Culture-Negative and Culture-Positive Sepsis: A Comparison of Characteristics and Outcomes

Pathogen detection by targeted next-generation sequencing test in adult hematological malignancies patients with suspected infections

Background

Infections in patients with hematological malignancies (HM) are a significant cause of morbidity and mortality. Timely and effective empirical anti-infective treatment can reduce the infection-related mortality rate. Targeted next-generation sequencing (tNGS) offers a rapid diagnostic approach for identifying diverse pathogens in these patients. However, relevant research is still limited to adult patients with HM.

Methods

We conducted a retrospective analysis of adult HM patients admitted to our hospital from March 2023 to September 2023, focusing on their clinical characteristics and the results of both tNGS and conventional microbiological tests (CMTs). We evaluated the performance of tNGS and CMTs in pathogenic diagnosis and described the distribution characteristics of pathogens in adult HM patients with infections.

Results

The study included 209 samples collected from 137 patients. Results showed that the overall pathogen detection rate differed significantly between tNGS and CMTs (60.3% vs. 24.4%, p < 0.001). The sensitivity (69.7% vs. 35.9%), negative predictive value (NPV) (48.2% vs. 42.4%), and accuracy (66.5% vs. 56.5%) of pathogen detection were notably superior with tNGS compared to CMTs. Among the 142 samples with clinically diagnosed infections, tNGS combined with CMTs identified a definite or probable microbial etiology in 114 samples (80.3%). Of the 36 samples with concordant positive results from both tNGS and CMTs, 72.2% (26/36) exhibited full or partial agreement. Our study further showed the highest detection rate for viral infections (57.0%), predominantly for Epstein-Barr virus (DNA-V, 18.3%). Followed by bacterial infections (46.5%), the detection rate of Gram-negative bacteria (G+, 35.9%) was higher than that of Gram-positive bacteria (G-, 21.8%) in this study. Klebsiella pneumoniae (G-, 12.7%) had the highest detection rate among these emerging bacteria, followed by Pseudomonas aeruginosa (G-, 10.6%) and Enterococcus faecium (G+, 7.7%). Bacterial-viral coinfections were the most common type of mixed infection (35.5%).

Conclusion

In conclusion, tNGS outperforms CMTs in both sensitivity and pathogen spectrum. Therefore, it can serve as an adjunct to CMTs to facilitate the precise adjustment of anti-infective regimens for adult HM patients. Our findings establish a basis for formulating empirical anti-infective therapy strategies tailored to the pathogen distribution in this patient population.

Study of Empiric Antibiotic Prescription Patterns and Microbiological Isolates in Hemodynamically Stable and Unstable ICU Patients With Community-Acquired Sepsis

Background: The efficacy of combination empiric antibiotic therapy for all intensive care unit (ICU) patients with community-acquired sepsis is a subject of ongoing debate in the era of increasing antibiotic resistance. This study was conducted to evaluate the patterns of antibiotic usage and microbial resistance in sepsis patients admitted to the ICU with both hemodynamically stable (HS) and unstable states and to analyze their clinical outcomes. Methods: In this observational study, patients aged 18 years and above who received antibiotics upon admission and had a culture report were included. These patients were categorized into the following groups: HS and hemodynamically unstable (HU), single or combined antibiotics group (more than one antibiotic used empirically to cover one or more groups of organisms), culture-positive and culture-negative group. The microbiological isolates were grouped according to their identified resistance patterns. The outcome parameters involved assessing the differences in empiric antibiotics use upon admission and microbial resistance with hemodynamic stability and investigating any associations with ICU and hospital outcomes. Results: The study included a total of 2675 patients, of which 70.3% were in the HS group, and 29.7% in the HU group. The use of combination antibiotics was significantly higher (p < 0 .0001) across all groups. Carbapenems were used more frequently in the single antibiotic group (p < 0 .001). The culture was positive in 27.8% (n  =  747) of patients. A significantly higher number of patients in the HU group (p < 0 .001) were found to have carbapenem-resistant and multidrug-resistant organisms. The ICU and hospital mortality rates were significantly higher in the HU group (p < 0 .001), the culture-positive group with resistance (p < 0 .001), and the HS patients who received combination antibiotics. Conclusion: The usage of combination antibiotics, coupled with the presence of resistant organisms, emerged as an important variable in predicting ICU and hospital mortality rates in cases of community-acquired sepsis.

Performance of 16S rRNA Gene Next-Generation Sequencing and the Culture Method in the Detection of Bacteria in Clinical Specimens

Effective treatment of infectious diseases requires prompt and accurate bacterial identification and tailored antimicrobial treatments. Traditional culture methods are considered the gold standard, but their effectiveness diminishes for fastidious and hard-to-grow microorganisms. In recent years, molecular diagnostic tools such as 16S rRNA gene next-generation sequencing (16S NGS) have gained popularity in the field. We analysed data from samples submitted for 16S NGS between July 2022 and July 2023 at the Department of Advanced Translational Microbiology in Trieste, Italy. The study included samples submitted for both culture-based identification and 16S NGS. Conventional media were used for culture, and bacterial identification was performed using MALDI-TOF mass spectrometry. The V3 region of the 16S rRNA gene was sequenced using the Ion PGM platform. Among the 123 samples submitted, drainage fluids (38%) and blood (23%) were the most common, with requests predominantly from the Infectious Diseases (31.7%) and Orthopedic (21.13%) Units. In samples collected from patients with confirmed infections, 16S NGS demonstrated diagnostic utility in over 60% of cases, either by confirming culture results in 21% or providing enhanced detection in 40% of instances. Among the 71 patients who had received antibiotic therapies before sampling (mean 2.3 prior antibiotic days), pre-sampling antibiotic consumption did not significantly affect the sensitivity of 16S NGS. In routine microbiology laboratories, combining 16S NGS with culture method enhances the sensitivity of microbiological diagnostics, even when sampling is conducted during antibiotic therapy.

Enhancing SAPS-3 Predictive Accuracy with Initial, Peak, and Last Lactate Measurements in Septic Shock

Background/Objectives: Septic shock is a severe condition with high mortality necessitating precise prognostic tools for improved patient outcomes. This study aimed to evaluate the collective predictive value of the Simplified Acute Physiology Score 3 (SAPS-3) and lactate measurements (initial, peak, last, and clearance rates within the first 24 h) in patients with septic shock. Specifically, it sought to determine how these markers enhance predictive accuracy for 28-day mortality beyond SAPS-3 alone. Methods: This retrospective cohort study analyzed data from 66 septic shock patients at two ICUs of Vienna General Hospital (2017-2019). SAPS-3 and lactate levels (initial, peak, last measurement within 24 h, and 24 h clearance) were obtained from electronic health records. Logistic regression models were constructed to identify predictors of 28-day mortality, and receiver operating characteristic (ROC) curves assessed predictive accuracy. Results: Among 66 patients, 36 (55%) died within 28 days. SAPS-3 scores significantly differed between survivors and non-survivors (76 vs. 85 points; p = 0.016). First, last, and peak lactate were significantly higher in non-survivors compared to survivors (all p < 0.001). The combination of SAPS-3 and first lactate produced the highest predictive accuracy (AUC = 80.6%). However, 24 h lactate clearance was not predictive of mortality. Conclusions: Integrating SAPS-3 with lactate measurements, particularly first lactate, improves predictive accuracy for 28-day mortality in septic shock patients. First lactate serves as an early, robust prognostic marker, providing crucial information for clinical decision-making and care prioritization. Further large-scale studies are needed to refine these predictive tools and validate their efficacy in guiding treatment strategies.

Fever and infections in surgical intensive care: an American Association for the Surgery of Trauma Critical Care Committee clinical consensus document

The evaluation and workup of fever and the use of antibiotics to treat infections is part of daily practice in the surgical intensive care unit (ICU). Fever can be infectious or non-infectious; it is important to distinguish between the two entities wherever possible. The evidence is growing for shortening the duration of antibiotic treatment of common infections. The purpose of this clinical consensus document, created by the American Association for the Surgery of Trauma Critical Care Committee, is to synthesize the available evidence, and to provide practical recommendations. We discuss the evaluation of fever, the indications to obtain cultures including urine, blood, and respiratory specimens for diagnosis of infections, the use of procalcitonin, and the decision to initiate empiric antibiotics. We then describe the treatment of common infections, specifically ventilator-associated pneumonia, catheter-associated urinary infection, catheter-related bloodstream infection, bacteremia, surgical site infection, intra-abdominal infection, ventriculitis, and necrotizing soft tissue infection.

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.

