omnibus (GEO) database. After merging and batch normalization, differentially expressed genes (DEGs) were obtained using the "limma" package. Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) were performed using "R" software. A Protein-Protein Interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING). The top 10 hub genes were identified using Cytoscape. A Nomogram model for predicting sepsis occurrence was constructed and evaluated.

RESULTS

Bioinformatic analysis of 210 sepsis and 91 control blood samples identified 72 DEGs. GO analyses revealed associations with immune response processes. GSEA indicated involvement in key signaling pathways. S100A12, MMP9, and PRTN3 were identified as independent risk factors for sepsis.

CONCLUSION

This study unveils critical genes and pathways in sepsis through bioinformatic methods. S100A12, MMP9, and PRTN3 may play essential roles in the immune response to infection, influencing sepsis prognosis.

Do-Not-Resuscitate Orders by COVID-19 Status Throughout the First Year of the COVID-19 Pandemic

BACKGROUND

At the beginning of the COVID-19 pandemic, whether performing CPR on patients with COVID-19 would be effective or increase COVID-19 transmission to health care workers was unclear.

RESEARCH QUESTION

Did the prevalence of do-not-resuscitate (DNR) orders by COVID-19 status change over the first year of the pandemic as risks such as COVID-19 transmission to health care workers improved?

STUDY DESIGN AND METHODS

This cross-sectional study assessed DNR orders for all adult patients admitted to ICUs at two academic medical centers in Chicago, IL, between April 2020 and April 2021. DNR orders by COVID-19 status were assessed using risk-adjusted mixed-effects logistic regression and propensity score matching by patient severity of illness.

RESULTS

The study population of 3,070 critically ill patients were 46% Black, 53% male, with median age (interquartile range [IQR]) 63 (50-73) years. Eighteen percent were COVID-19 positive and 27% had a DNR order. Black and Latinx patients had higher absolute rates of DNR orders than White patients (30% vs 29% vs 23%; P = .006). After adjustment for patient characteristics, illness severity, and hospital location, DNR orders were more likely in patients with COVID-19 in the nonpropensity score-matched (n = 3,070; aOR, 2.01; 95% CI, 1.64-2.38) and propensity score-matched (n = 1,118; aOR, 1.91; 95% CI, 1.45-2.52) cohorts. The prevalence of DNR orders remained higher for patients with COVID-19 than patients without COVID-19 during all months of the study period (difference in prevalence over time, P = .751).

INTERPRETATION

In this multihospital study, DNR orders remained persistently higher for patients with COVID-19 vs patients without COVID-19 with similar severity of illness during the first year of the pandemic. The specific reasons why DNR orders remained persistently elevated for patients with COVID-19 should be assessed in future studies, because these changes may continue to affect COVID-19 patient care and outcomes.

Temporal Trends in Mortality of Critically Ill Patients with Sepsis in the United Kingdom, 1988-2019

Rationale: Sepsis is a frequent cause of ICU admission and mortality. Objectives: To evaluate temporal trends in the presentation and outcomes of patients admitted to the ICU with sepsis and to assess the contribution of changing case mix to outcomes. Methods: We conducted a retrospective cohort study of patients admitted to 261 ICUs in the United Kingdom during 1988-1990 and 1996-2019 with nonsurgical sepsis. Measurements and Main Results: A total of 426,812 patients met study inclusion criteria. The patients had a median (interquartile range) age of 66 (53-75) years, and 55.6% were male. The most common sites of infection were respiratory (60.9%), genitourinary (11.5%), and gastrointestinal (10.3%). Compared with patients in 1988-1990, patients in 2017-2019 were older (median age, 66 vs. 63 yr), were less acutely ill (median Acute Physiology and Chronic Health Evaluation II acute physiology score, 14 vs. 20), and more often had genitourinary sepsis (13.4% vs. 2.0%). Hospital mortality decreased from 54.6% (95% confidence interval [CI], 51.0-58.1%) in 1988-1990 to 32.4% (95% CI, 32.1-32.7%) in 2017-2019, with an adjusted odds ratio of 0.64 (95% CI, 0.54-0.75). The adjusted absolute hospital mortality reduction from 1988-1990 to 2017-2019 was 8.8% (95% CI, 5.6-12.1). Thus, of the observed 22.2-percentage point reduction in hospital mortality, 13.4 percentage points (60% of total reduction) were explained by case mix changes, whereas 8.8 percentage points (40% of total reduction) were not explained by measured factors and may be a result of improvements in ICU management. Conclusions: Over a 30-year period, mortality for ICU admissions with sepsis decreased substantially. Although changes in case mix accounted for the majority of observed mortality reduction, there was an 8.8-percentage point reduction in mortality not explained by case mix.

