Clinical and laboratory variables identifying bacterial infection and bacteraemia in the emergency department

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.

Detection and Analysis of Commonly Used Infection Indicators in Patients with Acute Urticaria

INTRODUCTION

In this study, we investigated the correlation and clinical significance of peripheral blood leukocytes, neutrophils, C-reactive protein (CRP), and procalcitonin (PCT) in patients with acute urticaria.

METHODS

Complete blood count with differential, CRP, and PCT tests were conducted on patients with acute urticaria. A total of 614 patients with acute urticaria were divided into three groups: the first group consisted of patients with elevated leukocyte and neutrophil count, the second group consisted of patients with normal leukocyte and neutrophil count, and the third group consisted of patients with abnormal leukocyte and neutrophil count. A correlation analysis was conducted to investigate the levels of leukocytes, neutrophils, CRP, and PCT in the three groups.

RESULTS

The results of Kruskal-Wallis' nonparametric test revealed statistically significant variations in leukocytes, neutrophils, CRP, and PCT among the three groups (p < 0.001). However, CRP and PCT showed no statistically significant differences between the second and third groups (p < 0.001, p = 0.0041, p = 0.0032). Additional multiple comparisons in Spearman correlation analysis indicated statistically significant differences (p = 0.55). Across all groups, there was a statistically significant difference in the correlation between CRP-PCT and leukocytes-neutrophils (p = 0.53).

CONCLUSION

Leukocytes and neutrophils are sensitive to the impact of medications and stress on the body. Combining CRP and PCT, as well as routine blood test, may be a comprehensive assessment of infection presence and severity in patients, providing guidance for antibiotic treatment.

Hemoglobin and Its Z Score Reference Intervals in Febrile Children: A Cohort Study of 98,572 Febrile Children

OBJECTIVES

Febrile disease and age of children were associated with a variation in hemoglobin (Hb) level. Both CRP and Hb serve as laboratory markers that offer valuable insights into a patient's health, particularly in relation to inflammation and specific medical conditions. Although a direct correlation between CRP and Hb levels is not established, the relationship between these markers has garnered academic attention and investigation. This study aimed to determine updated reference ranges for Hb levels for age and investigated its correlation with CRP in febrile children under the age of 18.

METHODS

This is a cohort study of in Chang Gung Memorial Hospitals conducted from January 2010 to December 2019. Blood samples were collected from 98,572 febrile children who were or had been admitted in the pediatric emergency department. The parameters of individuals were presented as the mean ± standard deviation or 2.5th and 97.5th percentiles. We also determined the variation of Hb and Z score of Hb between CRP levels in febrile children.

RESULT

We observed that the Hb levels were the highest immediately after birth and subsequently underwent a rapid decline, reaching their lowest point at around 1-2 months of age, and followed by a steady increment in Hb levels throughout childhood and adolescence. In addition, there was a significant and wide variation in Hb levels during the infant period. It revealed a significant association between higher CRP levels and lower Hb levels or a more negative Z score of Hb across all age subgroups. Moreover, in patients with bacteremia, CRP levels were higher, Hb concentrations were lower, and Z scores of Hb were also lower compared to the non-bacteremia group. Furthermore, the bacteremia group exhibited a more substantial negative correlation between CRP levels and a Z score of Hb (r = -0.41, p < 0.001) compared to the non-bacteremia group (r = -0.115, p < 0.049).

CONCLUSION

The study findings revealed that the Hb references varied depending on the age of the children and their CRP levels. In addition, we established new reference values for Hb and its Z scores and explore their relationship with CRP. It provides valuable insights into the Hb status and its potential association with inflammation in febrile pediatric patients.