Development of an automated amplicon-based next-generation sequencing pipeline for rapid detection of bacteria and fungi directly from clinical specimens

The timely identification of microbial pathogens is essential to guide targeted antimicrobial therapy and ultimately, successful treatment of an infection. However, the yield of standard microbiology testing (SMT) is directly related to the duration of antecedent antimicrobial therapy as SMT culture methods are dependent on the recovery of viable organisms, the fastidious nature of certain pathogens, and other pre-analytic factors. In the last decade, metagenomic next-generation sequencing (mNGS) has been successfully utilized as a diagnostic tool for various applications within the clinical laboratory. However, mNGS is resource, time, and labor-intensive-requiring extensive laborious preliminary benchwork, followed by complex bioinformatic analysis. We aimed to address these shortcomings by developing a largely Automated targeted Metagenomic next-generation sequencing (tmNGS) PipeLine for rapId inFectIous disEase Diagnosis (AMPLIFIED) to detect bacteria and fungi directly from clinical specimens. Therefore, AMPLIFIED may serve as an adjunctive approach to complement SMT. This tmNGS pipeline requires less than 1 hour of hands-on time before sequencing and less than 2 hours of total processing time, including bioinformatic analysis. We performed tmNGS on 50 clinical specimens with concomitant cultures to assess feasibility and performance in the hospital laboratory. Of the 50 specimens, 34 (68%) were from true clinical infections. Specimens from cases of true infection were more often tmNGS positive compared to those from the non-infected group (82.4% vs 43.8%, respectively, P = 0.0087). Overall, the clinical sensitivity of AMPLIFIED was 54.6% with 85.7% specificity, equating to 70.6% and 75% negative and positive predictive values, respectively. AMPLIFIED represents a rapid supplementary approach to SMT; the typical time from specimen receipt to identification of potential pathogens by AMPLIFIED is roughly 24 hours which is markedly faster than the days, weeks, and months required to recover bacterial, fungal, and mycobacterial pathogens by culture, respectively.

IMPORTANCE

To our knowledge, this represents the first application of an automated sequencing and bioinformatics pipeline in an exclusively pediatric population. Next-generation sequencing is time-consuming, labor-intensive, and requires experienced personnel; perhaps contributing to hesitancy among clinical laboratories to adopt such a test. Here, we report a strong case for use by removing these barriers through near-total automation of our sequencing pipeline.

Next-generation microbiological testing in intraabdominal infections with PCR technology

PURPOSE

Intraabdominal infections (IAI) are increasing worldwide and are a major contributor to morbidity and mortality. Among IAI, the number of multi-drug resistant organisms (MDRO) is increasing globally. We tested the Unyvero A50® for intraabdominal infections, compared the detected microorganisms and antibiotic resistance, and compared the results with those of routine microbiology.

METHODS

We prospectively compared samples obtained from surgical patients using PCR-based Unyvero IAI cartridges against routine microbiology for the detection of microorganisms. Additionally, we identified clinical parameters that correlated with the microbiological findings. Data were analyzed using the t-test and Mann-Whitney U test.

RESULTS

Sixty-two samples were analyzed. The PCR system identified more microorganisms, mostly Bacteroides species, Escherichia coli, and Enterococcus spp. For bacterial resistance, the PCR system results were fully concordant with those of routine microbiology, resulting in a sensitivity, specificity, and positive and negative predictive value (PPV, NPV) of 100%. The sensitivity, specificity, PPV, and NPV for the detection of microorganisms were 74%, 58%, 60%, and 72%, respectively. CRP levels were significantly higher in patients with detectable microorganisms. We identified more microorganisms and bacterial resistance in hospital-acquired intra-abdominal infections by using the PCR system.

DISCUSSION

IAI warrants early identification of the microorganisms involved and their resistance to allow for adequate antibiotic therapy. PCR systems enable physicians to rapidly adjust their antibiotic treatment. Conventional microbiological culture and testing remain essential for determining the minimal growth inhibition concentrations for antibiotic therapy.

Re-visiting humoral constitutive antibacterial heterogeneity in bloodstream infections

Although cellular immunity has garnered much attention in the era of single-cell technologies, humoral innate immunity has receded in priority due to its presumed limited roles. Hence, despite the long-recognised bactericidal activity of serum-a functional characteristic of constitutive humoral immunity-much remains unclear regarding mechanisms underlying its inter-individual heterogeneity and clinical implications in bloodstream infections. Recent work suggests that the immediate antimicrobial effect of humoral innate immunity contributes to suppression of the excessive inflammatory responses to infection by reducing the amount of pathogen-associated molecular patterns. In this Personal View, we propose the need to re-explore factors underlying the inter-individual heterogeneity in serum antibacterial competence as a new approach to better understand humoral innate immunity and revisit the clinical use of measuring serum antibacterial activity in the management of bacterial bloodstream infections. Given the current emphasis on subtyping sepsis, a serum bactericidal assay might prove useful in defining a distinct sepsis endotype, to enable more personalised management.

Comparison of Clinical Characteristics and Biomarkers in Culture-Positive and Culture-Negative Sepsis Patients

OBJECTIVES

Sepsis is one of the leading causes of morbidity and mortality worldwide, and culture-negative sepsis, despite its prevalence, is largely understudied. The current study intends to examine clinical characteristics and biomarkers in culture-positive and culture-negative sepsis, focusing on 30-day mortality and duration of hospital stay in both groups.  Materials and methods: A prospective observational comparative cohort study was done on 150 patients admitted to the intensive care unit (ICU) and wards of Jaipur Golden Hospital. Patients with documented fungal, viral, or parasitic infections, as well as those who had undergone surgery or experienced trauma, were excluded.  Results: The mean age of the patients was 51.31±18.94 years. Of 150 patients, 95 (63.3%) were culture-negative, whereas 55 (36.7%) were culture-positive, with more men in the former and more women in the latter. Patients with negative cultures had fewer comorbidities. The levels of procalcitonin (PCT), C-reactive protein (CRP), and serum lactate were within the prescribed limit for both culture-negative and positive patients. A higher proportion (87.3%) of the organisms isolated from culture-positive individuals were gram-negative, with Escherichia coli (E. coli) having the highest prevalence (27.3%), followed by Klebsiella (20%). There were 12.7% gram-positive isolates. The culture-negative patients had significantly better outcomes (P=0.003) as well as the duration of hospital stay (P<0.001) than the culture-positive patients. Culture-positive patients had a more severe illness, a higher incidence of septic shock, and a higher fatality rate than culture-negative patients.

CONCLUSION

It can be concluded that CRP and PCT can be used as clinically reliable sepsis biomarkers in both culture-positive and culture-negative patients. The study found that culture-negative sepsis is more prevalent and that there are substantial differences between culture-negative and culture-positive sepsis, with the former group having fewer comorbidities, less severe illness, a shorter duration of hospital stays, lower death rates, and better outcomes.

Destabilisation of T cell-dependent humoral immunity in sepsis

Sepsis is a heterogeneous condition defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. For some, sepsis presents as a predominantly suppressive disorder, whilst others experience a pro-inflammatory condition which can culminate in a 'cytokine storm'. Frequently, patients experience signs of concurrent hyper-inflammation and immunosuppression, underpinning the difficulty in directing effective treatment. Although intensive care unit mortality rates have improved in recent years, one-third of discharged patients die within the following year. Half of post-sepsis deaths are due to exacerbation of pre-existing conditions, whilst half are due to complications arising from a deteriorated immune system. It has been suggested that the intense and dysregulated response to infection may induce irreversible metabolic reprogramming in immune cells. As a critical arm of immune protection in vertebrates, alterations to the adaptive immune system can have devastating repercussions. Indeed, a marked depletion of lymphocytes is observed in sepsis, correlating with increased rates of mortality. Such sepsis-induced lymphopenia has profound consequences on how T cells respond to infection but equally on the humoral immune response that is both elicited by B cells and supported by distinct CD4+ T follicular helper (TFH) cell subsets. The immunosuppressive state is further exacerbated by functional impairments to the remaining lymphocyte population, including the presence of cells expressing dysfunctional or exhausted phenotypes. This review will specifically focus on how sepsis destabilises the adaptive immune system, with a closer examination on how B cells and CD4+ TFH cells are affected by sepsis and the corresponding impact on humoral immunity.

Antibiotic treatment duration for culture-negative sepsis in the pediatric intensive care unit

Objective

Sepsis remains a leading cause of morbidity and mortality in children. There is very limited guidance for sepsis treatment when cultures remain negative. This study sought to determine the effectiveness of short versus long course of antibiotics when treating culture-negative sepsis and assess for subsequent multidrug-resistant organism (MDRO) acquisition.

Design

Retrospective cohort study.

Setting

Quaternary academic children's hospital.

Patients

Pediatric intensive care unit (ICU) patients with culture-negative sepsis receiving a minimum of 72 hours of antibiotics.

Methods

Patients found to have culture-negative sepsis from January 2017 to May 2020 were divided into two groups: short and long course of antibiotics. Various demographic and laboratory results were collected for each subject as available. Primary outcomes included mortality and lengths of stay. The secondary outcome was subsequent acquisition of a new MDRO.

