Plasma procalcitonin levels remain low at the onset of gram-positive bacteremia regardless of severity or the presence of shock: A retrospective analysis of patients with detailed clinical characteristics

Early diagnosis of necrotizing fasciitis: Imaging techniques and their combined application

Necrotizing fasciitis is a clinical, surgical emergency characterized by an insidious onset, rapid progression, and a high mortality rate. The disease's mortality rate has remained high for many years, mainly because of its atypical clinical presentation, which prevents many cases from being diagnosed early and accurately, resulting in patients who may die from uncontrollable septic shock and multi-organ failure. But unfortunately, no diagnostic indicator can provide a certain early diagnosis of NF, and clinical judgement of NF is still based on the results of various ancillary tests combined with the patient's medical history, clinical manifestations, and the physician's experience. This review provides a brief overview of the epidemiological features of NF and then discusses the most important laboratory indicators and scoring systems currently employed to diagnose NF. Finally, the latest progress of several imaging techniques in the early diagnosis of NF and their combined application with other diagnostic indices are highlighted. We point out promising research directions based on an objective evaluation of the advantages and shortcomings of different methods, which provide a basis for further improving the early diagnosis of NF.

Blood Culture Result Profile in Patients With Central Line-Associated Bloodstream Infection (CLABSI): A Single-Center Experience

Background Central line-associated bloodstream infection (CLABSI) is among the most common bloodstream infections in the university hospital and intensive care unit settings. This study evaluated the routine blood test findings and microbe profiles of bloodstream infection (BSI) by the presence and types of central vein (CV) access devices (CVADs). Methods A total of 878 inpatients at a university hospital who were clinically suspected for BSI and underwent blood culture (BC) testing between April 2020 and September 2020 were enrolled. Data regarding age at BC testing, sex, WBC count, serum C-reactive protein (CRP) level, BC test results, yielded microbes, and usage and types of CVADs were evaluated. Results The BC yields were detected in 173 patients (20%), suspected contaminating pathogens in 57 (6.5%), and 648 (74%) with a negative yield. The WBC count (p=0.0882) and CRP level (p=0.2753) did not significantly differ between the 173 patients with BSI and the 648 patients with negative BC yields. Among the 173 patients with BSI, 74 used CVADs and met the diagnosis of CLABSI; 48 had a CV catheter, 16 had CV access ports, and 10 had a peripherally inserted central catheter (PICC). Patients with CLABSI showed lower WBC counts (p=0.0082) and serum CRP levels (p=0.0024) compared to those with BSI who did not use CVADs. The most commonly yielded microbes in those with CV catheters, CV-ports, and PICC were Staphylococcus epidermidis (n=9; 19%), Staphylococcus aureus (n=6; 38%), and S. epidermidis (n=8; 80%), respectively. Among those with BSI who did not use CVADs, Escherichia coli (n=31; 31%) was the most common pathogen, followed by S. aureus (n=13; 13%). Conclusion Patients with CLABSI showed lower WBC counts and CRP levels than those with BSI who did not use CVADs. Staphylococcus epidermidis was among the most common microbes in CLABSI and accounted for the majority of yielded microbes in patients who used PICC.

Causative Micro-Organisms in Necrotizing Fasciitis and their Influence on Inflammatory Parameters and Clinical Outcome

Background: Necrotizing fasciitis (NF) is a potentially fatal soft tissue infection. Four types of pathogens can be distinguished in the pathogen spectrum, although there are strong regional differences with regard to the most common pathogens. Patients and Methods: All cases of NF between 2003 and 2021 with an identified causative agent were analyzed retrospectively. The cases were divided into three groups: polymicrobial, gram-positive and gram-negative. Demographic factors, localization of infection, inflammatory parameters, and clinical outcome were compared between the three groups. Results: A total of 95 cases were analyzed, 41% of which were caused by multiple pathogens. A gram-positive pathogen was reported in 40% of cases and a gram-negative pathogen in 19%. There were significant differences between the three groups with respect to age (with patients in the gram-negative group being on average the oldest) and intensive care unit admissions (which was most frequent in the polymicrobial group). Conclusions: The pathogen spectrum of NF has rarely been studied in a large patient population. Gram-positive pathogens account for the majority of monomicrobial infections in our study. Nevertheless, we recommend calculated broad-spectrum antibiotic therapy given the high number of polymicrobial infections and gram-negative infections. Gram-negative infections may be associated with increased mortality, elevated procalcitonin levels, and are relatively frequent in NF of the lower extremities.