Development and validation of machine learning-driven prediction model for serious bacterial infection among febrile children in emergency departments

Serious bacterial infection (SBI) in children, such as bacterial meningitis or sepsis, is an important condition that can lead to fatal outcomes. Therefore, since it is very important to accurately diagnose SBI, SBI prediction tools such as ‘Refined Lab-score’ or ‘clinical prediction rule’ have been developed and used. However, these tools can predict SBI only when there are values of all factors used in the tool, and if even one of them is missing, the tools become useless. Therefore, the purpose of this study was to develop and validate a machine learning-driven model to predict SBIs among febrile children, even with missing values. This was a multicenter retrospective observational study including febrile children <6 years of age who visited Emergency departments (EDs) of 3 different tertiary hospitals from 2016 to 2018. The SBI prediction model was trained with a derivation cohort (data from two hospitals) and externally tested with a validation cohort (data from a third hospital). A total of 11,973 and 2,858 patient records were included in the derivation and validation cohorts, respectively. In the derivation cohort, the area under the receiver operating characteristic curve (AUROC) of the RF model was 0.964 (95% confidence interval [CI], 0.943–0.986), and the area under the precision-recall curve (AUPRC) was 0.753 (95% CI, 0.681–0.824). The conventional LR (CLR) model showed corresponding values of 0.902 (95% CI, 0.894–0.910) and 0.573 (95% CI, 0.560–0.586), respectively. In the validation cohort, the AUROC (95% CI) of the RF model was 0.950 (95% CI, 0.945–0.956), the AUPRC was 0.605 (95% CI, 0.593–0.616), and the CLR presented corresponding values of 0.815 (95% CI, 0.789–0.841) and 0.586 (95% CI, 0.553–0.619), respectively. We developed a machine learning-driven prediction model for SBI among febrile children, which works robustly despite missing values. And it showed superior performance compared to CLR in both internal validation and external validation.

The Interrelationship between Liver Function Test and the Coronavirus Disease 2019: A Systematic Review and Meta-Analysis

Background

The outbreak of the coronavirus disease-2019 (COVID-19) has become a global public health challenge. Assessing the effect of COVID-19 on liver injury is of great importance. A systematic review and meta-analysis were conducted to establish the characteristics of liver function tests in COVID-19 patients.

Methods

A systematic search of publications from December 2019 up to April 2020 in Web of Science, Scopus, and Medline (via PubMed) databases was performed. Both cross-sectional and case series studies reporting an association between liver injury and COVID-19 infection were included. The data were analyzed using the STATA software (version 11.0) and the random-effects model for I2>50% was used to pool the results.

Results

In this meta-analysis, 42 articles comprising a total of 6,557 COVID-19 patients were studied. The prevalence of increase in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels was 30% and 21% in non-severe patients and 38% and 48% in severe patients, respectively. Patients with severe COVID-19 infection were 4.22, 4.96, and 4.13 times more likely to have elevated AST, ALT, and lactate dehydrogenase (LDH) levels, respectively.

Conclusion

Elevation in liver function tests was higher in patients with severe than non-severe COVID-19 infection. Given the widespread use of drugs that increases the risk of hepatotoxicity, healthcare providers should be aware of changes in liver enzymes in COVID-19 patients. The inclusion of other studies from outside China could confirm the pattern of elevation in liver function tests in COVID-19 patients across the globe. Preprint of this article is available on medRxiv, https://www.medrxiv.org/content/10.1101/2020.05.20.20108357v1.

Optimal combination of early biomarkers for infection and sepsis diagnosis in the emergency department: The BIPS study

OBJECTIVE

To define the best combination of biomarkers for the diagnosis of infection and sepsis in the emergency room.

METHODS

In this prospective study, consecutive patients with a suspicion of infection in the emergency room were included. Eighteen different biomarkers measured in plasma, and twelve biomarkers measured on monocytes, neutrophils, B and T-lymphocytes were studied and the best combinations determined by a gradient tree boosting approach.

RESULTS

Overall, 291 patients were included and analysed, 148 with bacterial infection, and 47 with viral infection. The best biomarker combination which first allowed the diagnosis of bacterial infection, included HLA-DR (human leukocyte antigen DR) on monocytes, MerTk (Myeloid-epithelial-reproductive tyrosine kinase) on neutrophils and plasma metaloproteinase-8 (MMP8) with an area under the curve (AUC) = 0.94 [95% confidence interval (IC95): 0.91;0.97]. Among patients in whom a bacterial infection was excluded, the combination of CD64 expression, and CD24 on neutrophils and CX3CR1 on monocytes ended to an AUC = 0.98 [0.96;1] to define those with a viral infection.