Results

Eighty-six patients were treated for culture-negative sepsis with 43 patients in both the short- (< or = 7 days) and long-course (>7 days) treatment cohorts. Patients who received a short course of antibiotics had a lower overall mortality than those who received a long course (9.3% vs 25.6% p = 0.047), but there was no difference in 30-day mortality (p > 0.99). Patients in the short-course group had a shorter hospital length of stay (22 vs 30 days p = 0.018). New MDROs were found in 10% of all patients.

Conclusions

Treatment of culture-negative sepsis with short-course antibiotics was not associated with worse outcomes in ICU patients. These findings warrant further investigation with a larger, prospective, multi-center study.

Evaluating the diagnostic accuracy and clinical utility of 16S and 18S rRNA gene targeted next-generation sequencing based on five years of clinical experience

BACKGROUND

The use of 16S/18S rRNA targeted next-generation sequencing (tNGS) has improved microbial diagnostics, however, the use of tNGS in a routine clinical setting requires further elucidation. We retrospectively evaluated the diagnostic accuracy and clinical utility of 16S/18S tNGS, routinely used in the North Denmark Region between 2017 and 2021.

METHODS

We retrieved 544 tNGS results from 491 patients hospitalised with suspected infection (e.g. meningitis, pneumonia, intraabdominal abscess, osteomyelitis and joint infection). The tNGS assays was performed using the Illumina MiSeq desktop sequencer, and BION software for annotation. The patients' diagnosis and clinical management was evaluated by medical chart review. We calculated sensitivity and specificity, and determined the diagnostic accuracy of tNGS by defining results as true positive, true negative, false positive, and false negative.

RESULTS

Overall, tNGS had a sensitivity of 56% and a specificity of 97%. tNGS was more frequently true positive compared to culture (32% vs 18%), and tNGS detected a greater variety of bacteria and fungi, and was more frequently polymicrobial. However, the total diagnostic turnaround time was 16 days, and although 73% of tNGS results were true positive or true negative, only 4.4% of results led to changes in clinical management.

CONCLUSIONS

As a supplement to culture, tNGS improves identification of pathogenic microorganisms in a broad range of clinical specimens. However, the long turnaround time of tNGS in our setting may have contributed to a limited clinical utility. An improved turnaround time can be the key to improved clinical utility in a future setting.

Bacteremia in Patients with Sepsis in the ICU: Does It Make a Difference?

Sepsis (and septic shock) is on of the most common causes of death worldwide. Bacteremia often, but not necessarily, occurs in septic patients, but the impact of true bacteremia on a patient's clinical characteristics and outcome remains unclear. The main aim of this study was to compare the characteristics and outcome of a well-defined cohort of 258 septic patients with and without bacteremia treated in the intensive care unit (ICU) of a tertiary center hospital in Prague, Czech Republic. As expected, more frequently, bacteremia was present in patients without previous antibiotic treatment. A higher proportion of bacteremia was observed in patients with infective endocarditis as well as catheter-related and soft tissue infections in contrast to respiratory sepsis. Multivariant analysis showed increased severity of clinical status and higher Charlson comorbidity index (CCI) as variables with significant influence on mortality. Bacteremia appears to be associated with higher mortality rates and length of ICU stay in comparison with nonbacteremic counterparts, but this difference did not reach statistical significance. The presence of bacteremia, apart from previous antibiotic treatment, may be related to the site of infection.

Empiric antimicrobial therapy in the intensive care unit based on the risk of multidrug-resistant bacterial infection: a single-centre case‒control study of blood culture results in Japan

BACKGROUND

Infections and sepsis are the leading causes of death in intensive care units (ICUs). Antimicrobial agent selection is challenging because the intervention is directly related to the outcome, and the problem of antimicrobial resistance (AMR) must be considered. Therefore, in this study, we aimed to clarify the epidemiological data and examine whether the detection rate of multidrug-resistant (MDR) bacteria differed depending on the presence or absence of the risk of MDR bacterial infections to establish guidance regarding the choice of antimicrobial therapy for ICU patients.

METHODS

This retrospective case‒control study was performed in a single ICU in Japan. Patients admitted to the ICU who underwent blood culture (BC) analysis were considered for inclusion in this study; patients were at risk of MDR bacterial infections, and controls were not. The primary outcome measure was the detection rate of MDR bacteria in BCs collected from patients and controls. The secondary outcome measure was the selection rate of anti-Pseudomonas and anti-methicillin-resistant Staphylococcus aureus (MRSA) drugs for patients and controls.

RESULTS

Among the 1,730 patients admitted to the ICU during the study period, BCs were obtained from 186 patients, and 173 samples were finally included in the analysis (n = 129 cases; n = 44 controls). No MDR bacteria or Pseudomonas aeruginosa were detected in the controls (14 (11%) vs. 0 (0%)) (P = 0.014) However, there was no difference in empiric antimicrobials, including anti-MRSA (30 (23%) vs. 12 (27%)) (P = 0.592) and anti-Pseudomonas aeruginosa (61 (47%) vs. 16 (36%)) (P = 0.208) drugs, that were administered to the two groups.

CONCLUSIONS

Even in critically ill patients in the ICU, MDR bacteria are unlikely to be detected in patients without the risk of MDR bacterial infections. Therefore, for such patients, a strategy of starting empiric narrow-spectrum antimicrobial therapy rather than empiric broad-spectrum therapy should be considered. This strategy, in conjunction with daily updates of clinical and epidemiological data at each facility, will promote the appropriate use of antimicrobials and reduce the emergence of MDR bacteria in the ICU.

TRIAL REGISTRATION

None.

Epidemiology, Resistance Profiles, and Outcomes of Bloodstream Infections in Community-Onset Sepsis in the United States

OBJECTIVES

To describe frequency of positive blood cultures, patterns of pathogens' characteristics and their resistance profile in patients with blood cultures drawn due to a presumed diagnosis of community-onset sepsis, and to examine the association between blood culture-positive pathogens and hospital mortality.

DESIGN

Retrospective cohort study.

SETTING

Two hundred one U.S. hospitals from 2016 to 2020 using the Premier Healthcare Database.

SUBJECTS

Adult patients presenting with community-onset sepsis who had blood cultures collected within 2 days of hospital admission. We defined sepsis using the U.S. Centers for Disease Control Adult Sepsis Event Surveillance criteria.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We identified 147,061 patients with community-onset sepsis. The number of blood culture-positive sepsis episodes was 21,167 (14%) and the number of nonblood culture-positive sepsis episodes was 20,326 (14%). Among patients with blood culture-positive sepsis, Gram-negative rods were isolated in 55% of patients, Gram-positive cocci were isolated in 47%. Of those, methicillin-resistant Staphylococcus aureus (MRSA) was 11%, ceftriaxone-resistant Enterobacterales /extended-spectrum β-lactamase was 7%, and carbapenem-resistant Enterobacterales was 1.3%. The crude in-hospital mortality was 17% for culture-negative sepsis, 13% for nonblood culture-positive sepsis, and 17% for blood culture-positive sepsis. In multilevel logistic regression models, compared with culture-negative sepsis, blood culture-positive sepsis (adjusted odds ratio [aOR], 0.89; 95% CI, 0.85-0.94) and nonblood culture-positive sepsis (aOR, 0.82; 95% CI, 0.78-0.87) were associated with lower odds of in-hospital mortality. Acinetobacter species, Pseudomonas aeruginosa , methicillin-sensitive Staphylococcus aureus , and MRSA were associated with higher in-hospital mortality, whereas Escherichia coli , Klebsiella species, Proteus species, and Streptococcus species were associated with lower in-hospital mortality.

CONCLUSIONS

In patients hospitalized with community-onset sepsis, the prevalence of blood culture-positive sepsis was 14%. Among positive blood culture sepsis resistant organisms were infrequent. Compared with culture-negative sepsis, blood culture-positive sepsis and nonblood culture-positive sepsis were associated with lower in-hospital mortality.

