The natural history of the systemic inflammatory response syndrome (SIRS). A prospective study

MLKL-mediated endothelial necroptosis drives vascular damage and mortality in systemic inflammatory response syndrome

The hypersecretion of cytokines triggers life-threatening systemic inflammatory response syndrome (SIRS), leading to multiple organ dysfunction syndrome (MODS) and mortality. Although both coagulopathy and necroptosis have been identified as important factors in the pathogenesis of SIRS, the specific cell types that undergo necroptosis and the interrelationships between coagulopathy and necroptosis remain unclear. In this study, we utilized visualization analysis via intravital microscopy to demonstrate that both anticoagulant heparin and nonanticoagulant heparin (NAH) pretreatment protect mice against TNF-α-induced mortality in SIRS. Moreover, the deletion of Mlkl or Ripk3 resulted in decreased coagulation and reduced mortality in TNF-α-induced SIRS. These findings suggest that necroptosis plays a key role upstream of coagulation in SIRS-related mortality. Furthermore, using a genetic lineage tracing mouse model (Tie2-Cre;Rosa26-tdT), we tracked endothelial cells (ECs) and verified that EC necroptosis is responsible for the vascular damage observed in TNF-α-treated mice. Importantly, Mlkl deletion in vascular ECs in mice had a similar protective effect against lethal SIRS by blocking EC necroptosis to protect the integrity of the endothelium. Collectively, our findings demonstrated that RIPK3-MLKL-dependent necroptosis disrupted vascular integrity, resulting in coagulopathy and multiorgan failure, eventually leading to mortality in SIRS patients. These results highlight the importance of targeting vascular EC necroptosis for the development of effective treatments for SIRS patients.

A knowledge-transfer-based approach for combining ordinal regression and medical scoring system in the early prediction of sepsis with electronic health records

OBJECTIVE

The prediction of sepsis, especially early diagnosis, has received a significant attention in biomedical research. In order to improve current medical scoring system and overcome the limitations of class imbalance and sample size of local EHR (electronic health records), we propose a novel knowledge-transfer-based approach, which combines a medical scoring system and an ordinal logistic regression model.

MATERIALS AND METHODS

Medical scoring systems (i.e. NEWS, SIRS and QSOFA) are generally robust and useful for sepsis diagnosis. With local EHR, machine-learning-based methods have been widely used for building prediction models/methods, but they are often impacted by class imbalance and sample size. Knowledge distillation and knowledge transfer have recently been proposed as a combination approach for improving the prediction performance and model generalization. In this study, we developed a novel knowledge-transfer-based method for combining a medical scoring system (after a proposed score transformation) and an ordinal logistic regression model. We mathematically confirmed that it was equivalent to a specific form of the weighted regression. Furthermore, we theoretically explored its effectiveness in the scenario of class imbalance.

RESULTS

For the local dataset and the MIMIC-IV dataset, the VUS (the volume under the multi-dimensional ROC surface, a generalization measure of AUC-ROC for ordinal categories) of the knowledge-transfer-based model (ORNEWS) based on the NEWS scoring system were 0.384 and 0.339, respectively, while the VUS of the traditional ordinal regression model (OR) were 0.352 and 0.322, respectively. Consistent analysis results were also observed for the knowledge-transfer-based models based on the SIRS/QSOFA scoring systems in the ordinal scenarios. Additionally, the predicted probabilities and the binary classification ROC curves of the knowledge-transfer-based models indicated that this approach enhanced the predicted probabilities for the minority classes while reducing the predicted probabilities for the majority classes, which improved AUCs/VUSs on imbalanced data.

DISCUSSION

Knowledge transfer, which combines a medical scoring system and a machine-learning-based model, improves the prediction performance for early diagnosis of sepsis, especially in the scenarios of class imbalance and limited sample size.

A metabolomics pipeline highlights microbial metabolism in bloodstream infections

The growth of antimicrobial resistance (AMR) highlights an urgent need to identify bacterial pathogenic functions that may be targets for clinical intervention. Although severe infections profoundly alter host metabolism, prior studies have largely ignored microbial metabolism in this context. Here, we describe an iterative, comparative metabolomics pipeline to uncover microbial metabolic features in the complex setting of a host and apply it to investigate gram-negative bloodstream infection (BSI) in patients. We find elevated levels of bacterially derived acetylated polyamines during BSI and discover the enzyme responsible for their production (SpeG). Blocking SpeG activity reduces bacterial proliferation and slows pathogenesis. Reduction of SpeG activity also enhances bacterial membrane permeability and increases intracellular antibiotic accumulation, allowing us to overcome AMR in culture and in vivo. This study highlights how tools to study pathogen metabolism in the natural context of infection can reveal and prioritize therapeutic strategies for addressing challenging infections.

Effects of intravenous inflammasome inhibitor (NuSepin) on suppression of proinflammatory cytokines release induced by cardiopulmonary bypass in swine model: a pilot study

The systemic inflammatory response syndrome can occur due to an inflammatory reaction to the release of cytokines, and it has been linked to the circulation of pro- and anti-inflammatory cytokines. The cardiopulmonary bypass (CPB) system is known to activate numerous inflammatory pathways. Applying CPB in large animals for an extended period may be useful as a controlled experimental model for systemic inflammatory responses. The authors hypothesized that 0.2 mg/kg NuSepin® would inhibit CBP-induced proinflammatory cytokine release, and attenuate CPB-induced vasoplegia. CPB was maintained for 2 h in 8 male Yorkshire pigs. Ten ml of saline was administered intravenously to the control group, while the study group received 10 ml of NuSepin® (0.2 mg/kg), before start of CPB. Blood samples were collected at four different time points to evaluating the level of cytokine (TNF-α, IL-1β, IL-6, IL-8) release during and after CBP. All vital signals were recorded as continuous waveforms using the vital recorder®. Our study demonstrated that IL-6 increased in both groups during CPB remained unchanged. However, in the Nusepin group, IL-6 levels rapidly decreased when CPB was stopped and the proinflammatory reaction subsided. Furthermore, the dose of norepinephrine required to maintain a mean pressure of 60 mmHg was also lower in the Nusepin group.

Comparison of clinical characteristics and outcomes of patients with sepsis identified by the Sepsis-3 criteria by blood and urine culture results: A multicentre retrospective cohort study

Background and Aims

Blood and urine are the most common culture testing for sepsis patients. This study aimed to compare clinical characteristics and outcomes of sepsis patients by blood and urine culture positivity and to identify factors associated with positive cultures.

Methods

This retrospective study included patients aged ≥16 years with sepsis identified by the Sepsis-3 criteria presenting to the emergency department at four hospitals between 2017 and 2019 in Australia. Patient clinical outcomes were in-hospital mortality, intensive care unit (ICU) admission, hospital length of stay, and representation following discharge. Four culture groups were defined based on the positivity of blood cultures (BC) and urine cultures (UC) ordered within 24 h of triage.

Results

Of 4109 patient encounters with sepsis, 2730 (66%) were nonbacteremic, urine culture-negative (BC-UC-); 767 (19%) nonbacteremic, urine culture-positive (BC-UC+); 359 (9%) bacteremic, urine culture-negative (BC+UC-); and 253 (6%) bacteremic, urine culture-positive (BC+UC+). Compared with BC-UC- patients, BC+UC- patients had the highest risk of ICU admission (adjusted odds ratio [AOR] 95% CI: 1.60 [1.18-2.18]) while BC-UC+ patients had lowest risk (adjusted odds ratio [AOR]: 0.56 [0.41-0.76]). BC+UC- patients had the highest risk of 3-day representation (AOR: 1.51 [1.02-2.25]) and second longest hospital stay (adjusted relative risk 1.17 [1.03-1.34]). Antibiotic administration before sample collection for culture was associated with lower odds of positive blood or urine culture results (AOR: 0.38, p < 0.0001).

Conclusions

Enhanced clinical care should be beneficial for nongenitourinary sepsis patients (BC+UC-) who had the highest comparative risk of adverse clinical outcomes. Every effort needs to be made to collect relevant culture samples before antibiotic administration, to follow up on culture results, and tailor treatment accordingly.

Antimicrobial resistance in intensive care patients hospitalized with SEPSIS: a comparison between the COVID-19 pandemic and pre-pandemic era

Introduction

Coronavirus disease 2019 (COVID-19) is a highly contagious viral illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has had a dramatic effect on the world, resulting in millions of deaths worldwide and causing drastic changes in daily life. A study reported that septic complications were associated with high mortality in COVID-19 patients. This study aimed to evaluate how the COVID-19 pandemic changed the pre-pandemic and post-pandemic prevalence of sepsis in ICUs and to evaluate the different risk factors associated with mortality and the different diffusion of microorganisms and their resistance.

Materials and methods

We conducted a single-center retrospective observational clinical study, observing all patients in the ICU of the SS Annunziata Hospital in Chieti (Italy) who were diagnosed with sepsis and had a bacterial isolate from their blood culture. Sepsis was diagnosed by SEPSIIS III criteria. We enrolled all in-patients in the ICU from January 2018 to December 2021. We divided the patients into three groups: (1) non-pandemic period (Np) hospitalized in 2018-2019, (2) pandemic period (Pp)-COVID hospitalized in 2020-2021 with a diagnosis of COVID-19, and (3) Pp-non-COVID patients hospitalized in 2020-2021 without a diagnosis of COVID-19.

