Characteristics and clinical outcomes of culture-negative and culture-positive septic shock: a single-center retrospective cohort study

Culture-negative sepsis may be a different entity from culture-positive sepsis: a prospective nationwide multicenter cohort study

BACKGROUND

The distinction between culture-positive sepsis and culture-negative sepsis regarding clinical characteristics and outcomes remains contentious. We aimed to elucidate these differences using large-scale nationwide data.

METHODS

This prospective cohort study analyzed data from the Korean Sepsis Alliance registry, comprising 21 intensive care units (ICUs) across 20 hospitals from September 2019 to December 2021. Patients meeting the Sepsis-3 criteria were included.

RESULTS

Among 11,981 sepsis patients, 3501 were analyzed, all of whom were referred to the ICU through the emergency department (mean age: 72 ± 13 years; 1976 [56%] males). Of these, 2213 (63%) were culture-positive sepsis and 1288 (37%) were culture-negative sepsis. Compared to the culture-positive sepsis group, the culture-negative sepsis group exhibited less severe illness, with lower Sequential Organ Failure Assessment scores and less deteriorated vital signs. While pulmonary-origin sepsis was common in both groups, culture-negative patients primarily presented with pulmonary infections and had a higher incidence of respiratory failure. In comparison to the culture-positive sepsis group, blood cultures and the administration of empirical antibiotics were performed less promptly in the culture-negative sepsis group. Patients with culture-negative sepsis also showed lower compliance with fluid resuscitation (98.4% vs. 96.9%, p = 0.038; culture-positive sepsis vs. culture-negative sepsis) and received vasopressors earlier (31.1% vs. 35.9%, p = 0.012). In-hospital mortality did not differ significantly between the two groups (31.6% vs. 34.9%, p = 0.073); however, in patients with septic shock, culture-negative sepsis had higher mortality rates (37.6% vs. 45.1%, p = 0.029). The apparent appropriateness of empirical antibiotics in the culture-negative septic shock was higher than that of the culture-positive septic shock (85.2% vs. 96.8%, p < 0.001). Culture-negativity independently predicted poor prognosis in septic shock patients (OR: 1.462, 95% CI [1.060-2.017], p = 0.021).

CONCLUSION

In patients with septic shock, culture-negativity was associated with increased mortality, despite the paradoxically higher appropriateness of empirical antibiotics than culture-positive patients. These contradictory findings suggest that the current criteria for determining the appropriateness of empirical antibiotic therapy may not be valid for culture-negative sepsis.

Effect of low vs. high vancomycin trough level on the clinical outcomes of adult patients with sepsis or gram-positive bacterial infections: a systematic review and meta-analysis

BACKGROUND & OBJECTIVE

The Infectious Disease Society of America guidelines recommend vancomycin trough levels of 15-20 mg/L for severe methicillin-resistant Staphylococcus aureus. However, recent consensus guidelines of four infectious disease organizations no longer recommend vancomycin dosing using minimum serum trough concentrations. Therefore, this study aimed to evaluate the impact of low (< 15 mg/L) vs. high (≥ 15 mg/L) vancomycin trough levels on clinical outcomes in adult patients with sepsis or gram-positive bacterial infections.

METHOD

A systematic literature review from inception to December 2022 was conducted using four online databases, followed by a meta-analysis. The outcomes of interest included clinical response/efficacy, microbial clearance, length of ICU stay, treatment failure, nephrotoxicity, and mortality.

RESULTS

Fourteen cohort studies met the inclusion criteria from which vancomycin trough concentration data were available for 5,228 participants. Our analysis found no association between vancomycin trough levels and clinical response [OR = 1.06 (95%CI 0.41-2.72], p = 0.91], microbial clearance [OR = 0.47 (95% CI 0.23-0.96), p = 0.04], ICU length of stay [MD=-1.01 (95%CI -5.73-3.71), p = 0.68], or nephrotoxicity [OR = 0.57 (95% CI 0.31-1.06), p = 0.07]. However, low trough levels were associated with a non-significant trend towards a lower risk of treatment failure [OR = 0.89 (95% CI 0.73-1.10), p = 0.28] and were significantly associated with reduced risk of all-cause mortality [OR = 0.74 (95% CI 0.62-0.90), p = 0.002].