Classification of Chemotherapy-Induced Febrile Neutropenic Episodes Into One of the Three Febrile Neutropenic Syndromes

Introduction Febrile neutropenia is a commonly encountered medical emergency in patients undergoing cancer treatment and can delay and modify the course of treatment and even lead to dire outcomes, including death. The cause of fever in a post-chemotherapy-induced neutropenic patient can be confusing to treating physicians. A review of the literature demonstrated that blood culture results could determine the cause of febrile neutropenia in only approximately 10% to 25% of patients. The objective of our study was to measure the incidence of positive blood cultures, urine cultures, and other body fluid cultures resulting in chemotherapy-induced neutropenia and further classify fever episodes into three neutropenic fever syndromes, such as microbiologically documented, clinically suspected, or unknown causes of fever, respectively. Methods We conducted a prospective observational study on 399 chemotherapy-induced neutropenic fever episodes with the aim of classifying them into one of the three neutropenic syndromes. We tried to document the cause of the fever in these patients. We also noted the type of cancer treatment regimen they were on and correlated their clinical profile with their body fluid cultures, including blood cultures, urine cultures, and other body fluid cultures. We then categorized each fever episode into one of three neutropenic syndromes. Results We studied 399 febrile neutropenic episodes. We were able to microbiologically document the cause of fever in 39% of the cases, and we obtained growth in 51 out of 399 blood cultures (13%), which was comparable to the available literature, and urine culture showed growth in 62 out of 399 cultures (16%), while other body cultures such as pus culture, bile culture, and bronchioalveolar lavage cultures collectively showed growth in 42 out of 399 episodes (10%). The most common bacteria isolated in both blood and urine cultures were Escherichia coli. Cumulatively, including blood, urine, and body fluid cultures, we were able to classify 39% (155 out of 399 cases) of febrile neutropenic episodes as microbiologically documented. The cause of fever was clinically suspected by means of careful history taking and an extensive physical examination in 31% (125 out of 399) without growth evidence in blood cultures, urine cultures, or any other body fluid culture. The cause of fever remained unknown in 119 cases (30%) of patients and was classified under the unknown cause of fever. Conclusions We conclude by stating that the study of fever in a neutropenic patient should include a thorough history and clinical evaluation of blood, urine, and other body fluid cultures instead of solely relying on blood culture results. We recommend further classifying patients into one of the three neutropenic fever syndromes, such as those that are microbiologically documented, clinically suspected, or unknown. Our blood cultures were able to give us a 13% positivity rate, whereas microbiologically, we were able to isolate an organism likely causing fever in 39% of patients. The cause of fever was suspected clinically in 31% of patients, but we were unsuccessful in microbiologically documenting any culture growth in blood, urine, or any other body fluid culture. The cause of fever remained a mystery and unknown to us without any microbiological or clinical cues in 119 cases (30%) of febrile neutropenic episodes.

Direct-from-Blood Detection of Pathogens: a Review of Technology and Challenges

Blood cultures have been the staple of clinical microbiology laboratories for well over half a century, but gaps remain in our ability to identify the causative agent in patients presenting with signs and symptoms of sepsis. Molecular technologies have revolutionized the clinical microbiology laboratory in many areas but have yet to present a viable alternative to blood cultures. There has been a recent surge of interest in utilizing novel approaches to address this challenge. In this minireview, I discuss whether molecular tools will finally give us the answers we need and the practical challenges of incorporating them into the diagnostic algorithm.

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.

Outcomes of Sepsis in Patients With and Without HIV Infection: A Retrospective Study

BACKGROUND

HIV infection is associated with increased infections.

OBJECTIVES

To (1) compare patients with sepsis with and without HIV, (2) assess whether HIV is associated with mortality in sepsis, and (3) identify factors associated with mortality in patients with HIV and sepsis.

METHODS

Patients who met Sepsis-3 criteria were studied. HIV infection was defined as administration of highly active antiretroviral therapy, a diagnosis of AIDS encoded by the International Classification of Diseases, or a positive HIV blood test result. Propensity scores were used to match patients with HIV to similar patients without HIV, and mortality was compared with χ2 tests. Logistic regression was used to determine factors independently associated with mortality.

RESULTS

Sepsis developed in 34 673 patients without HIV and 326 patients with HIV. Of these, 323 (99%) patients with HIV were matched to similar patients without HIV. The 30-60- and 90-day mortality was 11%, 15%, and 17%, respectively, in patients with sepsis and HIV, which was similar to the 11% (P > .99), 15% (P > .99), and 16% (P = .83) in patients without HIV. Logistic regression to adjust for confounders showed that obesity (odds ratio, 0.12; 95% CI, 0.03-0.46; P = .002) and high total protein on admission (odds ratio, 0.71; 95% CI, 0.56-0.91; P = .007) were associated with lower mortality. Mechanical ventilation at sepsis onset, renal replacement therapy, positive blood culture, and platelet transfusion were associated with increased mortality.

CONCLUSIONS

HIV infection was not associated with increased mortality in patients with sepsis.

Organism type of infection is associated with prognosis in sepsis: an analysis from the MIMIC-IV database

BACKGROUND

Sepsis has a high mortality rate, which is expensive to treat, and is a major drain on healthcare resources; it seriously impacts the quality of human life. The clinical features of positive or non-positive blood cultures have been reported, but the clinical features of sepsis with different microbial infections and how they contribute to clinical outcomes have not been adequately described.

METHODS

We extracted clinical data of septic patients with a single pathogen from the online Medical Information Mart for Intensive Care(MIMIC)-IV database. Based on microbial cultures, patients were classified into Gram-negative, Gram-positive, and fungal groups. Then, we analyzed the clinical characteristics of sepsis patients with Gram-negative, Gram-positive, and fungal infections. The primary outcome was 28-day mortality. The secondary outcomes were in-hospital mortality, the length of hospital stay, the length of ICU stay, and the ventilation duration. In addition, Kaplan-Meier analysis was used for the 28-day cumulative survival rate of patients with sepsis. Finally, we performed further univariate and multivariate regression analyses for 28-day mortality and created a nomogram for predicting 28-day mortality.

RESULTS

The analysis showed that bloodstream infections showed a statistically significant difference in survival between Gram-positive and fungal organisms; drug resistance only reached statistical significance for Gram-positive bacteria. Through univariate and multivariate analysis, it was found that both the Gram-negative bacteria and fungi were independent risk factors for the short-term prognosis of sepsis patients. The multivariate regression model showed good discrimination, with a C-index of 0.788. We developed and validated a nomogram for the individualized prediction of 28-day mortality in patients with sepsis. Application of the nomogram still gave good calibration.

CONCLUSIONS

Organism type of infection is associated with mortality of sepsis, and early identification of the microbiological type of a patient with sepsis will provide an understanding of the patient's condition and guide treatment.

Culture-Positive and Culture-Negative Empyema After Thoracoscopic Decortication: A Comparison of Short-term and Long-term Outcomes

Background

Empyema thoracis is a serious infectious disease and is associated with high morbidity and mortality. The perioperative outcomes between culture-positive and culture-negative empyema after thoracoscopic decortication remained controversial, especially since there were no studies that reported the survival outcomes between culture-positive and culture-negative empyema.

Methods

This single-institute study involved a retrospective analysis. Patients with empyema thoracis who underwent thoracoscopic decortication between January 2012 and December 2021 were included in the study. Patients were grouped into a culture-positive group and a culture-negative group according to culture results obtained no later than 2 weeks after surgery.

Results

A total of 1087 patients with empyema received surgery, and 824 were enrolled after exclusion. Among these, 366 patients showed positive culture results and 458 patients showed negative results. Longer intensive care unit stays (11.69 vs 5.64 days, P < .001), longer ventilator usage (24.70 vs 14.01 days, P = .002), and longer postoperative hospital stays (40.83 vs 28.37 days, P < .001) were observed in the culture-positive group. However, there was no significant difference in 30-day mortality between the 2 groups (5.2% in culture negative vs 5.0% in culture positive, P = .913). The 2-year survival was not significantly different between the 2 groups (P = .236).

Conclusions

Patients with culture-positive or culture-negative empyema who underwent thoracoscopic decortication showed similar short-term and long-term survival outcomes. A higher risk of death was associated with advanced age, a higher Charlson Comorbidity Index score, phase III empyema, and a cause other than pneumonia.

The diagnostic accuracy of an initial point-of-care lactate at the emergency department as a predictor of in-hospital mortality among adult patients with sepsis and septic shock

Background

In patients with sepsis, elevated lactate has been shown to be a strong predictor of in-hospital mortality. However, the optimal cutoff for rapidly stratifying patients presenting to the emergency department at risk for increased in-hospital mortality has not been well defined. This study aimed to establish the optimal point-of-care (POC) lactate cutoff that best predicted in-hospital mortality in adult patients presenting to the emergency department.

Methods

This was a retrospective study. All adult patients who presented to the emergency department at the Aga Khan University Hospital, Nairobi, between 1 January 2018 and 31 August 2020 with suspected sepsis or septic shock and were admitted to the hospital were included in the study. Initial POC lactate results (GEM 3500^® blood gas analyzer) and demographic and outcome data were collected. A receiver operating characteristic (ROC) curve for initial POC lactate values was plotted to determine the area under the curve (AUC). An optimal initial lactate cutoff was then determined using the Youden Index. Kaplan-Meier curves were used to determine the hazard ratio (HR) for the identified lactate cutoff.

Results

A total of 123 patients were included in the study. They had a median age of 61 years [interquartile range (IQR) 41.0-77.0]. Initial lactate independently predicted in-hospital mortality [adjusted odds ratio (OR) 1.41 95% confidence interval (CI 1.06, 1.87) p = 0.018]. Initial lactate was found to have an area under the curve (AUC) of 0.752 (95% CI, 0.643 to 0.86). Additionally, a cutoff of 3.5 mmol/L was found to best predict in-hospital mortality (sensitivity 66.7%, specificity 71.4%, PPV 70%, NPV 68.2%). Mortality was 42.1% (16/38) in patients with an initial lactate of ≥ 3.5 mmol/L and 12.7% (8/63) in patients with an initial lactate of <3.5 mmol/L (HR, 3.388; 95% CI, 1.432-8.018; p < 0.005).