Sepsis-induced Coagulopathy: The Different Prognosis in Severe Pneumonia and Bacteremia Infection Patients

Sepsis-induced coagulopathy (SIC) is a critical condition in sepsis patients, with varying outcomes depending on the type of infection. This study aims to analyze the prognosis of different infections in SIC cohort. A retrospective cohort study was conducted on 525 patients diagnosed with SIC in the intensive care unit from December 2013 to December 2022. These patients were divided into four groups: a non-pneumonia or bacteremia group, a severe pneumonia group, a bacteremia group, and a severe pneumonia concomitant with bacteremia group. The 28-day mortality was 18% (49/271) in the other infections group, 31% (33/106) in the lung infections group, 23% (29/126) in the blood infections group and 36% (8/36) in the lung and blood co-infections group, respectively. Pearson correlation analysis showed that procalcitonin (PCT) correlated strongly with all detected hemostatic markers (p < 0.001). The 28-day mortality rate in Lung infections group was significantly higher (p = 0.019), while Blood infections group had a higher incidence of disseminated intravascular coagulation (p = 0.011). By multivariable model analyses, longer duration of ventilation (p = 0.039) and severe pneumonia (p = 0.040) are risk factors associated with mortality. Different infections, including Lung and Blood infections, indicated different conditions in vivo. Longer duration of ventilation is associated with mortality, while Lung infections indicated higher 28-day mortality rate.

Time Is Fascia: Laboratory and Anamnestic Risk Indicators for Necrotizing Fasciitis

Background: Necrotizing fasciitis is a potentially fatal soft tissue infection in which the timing of surgical intervention significantly affects clinical outcome. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score, the Site other than the lower limb, Immunosuppression, Age <60 years, Renal impairment (creatinine >141), and Inflammatory markers (CRP ≥150, WCC >25) (SIARI) score, and procalcitonin levels are intended to aid in the decision-making process to differentiate between necrotizing fasciitis and soft tissue infections. Methods: A retrospective analysis of cases of necrotizing fasciitis and soft tissue infections treated at Klinikum Nürnberg was performed. The two scores as well as procalcitonin levels were tested for their diagnostic value and a new score, the Laboratory and Anamnestic Risk Indicator for Necrotizing Fasciitis (LARINF), was created based on the results. Results: Procalcitonin, LRINEC score, and SIARI score showed insufficient discriminatory ability in our study. The newly created LARINF score combined laboratory parameters of the LRINEC score (hemoglobin and C-reactive protein) with procalcitonin and three comorbidities, resulting in a sensitivity of 84% and a specificity of 75% and the highest area under the receiver operating characteristic (ROC) curve of 0.83. Conclusions: The LARINF score is a novel decision-supporting tool. The decision, in which cases surgical exploration should be initiated, remains a clinical one. However, the score seems to provide an improved basis for identifying a rare clinical picture.

Distinctions between Fournier's gangrene and lower extremity necrotising fasciitis: microbiology and factors affecting mortality

OBJECTIVES

In this study, we aimed to illustrate distinctions between Fournier's gangrene (FG) and lower extremity necrotising fasciitis (NF) and screen out possible risk factors of poor prognosis for each cohort.

METHODS

The medical records of qualified patients with NF admitted to the Second People's Hospital of Yibin from January 2016 to June 2021 were retrospectively reviewed. All participants were anatomically categorised into FG and lower extremity NF groups, and their baseline data and microbiological results were compared. Further comparisons of critical parameters were conducted between survivors and nonsurvivors within each group.

