The Effect of Inadequate Initial Empiric Antimicrobial Treatment on Mortality in Critically Ill Patients with Bloodstream Infections: A Multi-Centre Retrospective Cohort Study

A machine learning model for the early diagnosis of bloodstream infection in patients admitted to the pediatric intensive care unit

Bloodstream infection (BSI) is associated with increased morbidity and mortality in the pediatric intensive care unit (PICU) and high healthcare costs. Early detection and appropriate treatment of BSI may improve patient's outcome. Data on machine-learning models to predict BSI in pediatric patients are limited and neither study included time series data. We aimed to develop a machine learning model to predict an early diagnosis of BSI in patients admitted to the PICU. This was a retrospective cohort study of patients who had at least one positive blood culture result during stay at a PICU of a tertiary-care university hospital, from January 1st to December 31st 2019. Patients with positive blood culture results with growth of contaminants and those with incomplete data were excluded. Models were developed using demographic, clinical and laboratory data collected from the electronic medical record. Laboratory data (complete blood cell counts with differential and C-reactive protein) and vital signs (heart rate, respiratory rate, blood pressure, temperature, oxygen saturation) were obtained 72 hours before and on the day of blood culture collection. A total of 8816 data from 76 patients were processed by the models. The machine committee was the best-performing model, showing accuracy of 99.33%, precision of 98.89%, sensitivity of 100% and specificity of 98.46%. Hence, we developed a model using demographic, clinical and laboratory data collected on a routine basis that was able to detect BSI with excellent accuracy and precision, and high sensitivity and specificity. The inclusion of vital signs and laboratory data variation over time allowed the model to identify temporal changes that could be suggestive of the diagnosis of BSI. Our model might help the medical team in clinical-decision making by creating an alert in the electronic medical record, which may allow early antimicrobial initiation and better outcomes.

Diagnostic and antibiotic use practices among COVID-19 and non-COVID-19 patients in the Indonesian National Referral Hospital

BACKGROUND

Little is known about diagnostic and antibiotic use practices in low and middle-income countries (LMICs) before and during COVID-19 pandemic. This information is crucial for monitoring and evaluation of diagnostic and antimicrobial stewardships in healthcare facilities.

METHODS

We linked and analyzed routine databases of hospital admission, microbiology laboratory and drug dispensing of Indonesian National Referral Hospital from 2019 to 2020. Patients were classified as COVID-19 cases if their SARS-CoV-2 RT-PCR result were positive. Blood culture (BC) practices and time to discontinuation of parenteral antibiotics among inpatients who received a parenteral antibiotic for at least four consecutive days were used to assess diagnostic and antibiotic use practices, respectively. Fine and Grey subdistribution hazard model was used.

RESULTS

Of 1,311 COVID-19 and 58,917 non-COVID-19 inpatients, 333 (25.4%) and 18,837 (32.0%) received a parenteral antibiotic for at least four consecutive days. Proportion of patients having BC taken within ±1 calendar day of parenteral antibiotics being started was higher in COVID-19 than in non-COVID-19 patients (21.0% [70/333] vs. 18.7% [3,529/18,837]; p<0.001). Cumulative incidence of having a BC taken within 28 days was higher in COVID-19 than in non-COVID-19 patients (44.7% [149/333] vs. 33.2% [6,254/18,837]; adjusted subdistribution-hazard ratio [aSHR] 1.71, 95% confidence interval [CI] 1.47-1.99, p<0.001). The median time to discontinuation of parenteral antibiotics was longer in COVID-19 than in non-COVID-19 patients (13 days vs. 8 days; aSHR 0.73, 95%Cl 0.65-0.83, p<0.001).

CONCLUSIONS

Routine electronic data could be used to inform diagnostic and antibiotic use practices in LMICs. In Indonesia, the proportion of timely blood culture is low in both COVID-19 and non-COVID-19 patients, and duration of parenteral antibiotics is longer in COVID-19 patients. Improving diagnostic and antimicrobial stewardship is critically needed.