CONCLUSION

Except for a lower risk of treatment failure and all-cause mortality at low vancomycin trough levels, this meta-analysis found no significant association between vancomycin trough levels and clinical outcomes in adult patients with sepsis or gram-positive bacterial infections.

Lactate/Pyruvate Ratio as an Early Predictor of Mortality in Patients with Sepsis: A Cohort Study

Background: The lactate/pyruvate (LP) ratio has been studied as an alternative to serum lactate to determine clinical prognosis. Despite its clinical utility, there is a paucity of evidence evaluating the role of the L/P ratio in patients with sepsis. Methods: We assessed the clinical utility of the L/P ratio in patients with sepsis. The L/P ratio was measured at baseline, 4 and 8 h after admission. Our primary outcome was to determine the prognostic utility of the L/P ratio on the 15-day mortality risk. Our secondary outcomes were to compare the L/P ratio across time and its prognostic utility against standard risk calculators such as APACHE-II and SOFA scores. Results: We had a total of 80 patients, with 18 (22.5%) survivors and 62 (77.5%) non-survivors. While we found that patients having higher L/P ratios at 8 h had an increased 30-mortality risk (OR 1.08, 95% CI 1.02-1.18), the model's performance showed no difference when compared to other measurements of the L/P ratio that showed no association with mortality (p-value: 0.45). For our secondary outcome, we found that the APACHE-II and SOFA scores have better performance and predictability than the L/P ratio (AUC 0.83 and AUC 0.80, respectively), but showed no association with mortality (OR 1.07, 95% CI 1.01-1.17 and OR 1.08, 95% CI 1.02-1.18). Conclusions: Based on our findings, the L/P ratio appears to function more effectively as an early predictor of mortality when used as an adjuvant biomarker with other clinical parameters.

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.

Evaluation of 16S-Based Metagenomic NGS as Diagnostic Tool in Different Types of Culture-Negative Infections

Bacterial infections pose significant global health challenges, often underestimated due to difficulties in accurate diagnosis, especially when culture-based diagnostics fail. This study assesses the effectiveness of 16S-based metagenomic next generation sequencing (NGS) for identifying pathogens in culture-negative clinical samples across various medical settings. Overall, 48% of samples were collected from orthopedics, 15% from neurosurgery, and 12% in cardiac surgery, among others. The detection rate of monomicrobial infections was 68.6%, and 5.7% for polymicrobial infections. In addition, NGS detected bacteria in all samples from the lungs, head and neck, and eye specimens. Cutibacterium acnes (11%, 12/105) was the most frequent microorganism, followed by Staphylococcus epidermidis (10.4%, 11/105), and Staphylococcus aureus (9.5%, 10/105). In conclusion, 16S-targeted metagenomic sequencing enhances pathogen detection capabilities, particularly in instances where traditional cultures fail. By the combination of NGS and bacterial cultures, microbiologists might provide a more accurate diagnosis, guiding more effective treatments and potentially reducing healthcare costs associated with empirical treatments.

Impact of Appropriate Empirical Antibiotic Treatment on the Clinical Response of Septic Patients in Intensive Care Unit: A Single-Center Observational Study

