Sepsis-Related Mortality Rates and Trends Based on Site of Infection

A Comparative Review of Cytokines and Cytokine Targeting in Sepsis: From Humans to Horses

With the emergence of COVID-19, there is an increased focus in human literature on cytokine production, the implications of cytokine overproduction, and the development of novel cytokine-targeting therapies for use during sepsis. In addition to viral infections such as COVID-19, bacterial infections resulting in exposure to endotoxins and exotoxins in humans can also lead to sepsis, resulting in organ failure and death. Like humans, horses are exquisitely sensitive to endotoxin and are among the veterinary species that develop clinical sepsis similar to humans. These similarities suggest that horses may serve as a naturally occurring model of human sepsis. Indeed, evidence shows that both species experience cytokine dysregulation, severe neutropenia, the formation of neutrophil extracellular traps, and decreased perfusion parameters during sepsis. Sepsis treatments that target cytokines in both species include hemoperfusion therapy, steroids, antioxidants, and immunomodulation therapy. This review will present the shared cytokine physiology across humans and horses as well as historical and updated perspectives on cytokine-targeting therapy. Finally, this review will discuss the potential benefits of increased knowledge of equine cytokine mechanisms and their potential positive impact on human medicine.

Association of 28-day mortality with non-high-density lipoprotein cholesterol and the high-density lipoprotein cholesterol ratio (NHHR) in patients with sepsis: Results of MIMIC-IV database analysis

BACKGROUND

The correlation between lipid profiles and sepsis has received increasing attention. The ratio of non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol (NHHR) is one of the key lipid profiles. However, in-depth exploration of the correlation between NHHR and the mortality risk of patients with sepsis is limited.

METHODS

Data from the MIMIC-IV (v2.2) database, we review the NHHR relevance and the sepsis severity index using Spearman's correlation analysis. Additionally, we research NHHR associated with sepsis patients' survival rate of 28 days using Cox regression analyses of continuous and categorical models. To further validate our findings, we conducted subgroup and sensitivity analyses.

RESULTS

The study involved 3,142 patients diagnosed with sepsis, according to 28 days after in-hospital survival condition, divided into two groups. In this study, 2932 patients were in the survival group and 210 patients died within 28 days (mortality group). Of note, the mean NHHR of patients in the mortality group exceeded that of the survival group (3.5 vs. 2.9). Additionally, NHHR was positively correlated with the severity index. After adjusting for demographic and laboratory data, an increased NHHR was positively correlated with higher sepsis mortality risk (OR = 1.06; 95% CI: 1.02-1.11; P = 0.013). Subgroup analysis shown the same results. Contributors were be categorized into two groups based on NHHR levels, with a threshold of 2.61. Contrast the mortality risk between low-NHHR group and high-NHHR group, high-NHHR show greater mortality risk on 28-day, 60-day, 90-day, in ICU, and in hospital.

CONCLUSION

Elevated NHHR is to be correlated with an increased risk of mortality in patients with sepsis. Further research on NHHR may contribute to advancements in sepsis prevention and treatment.

Sepsis-related mortality: long-term trends in Northeastern Italy, including pandemic years

BACKGROUND

Global estimates of sepsis mortality are based on multiple causes of death (MCOD, any mention of the condition on death certificates); however, MCOD data are sparse and mainly referring to the pre-pandemic period.

OBJECTIVES

To investigate recent trends in sepsis-related mortality, associated sites of infection, and comorbidities in Veneto (Northeastern Italy).

METHODS

Mortality records from 2008 to 2022 were extracted, and sepsis-related mortality was assessed based both on the underlying cause of death (UCOD) and on MCOD. The average annual percent change in age-standardised rates was estimated by join point regression through the whole study period. MCOD records were investigated to retrieve infection sites and comorbidities.

RESULTS

Sepsis was mentioned in 63,479 death certificates, growing from 4.9% out of all deaths in 2008 to 12.9% in 2022. Age-standardised mortality rates increased yearly by 8.2% (95%CI 2.1-14.7%) based on the UCOD and by 5.9% (95%CI 5.3-6.5%) based on MCOD. Sharp peaks in monthly mortality were observed in correspondence with flu epidemics, COVID-19 pandemic waves, and periods of extreme heat. The percentage of sepsis-related deaths associated to urinary tract infections, and with mention of neurodegenerative disorders and chronic kidney disease increased over time.