Discussion

An initial POC lactate of ≥ 3.5 mmol/L best predicted in-hospital mortality in patients presenting with suspected sepsis and septic shock to the emergency department. A review of the sepsis and septic shock protocols will help in the early identification and management of these patients to reduce their in-hospital mortality.

The Diagnostic Value of Triggering Receptor Expressed on Myeloid Cells-1 in Post-Traumatic Bacterial Endophthalmitis

Purpose

To determine whether soluble-triggering receptor expressed on myeloid cells-1 (sTREM-1) could serve as a reliable diagnostic biomarker of post-traumatic bacterial endophthalmitis (PTBE).

Methods

Thirty-two patients (32 eyes) clinically diagnosed having PTBE were further divided into a culture-positive (CP) group and a culture-negative (CN) group. Sixty-two patients (62 eyes) without traumatic endophthalmic infection were also enrolled. Twenty-one eyes from 11 donors without globe ocular injuries were included as control group. Vitreous sTREM-1 levels were detected by ELISA. The expression and tissue distribution of TREM-1 were revealed by immunohistochemistry. The diagnostic value of sTREM-1 was determined by receiver operating characteristic curve (ROC). The correlation between sTREM-1 concentration and final best-corrected visual acuity (FBCVA) and Peyman endophthalmitis score (PES) were also assessed.

Results

The vitreous sTREM-1 level in the PTBE group was higher than that in noninfected group and control group (P < 0.05). No remarkable difference was found between the CP group and the CN group in vitreous sTREM-1 levels (P > 0.05). No remarkable difference was found between the noninfected group and the control group (P > 0.05). No remarkable difference in TREM-1 level was found before and after intravitreal antibiotics (P > 0.05). TREM-1 was selectively highly expressed on the surface of cell membrane of neutrophils and monocytes/macrophages infiltrated in vitreous and uveal of the PTBE group. The area under the ROC curve (AUC) was 0.79 (>0.75), with a medium diagnostic efficiency. The sensitivity and specificity of sTREM-1 to differentiate PTBE from the noninfected intraocular condition were 62.50% and 86.25% separately. A cutoff value >524.50 pg/mL for sTREM-1 was predicted to be PTBE. Vitreous sTREM-1 levels in PTBE group were positively correlated with PES (r = 0.428, P < 0.05). However, sTREM-1 levels and FBCVA did not significantly correlate with one another (P > 0.05).

Conclusions

The sTREM-1 was a promising diagnostic biomarker of PTBE, especially CN-PTBE. Vitreous sTREM-1 levels were linked with intraocular inflammation levels and severity of PTBE.

Target product profiles for diagnosis of sepsis: Proposing a new approach for diagnostic innovation

Background & objectives

Sepsis, including neonatal sepsis, remains a prevalent cause of morbidity and mortality in low- and middle-income countries such as India, representing 85 per cent of all sepsis-related deaths globally. Early diagnosis and timely initiation of treatment is challenging due to non-specific clinical manifestations and non-availability of rapid diagnostic tests. There is an urgent need for affordable diagnostics with fast turnaround time catering to the needs of end-users. Target product profiles (TPPs) have been found instrumental in developing 'fit-for-use' diagnostics, thus reducing the time taken to facilitate development and improving diagnosis. Hitherto, no such guidance or criteria has been defined for rapid diagnostics for sepsis/neonatal sepsis. We propose an innovative approach for developing the diagnostics for sepsis screening and diagnosis which can be utilized by diagnostic developers in the country.

Methods

Thr@ee-round Delphi method, including two online surveys and one virtual consultation, was adopted to define criteria for minimum and optimum attributes of TPPs and build consensus on characteristics. Expert panel (n=23) included infectious disease physicians, public health specialists, clinical microbiologists, virologists, researchers/scientists and technology experts/innovators.

Results

We present a three-component product profile for sepsis diagnosis, (i) screening with high sensitivity, (ii) detection of aetiological agent, and (iii) profiling of antimicrobial susceptibility/resistance, in adults and neonates with an option of testing different considerations. An agreement of >75 per cent was achieved for all TPP characteristics by Delphi. These TPPs are tailored to the Indian healthcare settings and can also be extrapolated to other resource-constraint and high-disease burden settings.

Interpretation & conclusions

Diagnostics developed using these TPPs will facilitate utilization of invested resources leading to development of the products that have potential to ease the economic burden on patient and save lives.

Comparison of Clinical Outcomes Between Culture-Positive and Culture-Negative Sepsis and Septic Shock Patients: A Meta-Analysis

This meta-analysis has been conducted to compare the clinical outcomes between culture-positive and culture-negative sepsis or septic patients. The present meta-analysis is reported as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic databases, including PubMed and EMBASE, were searched by two authors independently from the inception to January 25, 2023, using the following key terms: "culture positive," "culture negative," "sepsis," and "septic shock." The primary outcome assessed in the present meta-analysis was all-cause mortality. Secondary outcomes included the need for mechanical ventilation, renal replacement therapy, length of ICU stay in days, and length of hospital stay in days. Total 10 studies met the inclusion criteria and were included in the meta-analysis involving 23,973 patients. No statistically significant difference was found between culture-positive and culture-negative patients in terms of all-cause mortality (risk ratio [RR]: 1.09, 95% CI: 0.95-1.24, p-value: 0.23), the need for mechanical ventilation (RR: 0.99, 95% CI: 0.93-1.05, p-value: 0.79), renal replacement therapy requirements (RR: 1.11, 95% CI: 0.95-1.31, p-value: 0.19), and ICU length of stay (mean difference [MD]: 1.70 days, 95% CI: -1.10, 4.49, p-value: 0.23). However, The mean hospital length of stay in days was significantly longer in patients in a culture-positive group compared to the culture-negative group (MD: 3.04, 95% CI: 2.25-3.82, p-value<0.001). In conclusion, the present meta-analysis of 10 studies, including 23,973 patients, found no significant differences in all-cause mortality, need for mechanical ventilation, need for renal replacement therapy, and length of ICU stay between culture-positive and culture-negative sepsis or septic patients. However, a significant difference was found in hospital length of stay, with culture-positive patients having a longer stay.

Clinical outcomes and prognostic factors of patients with sepsis caused by intra-abdominal infection in the intensive care unit: a post-hoc analysis of a prospective cohort study in Korea

BACKGROUND

Sepsis is the most common cause of death in hospitals, and intra-abdominal infection (IAI) accounts for a large portion of the causes of sepsis. We investigated the clinical outcomes and factors influencing mortality of patients with sepsis due to IAI.

METHODS

This post-hoc analysis of a prospective cohort study included 2126 patients with sepsis who visited 16 tertiary care hospitals in Korea (September 2019-February 2020). The analysis included 219 patients aged > 19 years who were admitted to intensive care units owing to sepsis caused by IAI.

RESULTS

The incidence of septic shock was 47% and was significantly higher in the non-survivor group (58.7% vs 42.3%, p = 0.028). The overall 28-day mortality was 28.8%. In multivariable logistic regression, after adjusting for age, sex, Charlson Comorbidity Index, and lactic acid, only coagulation dysfunction (odds ratio: 2.78 [1.47-5.23], p = 0.001) was independently associated, and after adjusting for each risk factor, only simplified acute physiology score III (SAPS 3) (p < 0.001) and continuous renal replacement therapy (CRRT) (p < 0.001) were independently associated with higher 28-day mortality.

CONCLUSIONS

The SAPS 3 score and acute kidney injury with CRRT were independently associated with increased 28-day mortality. Additional support may be needed in patients with coagulopathy than in those with other organ dysfunctions due to IAI because patients with coagulopathy had worse prognosis.

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.

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.

Introducing the Escalation Antibiogram: A Simple Tool to Inform Changes in Empiric Antimicrobials in the Non-Responding Patient

BACKGROUND

Hospital antibiograms guide initial empiric antibiotic treatment selections, but do not directly inform escalation of treatment among non-responding patients.

METHODS

Using Gram-negative bacteremia (GNB) as an exemplar condition, we sought to introduce the concept of an Escalation Antibiogram. Among GNBs between 2017-2020 from six hospitals in the Greater Toronto Area, we generated escalation antibiograms for each of 12 commonly used agents. Among organisms resistant to that antibiotic, we calculated the likelihood of susceptibility to each of the other 11 agents. In subgroup analyses, we examined escalation antibiograms across study years, individual hospitals, community versus hospital onset, and pathogen type.