Infectious Inequity: How the Gut Microbiome and Social Determinants of Health May Contribute to Clostridioides difficile Infection Among Racial and Ethnic Minorities

Infectious diseases are a leading contributor to death in the United States, and racial differences in clinical outcomes have been increasingly reported. Clostridioides difficile infection (CDI) is a growing public health concern, as it causes nearly half a million infections per year and considerable excess hospital costs. Concurrent with other infectious diseases, recent literature denotes racial disparities in CDI incidence rates, mortality, and associated morbidity. Of note, investigations into CDI and causative factors suggest that inequities in health-related social needs and other social determinants of health (SDoH) may cause disruption to the gut microbiome, thereby contributing to the observed deleterious outcomes in racially and ethnically minoritized individuals. Despite these discoveries, there is limited literature that provides context for the recognized racial disparities in CDI, particularly the influence of structural and systemic barriers. Here, we synthesize the available literature describing racial inequities in CDI outcomes and discuss the interrelationship of SDoH on microbiome dysregulation. Finally, we provide actionable considerations for infectious diseases professionals to aid in narrowing CDI equity gaps.

Impact of Irrational Use of Antibiotics Among Patients in the Intensive Care Unit on Clinical Outcomes in Sudan

Background

Intensive Care Unit (ICU) is a specialized ward where critically ill patients are admitted to provide intensive health care Inappropriate antimicrobial therapy (AMT) and high mortality rates were documented in the ICU. The influence of irrational use of empiric antibiotics on clinical outcomes in ICU patients is not well studied in Sudan.

Aim

This study aims to determine the rational use of antibiotics and its impact on clinical outcomes among ICU patients.

Methods

Using data collection form, a retrospective longitudinal study was conducted among ICU patients at Omdurman Military Hospital, Khartoum State. Patients admitted from January 2019 to December 2019 were included in the study. Patients who stayed in ICU < 48 hr were excluded. Appropriateness of AMT is assessed using culture sensitivity test (CST) and the American Society of Infectious Diseases (IDSA) guideline.

Results

Among 102 patients, 54.9% male, one-third of patients developed nosocomial infections, 80.4% received empiric therapy with broad-spectrum antibiotics. The CST is done in 19%, and 43% patients are prescribed inappropriate AMT. Inappropriate AMT is associated with recurrent infections 38.4% (p=0.028) and high mortality 33.8% (p=0.014). Overall mortality rate 63.7% ICU patients. Elevated mortality in nosocomial 57.8%, decreased with inappropriate AMT in 21.6% patients. Significantly higher mortality rates 90.7% among uncontrolled infections (p<0.001), 80.6% nosocomial infections (p=0.001), and 76.7% renal compromised (p=0.002).

Conclusion

Empirical AMT reduces the frequency of nosocomial infections, which has an impact on mortality. Inappropriate AMT is significantly associated with uncontrolled infections and lower mortality. Implementing a restrictive infectious control system and effective stewardship programs in hospital ICU wards is recommended.

Clinical utility of prior positive cultures to optimize empiric antibiotic therapy selection: A cross-sectional analysis

Background

Despite reduced infectious disease mortality and improved survival, infectious diseases continue to pose health threats due to their contagiousness, societal harm, and morbidity. Empiric antibiotic therapy, often prescribed without knowledge of the causative pathogen, faces challenges from rising antibiotic resistance. This study explores the potential of prior positive culture results to guide empiric antibiotic therapy.

Methods

Data from King Abdullah University Hospital (Jan 2014-Dec 2019) included adult patients with recurrent bacterial infections (pneumonia, sepsis, UTIs, wounds). Excluded cases included: mixed infections, transfers, <14 days or >12 months between episodes. The study compared bacterial growth and sensitivity patterns between previous and recent cultures.

Results

The study included 970 episodes from 650 patients, mainly UTIs (60.3%) and gram-negative bacteria (77.9%). The study found that (65.1%) of culture pairs matched. Empirical therapy was accurate in (71.8%) of cases. Further, accuracy of selected empiric antibiotic therapy was significantly predicted (p ​< ​0.001) by: type of infection, type of antibiotics, and concordance with prior microbiologic data. Multivariate logistic analysis showed blood culture as less predictive of pending identity (OR: 0.234, P ​< ​0.001) compared to urine culture; and prior affirmed gram negative bacterial culture was less predictive (OR: 0.606, P ​= ​0.021) compared to gram positive bacterial culture.

Conclusion

This study underscores the potential of prior positive culture results in guiding empiric antibiotic therapy, enhancing accuracy and identity agreement. Future research should explore this approach in different infection contexts and across multiple centers. Reducing the indiscriminate use of broad-spectrum antibiotics is essential to combat antibiotic resistance.