RESULTS

A total of 49 patients were included in the study with a median age of 58 years, and overall mortality was 20.4%. There were 18 patients with FG and 31 patients with lower extremity NF. A microbiology distinction was found-the predominance of gram-negative infection in FG and gram-positive infection in lower extremity NF. High Fournier's gangrene severity index scores (greater than 7), advanced age, procalcitonin and D-dimer value were identified as risk factors for FG, and the presentation of sepsis was an alarming indicator for lower extremity NF.

CONCLUSIONS

The distinction of microbiology might provide advice for appropriate antibacterial administrations. In addition, with practical prognostic predicting tools, clinicians might be able to identify patients at increased risk and intervene promptly to avoid unfavourable outcomes.

Nocardia Infection in Nephrotic Syndrome Patients: Three Case Studies and A Systematic Literature Review

Objective

The multicenter literature review and case studies of 3 patients were undertaken to provide an updated understanding of nocardiosis, an opportunistic bacterial infection affecting immunosuppressed nephrotic syndrome (NS) patients receiving long-term glucocorticoid and immunosuppressant treatment. The results provided clinical and microbiological data to assist physicians in managing nocardiosis patients.

Methods

Three cases between 2017 and 2018 from a single center were reported. Additionally, a systematic review of multicenter cases described in the NCBI PubMed, Web of Science, and Embase in English between January 1, 2001 and May 10, 2021 was conducted.

Results

This study described three cases of Nocardia infection in NS patients. The systematic literature review identified 24 cases with sufficient individual patient data. A total of 27 cases extracted from the literature review showed that most patients were > 50 years of age and 70.4% were male. Furthermore, the glucocorticoid or corticosteroid mean dose was 30.9 ± 13.7 mg per day. The average time between hormone therapy and Nocardia infection was 8.5 ± 9.7 months. Pulmonary (85.2%) and skin (44.4%) infections were the most common manifestations in NS patients, with disseminated infections in 77.8% of patients. Nodule/masses and consolidations were the major radiological manifestations. Most patients showed elevated inflammatory biomarkers levels, including white blood cell counts, neutrophils percentage, and C-reactive protein. Twenty-five patients received trimethoprim-sulfamethoxazole monotherapy (18.5%) or trimethoprim-sulfamethoxazole-based multidrug therapy (74.1%), and the remaining two patients (7.4%) received biapenem monotherapy. All patients, except the two who were lost to follow-up, survived without relapse after antibiotic therapy.

Conclusions

Nephrotic syndrome patients are at high risk of Nocardia infection even if receiving low-dose glucocorticoid during the maintenance therapy. The most common manifestations of nocardiosis in NS patients include abnormal lungs revealing nodules and consolidations, skin and subcutaneous abscesses. The NS patients have a high rate of disseminated and cutaneous infections but a low mortality rate. Accurate and prompt microbiological diagnosis is critical for early treatment, besides the combination of appropriate antibiotic therapy and surgical drainage when needed for an improved prognosis.

Practice Summary of Antimicrobial Therapy for Commonly Encountered Conditions in the Neonatal Intensive Care Unit: A Canadian Perspective

Neonates are highly susceptible to infections owing to their immature cellular and humoral immune functions, as well the need for invasive devices. There is a wide practice variation in the choice and duration of antimicrobial treatment, even for relatively common conditions in the NICU, attributed to the lack of evidence-based guidelines. Early decisive treatment with broad-spectrum antimicrobials is the preferred clinical choice for treating sick infants with possible bacterial infection. Prolonged antimicrobial exposure among infants without clear indications has been associated with adverse neonatal outcomes and increased drug resistance. Herein, we review and summarize the best practices from the existing literature regarding antimicrobial use in commonly encountered conditions in neonates.

Prognostic Value of Procalcitonin, C-Reactive Protein, and Lactate Levels in Emergency Evaluation of Cancer Patients with Suspected Infection

Simple Summary

Cancer patients are at increased risk of infections and related complications, including sepsis. We developed a scoring system for mortality prediction based on readily available clinical and laboratory data, including the quick sequential organ failure assessment (qSOFA) score, cancer subtype, and several laboratory markers (procalcitonin, C-reactive protein, lactate dehydrogenase, and albumin) that can be used in emergency departments for cancer patients with suspected infection. The prediction score, which stratifies patients into four different risk groups (from low risk to very high risk), achieved excellent performance in predicting 14-day mortality, with an area under the receiver operating characteristic curve value of 0.88 (95% confidence interval 0.85–0.91). The score was also effective in predicting intensive care unit admission and 30-day mortality.