Defining Parameters That Modulate Susceptibility and Protection to Respiratory Murine Coronavirus MHV1 Infection

Patients infected with SARS-CoV-2 experience variable disease susceptibility, and patients with comorbidities such as sepsis are often hospitalized for COVID-19 complications. However, the extent to which initial infectious inoculum dose determines disease outcomes and whether this can be used for immunological priming in a genetically susceptible host has not been completely defined. We used an established SARS-like murine model in which responses to primary and/or secondary challenges with murine hepatitis virus type 1 (MHV-1) were analyzed. We compared the response to infection in genetically susceptible C3H/HeJ mice, genetically resistant C57BL/6J mice, and genetically diverse, variably susceptible outbred Swiss Webster mice. Although defined as genetically susceptible to MHV-1, C3H/HeJ mice displayed decreasing dose-dependent pathological changes in disease severity and lung infiltrate/edema, as well as lymphopenia. Importantly, an asymptomatic dose (500 PFU) was identified that yielded no measurable morbidity/mortality postinfection in C3H/HeJ mice. Polymicrobial sepsis induced via cecal ligation and puncture converted asymptomatic infections in C3H/HeJ and C57BL/6J mice to more pronounced disease, modeling the impact of sepsis as a comorbidity to β-coronavirus infection. We then used low-dose infection as an immunological priming event in C3H/HeJ mice, which provided neutralizing Ab-dependent, but not circulating CD4/CD8 T cell-dependent, protection against a high-dose MHV-1 early rechallenge. Together, these data define how infection dose, immunological status, and comorbidities modulate outcomes of primary and secondary β-coronavirus infections in hosts with variable susceptibility.

Advances in sepsis biomarkers

Sepsis, a dysregulated host immune response to an infectious agent, significantly increases morbidity and mortality for hospitalized patients worldwide. This chapter reviews (1) the basic principles of infectious diseases, pathophysiology and current definition of sepsis, (2) established sepsis biomarkers such lactate, procalcitonin and C-reactive protein, (3) novel, newly regulatory-cleared/approved biomarkers, such as assays that evaluate white blood cell properties and immune response molecules, and (4) emerging biomarkers and biomarker panels to highlight future directions and opportunities in the diagnosis and management of sepsis.

Prevalence and outcomes of chronic comorbid conditions in patients with sepsis in Korea: a nationwide cohort study from 2011 to 2016

BACKGROUND

Chronic comorbid conditions are common in patients with sepsis and may affect the outcomes. This study aimed to evaluate the prevalence and outcomes of common comorbidities in patients with sepsis.

METHODS

We conducted a nationwide retrospective cohort study. Using data from the National Health Insurance Service of Korea. Adult patients (age ≥ 18 years) who were hospitalized in tertiary or general hospitals with a diagnosis of sepsis between 2011 and 2016 were analyzed. After screening of all International Classification of Diseases 10th revision codes for comorbidities, we identified hypertension, diabetes mellitus (DM), liver cirrhosis (LC), chronic kidney disease (CKD), and malignancy as prevalent comorbidities.