Clinical, contextual and hospital-level factors associated with escalation and de-escalation of empiric Gram-negative antibiotics among US inpatients

Background

Empiric Gram-negative antibiotics are frequently changed in response to new information. To inform antibiotic stewardship, we sought to identify predictors of antibiotic changes using information knowable before microbiological test results.

Methods

We performed a retrospective cohort study. Survival-time models were used to evaluate clinical factors associated with antibiotic escalation and de-escalation (defined as an increase or decrease, respectively, in the spectrum or number of Gram-negative antibiotics within 5 days of initiation). Spectrum was categorized as narrow, broad, extended or protected. Tjur's D statistic was used to estimate the discriminatory power of groups of variables.

Results

In 2019, 2 751 969 patients received empiric Gram-negative antibiotics at 920 study hospitals. Antibiotic escalation occurred in 6.5%, and 49.2% underwent de-escalation; 8.8% were changed to an equivalent regimen. Escalation was more likely when empiric antibiotics were narrow-spectrum (HR 19.0 relative to protected; 95% CI: 17.9-20.1), broad-spectrum (HR 10.3; 95% CI: 9.78-10.9) or extended-spectrum (HR 3.49; 95% CI: 3.30-3.69). Patients with sepsis present on admission (HR 1.94; 95% CI: 1.91-1.96) and urinary tract infection present on admission (HR 1.36; 95% CI: 1.35-1.38) were more likely to undergo antibiotic escalation than patients without these syndromes. De-escalation was more likely with combination therapy (HR 2.62 per additional agent; 95% CI: 2.61-2.63) or narrow-spectrum empiric antibiotics (HR 1.67 relative to protected; 95% CI: 1.65-1.69). Choice of empiric regimen accounted for 51% and 74% of the explained variation in antibiotic escalation and de-escalation, respectively.

Conclusions

Empiric Gram-negative antibiotics are frequently de-escalated early in hospitalization, whereas escalation is infrequent. Changes are primarily driven by choice of empiric therapy and presence of infectious syndromes.

Multicenter evaluation of rapid antimicrobial susceptibility testing by VITEK®2 directly from positive blood culture

STUDY OBJECTIVE

To compare the antimicrobial susceptibility testing (AST) performance of positive blood cultures (PBC) VITEK®2 off-label use (D0) and traditional VITEK®2 workflow using isolated colonies after overnight (D1).

METHODS

Patient samples with monomicrobial Gram-negative rod or Gram-positive cocci in clusters bacteremia were tested on D0 and compared to D1 AST results in 7 laboratories in France.

RESULTS

Overall, categorical and essential agreement rates were 98.4% and 96.7%, respectively. Very major discrepancy and major discrepancy rates for Enterobacterales and Staphylococci satisfied the NF EN ISO 20776-2 (2007) criteria for sepsis-relevant drugs. Very major discrepancies were >3% for amoxicillin-clavulanate (4.9%, 6/122), piperacillin-tazobactam (7.5%, 4/53) and meropenem (33%,1/3) for Enterobacterales and gentamicin for Staphylococci (4.6%, 4/87).

CONCLUSION

Direct AST from PBC broths by VITEK®2 for Enterobacterales and Staphylococci is reliable and fast and may positively influence antimicrobial stewardship.

Risk factors associated with inappropriate empirical antimicrobial treatment in bloodstream infections. A cohort study