Results

From January 2018 to December 2021, 1,559 patients were admitted to the ICU, of which 211 patients [36 (17.1%) in 2018, 52 (24.6%) in 2019, 73 (34.6%) in 2020, and 50 (23.7%) in 2021, respectively] met the selection criteria: 88 patients in period Np, 67 patients in Pp without COVID-19, and 56 patients Pp with COVID-19. The overall mortality of these patients was high (65.9% at 30 days in Np), but decreased during the Pp (60.9%): Pp-non-COVID was 56.7% vs. Pp-COVID 66.1%, with a statistically significant association with APACHE III score (OR 1.08, 95%CI 1.04-1.12, p < 0.001), SOFA score (OR 1.12, 95%CI 1.03-1.22, p = 0.004), and age (OR 1.04, 95%CI 1.02-1.07, p < 0.0001). Between the Np vs. Pp periods, we observed an increase in a few Gram-positive bacteria such as S. capitis (1 pt. -0.9% vs. 14 pt. -7.65%- p = 0.008), S. epidermidis, Streptococcus spp., and E. faecalis, as well as a decrease in a case of blood culture positive for S. aureus, S. hominis, and E. faecium. In Gram-negative bacteria, we observed an increase in cases of Acinetobacter spp. (Np 6 pt. -5.1%- vs. Pp 20 pt. -10.9%, p = 0.082), and Serratia spp., while cases of sepsis decreased from E. faecium (Np 11 pt. -9.4%- vs. Pp 7 pt. -3.8%, p = 0.047), and Enterobacter spp., S. haemolyticus, S. maltophilia, Proteus spp., and P. aeruginosa have not changed. Finally, we found that resistance to OXA-48 (p = 0.040), ESBL (p = 0.002), carbapenems (p = 0.050), and colistin (p = 0.003) decreased with time from Np to Pp, particularly in Pp-COVID.

Conclusion

This study demonstrated how the COVID-19 pandemic changed the prevalence of sepsis in the ICU. It emerged that the risk factors associated with mortality were APACHE and SOFA scores, age, and, above all, the presence of ESBL-producing bacteria. Despite this, during the pandemic phase, we have observed a significant reduction in the emergence of resistant germs compared to the pre-pandemic phase.

Melting temperature mapping method using imperfect-match linear long probes

Identifying pathogenic microorganisms as early as possible is critical for selecting the appropriate antimicrobial therapy in infected patients. We previously reported the development of the Tm mapping method for identifying a broad range of pathogenic bacteria within 3 h of blood collection. However, the Tm mapping identification requires an analytical instrument with a tube-to-tube variation of no more than 0.1 °C, so we can only use a few instruments that have such high thermal accuracy. To address the problem, we developed the improved Tm mapping method using imperfect-match linear long quenching probes (IMLL Q-probes). Using IMLL Q-probes, almost all commercially available analytical instruments can be used for the Tm mapping method. Some bacterial species cannot be narrowed down to one species, but they can at least be narrowed down to the genus level. The Tm mapping method using IMLL Q-probes is useful for deciding on antimicrobial therapy in infected patients.

Systemic inflammatory response syndrome in patients undergoing transcatheter aortic valve implantation

BACKGROUND

Data on systemic inflammatory response syndrome (SIRS) after transcatheter aortic valve implantation (TAVI) are scarce and limited to small cohorts. We aimed to investigate its incidence and mid-term impact in a large cohort of TAVI patients.

METHODS

From January 2018 to December 2020, 717 patients with severe aortic valve stenosis undergoing TAVI were included. SIRS was defined as fulfilling at least two of the following criteria within 48 h from the procedure: leucocyte count >12.0 or <4.0 × 109/l, respiratory rate > 20 breaths per minute or PaCO2 ≤ 4.3 kPa/32 mmHg, heart rate > 90 beats per minute and temperature > 38.0 °C or <36.0 °C. Clinical endpoints were 1-year rehospitalization for chronic heart failure (CHF) and 2-years all-cause mortality. Event rates during follow-up were calculated as Kaplan-Meier estimates.

RESULTS

SIRS developed in 56.3 % (404/717) of patients after TAVI. SIRS occurred more frequently in patients with post-dilatation (SIRS 34.7 % (140/404) vs. no SIRS 23.3 % (73/313); p < 0.001) and major vascular complications (SIRS 16.1 % (65/404) vs. no SIRS 8.6 % (27/313); p = 0.004). Further, ICU days were more in patients who developed SIRS (SIRS 1.56 ± 1.50 days vs. no SIRS 1.22 ± 1.02 days; p = 0.001). At 2-years, all-cause mortality in the entire population was 23.9 %. However, there was no difference in CHF at 1-year (5.9 % vs. 4.1 %; log-rank = 0.347) nor in all-cause mortality at 2-years (22.0 % vs. 26.2 %; log-rank = 0.690) between the groups.

CONCLUSIONS

SIRS is a common finding after TAVI, which may prolong hospital stay but is without effect on mortality during 2-years follow-up.

Do all Emergency Room Patients With Influenza-like Symptoms Need Blood Cultures? A Retrospective Cohort Study of 2 Annual Influenza Seasons

In this retrospective cohort study, we evaluated risk factors for bacteremia in emergency department patients presenting with influenza-like symptoms during influenza epidemic seasons. In patients without fever, chronic heart or chronic liver disease, blood culture collection might be omitted.

Better Performance of Modified Scoring Systems to Predict the Clinical Outcomes of Vibrio Bacteremia in the Emergency Department: An Observational Study

BACKGROUND

Vibrio is a genus of Gram-negative bacteria found in various aquatic environments, including saltwater and freshwater. Vibrio bacteremia can lead to sepsis, a potentially life-threatening condition in which the immune system enters overdrive in response to the disease, causing widespread inflammation and damage to tissues and organs. V. vulnificus had the highest case fatality rate (39%) of all reported foodborne infections in the United States and a high mortality rate in Asia, including Taiwan. Numerous scoring systems have been created to estimate the mortality risk in the emergency department (ED). However, there are no specific scoring systems to predict the mortality risk of Vibrio bacteremia. Therefore, this study modified the existing scoring systems to better predict the mortality risk of Vibrio bacteremia.

METHODS

Cases of Vibrio bacteremia were diagnosed based on the results from at least one blood culture in the ED. Patient data were extracted from the electronic clinical database, covering January 2012 to December 2021. The primary outcome was in-hospital mortality.This study used univariate and multivariate analyses to evaluate the mortality risk.

RESULTS

This study enrolled 36 patients diagnosed with Vibrio bacteremia, including 23 males (63.9%) and 13 females (36.1%), with a mean age of 65.1 ± 15.7 years. The in-hospital mortality rate amounted to 25% (9/36), with 31.5% in V. vulnificus (6/19) and 17.6% in V. non-vulnificus (3/17). The non-survivors demonstrated higher MEDS (10.3 ± 2.4) than the survivors (6.2 ± 4.1) (p = 0.002). Concerning the qSOFA, the survivors scored 0.3 ± 0.5, and the non-survivors displayed a score of 0.6 ± 0.7 (p = 0.387). The AUC of the ROC for the MEDS and qSOFA was 0.833 and 0.599, respectively. This study modified the scoring systems with other predictive factors, including BUN and pH. The AUC of the ROC for the modified MEDS and qSOFA reached up to 0.852 and 0.802, respectively.

CONCLUSION

The MEDS could serve as reliable indicators for forecasting the mortality rate of patients grappling with Vibrio bacteremia. This study modified the MEDS and qSOFA to strengthen the predictive performance of mortality risk for Vibrio bacteremia. We advocate the prompt initiation of targeted therapeutic interventions and judicious antibiotic treatments to curb fatality rates.

How well does peripheral blood neutrophil-to-lymphocyte ratio predict the severity and prognosis of hemorrhagic Stroke

OBJECTIVE

We explored the blood neutrophil-to-lymphocyte ratio (NLR) as a prognostic marker and its relation with mortality and Modified Rankin Scale (mRS) score at discharge and at 3 months following ICH and also compared NLR with intracerebral hemorrhage (ICH) score, Sequential Organ Failure Assessment (SOFA) score and National Institutes of Health Stroke Scale (NIHSS) score.

METHODS

The investigators calculated the NIHSS score, SOFA score, ICH score and NLR of 90 adult patients within 3 days of onset of stroke with evidence of hemorrhagic stroke in brain imaging and correlated it with in-hospital mortality, 3-month mortality and mRS at 3 months following stroke using regression analysis.

RESULTS

Out of 90 individuals, there were 54 (60%) males and 36 (40%) females. The mRS score at 3 months significantly related to the admission NLR ratio >7 and SOFA score. Similarly, the in-hospital death and 3-month mortality was related to the admission NLR ratio >7 and ICH score. However, at a cut off value of NLR>3 for assessing the prognosis of the patients, we did not get significant results for mRS at 3 months following stroke and for in-hospital and 3-month mortality.

CONCLUSION

A high NLR ratio >7 predicted worse outcomes in terms of mortality and morbidity at 3-months following haemorrhagic stroke. Hence, like ICH score, NLR can predict 3-month mortality following an acute haemorrhagic stroke and can also predict morbidity following 3 months of brain haemorrhage.

Association between body mass index and delirium incidence in critically ill patients: a retrospective cohort study based on the MIMIC-IV Database

OBJECTIVES

Delirium is a form of brain dysfunction with high incidence and is associated with many negative outcomes in the intensive care unit. However, few studies have been large enough to reliably examine the associations between body mass index (BMI) and delirium, especially in critically ill patients. The objective of this study was to investigate the association between BMI and delirium incidence in critically ill patients.

DESIGN

A retrospective cohort study.