CONCLUSION

Raised awareness of physicians, ageing of the population, spread of antimicrobial resistance further fuelled by the COVID-19 pandemic are among reasons of increasing sepsis-related mortality in Italy. Continuous monitoring of sepsis by means of MCOD data and other surveillance tools is warranted.

Primary Infection Site as a Predictor of Sepsis Development in Emergency Department Patients

BACKGROUND

Sepsis is a life-threatening condition but predicting its development and progression remains a challenge.

OBJECTIVE

This study aimed to assess the impact of infection site on sepsis development among emergency department (ED) patients.

METHODS

Data were collected from a single-center ED between January 2016 and December 2019. Patient encounters with documented infections, as defined by the Systematized Nomenclature of Medicine-Clinical Terms for upper respiratory tract (URI), lower respiratory tract (LRI), urinary tract (UTI), or skin or soft-tissue infections were included. Primary outcome was the development of sepsis or septic shock, as defined by Sepsis-1/2 criteria. Secondary outcomes included hospital disposition and length of stay, blood and urine culture positivity, antibiotic administration, vasopressor use, in-hospital mortality, and 30-day mortality. Analysis of variance and various different logistic regression approaches were used for analysis with URI used as the reference variable.

RESULTS

LRI was most associated with sepsis (relative risk ratio [RRR] 5.63; 95% CI 5.07-6.24) and septic shock (RRR 21.2; 95% CI 17.99-24.98) development, as well as hospital admission rates (odds ratio [OR] 8.23; 95% CI 7.41-9.14), intensive care unit admission (OR 4.27; 95% CI 3.84-4.74), in-hospital mortality (OR 6.93; 95% CI 5.60-8.57), and 30-day mortality (OR 7.34; 95% CI 5.86-9.19). UTIs were also associated with sepsis and septic shock development, but to a lesser degree than LRI.

CONCLUSIONS

Primary infection sites including LRI and UTI were significantly associated with sepsis development, hospitalization, length of stay, and mortality among patients presenting with infections in the ED.

The Role of Programmed Cell Death 1/Programmed Death Ligand 1 (PD-1/PD-L1) Axis in Sepsis-Induced Apoptosis

Background and Objectives: Sepsis involves a dysregulated host response, characterized by simultaneous immunosuppression and hyperinflammation. Initially, there is the release of pro-inflammatory factors and immune system dysfunction, followed by persistent immune paralysis leading to apoptosis. This study investigates sepsis-induced apoptosis and its pathways, by assessing changes in PD-1 and PD-L1 serum levels, CD4+ and CD8+ T cells, and Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE II) severity scores. Materials and Methods: This prospective, observational, single-centre study enrolled 87 sepsis patients admitted to the intensive care unit at the County Emergency Clinical Hospital in Târgu Mureș, Romania. We monitored the parameters on day 1 (the day sepsis or septic shock was diagnosed as per the Sepsis-3 Consensus) and day 5. Results: Our study found a statistically significant variation in the SOFA score for the entirety of the patients between the studied days (p = 0.001), as well as for the studied patient groups: sepsis, septic shock, survivors, and non-survivors (p = 0.001, p = 0.003, p = 0.01, p = 0.03). On day 1, we found statistically significant correlations between CD8+ cells and PD-1 (p = 0.02) and PD-L1 (p = 0.04), CD4+ and CD8+ cells (p < 0.0001), SOFA and APACHE II scores (p < 0.0001), and SOFA and APACHE II scores and PD-L1 (p = 0.001 and p = 0.01). On day 5, we found statistically significant correlations between CD4+ and CD8+ cells and PD-L1 (p = 0.03 and p = 0.0099), CD4+ and CD8+ cells (p < 0.0001), and SOFA and APACHE II scores (p < 0.0001). Conclusions: The reduction in Th CD4+ and Tc CD8+ lymphocyte subpopulations were evident from day 1, indicating that apoptosis is a crucial factor in the progression of sepsis and septic shock. The increased expression of the PD-1/PD-L1 axis impairs costimulatory signalling, leading to diminished T cell responses and lymphopenia, thereby increasing the susceptibility to nosocomial infections.