CONCLUSION

In a convenient cohort of patients admitted with a suspicion of infection, two different combinations of plasma and cell surface biomarkers were performant to identify bacterial and viral infection.

COVID-19 and multiorgan failure: A narrative review on potential mechanisms

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) in December 2019 form Wuhan, China leads to coronavirus disease 2019 (COVID-19) pandemic. While the common cold symptoms are observed in mild cases, COVID-19 is accompanied by multiorgan failure in severe patients. The involvement of different organs in severe patients results in lengthening the hospitalization duration and increasing the mortality rate. In this review, we aimed to investigate the involvement of different organs in COVID-19 patients, particularly in severe cases. Also, we tried to define the potential underlying mechanisms of SARS-CoV2 induced multiorgan failure. The multi-organ dysfunction is characterized by acute lung failure, acute liver failure, acute kidney injury, cardiovascular disease, and as well as a wide spectrum of hematological abnormalities and neurological disorders. The most important mechanisms are related to the direct and indirect pathogenic features of SARS-CoV2. Although the presence of angiotensin-converting enzyme 2, a receptor of SARS-CoV2 in the lung, heart, kidney, testis, liver, lymphocytes, and nervous system was confirmed, there are controversial findings to about the observation of SARS-CoV2 RNA in these organs. Moreover, the organ failure may be induced by the cytokine storm, a result of increased levels of inflammatory mediators, endothelial dysfunction, coagulation abnormalities, and infiltration of inflammatory cells into the organs. Therefore, further investigations are needed to detect the exact mechanisms of pathogenesis. Since the involvement of several organs in COVID-19 patients is important for clinicians, increasing their knowledge may help to improve the outcomes and decrease the rate of mortality and morbidity.

Liver impairment in COVID-19 patients: A retrospective analysis of 115 cases from a single centre in Wuhan city, China

BACKGROUND

The SARS-CoV-2 pandemic is an ongoing global health emergency. The aim of our study was to investigate the changes of liver function and its clinical significance in COVID-19 patients.

METHOD

This retrospective, single-centre study was conducted on 115 confirmed cases of COVID-19 in Zhongnan hospital of Wuhan University from 18 January 2020 to 22 February 2020. Liver function and related indexes were analysed to evaluate its relationship with disease progression in COVID-19 patients.

RESULTS

Part of the COVID-19 patients presented with varying degrees of abnormality in liver function indexes. However, the levels of ALT, AST, TBIL, GGT and LDH in COVID-19 patients were not significantly different when compared with hospitalised community-acquired pneumonia patients, and the levels of albumin is even significantly higher. The levels of ALT, AST, TBIL, LDH and INR showed statistically significant elevation in severe COVID-19 cases compared with that in mild cases. However, the clinical significance of the elevation is unremarkable. Majority of severe COVID-19 patients showed significantly decreasing in albumin level and continuously decreasing in the progress of illness. Most of the liver function indexes in COVID-19 patients were correlated with CRP and NLR, the markers of inflammation. Logistic regression analysis further identified NLR as the independent risk factor for severe COVID-19, as well as age.

CONCLUSIONS

Although abnormalities of liver function indexes are common in COVID-19 patients, the impairment of liver function is not a prominent feature of COVID-19, and also may not have serious clinical consequences.

Plasma interleukin-6 concentration for the diagnosis of sepsis in critically ill adults

BACKGROUND

The definition of sepsis has evolved over time, along with the clinical and scientific knowledge behind it. For years, sepsis was defined as a systemic inflammatory response syndrome (SIRS) in the presence of a documented or suspected infection. At present, sepsis is defined as a life-threatening organ dysfunction resulting from a dysregulated host response to infection. Even though sepsis is one of the leading causes of mortality in critically ill patients, and the World Health Organization (WHO) recognizes it as a healthcare priority, it still lacks an accurate diagnostic test. Determining the accuracy of interleukin-6 (IL-6) concentrations in plasma, which is proposed as a new biomarker for the diagnosis of sepsis, might be helpful to provide adequate and timely management of critically ill patients, and thus reduce the morbidity and mortality associated with this condition.