The appropriate antibiotic treatment of patients with bacterial sepsis in the intensive care unit (ICU) remains a challenge. Considering that current international guidelines recommend 7 days of antibiotic therapy as sufficient for most severe infections, our primary outcome was a comparison of clinical response to initial empirical therapy on day 7 and mortality between two groups of septic patients-with appropriate (AEAT) and inappropriate (IEAT) empirical antibiotic therapy according to the in vitro sensitivity of bacteria detected in a blood culture (BC). Adult patients admitted to the ICU between 2020 and 2023, who were diagnosed with sepsis according to the Sequential Organ Failure Assessment (SOFA) score ≥ 2 in association with a suspected or documented infection, were selected for the study. Of the 418 patients, 149 (35.6%) died within 7 days. Although the AEAT group had a lower mortality rate (30.3% vs. 34.2%) and better clinical improvement (52.8% vs. 47.4%) on day 7 after starting empirical antibiotic therapy, there was no significant difference. A causative organism was isolated from BCs in 30% of septic patients, with gram-negative bacteria (GNB) predominating in 60% of cases, and multidrug-resistant (MDR) or extensively drug-resistant (XDR) bacteria predominantly detected in the BCs of the IEAT group. Although the AEAT group had slightly worse clinical characteristics at the onset of sepsis than the IEAT group, the AEAT group showed faster improvement on days 7 and 14 of sepsis. In this retrospective cross-sectional study, the AEAT group was associated with better clinical response at day 7 after sepsis onset and lower mortality, but without a significant difference. Comorbidities and the type of bacterial pathogen should also be taken into account as they can also contribute to the prediction of the final outcome. These results demonstrate the importance of daily assessment of clinical factors to more accurately predict the clinical outcome of a septic patient.

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.

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.

Association between positive blood culture and clinical outcomes among children treated for sepsis in the emergency department

OBJECTIVE

Among children treated for sepsis in a pediatric emergency department (ED), compare clinical features and outcomes between those with blood cultures positive versus negative for a bacterial pathogen.

DESIGN

Single-center retrospective cohort study.

SETTING

Pediatric emergency department (ED) at a quaternary pediatric care center.

PATIENTS

Children aged 0-18 years treated for sepsis defined by the Children's Hospital Association's Improving Pediatric Sepsis Outcomes (IPSO) definition.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We analyzed 1307 patients treated for sepsis during the study period, of which 117 (9.0%) had blood cultures positive for a bacterial pathogen. Of children with blood culture positive sepsis, 62 (53.0%) had organ dysfunction compared to 514 (43.2%) with culture negative sepsis (adjusted odds ratio 1.56, 95% confidence interval (CI) 1.04-2.34, adjusting for age, high risk medical conditions, and time to antibiotics). Children with blood culture positive sepsis had a larger base deficit, -4 vs -1 (p < 0.01), and higher procalcitonin, 3.84 vs 0.56 ng/mL (p < 0.01).

CONCLUSIONS

Children meeting the IPSO Sepsis definition with blood culture positive for a bacterial pathogen have higher rates of organ dysfunction than those who are culture negative, although our 9% rate of blood culture positivity is lower than previously cited literature from the pediatric intensive care unit.

The microbial pathology of maternal perinatal sepsis: A single-institution retrospective five-year review

INTRODUCTION

Greater than half of in-hospital maternal deaths are caused by sepsis, a condition that occurs when infection exceeds local tissue containment and results in organ dysfunction. Determining the source of infection can be challenging. Microbiological cultures of the uterine cavity are often difficult to obtain, so antimicrobial susceptibility results may not be available to guide treatment. The aim of this retrospective study was to assess the potential clinical value of microbiology samples used in the maternal "septic screen" of patients in an Irish maternity hospital.

METHODS

A review was completed of all maternal "septic screen" (i.e., high vaginal swabs, placenta swabs, blood cultures, throat swabs and urine samples) microbiology results from July 2016 to December 2021.

RESULTS

In the relevant period, 845 patients were subject to a "septic screen", of whom 430 also had a placental swab collected. These 430 patients comprise our study population. 2% of blood cultures yielded potential pathogens, compared with 37%, 33%, 9% and 7% respectively for placental swabs, high vaginal swabs, throat swabs and urine specimens. 95% of blood cultures were sterile, compared with 52%, 0%, 0% and 53% respectively for placental swabs, high vaginal swabs, throat swabs and urine specimens.