SETTING

Data were collected from the Medical Information Mart for Intensive Care-IV V2.0 Database consisting of critically ill participants between 2008 and 2019 at the Beth Israel Deaconess Medical Center in Boston.

PARTICIPANTS

A total of 20 193 patients with BMI and delirium records were enrolled in this study and were divided into six groups.

PRIMARY OUTCOME MEASURE

Delirium incidence.

RESULTS

Generalised linear models and restricted cubic spline analysis were used to estimate the associations between BMI and delirium incidence. A total of 30.81% of the patients (6222 of 20 193) developed delirium in the total cohort. Compared with those in the healthy weight group, the patients in the different groups (underweight, overweight, obesity grade 1, obesity grade 2, obesity grade 3) had different relative risks (RRs): RR=1.10, 95% CI=1.02 to 1.19, p=0.011; RR=0.93, 95% CI=0.88 to 0.97, p=0.003; RR=0.88, 95% CI=0.83 to 0.94, p<0.001; RR=0.94, 95% CI=0.86 to 1.03, p=0.193; RR=1.14, 95% CI=1.03 to 1.25, p=0.010, respectively. For patients with or without adjustment variables, there was an obvious U-shaped relationship between BMI as a continuous variable and delirium incidence.

CONCLUSION

BMI was associated with the incidence of delirium. Our results suggested that a BMI higher or lower than obesity grade 1 rather than the healthy weight in critically ill patients increases the risk of delirium incidence.

Hemoperfusion with high-affinity polyethylene microbeads (Seraph-100®) for the removal of pathogens in chronic critically ill patients: Clinical experience

Critically ill septic patients present variable clinical trajectories, with some succumbing to hyperinflammatory responses while others develop a chronic critical illness, characterized by a prolonged low-grade inflammation, muscle atrophy, and mechanical ventilation dependency and often develop secondary infections often caused by from low-virulence microorganisms or reactivated latent viruses. The Seraph-100® hemoperfusion cartridge takes advantage from heparin-coated ultra-high molecular weight polyethylene microbeads mimicking pathogen-binding cell receptors and can adsorb both pathogens and damage-associated molecular patterns released by injured tissues. We describe two chronic critically ill patients who developed secondary viral bloodstream infections successfully treated with this device.

Trauma-induced innate immune activation and disseminated intravascular coagulation

Dysregulated innate immunity participates in the pathomechanisms of disseminated intravascular coagulation (DIC) in trauma-induced coagulopathy. Accidental and regulated cell deaths and neutrophil extracellular traps release damage-associated molecular patterns (DAMPs), such as histones, nuclear and mitochondrial DNA, and high-mobility group box 1, into circulation immediately after trauma. DAMP-induced inflammation activation releases tissue factor-bearing procoagulant extracellular vesicles through gasdermin D-mediated pore formation and plasma membrane rupture by regulated cell death. DAMPs also evoke systemic inflammation, platelet, coagulation activation, and impaired fibrinolysis associated with endothelial injury, leading to the dysfunction of anticoagulation systems, which are the main pathophysiological mechanisms of DIC. All these processes induce systemic thrombin generation in vivo, not restricted to the injury sites immediately after trauma. Thrombin generation at the site of injury stops bleeding and maintains homeostasis. However, DIC associated with endothelial injury generates massive thrombin, enhancing protease-activated, receptor-mediated bidirectional interplays between inflammation and coagulation, aggravating the diverse actions of thrombin and disturbing homeostasis. Insufficiently regulated thrombin causes disseminated microvascular thrombosis, resulting in tissue hypoxia due to reduced oxygen delivery, and mitochondrial dysfunction due to DAMPs causes tissue dysoxia. In addition, DAMP-induced calcium influx and overload, as well as neutrophil activation, play a role in endothelial cell injury. Tissue hypoxia and cytotoxicity result in multiple organ dysfunction in DIC after trauma. Controls against dysregulated innate immunity evoking systemic inflammation, thrombin generation, and cytotoxicity are key issues in improving the prognosis of DIC in trauma-induced coagulopathy.

Deep learning-based prediction of in-hospital mortality for sepsis

As a serious blood infection disease, sepsis is characterized by a high mortality risk and many complications. Accurate assessment of mortality risk of patients with sepsis can help physicians in Intensive Care Unit make optimal clinical decisions, which in turn can effectively save patients' lives. However, most of the current clinical models used for assessing mortality risk in sepsis patients are based on conventional indicators. Unfortunately, some of the conventional indicators have been shown to be inapplicable in the accurate clinical diagnosis nowadays. Meanwhile, traditional evaluation models only focus on a small amount of personal data, causing misdiagnosis of sepsis patients. We refine the core indicators for mortality risk assessment of sepsis from massive clinical electronic medical records with machine learning, and propose a new mortality risk assessment model, DGFSD, for sepsis patients based on deep learning. The DGFSD model can not only learn individual clinical information about unassessed patients, but also obtain information about the structure of the similarity graph between diagnosed patients and patients to be assessed. Numerous experiments have shown that the accuracy of the DGFSD model is superior to baseline methods, and can significantly improve the efficiency of clinical auxiliary diagnosis.

Exploring the Mediating Role of Multiple Organ Dysfunction in Sepsis-Induced Disseminated Intravascular Coagulation and Its Impact on Worsening Prognosis

Disseminated intravascular coagulation (DIC) poses a high mortality risk, yet its exact impact remains contentious. This study investigates DIC's association with mortality in individuals with sepsis, emphasizing multiple organ function. Using data from the Peking University People's Hospital Investigation on Sepsis-Induced Coagulopathy database, we categorized patients into DIC and non-DIC groups based on DIC scores within 24 h of ICU admission (< 5 cutoff). ICU mortality was the main outcome. Initial data comparison preceded logistic regression analysis of mortality factors post-propensity score matching (PSM). Employing mediation analysis estimated direct and indirect associations. Of 549 participants, 131 were in the DIC group, with the remaining 418 in the non-DIC group. Following baseline characteristic presentation, PSM was conducted, revealing significantly higher nonplatelet sequential organ failure assessment (nonplt-SOFA) scores (6.3 ± 2.7 vs 5.0 ± 2.5, P < 0.001) and in-hospital mortality rates (47.3% vs 29.5%, P = 0.003) in the DIC group. A significant correlation between DIC and in-hospital mortality persisted (OR 2.15, 95% CI 1.29-3.59, P = 0.003), with nonplt-SOFA scores (OR 1.16, 95% CI 1.05-1.28, P = 0.004) and hemorrhage (OR 2.33, 95% CI 1.08-5.03, P = 0.032) as predictors. The overall effect size was 0.1786 (95% CI 0.0542-0.2886), comprising a direct effect size of 0.1423 (95% CI 0.0153-0.2551) and an indirect effect size of 0.0363 (95% CI 0.0034-0.0739), with approximately 20.3% of effects mediated. These findings underscore DIC's association with increased mortality risk in patients with sepsis, urging anticoagulation focus over bleeding management, with organ dysfunction assessment recommended for anticoagulant treatment efficacy.

Identification of Clinically Significant Cytokine Signature Clusters in Patients With Septic Shock

OBJECTIVES

To identify cytokine signature clusters in patients with septic shock.

DESIGN

Prospective observational cohort study.

SETTING

Single academic center in the United States.

PATIENTS

Adult (≥ 18 yr old) patients admitted to the medical ICU with septic shock requiring vasoactive medication support.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred fourteen patients with septic shock completed cytokine measurement at time of enrollment (t 1 ) and 24 hours later (t 2 ). Unsupervised random forest analysis of the change in cytokines over time, defined as delta (t 2 -t 1 ), identified three clusters with distinct cytokine profiles. Patients in cluster 1 had the lowest initial levels of circulating cytokines that decreased over time. Patients in cluster 2 and cluster 3 had higher initial levels that decreased over time in cluster 2 and increased in cluster 3. Patients in clusters 2 and 3 had higher mortality compared with cluster 1 (clusters 1-3: 11% vs 31%; odds ratio [OR], 3.56 [1.10-14.23] vs 54% OR, 9.23 [2.89-37.22]). Cluster 3 was independently associated with in-hospital mortality (hazard ratio, 5.24; p = 0.005) in multivariable analysis. There were no significant differences in initial clinical severity scoring or steroid use between the clusters. Analysis of either t 1 or t 2 cytokine measurements alone or in combination did not reveal clusters with clear clinical significance.

CONCLUSIONS

Longitudinal measurement of cytokine profiles at initiation of vasoactive medications and 24 hours later revealed three distinct cytokine signature clusters that correlated with clinical outcomes.