Introduction: Bloodstream infections (BSI) are a major cause of mortality all over the world. Inappropriate empirical antimicrobial treatment (i-EAT) impact on mortality has been largely reported. However, information on related factors for the election of i-EAT in the treatment of BSI in adults is lacking. The aim of the study was the identification of risk-factors associated with the use of i-EAT in BSI. Methods: A retrospective, observational cohort study, from a prospective database was conducted in a 400-bed acute-care teaching hospital including all BSI episodes in adult patients between January and December 2018. The main outcome variable was EAT appropriation. Multivariate analysis using logistic regression was performed. Results: 599 BSI episodes were included, 146 (24%) received i-EAT. Male gender, nosocomial and healthcare-associated acquisition of infection, a high Charlson Comorbidity Index (CCI) score and the isolation of multidrug resistant (MDR) microorganisms were more frequent in the i-EAT group. Adequation to local guidelines' recommendations on EAT resulted in 91% of appropriate empirical antimicrobial treatment (a-EAT). Patients receiving i-EAT presented higher mortality rates at day 14 and 30 when compared to patients with a-EAT (14% vs. 6%, p = 0.002 and 22% vs. 9%, p < 0.001 respectively). In the multivariate analysis, a CCI score ≥3 (OR 1.90 (95% CI 1.16-3.12) p = 0.01) and the isolation of a multidrug resistant (MDR) microorganism (OR 3.79 (95% CI 2.28-6.30), p < 0.001) were found as independent risk factors for i-EAT. In contrast, female gender (OR 0.59 (95% CI 0.35-0.98), p = 0.04), a correct identification of clinical syndrome prior to antibiotics administration (OR 0.26 (95% CI 0.16-0.44), p < 0.001) and adherence to local guidelines (OR 0.22 (95% CI 0.13-0.38), p < 0.001) were identified as protective factors against i-EAT. Conclusion: One quarter of BSI episodes received i-EAT. Some of the i-EAT related factors were unmodifiable (male gender, CCI score ≥3 and isolation of a MDR microorganism) but others (incorrect identification of clinical syndrome before starting EAT or the use of local guidelines for EAT) could be addressed to optimize the use of antimicrobials.

Three-Year Evaluation of Pseudomonas aeruginosa Bacteremia in Patients Admitted to a University-Affiliated Hospital, Mashhad, Iran

Background: Pseudomonas aeruginosa is an opportunistic gram-negative pathogen that can cause infection in almost any body part. Objectives: We aimed to evaluate the characteristics of patients with P. aeruginosa bloodstream infection (BSI). Methods: In this cross-sectional study, we retrospectively evaluated the records of 35 patients with P. aeruginosa BSI admitted to the Imam Reza Hospital, Mashhad, Iran, during 2012 - 2015. Age, sex, clinical symptoms, risk factors, underlying diseases, and the antibiogram test results were recorded and compared between nosocomial and community-acquired infection (CAI) dead and alive patients using the chi-square test. Data were analyzed using SPSS software, version 21. Results: The patients had a mean age of 54.57 ± 20.75 years, with 19 of them being men (54.3%). Intubation was only required in the deceased group (N = 19; P = 0.014). Tachypnea was more frequent (63.2% vs. 13.2%, P = 0.003), and appropriate treatment was less frequent (27.8% vs. 66.7%; P = 0.02) in the deceased group compared to the control group. Most patients with nosocomial infection (N = 24) passed away (66.7%; P = 0.03). All nine patients with a history of burning had a nosocomial infection (P = 0.01). Shivering and decreased consciousness were more frequent in patients with CAI (both P = 0.03) than in other patients. The antibiogram test results showed high resistance to multiple antibiotics. Conclusions: Considering the high mortality rate of P. aeruginosa BSI and resistance to multiple antibiotics, it is necessary to pay greater attention to the prevention of nosocomial infection with this pathogen, especially in patients admitted to burn centers and those with specific clinical signs, like tachypnea and leukocytosis.

Effects of Inappropriate Administration of Empirical Antibiotics on Mortality in Adults With Bacteraemia: Systematic Review and Meta-Analysis

Introduction

Bloodstream infections are associated with high mortality rates and contribute substantially to healthcare costs, but a consensus on the prognostic benefits of appropriate empirical antimicrobial therapy (EAT) for bacteraemia is lacking.

Methods

We performed a systematic search of the PubMed, Cochrane Library, and Embase databases through July 2021. Studies comparing the mortality rates of patients receiving appropriate and inappropriate EAT were considered eligible. The quality of the included studies was assessed using Joanna Briggs Institute checklists.