Development of two multiplex PCR assays for rapid detection of eleven Gram-negative bacteria in children with septicemia

AIM

This study aimed to develop a multiplex PCR assay for simultaneous detection of major Gram-negative etiologies of septicemia and evaluate its performance.

METHODS

Multiplex PCR (mPCR) assays were developed targeting 11 bacterial strains. Species-specific primers were confirmed using known clinical isolates and standard strains. Gradient PCR was performed on each primer against its target bacterial gene to determine its optimal amplification condition. The minimum detectable DNA concentration of the two assays was evaluated by adjusting bacterial DNA concentration to 100 ng/μL and, tenfold serially diluting it up to 10 pg/μL with DNAse-free water. The diagnostic accuracy of mPCR assays was established by subjecting the assays to 60 clinical blood samples.

RESULTS

Two mPCR assays were developed. Optimal primer annealing temperature of 55 °C was established and utilized in the final amplification conditions. The assays detected all targeted bacteria, with a 100 pg minimum detectable DNA concentration. Pathogens were not detected directly from whole blood, but after 4 h and 8 h of incubation, 41% (5/12) and 100% (12/12) of the bacteria were detected in culture fluids, respectively. The assays also identified Salmonella spp. and Klebsiella pneumoniae co-infections and extra pathogens (1 E. coli and 2 K. pneumoniae) compared with culture. The sensitivity and specificity of the mPCR were 100.0% (71.7-100.0) and 98.0% (90.7-99.0), respectively. The area under the ROC curve was 1.00 (1.00-1.00).

CONCLUSIONS

The mPCR assays demonstrated substantial potential as a rapid tool for septicemia diagnosis alongside the traditional blood culture method. Notably, it was able to identify additional isolates, detect co-infections, and efficiently detect low bacterial DNA loads with high sensitivity, implying its value in enhancing efficiency of diagnosis of septicemia.

Survivors of polymicrobial sepsis are refractory to G-CSF-induced emergency myelopoiesis and hematopoietic stem and progenitor cell mobilization

Sepsis survivors exhibit immune dysfunction, hematological changes, and increased risk of infection. The long-term impacts of sepsis on hematopoiesis were analyzed using a surgical model of murine sepsis, resulting in 50% survival. During acute disease, phenotypic hematopoietic stem and progenitor cells (HSPCs) were reduced in the bone marrow (BM), concomitant with increased myeloid colony-forming units and extramedullary hematopoiesis. Upon recovery, BM HSPCs were increased and exhibited normal function in the context of transplantation. To evaluate hematopoietic responses in sepsis survivors, we treated recovered sham and cecal ligation and puncture mice with a mobilizing regimen of granulocyte colony-stimulating factor (G-CSF) at day 20 post-surgery. Sepsis survivors failed to undergo emergency myelopoiesis and HSPC mobilization in response to G-CSF administration. G-CSF is produced in response to acute infection and injury to expedite the production of innate immune cells; therefore, our findings contribute to a new understanding of how sepsis predisposes to subsequent infection.

Impact of Invasive Escherichia Coli Disease on Clinical Outcomes and Medical Resource Utilization Among Asian Patients in the United States

INTRODUCTION

Invasive Escherichia coli disease (IED) can lead to sepsis and death and is associated with a substantial burden. Yet, there is scarce information on the burden of IED in Asian patients.

METHODS

This retrospective study used US hospital data from the PINC AI™ Healthcare database (October 2015-March 2020) to identify IED cases among patients aged ≥ 60 years. IED was defined as a positive E. coli culture in blood or other normally sterile body site (group 1 IED) or positive culture of E. coli in urine with signs of sepsis (group 2 IED). Eligible patients with IED were classified into Asian and non-Asian cohorts based on their reported race. Entropy balancing was used to create cohorts with similar characteristics. Outcomes following IED were descriptively reported in the balanced cohorts.