Thrombin worsens extravascular lung water and outcomes of septic patients with acute respiratory distress syndrome: A case control study

Endothelial cell (EC) activation may increase systemic vascular permeability, causing extravascular lung water (EVLW) in sepsis with acute respiratory distress syndrome (ARDS). However, the correlation between thrombin and EVLW in sepsis and ARDS has not yet been addressed. Patients with sepsis and ARDS were prospectively enrolled between 2014 and 2016, and EVLW and serum thrombin levels on days 1 and 3 were measured and compared between surviving and non-surviving patients. Additionally, morphological changes in human umbilical vein endothelial cells (HUVECs) in the serum of patients with high and low EVLW were evaluated. The levels of EVLW, endothelial cells, and thrombin may positively correlate with the survival of patients with severe sepsis and ARDS. Twenty-seven patients were enrolled, and baseline characteristics, including age, sex, Acute Physiology and Chronic Health Evaluation (APACHE) II, prior 24-h fluid balance, body mass index, and shock status, were similar between survivors and non-survivors; however, day 1 EVLW was higher in non-survivors (27.5 ± 8.4 vs 22 ± 6.5 mL/kg, P = .047). EVLW of survivors improved from day 1 to day 3 (22 ± 6.5 vs 11 ± 3.8 mL/kg, P < .001), but did not improve in non-survivors (27.5 ± 8.4 vs 28 ± 6.7 mL/kg, P = .086), which means that patients had significantly lower EVLW on day 3 than on day 1. Thrombin levels of survivors significantly improved (1.03 ± 0.55 vs 0.87 ± 0.25 U/mL, P = .04) but did not improve in non-survivors (1.97 ± 0.75 vs 2.2 ± 0.75 U/mL, P = .08) from day 1 to day 3. EVLW and thrombin levels were positively correlated (r2 = 0.71, P < .0001). In vitro, the morphology and junctions of HUVECs changed when the serum from patients with high EVLW was added. The intercellular distances among the control, high EVLW, and low EVLW groups were 5.25 ± 1.22, 21.33 ± 2.15, and 11.17 ± 1.64 µm, respectively (P < .05).

End-to-End Sepsis Solution Incorporating Expert Telemedicine Consultation

Introduction: Early detection and optimal resuscitation of critically ill sepsis patients may improve sepsis care delivery. The objective was to assess the feasibility of developing and implementing an end-to-end sepsis solution including early detection, monitoring, and teleconsultation. Methods: Prospective implementation of an end-to-end sepsis solution for potential sepsis patients presenting to a community hospital emergency department (ED) between 11 AM and 5 PM, Monday to Friday, during a 40-day period in 2019. Qualifying patients were compared with patients presenting at other times during the pilot screening period and to historic controls. Results: During the initial period, 203 patients met the screening criteria for potential sepsis; 77 patients (37.9%) had a primary diagnosis of sepsis, present on admission. Mean age was 60 ± 20 years; 50.7% were female; and 24 patients (11.8%) were primary sepsis, SEP-1 bundle eligible. Eighty of 203 (39.4%) had an initial lactate performed, mean, 2.7 ± 1.7 mmol/L. For the 24 primary sepsis, SEP-1 bundle eligible patients, 100% received antibiotics and intravenous fluid. Thirteen consults were performed on 12 patients; mean time from consult decision to beam in to the telemedicine robot was 7.3 ± 5.5 min; mean time from beam in to robot connection with the expert was 23.6 ± 13.2 s; mean consultation call time was 6.3 ± 4.3 min. Conclusions: In a convenience sample of patients with potential sepsis presenting to a community hospital ED, an end-to-end sepsis solution using early detection, tracking, and consultation was feasible and has the potential to improve sepsis detection and treatment.

Inflammasome activation and pyroptosis mediate coagulopathy and inflammation in Salmonella systemic infection

Inflammasome activation is a critical defense mechanism against bacterial infection. Previous studies suggest that inflammasome activation protects against Salmonella oral infection. Here we find inflammasome activation plays a critical role in the pathogenesis of Salmonella systemic infection. We show that in a systemic infection model by i.p. injection of Salmonella, deficiency of caspase-1 or gasdermin-D prolonged survival time, reduced plasma concentrations of the proinflammatory cytokines IL-1β, IL-6 and TNFα. These deficiencies also protected against coagulopathy during Salmonella infection as evidenced by diminished prolongation of prothrombin time and increase in plasma thrombin-antithrombin complex concentrations in the caspase-1 or gasdermin-D deficient mice. Activation of the NAIP/NLRC4 inflammasome by flagellin and/or the components of the SPI1 type 3 secretion system played a critical role in Salmonella-induced coagulopathy. In the absence of flagellin and SPI1, the Salmonella mutant strain still triggered coagulopathy through the caspase-11/NLRP3 pathway. Our results reveal a previously undisclosed role of the inflammasomes and pyroptosis in the pathogenesis of Salmonella systemic infection.

[Importance of outpatient medical consultation prior to going to the hospital emergency department in patients over 65 years of age: Impact on hospitalization results]

OBJECTIVE

Investigate factors associated with a previous outpatient medical consultation (POMC), to the health center or another physician, before attending a hospital emergency department (ED), in patients aged >65 and its impact on the hospitalization rate and variables related to ED stay. SITE: Fifty-two Spanish EDs.

PARTICIPANTS

Patients over 65 years consulting an ED.

MAIN MEASUREMENTS AND DESIGN

A cohort (n=24645) of patients aged >65 attended for one week in 52 ED. We recorded five sociodemographic variables, six functional, three episode-related severity and analyzed their crude and adjusted association with the existence of a POMC at ED consultation. The primary outcome variable was the need for admission and the secondary variables were complementary examinations and ED stay length. We analyzed whether the POMC influenced these outcomes.

RESULTS

28.5% of the patients had performed a POMC prior to their visit to the ED. Living in a residence, NEWS-2 score ≥5, aged ≥80, dependency functions, severe comorbidity, living alone, cognitive impairment, male gender and depression were independently associated with a POMC. Also was associated with a greater need for hospitalization and shorter length of stay in the ED. No minor consumption of diagnostic resources in patients with POMC.

CONCLUSION

Patients presenting to the ED following POMC are admitted more frequently, suggesting that they are appropriately referred and that minor emergencies are probably effectively resolved in the POMC. Their stay in the ED prior to hospitalization is shorter, so the POMC would facilitate clinical resolution in the ED.

Identification and targeting of microbial putrescine acetylation in bloodstream infections

The growth of antimicrobial resistance (AMR) has highlighted an urgent need to identify bacterial pathogenic functions that may be targets for clinical intervention. Although severe bacterial infections profoundly alter host metabolism, prior studies have largely ignored alterations in microbial metabolism in this context. Performing metabolomics on patient and mouse plasma samples, we identify elevated levels of bacterially-derived N-acetylputrescine during gram-negative bloodstream infections (BSI), with higher levels associated with worse clinical outcomes. We discover that SpeG is the bacterial enzyme responsible for acetylating putrescine and show that blocking its activity reduces bacterial proliferation and slows pathogenesis. Reduction of SpeG activity enhances bacterial membrane permeability and results in increased intracellular accumulation of antibiotics, allowing us to overcome AMR of clinical isolates both in culture and in vivo. This study highlights how studying pathogen metabolism in the natural context of infection can reveal new therapeutic strategies for addressing challenging infections.

Biomarkers in the intensive care setting: A focus on using procalcitonin and C-reactive protein to optimize antimicrobial duration of therapy

Managing the critically ill patient with infection is complex, requiring clinicians to synthesize considerable information relating to antimicrobial efficacy and treatment duration. The use of biomarkers may play an important role in identifying variation in treatment response and providing information about treatment efficacy. Though a vast number of biomarkers for clinical application have been described, procalcitonin and C-reactive protein (CRP) are the most thoroughly investigated in the critically ill. However, the presence of heterogeneous populations, variable end points, and incongruent methodology in the literature complicates the use of such biomarkers to guide antimicrobial therapy. This review focuses on an appraisal of evidence for use of procalcitonin and CRP to optimize antimicrobial duration of therapy (DOT) in critically ill patients. Procalcitonin-guided antimicrobial therapy in mixed critically ill populations with varying degrees of sepsis appears to be safe and might assist in reducing antimicrobial DOT. Compared to procalcitonin, fewer studies exist examining the impact of CRP on antimicrobial DOT and clinical outcomes in the critically ill. Procalcitonin and CRP have been insufficiently studied in many key intensive care unit populations, including surgical patients with concomitant trauma, renally insufficient populations, the immunocompromised, and patients with septic shock. We believe the available evidence is not strong enough to warrant routine use of procalcitonin or CRP to guide antimicrobial DOT in critically ill patients with infection. So long as its limitations are recognized, procalcitonin could be considered to tailor antimicrobial DOT on a case-by-case basis in the critically ill patient.

Clinical and time-related predictors of sepsis in patients with obstructive uropathy due to ureteral stones in the emergency setting

PURPOSE

Well-defined clinical predictors of sepsis after upper tract drainage for obstructive uropathy due to ureteral stones are needed. We aim to determine whether sepsis after decompression of the upper urinary tract may be predicted by clinical and time-related factors, specifically delay time from symptom onset to hospital presentation (StH) and from hospital presentation to surgical decompression (HtD).

METHODS

In this single-center retrospective study, data from 196 consecutive patients presenting to the emergency department for obstructive uropathy due to ureteral stones and submitted to surgical decompression were evaluated. Postoperative sepsis was defined as an acute increase in ≥ 2 SOFA points and documented blood or urine cultures.

RESULTS

Median StH and HtD were 24 (6-48) and 17 (10-30) hours, respectively. Thirty-three (16.8%) patients developed sepsis. Septic patients were more frequently female (75.8% vs. 37.4%, p < 0.001), had higher preoperative max body temperature (p < 0.001), white blood cells (WBC) count (p < 0.01), C-reactive protein (CRP) values (p < 0.001) and larger stone diameter (7.2 vs. 6 mm, p = 0.02). StH and HtD did not differ according to sepsis status. Time for WBC normalization and CRP halving were longer for septic patients (all p < 0.02). At multivariable logistic regression analysis, max body temperature ≥ 38 °C (OR 21.5; p < 0.001), female gender (OR 3.6; p = 0.02) and higher CRP (OR 1.1; p < 0.001) were independently associated with sepsis status.

CONCLUSION

Clinical and laboratory parameters are associated with an increased risk of sepsis after decompression. StH and HtD timing are not associated with higher sepsis rates. In selected patients, urinary decompression could be delayed or primary ureteroscopy could be considered.