Results

We ultimately assessed 198 studies of 89,962 total patients. The pooled odds ratio (OR) for the prognostic impacts of inappropriate EAT was 2.06 (P < 0.001), and the funnel plot was symmetrically distributed. Among subgroups without between-study heterogeneity (I² = 0%), those of patients with severe sepsis and septic shock (OR, 2.14), Pitt bacteraemia scores of ≥4 (OR, 1.88), cirrhosis (OR, 2.56), older age (OR, 1.78), and community-onset/acquired Enterobacteriaceae bacteraemia infection (OR, 2.53) indicated a significant effect of inappropriate EAT on mortality. The pooled adjusted OR of 125 studies using multivariable analyses for the effects of inappropriate EAT on mortality was 2.02 (P < 0.001), and the subgroups with low heterogeneity (I² < 25%) exhibiting significant effects of inappropriate EAT were those of patients with vascular catheter infections (adjusted OR, 2.40), pneumonia (adjusted OR, 2.72), or Enterobacteriaceae bacteraemia (adjusted OR, 4.35). Notably, the pooled univariable and multivariable analyses were consistent in revealing the negligible impacts of inappropriate EAT on the subgroups of patients with urinary tract infections and Enterobacter bacteraemia.

Conclusion

Although the current evidence is insufficient to demonstrate the benefits of prompt EAT in specific bacteraemic populations, we indicated that inappropriate EAT is associated with unfavorable mortality outcomes overall and in numerous subgroups. Prospective studies designed to test these specific populations are needed to ensure reliable conclusions.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021270274.

A visual representation of microbiological culture data improves comprehension: a randomized controlled trial

OBJECTIVE

While the judicious use of antibiotics takes past microbiological culture results into consideration, this data's typical format in the electronic health record (EHR) may be unwieldy when incorporated into clinical decision-making. We hypothesize that a visual representation of sensitivities may aid in their comprehension.

MATERIALS AND METHODS

A prospective parallel unblinded randomized controlled trial was undertaken at an academic urban tertiary care center. Providers managing emergency department (ED) patients receiving antibiotics and having previous culture sensitivity testing were included. Providers were randomly selected to use standard EHR functionality or a visual representation of patients' past culture data as they answered questions about previous sensitivities. Concordance between provider responses and past cultures was assessed using the kappa statistic. Providers were surveyed about their decision-making and the usability of the tool using Likert scales.

RESULTS

518 ED encounters were screened from 3/5/2018 to 9/30/18, with providers from 144 visits enrolled and analyzed in the intervention arm and 129 in the control arm. Providers using the visualization tool had a kappa of 0.69 (95% CI: 0.65-0.73) when asked about past culture results while the control group had a kappa of 0.16 (95% CI: 0.12-0.20). Providers using the tool expressed improved understanding of previous cultures and found the tool easy to use (P < .001). Secondary outcomes showed no differences in prescribing practices.

CONCLUSION

A visual representation of culture sensitivities improves comprehension when compared to standard text-based representations.

Feasibility and potential significance of rapid in vitro qualitative phenotypic antimicrobial susceptibility testing of gram-negative bacilli with the ProMax system

The emergence and evolution of antibiotic resistance has been accelerated due to the widespread use of antibiotics and a lack of timely diagnostic tests that guide therapeutic treatment with adequate sensitivity, specificity, and antimicrobial susceptibility testing (AST) accuracy. Automated AST instruments are extensively used in clinical microbiology labs and provide a streamlined workflow, simplifying susceptibility testing for pathogenic bacteria isolated from clinical samples. Although currently used commercial systems such as the Vitek2 and BD Phoenix can deliver results in substantially less time than conventional methods, their dependence on traditional AST inoculum concentrations and optical detection limit their speed somewhat. Herein, we describe the GeneFluidics ProMax lab automation system intended for a rapid 3.5-hour molecular AST from clinical isolates. The detection method described utilizes a higher starting inoculum concentration and automated molecular quantification of species-specific 16S rRNA through the use of an electrochemical sensor to assess microbiological responses to antibiotic exposure. A panel of clinical isolates consisting of species of gram-negative rods from the CDC AR bank and two hospitals, New York-Presbyterian Queens and Medical College of Wisconsin, were evaluated against ciprofloxacin, gentamicin, and meropenem in a series of reproducibility and clinical studies. The categorical agreement and reproducibility for Citrobacter freundii, Enterobacter cloacae, Escherichia coli, Klebsiella aerogenes, Klebsiella oxytoca, Klebsiella pneumoniae, and Pseudomonas aeruginosa were 100% and 100% for ciprofloxacin, 98.7% and 100% for gentamicin and 98.5% and 98.5% for meropenem, respectively.

Local audit of empiric antibiotic therapy in bacteremia: A retrospective cohort study

Background

It is unclear if a local audit would be useful in providing guidance on how to improve local practice of empiric antibiotic therapy. We performed an audit of antibiotic therapy in bacteremia to evaluate the proportion and risk factors for inadequate empiric antibiotic coverage.