OBJECTIVES

To determine the diagnostic accuracy of plasma interleukin-6 (IL-6) concentration for the diagnosis of bacterial sepsis in critically ill adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, and Web of Science on 25 January 2019. We screened references in the included studies to identify additional studies. We did not apply any language restriction to the electronic searches.

SELECTION CRITERIA

We included diagnostic accuracy studies enrolling critically ill adults aged 18 years or older under suspicion of sepsis during their hospitalization, where IL-6 concentrations were evaluated by serological measurement.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and extracted data. We assessed the methodological quality of studies using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. We estimated a summary receiver operating characteristic (SROC) curve by fitting a hierarchical summary ROC (HSROC) non-linear mixed model. We explored sources of heterogeneity using the HSROC model parameters. We conducted all analyses in the SAS statistical software package and R software.

MAIN RESULTS

We included 23 studies (n = 4192) assessing the accuracy of IL-6 for the diagnosis of sepsis in critically ill adults. Twenty studies that were available as conference proceedings only are awaiting classification. The included participants were heterogeneous in terms of their distribution of age, gender, main diagnosis, setting, country, positivity threshold, sepsis criteria, year of publication, and origin of infection, among other factors. Prevalence of sepsis greatly varied across studies, ranging from 12% to 78%. We considered all studies to be at high risk of bias due to issues related to the index test domain in QUADAS-2. The SROC curve showed a great dispersion in individual studies accuracy estimates (21 studies, 3650 adult patients), therefore the considerable heterogeneity in the collected data prevented us from calculating formal accuracy estimates. Using a fixed prevalence of sepsis of 50% and a fixed specificity of 74%, we found a sensitivity of 66% (95% confidence interval 60 to 72). If we test a cohort 1000 adult patients under suspicion of sepsis with IL-6, we will find that 330 patients would receive appropriate and timely antibiotic therapy, while 130 patients would be wrongly considered to have sepsis. In addition, 370 out of 1000 patients would avoid unnecessary antibiotic therapy, and 170 patients would have been undiagnosed of sepsis. This numerical approach should be interpreted with caution due to the limitations described above.

AUTHORS' CONCLUSIONS

Our evidence assessment of plasma interleukin-6 concentrations for the diagnosis of sepsis in critically ill adults reveals several limitations. High heterogeneity of collected evidence regarding the main diagnosis, setting, country, positivity threshold, sepsis criteria, year of publication, and the origin of infection, among other factors, along with the potential number of misclassifications, remain significant constraints for its implementation. The 20 conference proceedings assessed as studies awaiting classification may alter the conclusions of the review once they are fully published and evaluated. Further studies about the accuracy of interleukin-6 for the diagnosis of sepsis in adults that apply rigorous methodology for conducting diagnostic test accuracy studies are needed. The conclusions of the review will likely change once the 20 studies pending publication are fully published and included.

Prognostic value of procalcitonin and lipopolysaccharide binding protein in cancer patients with chemotherapy-associated febrile neutropenia presenting to an emergency department

INTRODUCTION

Cancer patients with chemotherapy-induced febrile neutropenia are a heterogeneous group with a significant risk of serious medical complications. In these patients, the Multinational Association for Supportive Care in Cancer (MASCC) score is the most widely used tool for risk-stratification. The aim of this prospective study was to analyse the value of procalcitonin (PCT) and lipopolysaccharide binding protein (LBP) to predict serious complications and bacteraemia in cancer patients with febrile neutropenia, compared with MASCC score.

MATERIALS AND METHODS

Data were collected from 111 episodes of febrile neutropenia admitted consecutively to the emergency department. In all of them, MASCC score was calculated and serum samples were collected for measurement of PCT and LBP by well-established methods. The main and secondary outcomes were the development of serious complications and bacteraemia, respectively.