RESULTS

Overall, 373,539 patients diagnosed with sepsis were hospitalized in Korea between 2011 and 2016. Among them, 46.7% had hypertension, 23.6% had DM, 7.4% had LC, 13.7% had CKD, and 30.7% had malignancy. In-hospital mortality rates for patients with hypertension, DM, LC, CKD, and malignancy were 25.5%, 25.2%, 34.5%, 28.0%, and 33.3%, respectively, showing a decreasing trend over time (P < 0.001). After adjusting for baseline characteristics, male sex, older age, use of mechanical ventilation, and continuous renal replacement therapy, LC, CKD, and malignancy were significantly associated with in-hospital mortality.

CONCLUSIONS

Hypertension is the most prevalent comorbidity in patients with sepsis, and it is associated with an increased survival rate. Additionally, liver cirrhosis, chronic kidney disease, and malignancy result in higher mortality rates than hypertension and DM, and are significant risk factors for in-hospital mortality in patients with sepsis.

Prevalence and mortality rate of sepsis among adults admitted to hospitals in sub-Saharan Africa: a systematic review and meta-analysis

Due to abundant pathogen diversity and mounting antimicrobial resistance, sepsis is more common in sub-Saharan Africa (sSA). However, there is a lack of consistent reports regarding the prevalence of adult sepsis in the region. Therefore, this study aimed to determine pooled estimates of sepsis prevalence and associated mortality among adults admitted to hospitals in sSA. Medline (through PubMed), Scopus, Embase, and Web of Science were systematically searched for studies of sepsis in sSA published before 13th February 2023. A random-effects meta-analysis of hospital-wide and intensive care unit (ICU)-based sepsis prevalence was performed with a 95% confidence interval (CI). Subgroup analysis was conducted considering geographic region and sepsis diagnostic criteria. Funnel plots and Egger's test were used to assess publication bias. The protocol was submitted to the Prospective Register for Systematic Reviews (PROSPERO) with an identifier (CRD42023396719). Overall, 14 observational studies, published between 2009 and 2022, from eight different sSA countries comprising 31,653 adult patients (5723 with sepsis) were included in the review. Nine studies that were conducted in a hospital-wide setting showed a pooled prevalence and mortality of 17% (95% CI: 12-21%) and 15% (95% CI: 17-35%), respectively. Five studies in the ICUs presented a pooled prevalence and mortality of 31% (95% CI: 24-38%) and 46% (95% CI: 39-54%), respectively. Based on the sub-group analysis, the pooled hospital-wide prevalence of sepsis in East and Southern Africa was 18% (95% CI: 11-25%), and 20% (95% CI: 2-42%), respectively. The pooled prevalence in the ICU was 14% (95% CI: 4-23%) and 13% (95% CI: 5-20%) for East and Southern Africa, respectively. The hospital-wide and ICU-based sepsis prevalence and mortality are high in sSA. Addressing the burden of adult sepsis should be a priority for healthcare systems in sub-Saharan Africa.

Knockdown of angiopoietin-like 4 suppresses sepsis-induced acute lung injury by blocking the NF-κB pathway activation and hindering macrophage M1 polarization and pyroptosis

OBJECTIVE

Sepsis-induced acute lung injury (ALI) is a life-threatening disease. Macrophage pyroptosis has been reported to exert function in ALI. We aimed to investigate the mechanisms of ANGPTL4-mediated cell pyroptosis in sepsis-induced ALI, thus providing new insights into the pathogenesis and prevention and treatment measures of sepsis-induced ALI.

METHODS

In vivo animal models and in vitro cell models were established by cecal ligation and puncture (CLP) method and lipopolysaccharide-induced macrophages RAW264.7. ANGPTL4 was silenced in CLP mice or macrophages, followed by the determination of ANGPTL4 expression in bronchoalveolar lavage fluid (BALF) or macrophages. Lung histopathology was observed by H&E staining, with pathological injury scores evaluated and lung wet and dry weight ratio recorded. M1/M2 macrophage marker levels (iNOS/CD86/Arg1), inflammatory factor (TNF-α/IL-6/IL-1β/iNOS) expression in BALF, cell death and pyroptosis, NLRP3 inflammasome, cell pyroptosis-related protein (NLRP3/Cleaved-caspase-1/caspase-1/GSDMD-N) levels, NF-κB pathway activation were assessed by RT-qPCR/ELISA/flow cytometry/Western blot, respectively.