RESULTS

Among 6577 GNB episodes, the likelihood of coverage was: ampicillin 31.8%, cefazolin 62.7%, ceftriaxone 67.1%, piperacillin-tazobactam 72.5%, ceftazidime 74.1%, trimethoprim-sulfamethoxazole 74.4%, ciprofloxacin 77.1%, tobramycin 88.3%, gentamicin 88.8%, ertapenem 91.0%, amikacin 97.5%, and meropenem 98.2%. The escalation antibiograms revealed marked shifts in likelihood of coverage by the remaining 11 agents. For example, among ceftriaxone-resistant isolates piperacillin-tazobactam susceptibility (21.2%) was significantly lower than trimethoprim-sulfamethoxazole (54.2%, p<0.0001), ciprofloxacin (63.0%, p<0.0001), ertapenem (73.4%, p<0.0001), tobramycin (80.1%, p<0.0001), gentamicin (82.8%, p<0.0001), meropenem (94.3%, p<0.0001), and amikacin (97.1%, p<0.0001). Trimethoprim-sulfamethoxazole was the second ranked agent in the meropenem escalation antibiogram (49.6%), and first in the amikacin escalation antibiogram (86.0%). Escalation antibiograms were consistent across 4 study years and 6 hospitals.

CONCLUSION

Escalation antibiograms can be generated to inform empiric treatment changes in non-responding patients. These tools can yield important insights such as avoiding the common maneuver of escalating from ceftriaxone to piperacillin-tazobactam in suspected GNB.

Targeted Metagenomic Sequencing-Based Approach Applied to 2,146 Tissue and Body Fluid Samples in Routine Clinical Practice

BACKGROUND

The yield of next generation sequencing (NGS) added to a Sanger sequencing-based 16S ribosomal RNA (rRNA) gene PCR assay was evaluated in clinical practice for diagnosis of bacterial infection.

METHODS

PCR targeting the V1 to V3 regions of the 16S rRNA gene was performed, with amplified DNA submitted to Sanger sequencing and/or NGS (Illumina MiSeq), or reported as negative, depending on cycle threshold (Ct) value. 2,146 normally sterile tissues or body fluids were tested between August 2020 and March 2021. Clinical sensitivity was assessed in 579 subjects from whom clinical data was available.

RESULTS

Compared to Sanger sequencing alone (400 positive tests), positivity increased by 87% by adding NGS (347 added positive tests). Clinical sensitivity of the assay incorporating NGS was 53%, higher than culture (42%, p<0.001), with an impact on clinical decision-making in 14% of infected cases. Clinical sensitivity in the subgroup receiving antibiotics at sampling was 41% for culture and 63% for the sequencing assay (p<0.001).

CONCLUSION

Adding NGS to Sanger sequencing of the PCR-amplified 16S rRNA gene substantially improved test positivity. In the patient population studied, the assay was more sensitive than culture, and especially so in patients who had received antibiotic therapy.

Genetic variants associated with sepsis

BACKGROUND

The variable presentations and different phenotypes of sepsis suggest that risk of sepsis comes from many genes each having a small effect. The cumulative effect can be used to create individual risk profile. The purpose of this study was to create a polygenic risk score and determine the genetic variants associated with sepsis.

METHODS

We sequenced ~14 million single nucleotide polymorphisms with a minimac imputation quality R2>0.3 and minor allele frequency >10-6 in patients with Sepsis-2 or Sepsis-3. Genome-wide association was performed using Firth bias-corrected logistic regression. Semi-parsimonious logistic regression was used to create polygenic risk scores and reduced regression to determine the genetic variants independently associated with sepsis.

FINDINGS

2261 patients had sepsis and 13,068 control patients did not. The polygenic risk scores had good discrimination: c-statistic = 0.752 ± 0.005 for Sepsis-2 and 0.752 ± 0.007 for Sepsis-3. We found 772 genetic variants associated with Sepsis-2 and 442 with Sepsis-3, p<0.01. After multivariate adjustment, 100 variants on 85 genes were associated with Sepsis-2 and 69 variants in 54 genes with Sepsis-3. Twenty-five variants were present in both the Sepsis-2 and Sepsis-3 groups out of 32 genes that were present in both groups. The other 7 genes had different variants present. Most variants had small effect sizes.

CONCLUSIONS

Sepsis-2 and Sepsis-3 have both separate and shared genetic variants. Most genetic variants have small effects sizes, but cumulatively, the polygenic risk scores have good discrimination.

Antimicrobial Susceptibility Characteristics and Risk Factors Associated with Adult Sepsis in Wenzhou, China

Purpose

To clarify the distribution of pathogenic bacteria by analyzing the bacterial susceptibility characteristics and risk factors for adult sepsis in The Wenzhou city, Zhejiang province, China, and to aid early diagnosis, monitoring, and prognosis prediction in cases of bacterial sepsis.

Patients and Methods

We retrospectively analyzed 329 patients with sepsis admitted to the Second Affiliated Hospital of Wenzhou Medical University between January 2018 and March 2021. Laboratory data were collected before and after treatment; moreover, the bacterial susceptibility characteristics and risk factors for sepsis were comprehensively analyzed using the Sequential Organ Failure Assessment (SOFA) score.

Results

The SOFA score was negatively correlated with the prognosis (P < 0.05). We isolated 47 pathogenic strains from blood culture samples, including 29 gram-positive strains, 18 gram-negative strains. The most common gram-negative pathogens in blood cultures are Klebsiella pneumoniae and Escherichia coli, while the most common gram-positive pathogens are Staphylococcus aureus and Staphylococcus hominis. Gram-negative pathogens had resistance rates of 77% and 62.5% to ciprofloxacin and ceftriaxone, respectively. Gram-positive bacteria had a high resistance to penicillin at 100%. Prognostic factors for sepsis included patients’ consciousness, SOFA score, prothrombin time, international normalized ratio, fibrinogen, D-dimer, and aspartate aminotransferase (P < 0.05). Of these, the D-dimer level could predict the outcome of patients with sepsis (AUC = 0.661, P < 0.05).

Conclusion

The pathogens detected in adult sepsis in Wenzhou are mainly Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, and Staphylococcus hominis. The pathogens exhibited differences in drug susceptibility. The optimal antibiotics should be chosen based on the principles of rational use and drug susceptibility. Combined with D-dimer levels, these parameters can be used to determine the optimal strategy for preventing and treating pathogenic bacteria.

The Role of Mid-Regional Proadrenomedullin in the Differential Diagnosis between Culture-Negative and Culture-Positive Sepsis at Emergency Department Admission

Background: The host response in culture-negative sepsis (CnS) has been marginally explored upon emergency department (ED) admission. It would be of paramount importance to create a clinical prediction rule to support the emergency department physician in identifying septic patients who can be treated with antibiotics immediately without waiting time to draw cultures if they are unlikely to provide useful diagnostic information. Methods: A multivariable logistic regression analysis was applied to identify the independent clinical variables and serum biomarkers of the culture-negative status among 773 undifferentiated septic patients. Those predictors were combined to build a nomogram predictive of CnS. Results: The serum concentrations of six biomarkers, among the eight biomarkers assayed in this study, were significantly lower in the patients with CnS (449) than in those with culture-positive sepsis (324). After correction for co-variates, only mid-regional proadrenomedullin (MR-proADM) was found to be independently correlated with culture-negative status. Absence of diabetes, hemoglobin concentrations, and respiratory source of infection were the other independent clinical variables integrated into the nomogram—its sensitivity and specificity for CnS were 0.80 and 0.79, respectively. Conclusions: Low concentrations of MR-proADM were independently associated with culture-negative sepsis. Our nomogram, based on the MR-proADM levels, did not predict culture-negative status with reasonable certainty in patients with a definitive diagnosis of sepsis at ED admission.

Endogenous Carboxyhemoglobin Level Variation in COVID-19 and Bacterial Sepsis: A Novel Approach?

Background: The increased production of carbon monoxide (CO) in sepsis has been proven, but the blood level variations of carboxyhemoglobin (COHb) as a potential evolutionary parameter of COVID-19 and sepsis/septic shock have yet to be determined. This study aims to evaluate the serum level variation of COHb as a potential evolutionary parameter in COVID-19 critically ill patients and in bacterial sepsis. Materials and method: A prospective and observational study was conducted on two groups of patients: the bacterial sepsis group (n = 52) and the COVID-19 group (n = 52). We followed paraclinical parameters on Day 1 (D1) and Day 5 (D5) of sepsis/ICU admission for COVID-19 patients. Results: D1 of sepsis: statistically significant positive correlations between: COHb values and serum lactate (p = 0.024, r = 0.316), and total bilirubin (p = 0.01, r = 0.359). In D5 of sepsis: a statistically significant positive correlations between: COHb values and procalcitonin (PCT) (p = 0.038, r = 0.402), and total bilirubin (p = 0.023, r = 0.319). D1 of COVID-19 group: COHb levels were statistically significantly positively correlated with C-reactive protein CRP values (p = 0.003, r = 0.407) and with PCT values (p = 0.022, r = 0.324) and statistically significantly negatively correlated with serum lactate values (p = 0.038, r = −0.285). Conclusion: COHb variation could provide rapid information about the outcome of bacterial sepsis/septic shock, having the advantages of a favorable cost-effectiveness ratio, and availability as a point-of-care test.