S-Adenosylhomocysteine Is a Useful Metabolic Factor in the Early Prediction of Septic Disease Progression and Death in Critically Ill Patients: A Prospective Cohort Study

A common final pathway of pathogenetic mechanisms in septic organ dysfunction and death is a lack or non-utilization of oxygen. Plasma concentrations of lactate serve as surrogates for the oxygen-deficiency-induced imbalance between energy supply and demand. As S-adenosylhomocysteine (SAH) was shown to reflect tissue hypoxia, we compared the ability of SAH versus lactate to predict the progression of inflammatory and septic disease to septic organ dysfunction and death. Using univariate and multiple logistic regression, we found that SAH but not lactate, taken upon patients' inclusion in the study close to ICU admission, significantly and independently contributed to the prediction of disease progression and death. Due to the stronger increase in SAH in relation to S-adenosylmethionine (SAM), the ratio of SAM to SAH, representing methylation potential, was significantly decreased in patients with septic organ dysfunction and non-survivors compared with SIRS/sepsis patients (2.8 (IQR 2.3-3.9) vs. 8.8 (4.9-13.8); p = 0.003) or survivors (4.9 (2.8-9.5) vs. 8.9 (5.1-14.3); p = 0.026), respectively. Thus, SAH appears to be a better contributor to the prediction of septic organ dysfunction and death than lactate in critically ill patients. As SAH is a potent inhibitor of SAM-dependent methyltransferases involved in numerous vital biochemical processes, the impairment of the SAM-to-SAH ratio in severely critically ill septic patients and non-survivors warrants further studies on the pathogenetic role of SAH in septic multiple organ failure.

Cytokine storm associated with severe COVID-19 infections: The potential mitigating role of omega-3 fatty acid triglycerides in the ICU

Cytokine storm during severe COVID-19 infection increases the risk of mortality in critically ill patients in the intensive care unit. Multiple therapeutic proposals include, for example, anti-inflammatory and immunosuppressive agents, selective inhibitors of key pro-inflammatory receptors, and key enzymes necessary for viral replication. Unfortunately, safe and effective therapy remains an elusive goal. An alternative anti-inflammatory approach vis á vis omega-3 fatty acids, which yields less pro-inflammatory mediators by altering eicosanoid metabolism, has been proposed. Although theoretically promising, enteral tube delivery or oral capsules containing specific doses of omega-3 fatty acids take precious time (7 days to 6 weeks) to be incorporated in plasma cell membranes to be most effective, making this route of administration in the acute care setting an unfeasible therapeutic approach. Parenteral administration of precise doses of omega-3 fatty acid triglycerides in an injectable emulsion can greatly accelerate the incorporation and potential therapeutic effects (within hours), but at present, there is no commercially available product designed for this purpose. We describe a potential formulation that may address this deficiency, while recognizing that the high incidence of hyperlipidemia that occurs during severe COVID-19 infection must be recognized as a complicating factor, and, therefore, caution is advised.

Glucocorticoid Treatment in Acute Respiratory Distress Syndrome: An Overview on Mechanistic Insights and Clinical Benefit

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS), triggered by various pathogenic factors inside and outside the lungs, leads to diffuse lung injury and can result in respiratory failure and death, which are typical clinical critical emergencies. Severe acute pancreatitis (SAP), which has a poor clinical prognosis, is one of the most common diseases that induces ARDS. When SAP causes the body to produce a storm of inflammatory factors and even causes sepsis, clinicians will face a two-way choice between anti-inflammatory and anti-infection objectives while considering the damaged intestinal barrier and respiratory failure, which undoubtedly increases the difficulty of the diagnosis and treatment of SAP-ALI/ARDS. For a long time, many studies have been devoted to applying glucocorticoids (GCs) to control the inflammatory response and prevent and treat sepsis and ALI/ARDS. However, the specific mechanism is not precise, the clinical efficacy is uneven, and the corresponding side effects are endless. This review discusses the mechanism of action, current clinical application status, effectiveness assessment, and side effects of GCs in the treatment of ALI/ARDS (especially the subtype caused by SAP).

Comparison of the clinical characteristics and clinical outcomes of culture-positive septic shock and culture-negative septic shock among pediatric patients

OBJECTIVES

Among pediatric patients with septic shock, culture-negative septic shock (CNSS) is common but there have been limited data on its clinical characteristics and prognosis. We compared the clinical characteristics and clinical outcomes between culture-positive septic shock (CPSS) and CNSS in pediatric patients.

DESIGN

Retrospective single-center study.

SETTING

Pediatric intensive care unit (PICU) of a tertiary referral hospital.

PATIENTS

All pediatric patients who were admitted to the PICU due to septic shock between January 2010 and November 2021, except for those with fungal or viral infections and those who expired on the day of admittance to the PICU. The primary outcome was 30-day mortality and in-hospital mortality.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 294 patients (CPSS group, n = 185 [62.9%]; CNSS group, n = 109 [37.1%]) were included. The rates of 30-day mortality and in-hospital mortality (30-day mortality 22.7% vs 22%, in-hospital mortality 29.7% vs 25.7%) were not significantly different between the CPSS group and the CNSS group. The two groups showed comparable results in clinical outcomes such as the requirement for mechanical ventilator and renal replacement therapy, PICU stay duration, and the duration of MV and vasopressor/inotrope support. Among the CPSS group, 98 (53%) patients who were infected with multi-drug resistance (MDR) bacteria had significantly higher rates of 30-day mortality and in-hospital mortality than those infected with non-MDR bacteria.

CONCLUSIONS

Among pediatric patients, the CPSS group and CNSS group did not show significant differences in clinical features and mortality. Among the CPSS group, those with MDR bacteria had poorer prognosis.

The Association between Influenza Vaccine and Risk of Chronic Kidney Disease/Dialysis in Patients with Hypertension

BACKGROUNDS

Influenza vaccination could decrease the risk of major cardiac events in patients with hypertension. However, the vaccine's effects on decreasing the risk of chronic kidney disease (CKD) development in such patients remain unclear.

METHODS

We retrospectively analysed the data of 37,117 patients with hypertension (≥55 years old) from the National Health Insurance Research Database during 1 January 2001 to 31 December 2012. After a 1:1 propensity score matching by the year of diagnosis, we divided the patients into vaccinated (n = 15,961) and unvaccinated groups (n = 21,156).

RESULTS

In vaccinated group, significantly higher prevalence of comorbidities such as diabetes, cerebrovascular disease, dyslipidemia, heart and liver disease were observed compared with unvaccinated group. After adjusting age, sex, comorbidities, medications (anti-hypertensive agents, metformin, aspirin and statin), level of urbanization and monthly incomes, significantly lower risk of CKD occurrence was observed among vaccinated patients in influenza season, non-influenza season and all season (Adjusted hazard ratio [aHR]: 0.39, 95% confidence level [C.I.]: 0.33-0.46; 0.38, 95% C.I.: 0.31-0.45; 0.38, 95% C.I.: 0.34-0.44, respectively). The risk of hemodialysis significantly decreased after vaccination (aHR: 0.40, 95% C.I.: 0.30-0.53; 0.42, 95% C.I.: 0.31-0.57; 0.41, 95% C.I.: 0.33-0.51, during influenza season, non-influenza season and all season). In sensitivity analysis, patients with different sex, elder and non-elder age, with or without comorbidities and with or without medications had significant decreased risk of CKD occurrence and underwent hemodialysis after vaccination. Moreover, the potential protective effect appeared to be dose-dependent.

CONCLUSIONS

Influenza vaccination decreases the risk of CKD among patients with hypertension and also decrease the risk of receiving renal replacement therapy. Its potential protective effects are dose-dependent and persist during both influenza and noninfluenza seasons.

Temporal convolution attention model for sepsis clinical assistant diagnosis prediction

Sepsis is an organ failure disease caused by an infection acquired in an intensive care unit (ICU), which leads to a high mortality rate. Developing intelligent monitoring and early warning systems for sepsis is a key research area in the field of smart healthcare. Early and accurate identification of patients at high risk of sepsis can help doctors make the best clinical decisions and reduce the mortality rate of patients with sepsis. However, the scientific understanding of sepsis remains inadequate, leading to slow progress in sepsis research. With the accumulation of electronic medical records (EMRs) in hospitals, data mining technologies that can identify patient risk patterns from the vast amount of sepsis-related EMRs and the development of smart surveillance and early warning models show promise in reducing mortality. Based on the Medical Information Mart for Intensive Care Ⅲ, a massive dataset of ICU EMRs published by MIT and Beth Israel Deaconess Medical Center, we propose a Temporal Convolution Attention Model for Sepsis Clinical Assistant Diagnosis Prediction (TCASP) to predict the incidence of sepsis infection in ICU patients. First, sepsis patient data is extracted from the EMRs. Then, the incidence of sepsis is predicted based on various physiological features of sepsis patients in the ICU. Finally, the TCASP model is utilized to predict the time of the first sepsis infection in ICU patients. The experiments show that the proposed model achieves an area under the receiver operating characteristic curve (AUROC) score of 86.9% (an improvement of 6.4% ) and an area under the precision-recall curve (AUPRC) score of 63.9% (an improvement of 3.9% ) compared to five state-of-the-art models.