CONCLUSION

Of the five microbiological specimen types examined, placental swabs yielded the highest number of potential pathogens. Our results suggest that placental swabs are useful specimens for detecting potential pathogens from the uterine cavity, the most common source of perinatal infections.

The value of plasma presepsin as a diagnostic and prognostic biomarker for sepsis in Southern China

BACKGROUND

Presepsin is a soluble CD14 subtype that has been considered as a novel marker for patients with sepsis. This study explored the clinical value of presepsin for sepsis in Southern China, and further established models for diagnosis and prognosis of sepsis through using machine learning (ML), by combining presepsin and other laboratory parameters.

METHODS

269 subjects (105 infected patients, 164 sepsis and septic shock) and 198 healthy controls were enrolled. Laboratory parameters (hematological parameters, coagulation parameters, liver function indices, renal function indices, and inflammatory markers) were collected. Plasma presepsin was tested by chemiluminescence enzyme immunoassay. ML of DxAI™ Research platform was used to establish diagnostic and prognostic models. Sensitivity, specificity, and other performance indicators were used to evaluate the performance of each model.

RESULTS

The level of presepsin was obviously increased in sepsis and sepsis shock, compared with that of infected and healthy group (all P < 0.0001). Presepsin concentration was positively correlated with positive blood culture and 30-day mortality in sepsis and septic shock patients. Through ROC curve analysis, Hb, UREA, APTT, CRP, PCT, and presepsin were incorporated into machine learning to construct diagnosis models. Ada Boost model had the best diagnostic efficiency (AUC: 0.94 (95% CI 0.919-0.968) in the training set and AUC: 0.86 (95% CI 0.813-0.900) in validation set). Furthermore, AST, APTT, UREA, PCT, and presepsin were included in the prognosis ML models, and the Bernoulli NB model had greater predictive ability for 30-day mortality risk of sepsis (AUC: 0.706), which was higher than that of PCT (AUC: 0.617) and presepsin (AUC: 0.634) alone.

CONCLUSION

Machine-learning model based on presepsin and routinely laboratory parameters showed good performance of diagnostic and prognostic ability for sepsis patients.

Modification of Initial Empirical Antibiotic Prescription and its Impact on Patient Outcome: Experience of an Indian Intensive Care Unit

Introduction

Data on the overall impact of antibiotic modification following initial empiric prescription in both culture-positive and culture-negative critically ill patients are exiguous.

Materials and methods

In a retrospective analysis of "ANT-CRITIC" study, we classified ICU patients receiving empirical antibiotics who remained in the ICU for >72 hours or till availability of culture results (whichever is longer) into five groups based on culture results and antibiotic modification: negative culture, no change (group I), positive culture, no change (group II), positive culture, de-escalation (group III), positive culture, escalation (group IV) and negative culture, antibiotic modification (group V). Baseline variables and clinical outcomes were compared. Logistic regression analysis was performed to look for independent variables associated with mortality.

Results

276 prescription episodes were analyzed. Group II was associated with worsening organ dysfunction at 72 hours, lower clinical cure rate at day 7, and higher hospital mortality. There was an independent association between group II prescription and hospital mortality [adjusted OR 2.774 (CI 1.178-6.533), p = 0.02]. Group III received longer duration of antibiotic (mean duration = 8.27 ± 4.11 days, median duration = 7 days [IQR 5-11]).

Conclusion

Outcomes of critically ill infected patients differ significantly when they are classified based on culture result and antibiotic modification pattern.

How to cite this article

Ghosh S, Singh A, Lyall A. Modification of Initial Empirical Antibiotic Prescription and its Impact on Patient Outcome: Experience of an Indian Intensive Care Unit. Indian J Crit Care Med 2023;27(8):583-589.

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.

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.

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.

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.