Impact of a Procalcitonin-Based Protocol on Antibiotic Exposure and Costs in Critically Ill Patients

Supplemental Digital Content is available in the text.

To examine the impact before and after adoption of a procalcitonin-based protocol to guide sepsis management has on antibiotic use, care costs, and outcomes of critically ill patients.

Comparison of Clinical Characteristics and Outcomes Between Positive and Negative Blood Culture Septic Patients: A Retrospective Cohort Study

Background

Few studies have studied the relationship between blood culture and mortality in sepsis patients. The aim of this study was to compare the characteristics and outcomes of positive and negative blood culture sepsis.

Methods

We performed a study on 640 patients suffering from sepsis in Beijing Chao-Yang Hospital from October 2017 to December 2019. The primary findings revolved around length and expenditure of hospital stay, the possibility of suffering from acute respiratory distress syndrome (ARDS), and any requirements for mechanical ventilation. The secondary findings revolved around whether the patient died early (28-day) or late (28-to-90-day).

Results

A total of 592 of the 640 patients met the inclusion criteria for sepsis, with 274 of them having culture-positive results. The culture-positive patients were mostly elderly suffering from diabetes and at risk of cancer, with a higher white blood cell count, and higher procalcitonin. Additionally, they scored higher in their acute physiology and chronic health evaluation II score (15 vs.11, P=0.010), as well as in their predisposition, infection, response, and organ dysfunction (17 vs 11, P<0.001) than the individuals in the culture-negative group. Culture-positive patients had a longer duration of hospital stay (14 vs 6, P<0.001) and higher in-hospital mortality (14.6% vs 8.5%, P=0.019) than culture-negative ones. No significant difference in intensive care unit (ICU) mortality (45.7% vs.36.4%, P=0.254) or early mortality (9.5% vs 7.2%, P=0.321) was noted between the two groups. However, the culture-positive patients had increased late mortality (15.7% vs.6.9%, P=0.001), when compared with those with culture-negative results in the cohort. Furthermore, the culture-positive patients who received the appropriate antibiotics early had a lower mortality rate than the culture-negative patients (7.3% vs.14.2%, P=0.008).

Conclusion

Culture-positive patients had higher in-hospital mortality, comparable early mortality, and worse late mortality than the culture-negative patients. Early appropriate use of antibiotics might reduce mortality and improve clinical prognosis.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members.As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

A 12-year study evaluating the outcomes and predictors of mortality in critically ill cancer patients admitted with septic shock

Background

Though sepsis is common in patients with cancer, there are limited studies that evaluated sepsis and septic shock in this patient population. The objective of this study was to evaluate the outcomes and to identify predictors of mortality in cancer patients admitted to the intensive care unit (ICU) with septic shock.

Methods

This was a retrospective study conducted at a medical-surgical oncologic ICU of a comprehensive cancer center. Adult cancer patients admitted with septic shock between January 1, 2008 and December 31, 2019 were enrolled. Septic shock was defined as an ICU admission diagnosis of sepsis that required initiating vasopressors within 24 h of admission. Patient baseline characteristics, ICU length of stay and ICU and hospital mortality were recorded. Univariate analysis and logistic regression were performed to identify predictors associated with ICU and hospital mortality.

Results

During the study period, 1408 patients met the inclusion criteria. The mean age was 56.8 ± 16.1 (SD) years and mean Acute Physiology and Chronic Health Evaluation (APACHE) II was 23.0 ± 7.91 (SD). Among the enrolled patients, 67.8% had solid tumors while the remaining had hematological malignancies. Neutropenia and thrombocytopenia were reported in 19.3 and 39.5% of the patients, respectively, and mechanical ventilation was required for 42% of the patients. Positive cultures were reported in 836 (59.4%) patients, most commonly blood (33%) and respiratory (26.6%). Upon admission, about half the patients had acute kidney injury, while elevated total bilirubin and lactic acid levels were reported in 13.8 and 65.2% of the patients, respectively. The median ICU length of stay was 4 days (IQR 3–8), and ICU and hospital mortality were reported in 688 (48.9%) and 914 (64.9%) patients, respectively. Mechanical ventilation, APACHE II, thrombocytopenia, positive cultures, elevated bilirubin and lactic acid levels were significantly associated with both ICU and hospital mortality.

Conclusions

In a relatively large cohort of patients with solid and hematological malignancies admitted to the ICU with septic shock, hospital mortality was reported in about two-third of the patients. Mechanical ventilation, APACHE II, thrombocytopenia, positive cultures, elevated bilirubin and lactic acid levels were significant predictors of mortality.

Comparison of culture-negative and culture-positive sepsis or septic shock: a systematic review and meta-analysis

Background

Mortality and other clinical outcomes between culture-negative and culture-positive septic patients have been documented inconsistently and are very controversial. A systematic review and meta-analysis was performed to compare the clinical outcomes of culture-negative and culture-positive sepsis or septic shock.

Methods

We searched the PubMed, Cochrane and Embase databases for studies from inception to the 1st of January 2021. We included studies involving patients with sepsis or septic shock. All authors reported our primary outcome of all-cause mortality and clearly compared culture-negative versus culture-positive patients with clinically relevant secondary outcomes (ICU length of stay, hospital length of stay, mechanical ventilation requirements, mechanical ventilation duration and renal replacement requirements). Results were expressed as odds ratio (OR) and mean difference (MD) with accompanying 95% confidence interval (CI).

Results

Seven studies including 22,655 patients were included. The primary outcome of this meta-analysis showed that there was no statistically significant difference in the all-cause mortality between two groups (OR = 0.95; 95% CI, 0.88 to 1.01; P = 0.12; Chi-² = 30.71; I² = 80%). Secondary outcomes demonstrated that there was no statistically significant difference in the ICU length of stay (MD = − 0.19;95% CI, − 0.42 to 0.04; P = 0.10;Chi-² = 5.73; I² = 48%), mechanical ventilation requirements (OR = 1.02; 95% CI, 0.94 to 1.11; P = 0.61; Chi² = 6.32; I² = 53%) and renal replacement requirements (OR = 0.82; 95% CI, 0.67 to 1.01; P = 0.06; Chi-² = 1.21; I² = 0%) between two groups. The hospital length of stay of culture-positive group was longer than that of the culture-negative group (MD = − 3.48;95% CI, − 4.34 to − 2.63; P < 0.00001;Chi-² = 1.03; I² = 0%). The mechanical ventilation duration of culture-positive group was longer than that of the culture-negative group (MD = − 0.64;95% CI, − 0.88 to − 0.4; P < 0.00001;Chi-² = 4.86; I² = 38%).

Conclusions

Culture positivity or negativity was not associated with mortality of sepsis or septic shock patients. Furthermore, culture-positive septic patients had similar ICU length of stay, mechanical ventilation requirements and renal replacement requirements as those culture-negative patients. The hospital length of stay and mechanical ventilation duration of culture-positive septic patients were both longer than that of the culture-negative patients. Further large-scale studies are still required to confirm these results.

Assessing the appropriateness of antimicrobial therapy in patients with sepsis at a Vietnamese national hospital

Objectives

To assess the appropriateness of empirical antimicrobial therapy for sepsis and septic shock and determine factors associated with patient treatment outcomes at a Vietnamese national hospital.

Methods

A cross-sectional study was conducted on 134 patients diagnosed with sepsis and/or septic shock at Thong-Nhat Hospital, Ho Chi Minh City, Vietnam, from January 2018 to June 2018. Appropriateness of antimicrobial therapy was defined as physician adherence to antimicrobial guidelines using the Sanford Guide to Antimicrobial Therapy and the Vietnam national guidelines. Bayesian model averaging technique was used to identify the related factors associated with patient treatment outcomes.

Results

The median age of patients was 70 years. Organisms were identified in 54.5% of cases and predominated by Escherichia coli and staphylococci. Appropriate empirical antimicrobial agents were initiated in 56.6% (n = 73) of all cases. Of these patients, 31 cases (42.5%) and 61 cases (83.6%) received the antimicrobials in accordance with recommendations related to dosage and route of administration, respectively, bringing the overall rate of appropriate empirical antimicrobial therapy down to 23.3%. Patients who progressed to septic shock, received inappropriate antimicrobial therapy and required ICU admission were more likely to suffer treatment failure.

Conclusions

The study findings suggest that clinicians should appropriately adhere to antimicrobial guidelines, especially in patients with septic shock and those who require ICU care, to improve treatment outcomes.