RESULTS

A total of 646 Asian and 19,127 non-Asian patients with IED were included (median age 79 years; 68% female after balancing). For both cohorts, most IED encounters had community-onset (> 95%) and required hospitalization (Asian 96%, mean duration 6.9 days; non-Asian 95%, mean duration 6.8 days), with frequent admission to intensive care (Asian 35%, mean duration 3.3 days; non-Asian 34%, mean duration 3.5 days), all standardized differences [SD] < 0.20. Compared to non-Asian patients, Asian patients were more likely to be discharged home (54% vs. 43%; SD = 0.22), and less likely to be discharged to a skilled nursing facility (24% vs. 31%; SD = 0.16). In-hospital fatality rates during the IED encounter were similar across cohorts (Asian 9%, non-Asian 10%; SD = 0.01). Most E. coli isolates showed resistance to ≥ 1 antibiotic (Asian 61%; non-Asian 64%) and 36% to ≥ 3 antibiotic classes (all SD < 0.20).

CONCLUSION

IED is associated with a substantial burden, including need for intensive care and considerable mortality, in Asian patients in the USA that is consistent with that observed for non-Asian patients.

Sepsis Stewardship: The Puzzle of Antibiotic Therapy in the Context of Individualization of Decision Making

The main recent change observed in the field of critical patient infection has been universal awareness of the need to make better use of antimicrobials, especially for the most serious cases, beyond the application of simple and effective formulas or rigid protocols. The increase in resistant microorganisms, the quantitative increase in major surgeries and interventional procedures in the highest risk patients, and the appearance of a significant number of new antibiotics in recent years (some very specifically directed against certain mechanisms of resistance and others with a broader spectrum of applications) have led us to shift our questions from "what to deal with" to "how to treat". There has been controversy about how best to approach antibiotic treatment of complex cases of sepsis. The individualized and adjusted dosage, the moment of its administration, the objective, and the selection of the regimen are pointed out as factors of special relevance in a critically ill patient where the frequency of resistant microorganisms, especially among the Enterobacterales group, and the emergence of multiple and diverse antibiotic treatment alternatives have made the appropriate choice of antibiotic treatment more complex, requiring a constant updating of knowledge and the creation of multidisciplinary teams to confront new infections that are difficult to treat. In this article, we have reviewed the phenomenon of the emergence of resistance to antibacterials and we have tried to share some of the ideas, such as stewardship, sparing carbapenems, and organizational, microbiological, pharmacological, and knowledge tools, that we have considered most useful and effective for individualized decision making that takes into account the current context of multidrug resistance. The greatest challenge, therefore, of decision making in this context lies in determining an effective, optimal, and balanced empirical antibiotic treatment.

Limited English Proficiency and Sepsis Mortality by Race and Ethnicity

Importance

Patients with limited English proficiency (LEP) face multiple barriers and are at risk for worse health outcomes compared with patients with English proficiency (EP). In sepsis, a major cause of mortality in the US, the association of LEP with health outcomes is not widely explored.

Objective

To assess the association between LEP and inpatient mortality among patients with sepsis and test the hypothesis that LEP would be associated with higher mortality rates.

Design, Setting, and Participants

This retrospective cohort study of hospitalized patients with sepsis included those who met the Centers for Disease Control and Prevention's sepsis criteria, received antibiotics within 24 hours, and were admitted through the emergency department. Data were collected from the electronic medical records of a large New England tertiary care center from January 1, 2016, to December 31, 2019. Data were analyzed from January 8, 2021, to March 2, 2023.

Exposures

Limited English proficiency, gathered via self-reported language preference in electronic medical records.

Main Outcomes and Measures

The primary outcome was inpatient mortality. The analysis used multivariable generalized estimating equation models with propensity score adjustment and analysis of covariance to analyze the association between LEP and inpatient mortality due to sepsis.