Abstract

Cancer patients have increased risk of infections, and often present to emergency departments with infection-related problems where physicians must make decisions based on a snapshot of the patient’s condition. Although C-reactive protein, procalcitonin, and lactate are popular biomarkers of sepsis, their use in guiding emergency care of cancer patients with infections is unclear. Using these biomarkers, we created a prediction model for short-term mortality in cancer patients with suspected infection. We retrospectively analyzed all consecutive patients who visited the emergency department of MD Anderson Cancer Center between 1 April 2018 and 30 April 2019. A clinical decision model was developed using multiple logistic regression for various clinical and laboratory biomarkers; coefficients were used to generate a prediction score stratifying patients into four groups according to their 14-day mortality risk. The prediction score had an area under the receiver operating characteristic curve value of 0.88 (95% confidence interval 0.85–0.91) in predicting 14-day mortality. The prediction score also accurately predicted intensive care unit admission and 30-day mortality. Our simple new scoring system for mortality prediction, based on readily available clinical and laboratory data, including procalcitonin, C-reactive protein, and lactate, can be used in emergency departments for cancer patients with suspected infection.

An Artificial Intelligence Approach to Bloodstream Infections Prediction

This study aimed to develop an early prediction model for identifying patients with bloodstream infections. The data resource was taken from 2015 to 2019 at Taichung Veterans General Hospital, and a total of 1647 bloodstream infection episodes and 3552 non-bloodstream infection episodes in the intensive care unit (ICU) were included in the model development and evaluation. During the data analysis, 30 clinical variables were selected, including patients’ basic characteristics, vital signs, laboratory data, and clinical information. Five machine learning algorithms were applied to examine the prediction model performance. The findings indicated that the area under the receiver operating characteristic curve (AUROC) of the prediction performance of the XGBoost model was 0.825 for the validation dataset and 0.821 for the testing dataset. The random forest model also presented higher values for the AUROC on the validation dataset and testing dataset, which were 0.855 and 0.851, respectively. The tree-based ensemble learning model enabled high detection ability for patients with bloodstream infections in the ICU. Additionally, the analysis of importance of features revealed that alkaline phosphatase (ALKP) and the period of the central venous catheter are the most important predictors for bloodstream infections. We further explored the relationship between features and the risk of bloodstream infection by using the Shapley Additive exPlanations (SHAP) visualized method. The results showed that a higher prothrombin time is more prominent in a bloodstream infection. Additionally, the impact of a lower platelet count and albumin was more prominent in a bloodstream infection. Our results provide additional clinical information for cut-off laboratory values to assist clinical decision-making in bloodstream infection diagnostics.

Future Biomarkers for Infection and Inflammation in Febrile Children

Febrile patients, suffering from an infection, inflammatory disease or autoimmunity may present with similar or overlapping clinical symptoms, which makes early diagnosis difficult. Therefore, biomarkers are needed to help physicians form a correct diagnosis and initiate the right treatment to improve patient outcomes following first presentation or admittance to hospital. Here, we review the landscape of novel biomarkers and approaches of biomarker discovery. We first discuss the use of current plasma parameters and whole blood biomarkers, including results obtained by RNA profiling and mass spectrometry, to discriminate between bacterial and viral infections. Next we expand upon the use of biomarkers to distinguish between infectious and non-infectious disease. Finally, we discuss the strengths as well as the potential pitfalls of current developments. We conclude that the use of combination tests, using either protein markers or transcriptomic analysis, have advanced considerably and should be further explored to improve current diagnostics regarding febrile infections and inflammation. If proven effective when combined, these biomarker signatures will greatly accelerate early and tailored treatment decisions.