The Impact of Myosteatosis Percentage on Short-Term Mortality in Patients with Septic Shock

The impact of myosteatosis on septic patients has not been fully revealed. The aim of the study was to evaluate the impact of the myosteatosis area and percentage on the 28-day mortality in patients with septic shock. We conducted a single center, retrospective study from a prospectively collected registry of adult patients with septic shock who presented to the emergency department and performed abdominal computed tomography (CT) from May 2016 to May 2020. The myosteatosis area defined as the sum of low attenuation muscle area and intramuscular adipose tissue at the level of the third lumbar vertebra was measured by CT. Myosteatosis percentages were calculated by dividing the myosteatosis area by the total abdominal muscle area. Of the 896 patients, 28-day mortality was 16.3%, and the abnormal myosteatosis area was commonly detected (81.7%). Among variables of body compositions, non-survivors had relatively lower normal attenuation muscle area, higher low attenuation muscle area, and higher myosteatosis area and percentage than that of survivors. Trends of myosteatosis according to age group were different between the male and female groups. In subgroup analysis with male patients, the multivariate model showed that the myosteatosis percentage (adjusted OR 1.02 [95% CI 1.01–1.03]) was an independent risk factor for 28-day mortality. However, this association was not evident in the female group. Myosteatosis was common and high myosteatosis percentage was associated with short-term mortality in patients with septic shock. Our results implied that abnormal fatty disposition in muscle could impact on increased mortality, and this effect was more prominent in male patients.

The Correlation Between the Types of Initial Bacterial Infection and Clinical Prognosis in Patients With Septic AKI

Background

Acute kidney injury (AKI) is a common complication of sepsis and is an independent risk factor for mortality. It is unclear whether different bacteria play different roles in the occurrence and development of sepsis-associated AKI (S-AKI). We observed the clinical characteristics and outcomes of patients that have types of bacterial infection, and different infections sites before the occurrence of AKI, respectively.

Methods

Data of patients who were diagnosed with sepsis and later developed AKI from 2008 to 2019 were retrieved from the MIMIC-IV 1.0 database. Patients were first divided into the two groups according to the bacterial culture results obtained prior to AKI occurrence: bacterial cultured positive (N = 1,785) and bacterial cultured negative (N = 8,777). Patients with bacteria culture positive were divided into culture bacteria Gram-positive (CGP, N = 1248) and Gram-negative (CGN, N = 537) groups.

Results

Overall, 1,785 patients were included in the present analysis. The patients in CGN group were older (70 vs. 66, p < 0.001), had lower body mass index (BMI) (27.0 vs. 28.4, p < 0.001), higher acute physiology III (APS III) score (63.0 vs. 58, p = 0.001), shorter time from positive microbial culture to diagnosis of AKI (2.94 vs. 3.16 days, p = 0.013) and longer intensive care unit (ICU) stay time (5.94 vs. 4.77 days, p < 0.001) compared with those in the CGP group (n = 1,248). In the culture gram-negative bacteria in patients with positive blood cultures (CGNb) group, the rate of vasopressors using (73.1 vs. 56.4%, P = 0.007), the Sequential Organ Failure Assessment (SOFA) score (10 vs. 9, p = 0.005), and the level of lactate (3.7 vs. 2.5, p = 0.001) were higher than those in the culture gram-positive bacteria in patients with positive blood cultures (CGPb) group. The time from positive microbial culture to the diagnosis of AKI was shorter (2.23 vs. 3 days, p = 0.001) in the CGNb group. However, there was no significant difference in the continuous renal replacement treatment (CRRT) application or short-term mortality rates between CGN and CGP groups.

Conclusion

The Gram types of bacteria cultured prior to S-AKI occurrence was not related to AKI stage, CRRT application, and short-term mortality. Compared with the Gram-positive bacterial infections, Gram-negative bacterial infections take a shorter time to develop into AKI, and had a higher disease severity score.

Comparing outcomes between culture-positive and culture-negative septic shock in a PICU: A retrospective cohort study

BACKGROUND

We assessed the outcomes and characteristics of culture-negative septic shock (CNSS) and culture-positive septic shock (CPSS) in pediatric intensive care unit (PICU).