A Retrospective Study of Staphylococcus aureus Bacteremia in a Tertiary Hospital and Factors Associated with Mortality

Staphylococcus aureus bacteremia (SAB) is a severe infection frequently associated with significant morbidity and mortality. Recent studies have shown that SAB mortality has decreased during the last decades. However, about 25% of patients suffering from the disease will ultimately die. Hence, there is an urgent need for more timely and efficient treatment of patients with SAB. The aim of the present study was to retrospectively evaluate a cohort of SAB patients hospitalized in a tertiary hospital and to identify factors independently associated with mortality. All 256 SAB patients hospitalized from January 2005 to December 2021 in the University Hospital of Heraklion, Greece, were evaluated. Their median age was 72 years, while 101 (39.5%) were female. Most SAB patients were cared for in medical wards (80.5%). The infection was community-acquired in 49.5%. Among all strains 37.9% were methicillin-resistant S. aureus (MRSA), however, definite treatment with an antistaphylococcal penicillin was given only in 22% of patients. Only 14.4% of patients had a repeat blood culture after the initiation of antimicrobial treatment. Infective endocarditis was present in 8%. In-hospital mortality has reached 15.9%. Female gender, older age, higher McCabe score, previous antimicrobial use, presence of a central venous catheter, neutropenia, severe sepsis, septic shock, and MRSA SAB were positively associated with in-hospital mortality, while monomicrobial bacteremia was negatively associated. The multivariate logistic regression model identified only severe sepsis (p = 0.05, odds ratio = 12.294) and septic shock (p = 0.007, odds ratio 57.18) to be independently positively associated with in-hospital mortality. The evaluation revealed high rates of inappropriate empirical antimicrobial treatment and non-adherence to guidelines, as shown, by the lack of repeat blood cultures. These data underline the urgent need for interventions with antimicrobial stewardship, increased involvement of infectious diseases physicians, educational sessions, and creation and implementation of local guidelines for improvement of the necessary steps for timely and efficient SAB treatment. Optimization of diagnostic techniques is needed to overcome challenges such as heteroresistance that may affect treatment. Clinicians should be aware of the factors associated with mortality in patients with SAB to identify those who are at a higher risk and optimize medical management.

Comparison of presepsin and Mid-regional pro-adrenomedullin in the diagnosis of sepsis or septic shock: a systematic review and meta-analysis

BACKGROUND

The early diagnosis of sepsis is hampered by the lack of reliable laboratory measures. There is growing evidence that presepsin and Mid-regional pro-adrenomedullin (MR-proADM) are promising biomarkers in the diagnosis of sepsis. This study was conducted to evaluate and compare the diagnostic value of MR-proADM and presepsin in sepsis patients.

METHODS

We searched Web of Science, PubMed, Embase, China national knowledge infrastructure, and Wanfang up to 22th July, 2022, for studies evaluating the diagnosis performance of presepsin and MR-proADM in adult sepsis patients. Risk of bias was assessed using quadas-2. Pooled sensitivity and specificity were calculated using bivariate meta-analysis. Meta-regression and subgroup analysis were used to find source of heterogeneity.

RESULTS

A total of 40 studies were eventually selected for inclusion in this meta-analysis, including 33 for presepsin and seven for MR-proADM. Presepsin had a sensitivity of 0.86 (0.82-0.90), a specificity of 0.79 (0.71-0.85), and an AUC of 0.90 (0.87-0.92). The sensitivity of MR-proADM was 0.84 (0.78-0.88), specificity was 0.86 (0.79-0.91), and AUC was 0.91 (0.88-0.93). The profile of control group, population, and standard reference may be potential sources of heterogeneity.

CONCLUSIONS

This meta-analysis demonstrated that presepsin and MR-proADM exhibited high accuracy (AUC ≥ 0.90) in the diagnosis of sepsis in adults, with MR-proADM showing significantly higher accuracy than presepsin.

Cytokine Biomarker Phenotype for Early Prediction and Triage of Sepsis in Blunt Trauma Patients

BACKGROUND

Altered levels of inflammatory markers secondary to severe trauma present a major problem to physicians and are prone to interfering with the clinical identification of sepsis events. This study aimed to establish the profiles of cytokines in trauma patients to characterize the nature of immune responses to sepsis, which might enable early prediction and individualized treatments to be developed for targeted intervention.

METHODS

A 15-plex human cytokine magnetic bead assay system was used to measure analytes in citrated plasma samples. Analysis of the kinetics of these cytokines was performed in 40 patients with severe blunt trauma admitted to our trauma center between March 2016 and February 2017, with an Injury Severity Score (ISS) greater than 20 with regard to sepsis (Sepsis-3) over a 14-d time course.

RESULTS

In total, the levels of six cytokines were altered in trauma patients across the 1-, 3-, 5-, 7-, and 14-d time points. Additionally, IL-6, IL-10, IL-15, macrophage derived chemokine (MDC), GRO, sCD40 L, granulocyte colony-stimulating factor (G-CSF), and fibroblast growth factor (FGF)-2 levels could be used to provide a significant discrimination between sepsis and nonsepsis patients at day 3 and afterward, with an area under the curve (AUC) of up to 0.90 through a combined analysis of the eight biomarkers (P < 0.001). Event-related analysis demonstrated 1.5- to 4-fold serum level changes for these cytokines within 72 h before clinically apparent sepsis.

CONCLUSIONS

Cytokine profiles demonstrate a high discriminatory ability enabling the timely identification of evolving sepsis in trauma patients. These abrupt changes enable sepsis to be detected up to 72 h before clinically overt deterioration. Defining cytokine release patterns that distinguish sepsis risk from trauma patients might enable physicians to initiate timely treatment and reduce mortality. Large prospective studies are needed to validate and operationalize the findings.

TRIAL REGISTRATION

Clinicaltrials, NCT01713205. Registered October 22, 2012, https://register.

CLINICALTRIALS

gov/NCT01713205.

Infection or Inflammation: Are Uncomplicated Acute Appendicitis, Acute Cholecystitis, and Acute Diverticulitis Infectious Diseases?

Background: It is recognized increasingly that common surgical infections of the peritoneal cavity may be treated with antibiotic agents alone, or source control surgery with short-course antimicrobial therapy. By extension, testable hypotheses have emerged that such infections may not actually be infectious diseases, but rather represent inflammation that can be treated successfully with neither surgery nor antibiotic agents. The aim of this review is to examine extant data to determine which of uncomplicated acute appendicitis (uAA), uncomplicated acute calculous cholecystitis (uACC), or uncomplicated mild acute diverticulitis (umAD) might be amenable to management using supportive therapy alone, consistent with the principles of antimicrobial stewardship. Methods: Review of pertinent English-language literature and expert opinion. Results: Only two small trials have examined whether uAA can be managed with observation and supportive therapy alone, one of which is underpowered and was stopped prematurely because of challenging patient recruitment. Data are insufficient to determine the safety and efficacy of non-antibiotic therapy of uAA. Uncomplicated acute calculous cholecystitis is not primarily an infectious disease; infection is a secondary phenomenon. Even when bactibilia is present, there is no high-quality evidence to suggest that mild disease should be treated with antibiotic agents. There is evidence to indicate that antibiotic prophylaxis is indicated for urgent/emergency cholecystectomy for uACC, but not in the post-operative period. Uncomplicated mild acute diverticulitis, generally Hinchey 1a or 1b in current nomenclature, does not benefit from antimicrobial agents based on multiple clinical studies. The implication is that umAD is inflammatory and not an infectious disease. Non-antimicrobial management is reasonable. Conclusions: Among the considered disease entities, the evidence is strongest that umAD is not an infectious disease and can be treated without antibiotic agents, intermediate regarding uACC, and lacking for uAA. A plausible hypothesis is that these inflammatory conditions are related to disruption of the normal microbiome, resulting in dysbiosis, which is defined as an imbalance of the natural microflora, especially of the gut, that is believed to contribute to a range of conditions of ill health. As for restorative pre- or probiotic therapy to reconstitute the microbiome, no recommendation can be made in terms of treatment, but it is not recommended for prevention of primary or recurrent disease.

Extracellular ATP: A powerful inflammatory mediator in the central nervous system

Nucleotides play a crucial role in extracellular signaling across species boundaries. All the three kingdoms of life (Bacteria, Archea and Eukariota) are responsive to extracellular ATP (eATP) and many release this and other nucleotides. Thus, eATP fulfills different functions, many related to danger-sensing or avoidance reactions. Basically all living organisms have evolved sensors for eATP and other nucleotides with very different affinity and selectivity, thus conferring a remarkable plasticity to this signaling system. Likewise, different intracellular transduction systems were associated during evolution to different receptors for eATP. In mammalian evolution, control of intracellular ATP (iATP) and eATP homeostasis has been closely intertwined with that of Ca²⁺, whether in the extracellular milieu or in the cytoplasm, establishing an inverse reciprocal relationship, i.e. high extracellular Ca²⁺ levels are associated to negligible eATP, while low intracellular Ca²⁺ levels are associated to high eATP concentrations. This inverse relationship is crucial for the messenger functions of both molecules. Extracellular ATP is sensed by specific plasma membrane receptors of widely different affinity named P2 receptors (P2Rs) of which 17 subtypes are known. This confers a remarkable plasticity to P2R signaling. The central nervous system (CNS) is a privileged site for purinergic signaling as all brain cell types express P2Rs. Accruing evidence suggests that eATP, in addition to participating in synaptic transmission, also plays a crucial homeostatic role by fine tuning microglia, astroglia and oligodendroglia responses. Drugs modulating the eATP concentration in the CNS are likely to be the new frontier in the therapy of neuroinflammation. This article is part of the Special Issue on 'Purinergic Signaling: 50 years'.