RESULTS

A serious complication occurred in 20 (18%) episodes and in 16 (14%) bacteraemia was detected. Areas under the receiver operating characteristic curve (ROC AUC) of MASCC score, PCT and LBP to select low-risk patients were 0.83 (95% confidence interval (CI): 0.74 - 0.89), 0.85 (95% CI: 0.77 - 0.91) and 0.70 (95% CI: 0.61 - 0.78), respectively. For bacteraemia, MASCC score, PCT and LBP showed ROC AUCs of 0.74 (95% CI: 0.64 - 0.82), 0.86 (95% CI: 0.78 - 0.92) and 0.76 (95% CI: 0.67 - 0.83), respectively.

CONCLUSION

A single measurement of PCT performs similarly as MASCC score to predict serious medical complications in cancer patients with febrile neutropenia and can be a useful tool for risk stratification. Besides, low PCT concentrations can be used to rule-out the presence of bacteraemia.

Diagnostic accuracy of lipopolysaccharide-binding protein for sepsis in patients with suspected infection in the emergency department

Background Biomarkers can facilitate the diagnosis of sepsis, enabling early management and improving outcomes. Lipopolysaccharide-binding protein (LBP) has been reported as a biomarker for the detection of infection, but its diagnostic value is controversial. In this study, we assessed the diagnostic accuracy of LBP for sepsis in the emergency department (ED) patients, comparing it with more established biomarkers of sepsis, including procalcitonin (PCT) and C-reactive protein (CRP). Methods LBP and other sepsis biomarkers, including PCT and CRP, were measured on admission in 102 adult patients presenting with suspected infection . Classification of patients was performed using the recently updated definition for sepsis (Sepsis-3). The diagnostic accuracy of LBP, CRP and PCT for sepsis was evaluated by using receiver operating characteristic curve (ROC) analysis. Results A total of 49 patients were classified as having sepsis. In these patients, median (interquartile range) LBP (41.8 [41.1] µg/dL vs. 26.2 [25] µg/dL), CRP (240 [205] mg/L vs. 160 [148] mg/dL) and PCT (5.19 [13.68] µg/L vs. 0.39 [1.09] µg/L) were significantly higher than in patients classified as not having sepsis ( P < 0.001 for all three biomarkers). ROC curve analysis and area under curve (AUC) revealed a value of 0.701 for LBP, similar to CRP (0.707) and lower than that for PCT (0.844) ( P = 0.012). Conclusion In adult ED patients with suspected infection, the diagnostic accuracy for sepsis of LBP is similar to that of CRP but lower than that of PCT.

Sepsis-related mortality in 497 cases with blood culture-positive sepsis in an emergency department

OBJECTIVE

Few studies have sought to establish how often death after sepsis is related to the sepsis and how often underlying diseases have a major role in case fatality.

METHODS

In this retrospective cohort study, data were collected on 497 cases with blood culture-positive sepsis in an emergency department (ED).

RESULTS

Sepsis was categorized as severe in 31% of cases; 7% had septic shock. The quick Sepsis-related Organ Failure Assessment score was positive in 136 out of 473 cases (29%). Ninety-eight patients died by day 90; in 16 of these cases (16%) the death was sepsis-related in a patient without a rapidly fatal underlying disease, in 45 cases (46%) the death was sepsis-related in a patient with a rapidly fatal underlying disease, and in 37 cases (38%) the death was unrelated to sepsis. Sepsis-related death occurred in 58 out of 61 cases (95%) by day 28.

CONCLUSIONS

Underlying diseases were found to have a considerable role in the death of patients suffering from blood culture-positive sepsis in an ED of a developed country, as only 16% of the deaths by day 90 occurred where death was sepsis-related and the patient had a life-expectancy of more than 6 months. Improving the outcome of sepsis with new treatments is thus challenging. It is possible that day 7+day 28 mortality is a more appropriate endpoint than day 90 mortality when studying the outcome of sepsis, as this time-span includes most of the patients whose death was related to sepsis.