METHODS

We performed a retrospective study on the data of children admitted to the PICU due to septic shock between January 2018 and December 2021. The primary outcome was in-hospital mortality. The secondary outcomes were the length of stay (LOS) of hospital, the need for mechanical ventilation (MV) and continue renal replacement therapy (CRRT).

RESULTS

Overall, 238 patients were enrolled. 114 patients (47.9%) had positive cultures (60 blood samples, 41 sputum samples, 17 pus samples, and 19 others), 18 of whom were cultured positive at two sites, 1 at three sites, and 3 had two different types of bacteria at same site. The in-hospital mortality was 47.1%. There were no significant differences in the in-hospital mortality (47.6% vs. 46.5%, P = 0.866), PRISM-III score (10 vs. 12, P = 0.409), PIM-3 score (0.08 vs. 0.07, P = 0.845), pSOFA score (10 vs. 10, P = 0.677) or the need for MV (64.5% vs. 68.4%, P = 0.524) and CRRT (29.8% vs. 34.2%, P = 0.470) between the CNSS group and the CPSS group. The Procalcitonin (8.89 ng/ml vs. 28.39 ng/ml, P = 0.001) and C-reactive protein (28 mg/L vs. 58 mg/L, P = 0.001) levels were significantly lower in the CNSS group than in the CPSS group, while WBC count (9.03 × 10⁹/L vs. 5.02 × 10⁹/L, P = 0.002) and serum sodium (137 mmol/L vs. 132 mmol/L, P = 0.001) was significantly higher in CNSS. The LOS of hospital was significantly longer (16 days vs. 11 days, P = 0.011) in the CPSS group than in the CNSS group, while the LOS of PICU (5 days vs. 4 days, P = 0.094) stay was not significantly different.

CONCLUSION

Compared with children with CNSS, children with CPSS had higher PCT and CRP levels, but lower WBC count. Children with CPSS had longer LOS of hospital. However, positive or negative culture results were not associated with in-hospital mortality, the LOS of PICU, the need for MV or CRRT in children with septic shock.

Multidrug-resistant organisms: A significant cause of severe sepsis in pediatric intestinal and multi-visceral transplantation

Severe sepsis in immunocompromised children is associated with increased mortality. This paper describes the epidemiology landscape, clinical acuity, and outcomes for severe sepsis in pediatric intestinal (ITx) and multi-visceral (MVTx) transplant recipients requiring admission to the pediatric intensive care unit (PICU). Severe sepsis episodes were retrospectively reviewed in 51 ITx and MVTx patients receiving organs between 2009 and 2015. Twenty-nine (56.8%) patients had at least one sepsis episode (total of 63 episodes) through December 2016. Bacterial etiologies accounted for 66.7% of all episodes (n = 42), occurring a median of 122.5 days following transplant (IQR 59-211.8 days). Multidrug-resistant organisms (MDROs) accounted for 73.8% of bacterial infections; extended spectrum beta-lactamase producers, vancomycin-resistant enterococcus, and highly-resistant Pseudomonas aeruginosa were the most commonly identified. Increased mechanical ventilation and vasoactive requirements were noted in MDRO episodes (OR 3.03, 95% CI 1.09-8.46 and OR 3.07, 95% CI 1.09-8.61, respectively; p < .05) compared to non-MDRO episodes. PICU length of stay was significantly increased for MDRO episodes (7 vs. 3 days, p = .02). Graft loss was 24.1% (n = 7) and mortality was 24.1% (n = 7) in patients who experienced severe sepsis. Further attention is needed for MDRO risk mitigation and modification of sepsis treatment guidelines to ensure MDRO coverage for this population.

Culture positivity may correlate with long-term mortality in critically ill patients

Background

The long-term outcome is currently a crucial issue in critical care, and we aim to address the association between culture positivity and long-term mortality in critically ill patients.

Methods

We used the 2015–2019 critical care database at Taichung Veterans General Hospital and Taiwanese nationwide death registration files. Multivariable Cox proportional hazards regression model was conducted to determine hazard ratio (HR) and 95% confidence interval (CI).