Methods

This retrospective cohort study included patients with positive blood cultures across 3 hospitals in Hamilton, Ontario, Canada during October of 2019. Antibiotic therapy was considered empiric if it was administered within 24 hours after blood culture collection. Adequate coverage was defined as when the isolate from blood culture was tested to be susceptible to the empiric antibiotic. A multivariable logistic regression model was used to predict inadequate empiric coverage. Diagnostic accuracy of a clinical pathway based on patient risk factors was compared to clinician’s decision in predicting which bacteria to empirically cover.

Results

Of 201 bacteremia cases, empiric coverage was inadequate in 56 (27.9%) cases. Risk factors for inadequate empiric coverage included unknown source at initiation of antibiotic therapy (adjusted odds ratio (aOR) of 2.76 95% CI 1.27–6.01, P = 0.010) and prior antibiotic therapy within 90 days (aOR of 2.46 95% CI 1.30–4.74, P = 0.006). A clinical pathway that considered community-associated infection as low risk for Pseudomonas was better at ruling out Pseudomonas bacteremia with a negative likelihood ratio of 0.17 (95% CI 0.03–1.10) compared to clinician’s decision with negative likelihood ratio of 0.34 (95% CI 0.10–1.22).

Conclusions

An audit of antibiotic therapy in bacteremia is feasible and may provide useful feedback on how to locally improve empiric antibiotic therapy.

Rapid Antifungal Susceptibility Testing of Yeasts and Molds by MALDI-TOF MS: A Systematic Review and Meta-Analysis

Due to the growing burden of fungal infections and a recent rise in antifungal resistance, antifungal susceptibility testing (AFST) is of increasing importance. The common methods of AFST have turnaround times of 24 to 48 h, and the available rapid methods are limited by applicability, cost-efficiency or accuracy. Given the urgency of adequate antifungal treatment in invasive mycoses, the need for the rapid and reliable detection of resistance is evident. In this systematic review and meta-analysis, we evaluated the diagnostic accuracy of AFST based on matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). Twelve studies were reviewed, and data for the comparative analysis of their accuracy and methodology were systematically extracted. Compared to broth dilution as the gold standard, MALDI-TOF MS-based AFST reached a pooled sensitivity and specificity of 91% (95% Confidence Interval [CI], 84% to 96%) and 95% (95% CI, 90% to 98%), respectively. A comparative analysis showed that the sensitivity was higher for the semi-quantitative matrix-assisted laser desorption ionization Biotyper antibiotic susceptibility test rapid assay (MBT ASTRA) technique (96%) than for the correlate composite index (CCI) approach (85%), which is based on spectrum changes. Turnaround times below eight hours reached better diagnostic values than longer incubation periods, qualifying MALDI-TOF MS-based AFST as a rapid and accurate method for the detection of antifungal resistance.

Clinical and economical improvements after introducing rapid identification of bacteria and early antibiotic susceptibility testing in sepsis and bloodstream infections. Results of the PHENOMENON study

Background: Sepsis and bloodstream infections pose severe challenges in intensive care. Early reliable diagnosis is the key to successful therapy. The objective of the study presented here was to investigate the clinical and economical effects of the new Pheno^TM BC test, which allows bacteria identification (ID) and antimicrobial susceptibility testing (AST) in approximately 7 hours after a blood culture becomes positive (BC+). Methods: Historically controlled interventional study. Population: patients with BC+ and ICU admission. Inadequate initial antimicrobial therapy (IAT) is need of therapy change based on result. Prospectively the new test was used in addition. Primary endpoint: time-to-result in hours. Contribution margin (CM) i.e. revenue - costs was computed. All patients formed the intention-to-treat population (ITT). Patients with complete cost data formed the modified ITT group (mITT). CM results were calculated for mITT and PP. Further analyses: length-of-stay (LOS) and mortality. Results: 223 historical and 200 prospective patients were included. Time to result (ITT) was shortened by 51.1 hours (83 vs. 31.9; p<0.001). Overall savings (mITT) were 257,100 € (-301,264 € vs. -44,164 €). 143 of 181 (79%) patients had a test performed, 126 of 143 (88%) having a clinically useable result. 40 (32%) had IAT vs. 65 (29%) in the historic cohort. Median time to AST in PP was shortened by 61.7 hours (89.5 vs. 27.8; p<0.001). LOS was shortened 7 days (28 vs. 19; p=0.226) and mortality was 8% (40.5% vs. 32.5%; p=0.440) lower. Median CM +3,074.80 € per case (-2,350.50 € vs. +724.70 €; p=0.040). Conclusion: The new Pheno^TM ID+AST test leads to faster and clinically meaningful results and saves money by shortening LOS on the ICU.