Diagnostic Accuracy of Lipopolysaccharide-Binding Protein as Biomarker for Sepsis in Adult Patients: A Systematic Review and Meta-Analysis

INTRODUCTION

Lipopolysaccharide-binding protein (LBP) is widely reported as a biomarker to differentiate infected from non-infected patients. The diagnostic use of LBP for sepsis remains a matter of debate. We aimed to perform a systematic review and meta-analysis to assess the diagnostic accuracy of serum LBP for sepsis in adult patients.

METHODS

We performed a systematic review and meta-analysis to assess the accuracy of LBP for sepsis diagnosis. A systematic search in PubMed and EMBASE for studies that evaluated the diagnostic role of LBP for sepsis through December 2015 was conducted. We searched these databases for original, English language, research articles that studied the diagnostic accuracy between septic and non-septic adult patients. Sensitivity, specificity, and other measures of accuracy, such as diagnostic odds ratio (DOR) and area under the receiver operating characteristic curve (AUC) of LBP were pooled using the Hierarchical Summary Receiver Operating Characteristic (HSROC) method.

RESULTS

Our search returned 53 reports, of which 8 fulfilled the inclusion criteria, accounting for 1684 patients. The pooled sensitivity and specificity of LBP for diagnosis of sepsis by the HSROC method were 0.64 (95% CI: 0.56-0.72) and 0.63 (95% CI: 0.53-0.73), respectively. The value of the DOR was 3.0 (95% CI: 2.0-4.0) and the AUC was 0.68 (95% CI: 0.64-0.72). Meta-regression analysis revealed that cut-off values accounted for the heterogeneity of sensitivity and sample size (> = 150) accounted for the heterogeneity of specificity.

CONCLUSIONS

Based on the results of our meta-analysis, LBP had weak sensitivity and specificity in the detection of sepsis. LBP may not be practically recommended for clinical utilization as a single biomarker.

Utility of immune response-derived biomarkers in the differential diagnosis of inflammatory disorders

Differentiating between inflammatory disorders is difficult, but important for a rational use of antimicrobial agents. Biomarkers reflecting the host immune response may offer an attractive strategy to predict the etiology of an inflammatory process and can thus be of help in decision making. We performed a review of the literature to evaluate the diagnostic value of inflammatory biomarkers in adult patients admitted to the hospital with suspected systemic acute infections. Elevated procalcitonin (PCT) concentrations indicate a bacterial infection in febrile patients with an auto-immune disease, rather than a disease flare. CD64 expression on neutrophils can discriminate between non-infectious systemic inflammation and sepsis, and limited evidence suggests the same for decoy receptor 3. PCT is useful for both diagnosing bacterial infection complicating influenza and guiding antibiotic treatment in lower respiratory tract infections in general. In undifferentiated illnesses, increased CD35 expression on neutrophils distinguishes bacterial from viral infections. Compared to bacterial infections, invasive fungal infections are characterized by low concentrations of PCT. No biomarker predicting a specific infecting agent could be identified.

Sustained elevation of resistin, NGAL and IL-8 are associated with severe sepsis/septic shock in the emergency department

OBJECTIVE

To identify biomarkers which distinguish severe sepsis/septic shock from uncomplicated sepsis in the Emergency Department (ED).

METHODS

Patients with sepsis underwent serial blood sampling, including arrival in the ED and up to three subsequent time points over the first 24 hours. Messenger RNA (mRNA) levels of 13 genes representing arms of the innate immune response, organ dysfunction or shock were measured in peripheral blood leucocytes using quantitative PCR, and compared with healthy controls. Serum protein concentrations of targets differentially expressed between uncomplicated sepsis and severe sepsis/septic shock were then measured at each time point and compared between the two patient groups.

RESULTS

Of 27 participants (median age 66 years, (IQR 35, 78)), 10 had uncomplicated sepsis and 17 had sepsis with organ failure (14 septic shock; 3 had other sepsis-related organ failures). At the time of first sample collection in the ED, gene expression of Interleukin (IL)-10 and Neutrophil Gelatinase Associated Lipocalin (NGAL) were significantly higher in severe sepsis than uncomplicated sepsis. Expression did not significantly change over time for any target gene. Serum concentrations of IL-6, IL-8, IL-10, NGAL and Resistin were significantly higher in severe sepsis than uncomplicated sepsis at the time of first sample collection in the ED, but only IL-8, NGAL and Resistin were consistently higher in severe sepsis compared to uncomplicated sepsis at all time points up to 24 h after presentation.