RESULTS

ANGPTL4 was highly expressed in mice with sepsis-induced ALI, and ANGPTL4 silencing ameliorated sepsis-induced ALI in mice. In vivo, ANGPTL4 silencing repressed M1 macrophage polarization and macrophage pyroptosis in mice with sepsis-induced ALI. In vitro, ANGPTL4 knockout impeded LPS-induced activation and pyroptosis of M1 macrophages and hindered LPS-induced activation of the NF-κB pathway in macrophages.

CONCLUSION

Knockdown of ANGPTL4 blocks the NF-κB pathway activation, hinders macrophage M1 polarization and pyroptosis, thereby suppressing sepsis-induced ALI.

PAI-1 as a critical factor in the resolution of sepsis and acute kidney injury in old age

Elevated plasma levels of plasminogen activator inhibitor type 1 (PAI-1) are documented in patients with sepsis and levels positively correlate with disease severity and mortality. Our prior work demonstrated that PAI-1 in plasma is positively associated with acute kidney injury (AKI) in septic patients and mice. The objective of this study was to determine if PAI-1 is causally related to AKI and worse sepsis outcomes using a clinically-relevant and age-appropriate murine model of sepsis. Sepsis was induced by cecal slurry (CS)-injection to wild-type (WT, C57BL/6) and PAI-1 knockout (KO) mice at young (5-9 months) and old (18-22 months) age. Survival was monitored for at least 10 days or mice were euthanized for tissue collection at 24 or 48 h post-insult. Contrary to our expectation, PAI-1 KO mice at old age were significantly more sensitive to CS-induced sepsis compared to WT mice (24% vs. 65% survival, p = 0.0037). In comparison, loss of PAI-1 at young age had negligible effects on sepsis survival (86% vs. 88% survival, p = 0.8106) highlighting the importance of age as a biological variable. Injury to the kidney was the most apparent pathological consequence and occurred earlier in aged PAI-1 KO mice. Coagulation markers were unaffected by loss of PAI-1, suggesting thrombosis-independent mechanisms for PAI-1-mediated protection. In summary, although high PAI-1 levels are clinically associated with worse sepsis outcomes, loss of PAI-1 rendered mice more susceptible to kidney injury and death in a CS-induced model of sepsis using aged mice. These results implicate PAI-1 as a critical factor in the resolution of sepsis in old age.

Potential impact of a new sepsis prediction model for the primary care setting: early health economic evaluation using an observational cohort

OBJECTIVES

To estimate the potential referral rate and cost impact at different cut-off points of a recently developed sepsis prediction model for general practitioners (GPs).

DESIGN

Prospective observational study with decision tree modelling.

SETTING

Four out-of-hours GP services in the Netherlands.

PARTICIPANTS

357 acutely ill adult patients assessed during home visits.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome is the cost per patient from a healthcare perspective in four scenarios based on different cut-off points for referral of the sepsis prediction model. Second, the number of hospital referrals for the different scenarios is estimated. The potential impact of referral of patients with sepsis on mortality and hospital admission was estimated by an expert panel. Using these study data, a decision tree with a time horizon of 1 month was built to estimate the referral rate and cost impact in case the model would be implemented.

RESULTS

Referral rates at a low cut-off (score 2 or 3 on a scale from 0 to 6) of the prediction model were higher than observed for patients with sepsis (99% and 91%, respectively, compared with 88% observed). However, referral was also substantially higher for patients who did not need hospital assessment. As a consequence, cost-savings due to referral of patients with sepsis were offset by increased costs due to unnecessary referral for all cut-offs of the prediction model.

CONCLUSIONS

Guidance for referral of adult patients with suspected sepsis in the primary care setting using any cut-off point of the sepsis prediction model is not likely to save costs. The model should only be incorporated in sepsis guidelines for GPs if improvement of care can be demonstrated in an implementation study.

TRIAL REGISTRATION NUMBER

Dutch Trial Register (NTR 7026).