Variation in antibiotic use across intensive care units (ICU): A population-based cohort study in Ontario, Canada

OBJECTIVES

Antibiotics are commonly used in intensive care units (ICUs), yet differences in antibiotic use across ICUs are unknown. Herein, we studied antibiotic use across ICUs and examined factors that contributed to variation.

METHODS

We conducted a retrospective cohort study using data from Ontario's Critical Care Information System (CCIS), which included 201 adult ICUs and 2,013,397 patient days from January 2012 to June 2016. Antibiotic use was measured in days of therapy (DOT) per 1,000 patient days. ICU factors included ability to provide ventilator support (level 3) or not (level 2), ICU type (medical-surgical or other), and academic status. Patient factors included severity of illness using multiple-organ dysfunction score (MODS), ventilatory support, and central venous catheter (CVC) use. We analyzed the effect of these factors on variation in antibiotic use.

RESULTS

Overall, 269,351 patients (56%) received antibiotics during their ICU stay. The mean antibiotic use was 624 (range 3-1460) DOT per 1,000 patient days. Antibiotic use was significantly higher in medical-surgical ICUs compared to other ICUs (697 vs 410 DOT per 1,000 patient days; P < .0001) and in level 3 ICUs compared to level 2 ICUs (751 vs 513 DOT per 1,000 patient days; P < .0001). Higher antibiotic use was associated with higher severity of illness and intensity of treatment. ICU and patient factors explained 47% of the variation in antibiotic use across ICUs.

CONCLUSIONS

Antibiotic use varies widely across ICUs, which is partially associated with ICUs and patient characteristics. These differences highlight the importance of antimicrobial stewardship to ensure appropriate use of antibiotics in ICU patients.

The clinical impact of implementing GenMark ePlex blood culture panels for around-the-clock blood culture identification; a prospective observational study

Background: Implementing rapid molecular blood culture diagnostics in the clinical management of sepsis is essential for early pathogen identification and resistance gene testing. The GenMark ePlex blood culture panels offer a broad microbial spectrum with minimal hands-on time and approximately 1.5 h to result. Therefore, ePlex can be utilized at times when the clinical microbiology laboratory is unavailable.Methods: From 23 October 2019 to 30 December 2019, consecutive non-duplicate positive blood cultures signalling microbial growth at the 24 h/7 days-a-week available clinical chemistry laboratory between 9 pm and 7 am were analysed with ePlex. All blood cultures were transported to the microbiology laboratory the following day for conventional identification and antibiotic susceptibility testing.Results: We used ePlex to test 91 blood cultures, of which 86 had confirmed microbial growth. Eighty-one were positive for ePlex target pathogens. The ePlex results were in complete agreement with conventional methods in 72/81 (88.9%) of cases and available within a median of 10.9 h earlier. Resistance gene targets (11 mecA and 1 CTX-M) were concordant with phenotypic susceptibility in all cases. In 18/86 (20.9%) of the patient cases, there was an opportunity to optimize antimicrobial therapy based on the ePlex result. The ePlex result affected clinical decision-making in 4/86 (4.7%) of the cases and reduced the average time to effective antimicrobial therapy by 8.9 h.Conclusions: Our implementation of ePlex is a feasible option to attain around-the-clock blood culture identification in many hospitals. It can significantly reduce time-to-pathogen identification and have an impact on clinical decision-making.

Impact of host- and early treatment-related factors on mortality in ICU patients with candidemia: a bicentric retrospective observational study

Background

Candidemia is one of the most life-threatening infections among critically ill patients in the intensive care unit. However, the number of studies on the impact of host- and early treatment-related factors on mortality in this cohort is limited. The aim of this study was to investigate the relationship between clinically relevant factors, including early treatment (appropriate antifungal therapy and/or central venous catheter removal) and mortality in intensive care unit patients with candidemia.