Complicated appendicitis wrongly diagnosed as nonspecific diarrhea: ways to decrease this continuous threat

BACKGROUND

The diagnostic assessment of right lower quadrant pain in children and adolescents is still a challenge. The aim of this study was to analyze the cases of complicated appendicitis wrongly diagnosed as nonspecific diarrhea, and based on the information obtained suggest a clear and simple policy in order to decrease misdiagnosis in the future.

METHODS

Three groups of patients were analyzed: children who underwent appendectomy (group 1); those with gastroenteritis (group 2), and those who underwent appendectomy following hospitalization under the wrong diagnosis of gastroenteritis (group 3).

RESULTS

Group 3 presented a more prolonged and complicated clinical course, higher fever, diffuse abdominal pain, repeat vomiting, higher C-reactive protein values, longer surgery duration and recovery.

CONCLUSIONS

When the etiology of right lower quadrant abdominal pain is not immediately evident and associated with atypical diarrhea, high fever, repeat vomiting, and significantly increased CRP values, early surgical consultation is required. If the clinical findings are unclear, an abdominal US should be performed as soon as possible. A limited abdominal computed tomography scan CT should follow those cases not resolved by history, physical examination, blood tests, and abdominal ultrasound.

Development and validation of a patient-specific model to predict postoperative SIRS in older patients: A two-center study

Introduction

Postoperative systemic inflammatory response syndrome (SIRS) is common in surgical patients especially in older patients, and the geriatric population with SIRS is more susceptible to sepsis, MODS, and even death. We aimed to develop and validate a model for predicting postoperative SIRS in older patients.

Methods

Patients aged ≥65 years who underwent general anesthesia in two centers of Third Affiliated Hospital of Sun Yat-sen University from January 2015 to September 2020 were included. The cohort was divided into training and validation cohorts. A simple nomogram was developed to predict the postoperative SIRS in the training cohort using two logistic regression models and the brute force algorithm. The discriminative performance of this model was determined by area under the receiver operating characteristics curve (AUC). The external validity of the nomogram was assessed in the validation cohort.

Results

A total of 5,904 patients spanning from January 2015 to December 2019 were enrolled in the training cohort and 1,105 patients from January 2020 to September 2020 comprised the temporal validation cohort, in which incidence rates of postoperative SIRS were 24.6 and 20.2%, respectively. Six feature variables were identified as valuable predictors to construct the nomogram, with high AUCs (0.800 [0.787, 0.813] and 0.822 [0.790, 0.854]) and relatively balanced sensitivity (0.718 and 0.739) as well as specificity (0.718 and 0.729) in both training and validation cohorts. An online risk calculator was established for clinical application.

Conclusion

We developed a patient-specific model that may assist in predicting postoperative SIRS among the aged patients.

The Key Drivers of Brain Injury by Systemic Inflammatory Responses after Sepsis: Microglia and Neuroinflammation

Sepsis is a leading cause of intensive care unit admission and death worldwide. Most surviving patients show acute or chronic mental disorders, which are known as sepsis-associated encephalopathy (SAE). Although accumulating studies in the past two decades focused on the pathogenesis of SAE, a systematic review of retrospective studies which exclusively focuses on the inflammatory mechanisms of SAE has been lacking yet. This review summarizes the recent advance in the field of neuroinflammation and sheds light on the activation of microglia in SAE. Activation of microglia predominates neuroinflammation. As the gene expression profile changes, microglia show heterogeneous characterizations throughout all stages of SAE. Here, we summarize the systemic inflammation following sepsis and also the relationship of microglial diversity and neuroinflammation. Moreover, a collection of neuroinflammation-related dysfunction has also been reviewed to illustrate the possible mechanisms for SAE. In addition, promising pharmacological or non-pharmacological therapeutic strategies, especially those which target neuroinflammation or microglia, are also concluded in the final part of this review. Collectively, clarification of the vital relationship between neuroinflammation and SAE-related mental disorders would significantly improve our understanding of the pathophysiological mechanisms in SAE and therefore provide potential targets for therapies of SAE aimed at inhibiting neuroinflammation.

Ethical Aspects of Personalized Research and Management of Systemic Inflammatory Response Syndrome (SIRS) in Children

Systemic inflammatory response syndrome (SIRS) is a life-threatening condition with nonspecific symptoms. Because of that, defining a targeted therapy against SIRS in children and adults remains a challenge. The identification of diagnostic patterns from individualized immuneprofiling can lead to development of a personalized therapy. The aim of this study was to identify and analyze ethical issues associated with personalized research and therapy for SIRS in pediatric populations. We conducted an ethical analysis based on a principled approach according to Beauchamp and Childress' four bioethical principles. Relevant information for the research objectives was extracted from a systematic literature review conducted in the scientific databases PubMed, Embase and Web of Science. We searched for pertinent themes dealing with at least one of the four bioethical principles: "autonomy", "non-maleficence", "beneficence" and "justice". 48 publications that met the research objectives were included in the thorough analysis, structured and discussed in a narrative synthesis. From the analysis of the results, it has emerged that traditional paradigms of patient's autonomy and physician paternalism need to be reexamined in pediatric research. Standard information procedures and models of informed consent should be reconsidered as they do not accommodate the complexities of pediatric omics research.

Factors associated with occurrence and severity of acute kidney injury in patients with Sepsis - A retrospective database study

PURPOSE

Sepsis remains the most common cause of acute kidney injury (AKI) and is associated with a high mortality. This study aims to identify laboratory, clinical and demographic factors that are associated with the different stages of AKI in sepsis.

METHODS

We studied patients >18 years who met Sepsis-3 criteria between July 10, 2009 and September 7, 2019 using ordinal logistic regression to determine the factors associated with different stages of AKI. Sensitivity analyses for development of any stage vs no AKI and, separately, the factors associated with receipt of kidney replacement therapy were also done.

RESULTS

Of 31,228 patients meeting Sepsis-3 criteria, 4684 (15%) developed AKI. Of the AKI patients, 53% were KDIGO stage 1, 9% stage 2, and 37% stage 3, with 27% of AKI patients receiving kidney replacement therapy (Stage 3b). Several comorbidities, mechanical ventilation, and pre-sepsis creatinine levels were associated with AKI occurrence and severity. Positive blood culture was associated with a higher risk (OR 1.10 [1.06, 1.15], p < 0.001), while positive respiratory, urine, and wound cultures were associated with lower risks of developing AKI and with lower severity.

CONCLUSION

Presepsis creatinine levels, mechanical ventilation, comorbidities, and positive blood cultures were associated with AKI.

An immune dysfunction score for stratification of patients with acute infection based on whole-blood gene expression

Dysregulated host responses to infection can lead to organ dysfunction and sepsis, causing millions of global deaths each year. To alleviate this burden, improved prognostication and biomarkers of response are urgently needed. We investigated the use of whole-blood transcriptomics for stratification of patients with severe infection by integrating data from 3149 samples from patients with sepsis due to community-acquired pneumonia or fecal peritonitis admitted to intensive care and healthy individuals into a gene expression reference map. We used this map to derive a quantitative sepsis response signature (SRSq) score reflective of immune dysfunction and predictive of clinical outcomes, which can be estimated using a 7- or 12-gene signature. Last, we built a machine learning framework, SepstratifieR, to deploy SRSq in adult and pediatric bacterial and viral sepsis, H1N1 influenza, and COVID-19, demonstrating clinically relevant stratification across diseases and revealing some of the physiological alterations linking immune dysregulation to mortality. Our method enables early identification of individuals with dysfunctional immune profiles, bringing us closer to precision medicine in infection.

Classifying sepsis from photoplethysmography

Sepsis is a life-threatening organ dysfunction. It is caused by a dysregulated immune response to an infection and is one of the leading causes of death in the intensive care unit (ICU). Early detection and treatment of sepsis can increase the survival rate of patients. The use of devices such as the photoplethysmograph could allow the early evaluation in addition to continuous monitoring of septic patients. The aim of this study was to verify the possibility of detecting sepsis in patients from whom the photoplethysmographic signal was acquired via a pulse oximeter. In this work, we developed a deep learning-based model for sepsis identification. The model takes a single input, the photoplethysmographic signal acquired by pulse oximeter, and performs a binary classification between septic and nonseptic samples. To develop the method, we used MIMIC-III database, which contains data from ICU patients. Specifically, the selected dataset includes 85 septic subjects and 101 control subjects. The PPG signals acquired from these patients were segmented, processed and used as input for the developed model with the aim of identifying sepsis. The proposed method achieved an accuracy of 76.37% with a sensitivity of 70.95% and a specificity of 81.04% on the test set. As regards the ROC curve, the Area Under Curve reached a value of 0.842. The results of this study indicate how the plethysmographic signal can be used as a warning sign for the early detection of sepsis with the aim of reducing the time for diagnosis and therapeutic intervention. Furthermore, the proposed method is suitable for integration in continuous patient monitoring.