Results

We enrolled 4488 critically ill patients, and the overall mortality was 55.2%. The follow-up duration among survivors was 2.2 ± 1.3 years. We found that 52.6% (2362/4488) of critically ill patients had at least one positive culture during the admission, and the number of patients with positive culture in the blood, respiratory tract and urinary tract were 593, 1831 and 831, respectively. We identified that a positive culture from blood (aHR 1.233; 95% CI 1.104–1.378), respiratory tract (aHR 1.217; 95% CI 1.109–1.364) and urinary tract (aHR 1.230; 95% CI 1.109–1.364) correlated with an increased risk of long-term mortality after adjusting relevant covariates.

Conclusions

Through linking two databases, we found that positive culture in the blood, respiratory tract and urinary tract during admission correlated with increased long-term overall mortality in critically ill patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06898-8.

The association between culture positivity and long-term mortality in critically ill surgical patients

BACKGROUND

The long-term outcome is an essential issue in critically ill patients, and the identification of early determinant is needed for risk stratification of the long-term outcome. In the present study, we investigate the association between culture positivity during admission and long-term outcome in critically ill surgical patients.

METHODS

We linked the 2015-2019 critical care database at Taichung Veterans General Hospital with the nationwide death registration files in Taiwan. We described the long-term mortality and proportion of culture positivity among enrolled subjects. We used a log-rank test to estimate survival curves between patients with and without positive cultures and a multivariable Cox proportional hazards regression model to determine hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

A total of 6748 critically ill patients were enrolled, and 32.5% (2196/6749) of them died during the follow-up period, with the overall follow-up duration was 1.8 ± 1.4 years. We found that 31.4% (2122/6748) of critically ill patients had at least one positive culture during the index admission, and the number of patients with positive culture in the blood, respiratory tract, urinary tract, skin and soft tissue and abdomen were 417, 1702, 554, 194 and 139, respectively. We found that a positive culture from any sites was independently associated with high long-term mortality (aHR 1.579, 95% CI 1.422-1.754) after adjusting relevant covariates, including age, sex, body-mass index, comorbidities, severity score, shock, early fluid overload, receiving mechanical ventilation and the need of renal replacement therapy for critical illness.

CONCLUSIONS

We linked two databases to identify that a positive culture during admission was independently correlated with increased long-term mortality in critically ill surgical patients. Our findings highlight the need for vigilance among patients with a positive culture during admission, and more studies are warranted to validate our findings and to clarify underlying mechanisms.

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.

Mortality and associated risk factors in patients with blood culture positive sepsis and acute kidney injury requiring continuous renal replacement therapy-A retrospective study

Objectives

Septic acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) carries a mortality risk nearing 50%. Risk factors associated with mortality in AKI patients undergoing CRRT with blood culture positive sepsis remain unclear as sepsis has been defined according to consensus criteria in previous studies.

Methods

Risk factors associated with intensive care unit (ICU), 90-day and overall mortality were studied in a retrospective cohort of 126 patients with blood culture positive sepsis and coincident severe AKI requiring CRRT. Comprehensive laboratory and clinical data were gathered at ICU admission and CRRT initiation.

Results

38 different causative pathogens for sepsis and associated AKI were identified. ICU mortality was 30%, 90-day mortality 45% and one-year mortality 50%. Immunosuppression, history of heart failure, APACHE II and SAPS II scores, C-reactive protein and lactate at CRRT initiation were independently associated with mortality in multivariable Cox proportional hazards models. Blood lactate showed good predictive power for ICU mortality in receiver operating characteristic curve analyses with AUCs of 0.76 (95%CI 0.66–0.85) for lactate at ICU admission and 0.84 (95%CI 0.72–0.95) at CRRT initiation.

Conclusions

Our study shows for the first time that lactate measured at CRRT initiation is predictive of ICU mortality and independently associated with overall mortality in patients with blood culture positive sepsis and AKI requiring CRRT. Microbial etiology for septic AKI requiring CRRT is diverse.