Results

A total of 2709 patients met the inclusion criteria, with a mean (SD) age of 65.0 (16.2) years; 1523 (56.2%) were men and 327 (12.1%) had LEP. Nine patients (0.3%) were American Indian or Alaska Native, 101 (3.7%) were Asian, 314 (11.6%) were Black, 226 (8.3%) were Hispanic, 38 (1.4%) were Native Hawaiian or Other Pacific Islander or of other race or ethnicity, 1968 (72.6%) were White, and 6 (0.2%) were multiracial. Unadjusted mortality included 466 of 2382 patients with EP (19.6%) and 69 of 327 with LEP (21.1%). No significant difference was found in mortality odds for the LEP compared with EP groups (odds ratio [OR], 1.12 [95% CI, 0.88-1.42]). When stratified by race and ethnicity, odds of inpatient mortality for patients with LEP were significantly higher among the non-Hispanic White subgroup (OR, 1.76 [95% CI, 1.41-2.21]). This significant difference was also present in adjusted analyses (adjusted OR, 1.56 [95% CI, 1.02-2.39]). No significant differences were found in inpatient mortality between LEP and EP in the racial and ethnic minority subgroup (OR, 0.99 [95% CI, 0.63-1.58]; adjusted OR, 0.91 [95% CI, 0.56-1.48]).

Conclusions and Relevance

In a large diverse academic medical center, LEP had no significant association overall with sepsis mortality. In a subgroup analysis, LEP was associated with increased mortality among individuals identifying as non-Hispanic White. This finding highlights a potential language-based inequity in sepsis care. Further studies are needed to understand drivers of this inequity, how it may manifest in other diverse health systems, and to inform equitable care models for patients with LEP.

Surviving Sepsis After Burn Campaign

INTRODUCTION

The Surviving Sepsis Campaign was developed to improve outcomes for all patients with sepsis. Despite sepsis being the primary cause of death after thermal injury, burns have always been excluded from the Surviving Sepsis efforts. To improve sepsis outcomes in burn patients, an international group of burn experts developed the Surviving Sepsis After Burn Campaign (SSABC) as a testable guideline to improve burn sepsis outcomes.

METHODS

The International Society for Burn Injuries (ISBI) reached out to regional or national burn organizations to recommend members to participate in the program. Two members of the ISBI developed specific "patient/population, intervention, comparison and outcome" (PICO) questions that paralleled the 2021 Surviving Sepsis Campaign [1]. SSABC participants were asked to search the current literature and rate its quality for each topic. At the Congress of the ISBI, in Guadalajara, Mexico, August 28, 2022, a majority of the participants met to create "statements" based on the literature. The "summary statements" were then sent to all members for comment with the hope of developing an 80% consensus. After four reviews, a consensus statement for each topic was created or "no consensus" was reported.

RESULTS

The committee developed sixty statements within fourteen topics that provide guidance for the early treatment of sepsis in burn patients. These statements should be used to improve the care of sepsis in burn patients. The statements should not be considered as "static" comments but should rather be used as guidelines for future testing of the best treatments for sepsis in burn patients. They should be updated on a regular basis.

CONCLUSION

Members of the burn community from the around the world have developed the Surviving Sepsis After Burn Campaign guidelines with the goal of improving the outcome of sepsis in burn patients.

Risk Factors and the Impact of Multidrug-Resistant Bacteria on Community-Acquired Urinary Sepsis

Risk factors for multidrug-resistant bacteria (MDRB) in nosocomial urinary tract infection (UTI) have been widely studied. However, these risk factors have not been analyzed in community-acquired urinary sepsis (US), nor have its outcomes been studied. The aim of our study is to determine risk factors for MDRB in community-acquired US and its influence on outcomes. Prospective observational study of patients with community-acquired US admitted to a university hospital. We compared epidemiological and clinical variables and outcomes of US due to MDRB and non-MDRB. Independent risk factors for MDRB were analyzed using logistic regression. A total of 193 patients were included, 33.7% of them with US due to MDRB. The median age of patients was 82 years. Hospital mortality was 17.6%, with no difference between the MDRB and non-MDRB groups. The length of hospital stay was 5 (4-8) days, with a non-significant tendency to longer hospital stays in the MDRB group (6 (4-10) vs. 5 (4-8) days, p = 0.051). Healthcare-associated US was found to be an independent risk factor for MDR bacteria by multivariate analysis. In conclusion, the impact of MDR bacteria on the outcomes of community-acquired urinary sepsis was mild. Healthcare-associated US was an independent risk factor for MDR bacteria.