CONCLUSIONS

These mediators, produced by both damaged tissues and circulating leukocytes, may have important roles in the development of severe sepsis. Further work will determine whether they have any value, in addition to clinical risk parameters, for the early identification of patients that will subsequently deteriorate and/or have a higher risk of death.

Sepsis outside intensive care unit: the other side of the coin

INTRODUCTION

A growing body of evidence points out that a large amount of patients with sepsis are admitted and treated in medical ward (MW). With most of the sepsis studies conducted in intensive care unit (ICU), these patients, older and with more comorbidities have received poor attention. Provided the differences between the two groups of patients, results of diagnostic and therapeutic trials from ICU should not be routinely transferred to MW, where sepsis seems to be at least as common as in ICU.

METHODS

We analyzed clinical trials on novel tools for an early diagnosis of sepsis published in the last two year adopting strict research criteria. Moreover we conducted a target review of the literature on non-invasive monitoring of severe sepsis and septic shock.

RESULTS AND CONCLUSIONS

The combination of innovative and non-invasive tools for sepsis rule in/out, as quick alternatives to blood cultures (gold standard) with bedside integrated ultrasonography could impact triage, diagnosis and prognosis of septic patients managed in MW, preventing ICU admissions, poor outcomes and costly complications, especially in elderly that are usually highly vulnerable to invasive procedures.

Utility of sepsis biomarkers and the infection probability score to discriminate sepsis and systemic inflammatory response syndrome in standard care patients

Physicians are regularly faced with severely ill patients at risk of developing infections. In literature, standard care wards are often neglected, although their patients frequently suffer from a systemic inflammatory response syndrome (SIRS) of unknown origin. Fast identification of patients with infections is vital, as they immediately require appropriate therapy. Further, tools with a high negative predictive value (NPV) to exclude infection or bacteremia are important to increase the cost effectiveness of microbiological examinations and to avoid inappropriate antibiotic treatment. In this prospective cohort study, 2,384 patients with suspected infections were screened for suffering from two or more SIRS criteria on standard care wards. The infection probability score (IPS) and sepsis biomarkers with discriminatory power were assessed regarding their capacity to identify infection or bacteremia. In this cohort finally consisting of 298 SIRS-patients, the infection prevalence was 72%. Bacteremia was found in 25% of cases. For the prediction of infection, the IPS yielded 0.51 ROC-AUC (30.1% sensitivity, 64.6% specificity). Among sepsis biomarkers, lipopolysaccharide binding protein (LBP) was the best parameter with 0.63 ROC-AUC (57.5% sensitivity, 67.1% specificity). For the prediction of bacteremia, the IPS performed slightly better with a ROC-AUC of 0.58 (21.3% sensitivity, 65% specificity). Procalcitonin was the best discriminator with 0.78 ROC-AUC, 86.3% sensitivity, 59.6% specificity and 92.9% NPV. Furthermore, bilirubin and LBP (ROC-AUC: 0.65, 0.62) might also be considered as useful parameters. In summary, the IPS and widely used infection parameters, including CRP or WBC, yielded a poor diagnostic performance for the detection of infection or bacteremia. Additional sepsis biomarkers do not aid in discriminating inflammation from infection. For the prediction of bacteremia procalcitonin, and bilirubin were the most promising parameters, which might be used as a rule for when to take blood cultures or using nucleic acid amplification tests for microbiological diagnostics.

The importance of serum procalcitonin in diagnosis and treatment of serious bacterial infections and sepsis

The clinical utility of serum procalcitonin (PCT) levels continues to evolve. PCT is regarded as a promising candidate marker for making a diagnosis and antibiotic stewardship in patients with systemic infections. The aim of this review is to summarize the current evidence for PCT in different infections and clinical settings, and to discuss the reliability of this marker when used with validated diagnostic algorithms.