Bacteremic sepsis leads to higher mortality when adjusting for confounders with propensity score matching

One can falsely assume that it is well known that bacteremia is associated with higher mortality in sepsis. Only a handful of studies specifically focus on the comparison of culture-negative and culture-positive sepsis with different conclusions depending on study design. The aim of this study was to describe outcome for critically ill patients with either culture-positive or -negative sepsis in a clinical review. We also aimed to identify subphenotypes of sepsis with culture status included as candidate clinical variables. Out of 784 patients treated in intensive care with a sepsis diagnosis, blood cultures were missing in 140 excluded patients and 95 excluded patients did not fulfill a sepsis diagnosis. Of 549 included patients, 295 (54%) had bacteremia, 90 (16%) were non-bacteremic but with relevant pathogens detected and in 164 (30%) no relevant pathogen was detected. After adjusting for confounders, 90-day mortality was higher in bacteremic patients, 47%, than in non-bacteremic patients, 36%, p = 0.04. We identified 8 subphenotypes, with different mortality rates, where pathogen detection in microbial samples were important for subphenotype distinction and outcome. In conclusion, bacteremic patients had higher mortality than their non-bacteremic counter-parts and bacteremia is more common in sepsis when studied in a clinical review. For reducing population heterogeneity and improve the outcome of trials and treatment for sepsis, distinction of subphenotypes might be useful and pathogen detection an important factor.

Comparing mortality between positive and negative blood culture results: an inverse probability of treatment weighting analysis of a multicenter cohort

Background

The association between blood culture status and mortality among sepsis patients remains controversial hence we conducted a tri-center retrospective cohort study to compare the early and late mortality of culture-negative versus culture-positive sepsis using the inverse probability of treatment weighting (IPTW) method.

Methods

Adult patients with suspected sepsis who completed the blood culture and procalcitonin tests in the emergency department or hospital floor were eligible for inclusion. Early mortality was defined as 30-day mortality, and late mortality was defined as 30- to 90-day mortality. IPTW was calculated from propensity score and was employed to create two equal-sized hypothetical cohorts with similar covariates for outcome comparison.

Results

A total of 1405 patients met the inclusion criteria, of which 216 (15.4%) yielded positive culture results and 46 (21.3%) died before hospital discharge. The propensity score model showed that diabetes mellitus, urinary tract infection, and hepatobiliary infection were independently associated with positive blood culture results. There was no significant difference in early mortality between patients with positive or negative blood culture results. However, culture-positive patients had increased late mortality as compared with culture-negative patients in the full cohort (IPTW-OR, 1.95, 95%CI: 1.14–3.32) and in patients with severe sepsis or septic shock (IPTW-OR, 1.92, 95%CI: 1.10–3.33). After excluding Staphylococcal bacteremia patients, late mortality difference became nonsignificant (IPTW-OR, 1.78, 95%CI: 0.87–3.62).

Conclusions

Culture-positive sepsis patients had comparable early mortality but worse late mortality than culture-negative sepsis patients in this cohort. Persistent Staphylococcal bacteremia may have contributed to the increased late mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05862-w.

Culture-negative sepsis

PURPOSE OF REVIEW

The traditional approach to sepsis treatment utilizes broad-spectrum antibiotics. Unfortunately, a significant proportion of infected patients have 'culture-negative' sepsis despite appropriate microbiologic assessment.

RECENT FINDINGS

There has been increased interest in the past decade on the treatment of culture-negative sepsis. Outcome data comparing culture-negative sepsis with culture-positive sepsis are mixed and it is unclear if culture-negative sepsis is a distinct entity. Recent recommendations promoting antibiotic de-escalation in culture-negative sepsis can be difficult to implement. A variety of strategies have been suggested for limiting antibiotic courses among patients with negative cultures, including limiting antibiotic durations, use of antibiotic stewardship programs, early consideration of narrow antibiotics, rapid diagnostic technology, and eliminating anti-MRSA therapy based on surveillance swabs.

SUMMARY

Owing to the difficulty inherent in studying the lack of positive data, and to the uncertainty surrounding diagnosis in patients with culture-negative sepsis, prospective data to guide antibiotic choices are lacking. However, antibiotic de-escalation in culture-negative sepsis is both recommended and feasible in patients showing clinical signs of improvement. Increased use of rapid diagnostics, careful consideration of antibiotic necessity, and antibiotic stewardship programs may result in less antibiotic days and better outcomes.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members. As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

Safety and Feasibility of Antibiotic De-escalation in Critically Ill Children With Sepsis - A Prospective Analytical Study From a Pediatric ICU

Introduction: De-escalation is the key to balance judicious antibiotic usage for life-threatening infections and reducing the emergence of antibiotic resistance caused by antibiotic overuse. Robust evidence is lacking regarding the safety of antibiotic de-escalation in culture negative sepsis. Materials and Methods: Children admitted to the PICU during the first 6 months of 2019 with suspected infection were included. Based on the clinical condition, cultures and septic markers, antibiotics were de-escalated or continued at 48-72 h. Outcome data like worsening of primary infection, acquisition of hospital acquired infection, level of ICU support and mortality were captured. Results: Among the 360 admissions, 247 (68.6%) children received antibiotics. After excluding 92 children, 155 children with 162 episodes of sepsis were included in the study. Thirty four episodes were not eligible for de-escalation. Among the eligible group of 128 episodes, antibiotics were de-escalated in 95 (74.2%) and continued in 33 (25.8%). The primary infection worsened in 5 (5.2%) children in the de-escalation group and in 1 (3%) in non de-escalation group [Hazard ratio: 2.12 (95%CI: 0.39-11.46)]. There were no significant differences in rates of hospital acquired infection, mortality or length of ICU stay amongst the groups. Blood cultures and assessment of clinical recovery played a major role in de-escalation of antibiotics and the clinician's hesitation to de-escalate in critically ill culture negative children was the main reason for not de-escalating among eligible children. Conclusion: Antibiotic de-escalation appears to be a safe strategy to apply in criticallly ill children, even in those with negative cultures.

Comparison of Vasopressor Duration in Septic Shock Patients With and Without Cirrhosis

BACKGROUND

Patients with cirrhosis have immune dysfunction, altered inflammatory response, and hemodynamic changes which increase risk of septic shock and potentially prolong management with fluids, vasopressors, and other therapies. Due to limited available guidance, this study aimed to characterize vasopressor use in patients with cirrhosis in relation to patients without cirrhosis in septic shock.

METHODS

This was a retrospective matched cohort analysis of 122 patients admitted to the intensive care unit (ICU) at an academic medical center from January 2015 to November 2017. Patients were grouped based on the presence or absence of cirrhosis and matched based on severity of illness scoring. The primary outcome was vasopressor duration. Secondary comparisons included total vasopressor requirement, length of hospital and ICU stay, in-hospital mortality, change in organ function, and discharge disposition.

RESULTS

The group with cirrhosis had significantly longer median (interquartile range [IQR]) durations of vasopressor therapy compared with the group without cirrhosis (86.0 [42.0-164.5] vs 39.0 [14.5-82.0] hours; P = 0.003) leading to increased median (IQR) vasopressor exposure (71.7 [15.5-239.5] vs 24.7 [5.3-77.9] mg norepinephrine [NE] equivalents; P = 0.003). No difference was found in in-hospital mortality between groups. However, regression analysis showed vasopressor exposure was associated with in-hospital mortality.

CONCLUSION AND RELEVANCE

Patients with cirrhosis in septic shock have increased vasopressor durations and overall requirements compared with patients without cirrhosis. Increased durations and requirements is associated with poorer outcomes independent of presence of cirrhosis. Future studies are needed to improve vasopressor treatment strategies and end points utilized in cirrhosis.

A Multi-mRNA Host-Response Molecular Blood Test for the Diagnosis and Prognosis of Acute Infections and Sepsis: Proceedings from a Clinical Advisory Panel

Current diagnostics are insufficient for diagnosis and prognosis of acute infections and sepsis. Clinical decisions including prescription and timing of antibiotics, ordering of additional diagnostics and level-of-care decisions rely on understanding etiology and implications of a clinical presentation. Host mRNA signatures can differentiate infectious from noninfectious etiologies, bacterial from viral infections, and predict 30-day mortality. The 29-host-mRNA blood-based InSep^TM test (Inflammatix, Burlingame, CA, formerly known as HostDx^TM Sepsis) combines machine learning algorithms with a rapid point-of-care platform with less than 30 min turnaround time to enable rapid diagnosis of acute infections and sepsis, as well as prediction of disease severity. A scientific advisory panel including emergency medicine, infectious disease, intensive care and clinical pathology physicians discussed technical and clinical requirements in preparation of successful introduction of InSep into the market. Topics included intended use; patient populations of greatest need; patient journey and sample flow in the emergency department (ED) and beyond; clinical and biomarker-based decision algorithms; performance characteristics for clinical utility; assay and instrument requirements; and result readouts. The panel identified clear demand for a solution like InSep, requirements regarding test performance and interpretability, and a need for focused medical education due to the innovative but complex nature of the result readout. Innovative diagnostic solutions such as the InSep test could improve management of patients with suspected acute infections and sepsis in the ED, thereby lessening the overall burden of these conditions on patients and the healthcare system.