Development and implementation of a customised rapid syndromic diagnostic test for severe pneumonia

Background: The diagnosis of pneumonia has been hampered by a reliance on bacterial cultures which take several days to return a result, and are frequently negative. In critically ill patients this leads to the use of empiric, broad-spectrum antimicrobials and compromises good antimicrobial stewardship. The objective of this study was to establish the performance of a syndromic molecular diagnostic approach, using a custom TaqMan array card (TAC) covering 52 respiratory pathogens, and assess its impact on antimicrobial prescribing. Methods: The TAC was validated against a retrospective multi-centre cohort of broncho-alveolar lavage samples. The TAC was assessed prospectively in patients undergoing investigation for suspected pneumonia, with a comparator cohort formed of patients investigated when the TAC laboratory team were unavailable. Co-primary outcomes were sensitivity compared to conventional microbiology and, for the prospective study, time to result. Metagenomic sequencing was performed to validate findings in prospective samples. Antibiotic free days (AFD) were compared between the study cohort and comparator group. Results: 128 stored samples were tested, with sensitivity of 97% (95% confidence interval (CI) 88-100%). Prospectively, 95 patients were tested by TAC, with 71 forming the comparator group. TAC returned results 51 hours (interquartile range 41-69 hours) faster than culture and with sensitivity of 92% (95% CI 83-98%) compared to conventional microbiology. 94% of organisms identified by sequencing were detected by TAC. There was a significant difference in the distribution of AFDs with more AFDs in the TAC group (p=0.02). TAC group were more likely to experience antimicrobial de-escalation (odds ratio 2.9 (95%1.5-5.5)). Conclusions: Implementation of a syndromic molecular diagnostic approach to pneumonia led to faster results, with high sensitivity and impact on antibiotic prescribing.

Clinical importance and characteristic features of secondary culture-negative sepsis after surgery due to abdominal infection: A retrospective study

PURPOSE

Herein, we identified whether the clinical outcomes differ according to secondary culture results in postoperative sepsis patients and determined the predictors of culture-negative sepsis after abdominal surgery based on the secondary culture results.

METHODS

Patients who admitted to the intensive care unit(ICU) after surgery due to abdominal infection and diagnosed with postoperative sepsis were included. Culture tests were obtained from body fluids and drains. Primary culture test was performed immediately after surgery, and secondary culture test was performed within 48 h to 7days after surgery. The participants were divided into the culture-positive sepsis(CPSS) and the culture-negative sepsis group(CNSS) according to culture positivity, and the clinical outcomes were compared. The predisposing factors of secondary CNSS were determined using multiple logistic regression analysis.

RESULTS

Among 83 participants, 51 patients (61.4%) showed secondary culture-positivity(2'CPSS) and 32 patients (38.6%) showed secondary culture-negativity(2'CNSS). ICU mortality and in-hospital mortality were not different between two groups, but the length of ICU and hospital stay were significantly longer in 2'CPSS. In multivariate analysis, non-bowel surgery [odds ratio(OR) = 6.934, 95% confidence interval(CI):1.609-29.884, p=0.009], no diabetes (OR = 4.027,95%CI:1.161-13.973, p=0.028), and the prolonged administration of preoperative antibiotics (OR = 1.187,95%CI:1.023-1.377, p=0.024) were revealed as significant predisposing factors of 2'CNSS.

CONCLUSION

Mortality showed no difference according to secondary culture positivity in postoperative sepsis patients after abdominal surgery. If a patient underwent non-bowel surgery or had no diabetes or administered preoperative antibiotics for more than 3 days, the physician should pay more attention to clinical deterioration, even if the seconday culture results are negative.

Cardiorenal syndrome in the pediatric population: A systematic review

The concept of cardiorenal syndrome (CRS) is derived from the crosstalk between the heart and kidneys in pathological conditions. Despite the rising importance of CRS, there is a paucity of information on the understanding of its pathophysiology and management, increasing both morbidity and mortality for patients. This review summarizes the existing conceptual pathophysiology of different types of CRS and delves into the associated therapeutic modalities with a focus on pediatric cases. Prospective or retrospective observational studies, comparative studies, case reports, case-control, and cross-sectional studies that include pediatric patients with CRS were included in this review. Literature was searched using PubMed, EMBASE, and Google Scholar with keywords including "cardio-renal syndrome, type," "reno-cardio syndrome," "children," "acute kidney injury," and "acute decompensated heart failure" from January 2000 to January 2021. A total of 14 pediatric studies were ultimately included and analyzed, comprising a combined population of 3608 children of which 32% had CRS. Of the 14 studies, 57% were based on type 1 CRS, 14% on types 2 and 3 CRS, and 7% were on types 4 and 5 CRS. The majority of included studies were prospective cohort, although a wide spectrum was observed in terms of patient age, comorbidities, etiologies, and treatment strategies. Commonly observed comorbidities in CRS type 1 were hematologic, oncologic, cardiology-related side effects, muscular dystrophy, and pneumonia/bronchiolitis. CRS, particularly type 1, is prevalent in children and has a significant risk of mortality. The current treatment regimen primarily involves diuretics, extracorporeal fluid removal, and treatment of underlying etiologies and comorbidities.

Preventive measures significantly reduced the risk of nosocomial infection in elderly inpatients during the COVID-19 pandemic

In December 2019, there was an outbreak of pneumonia of unknown causes in Wuhan, China. The etiological pathogen was identified to be a novel coronavirus, named severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19). The number of infected patients has markedly increased since the 2019 outbreak and COVID-19 has also proven to be highly contagious. In particular, the elderly are among the group of patients who are the most susceptible to succumbing to COVID-19 within the general population. Cross-infection in the hospital is one important route of SARS-CoV-2 transmission, where elderly patients are more susceptible to nosocomial infections due to reduced immunity. Therefore, the present study was conducted to search for ways to improve the medical management workflow in geriatric departments to ultimately reduce the risk of nosocomial infection in elderly inpatients. The present observational retrospective cohort study analysed elderly patients who were hospitalised in the Geriatric Department of the First Affiliated Hospital with Nanjing Medical University (Nanjing, China). A total of 4,066 elderly patients, who were admitted between January and March in 2019 and 2020 and then hospitalised for >48 h were selected. Among them, 3,073 (75.58%) patients hospitalised from January 2019 to March 2019 were allocated into the non-intervention group, whereas the remaining 933 (24.42%) patients hospitalised from January 2020 to March 2020 after the COVID-19 outbreak were allocated into the intervention group. Following multivariate logistic regression analysis, the risk of nosocomial infections was found to be lower in the intervention group compared with that in the non-intervention group. After age stratification and adjustment for sex, chronic disease, presence of malignant tumour and trauma, both inverse probability treatment weighting and standardised mortality ratio revealed a lower risk of nosocomial infections in the intervention group compared with that in the non-intervention group. To rule out interference caused by changes in the community floating population and social environment during this 1-year study, 93 long-stay patients in stable condition were selected as a subgroup based on 4,066 patients. The so-called floating population refers to patients who have been in hospital for <2 years. Patients aged ≥65 years were included in the geriatrics program. The incidence of nosocomial infections during the epidemic prevention and control period (24 January 2020 to 24 March 2020) and the previous period of hospitalisation (24 January 2019 to 24 March 2019) was also analysed. In the subgroup analysis, a multivariate analysis was also performed on 93 elderly patients who experienced long-term hospitalisation. The risk of nosocomial and pulmonary infections was found to be lower in the intervention group compared with that in the non-intervention group. During the pandemic, the geriatric department took active preventative measures. However, whether these measures can be normalised to reduce the risk of nosocomial infections among elderly inpatients remain unclear. In addition, the present study found that the use of an indwelling gastric tube is an independent risk factor of nosocomial pulmonary infection in elderly inpatients. However, nutritional interventions are indispensable for the long-term wellbeing of patients, especially for those with dysphagia in whom an indwelling gastric tube is the most viable method of providing enteral nutrition. To conclude, the present retrospective analysis of the selected cases showed that enacting preventative and control measures resulted in the effective control of the incidence of nosocomial infections.

Parenteral Vitamin C in Patients with Severe Infection: A Systematic Review

BACKGROUND: Inflammation and oxidative damage caused by severe infections may be attenuated by vitamin C. METHODS: We conducted a systematic review of randomized controlled trials (RCTs) of parenteral vitamin C as combined therapy or monotherapy versus no parenteral vitamin C administered to adults hospitalized with severe infection. The primary outcome was mortality. We performed random-effects meta-analyses and assessed certainty in effect estimates. RESULTS: Of 1547 citations, 41 RCTs (n = 4915 patients) were eligible for inclusion. Low-certainty evidence suggested that vitamin C may reduce in-hospital mortality (21 RCTs, 2762 patients; risk ratio, 0.88 [95% confidence interval (CI), 0.73 to 1.06]), 30-day mortality (24 RCTs, 3436 patients; risk ratio, 0.83 [95% CI, 0.71 to 0.98]), and early mortality (before hospital discharge or 30 days; 34 RCTs, 4366 patients; risk ratio, 0.80 [95% CI, 0.68 to 0.93]). Effects were attenuated in sensitivity analyses limited to published blinded trials at low risk-of-bias (in-hospital mortality: risk ratio, 1.07 [95% CI, 0.92 to 1.24], moderate certainty; 30-day mortality: risk ratio, 0.88 [95% CI, 0.71 to 1.10], low certainty; and early mortality: risk ratio, 0.88 [95% CI, 0.73 to 1.06], low certainty). For 90-day mortality, all trials had low risk-of-bias; moderate-certainty evidence suggested harm (five RCTs, 1722 patients; risk ratio, 1.07 [95% CI, 0.94 to 1.21]). Moderate-certainty evidence suggested an increased risk of hypoglycemia (risk ratio, 1.20 [95% CI, 0.69 to 2.08]). Effects on other secondary outcomes were mixed and informed by low-certainty evidence. No credible subgroup effects were observed for mortality related to cointerventions (monotherapy vs. combined therapy), dose, or type of infection (Covid-19 vs. other). CONCLUSIONS: Overall, evidence from RCTs does not establish a survival benefit for vitamin C in patients with severe infection. (PROSPERO number, CRD42020209187.)