Methods

We performed a retrospective observational study in two Japanese University hospitals between January 2007 and December 2016. Adult intensive care unit patients with candidemia who met the following inclusion criteria: (1) ≥ 18 years old; (2) admitted in intensive care unit at the time of onset; and (3) central venous catheter in situ at the time of onset were included. We performed univariate and multivariate logistic regression analysis to identify factors associated with 30-day crude mortality.

Results

A total of 68 patients met the inclusion criteria, 47 (69%) of whom were males. The median age was 68.0 (interquartile range, 61.0-76.0) years. The most common causative Candida species was Candida albicans (40 [59%] patients). With respect to the source of infection, central venous catheter-related candidemia was the most frequent (30 [44%] patients). Thirty-day crude mortality was 54% (37 patients). In multivariate logistic regression analysis, Acute Physiology and Chronic Health Evaluation II score (1-point increments) was the only factor that was independently associated with higher 30-day crude mortality. Other variables, including appropriate antifungal therapy and/or central venous catheter removal ≤ 24 h and ≤ 48 h following onset, did not significantly influence mortality.

Conclusions

Candidemia in intensive care unit patients is still associated with high 30-day crude mortality rates. The only predictor of death was Acute Physiology and Chronic Health Evaluation II score ≤ 24 h following candidemia onset. Early empiric antifungal therapy and/or early CVC removal conferred no significant clinical benefit on survival in this patient population.

Sepsis therapies: learning from 30 years of failure of translational research to propose new leads

Sepsis has been identified by the World Health Organization (WHO) as a global health priority. There has been a tremendous effort to decipher underlying mechanisms responsible for organ failure and death, and to develop new treatments. Despite saving thousands of animals over the last three decades in multiple preclinical studies, no new effective drug has emerged that has clearly improved patient outcomes. In the present review, we analyze the reasons for this failure, focusing on the inclusion of inappropriate patients and the use of irrelevant animal models. We advocate against repeating the same mistakes and propose changes to the research paradigm. We discuss the long-term consequences of surviving sepsis and, finally, list some putative approaches-both old and new-that could help save lives and improve survivorship.

Early diagnosis of bloodstream infections in the intensive care unit using machine-learning algorithms

PURPOSE

We aimed to develop a machine-learning (ML) algorithm that can predict intensive care unit (ICU)-acquired bloodstream infections (BSI) among patients suspected of infection in the ICU.

METHODS

The study was based on patients' electronic health records at Beth Israel Deaconess Medical Center (BIDMC) in Boston, Massachusetts, USA, and at Rambam Health Care Campus (RHCC), Haifa, Israel. We included adults from whom blood cultures were collected for suspected BSI at least 48 h after admission. Clinical data, including time-series variables and their interactions, were analyzed by an ML algorithm at each site. Prediction ability for ICU-acquired BSI was assessed by the area under the receiver operating characteristics (AUROC) of ten-fold cross-validation and validation sets with 95% confidence intervals.

RESULTS

The datasets comprised 2351 patients from BIDMC (151 with BSI) and 1021 from RHCC (162 with BSI). The median (inter-quartile range) age was 62 (51-75) and 56 (38-69) years, respectively; the median Acute Physiology and Chronic Health Evaluation II scores were 26 (21-32) and 24 (20-29), respectively. The means of the cross-validation AUROCs were 0.87 ± 0.02 for BIDMC and 0.93 ± 0.03 for RHCC. AUROCs of 0.89 ± 0.01 and 0.92 ± 0.02 were maintained in both centers with internal validation, while external validation deteriorated. Valuable predictors were mainly the trends of time-series variables such as laboratory results and vital signs.

CONCLUSION

An ML approach that uses temporal and site-specific data achieved high performance in recognizing BC samples with a high probability for ICU-acquired BSI.

Appropriate empirical antibiotic therapy and mortality: Conflicting data explained by residual confounding

Objective

Clinical practice universally assumes that appropriate empirical antibiotic therapy improves survival in patients with bloodstream infection. However, this is not generally supported by previous studies. We examined the association between appropriate therapy and 30-day mortality, while minimizing bias due to confounding by indication.

Methods

We conducted a retrospective cohort study between 2012 and 2017 at a tertiary university hospital in the Netherlands. Adult patients with bloodstream infection attending the emergency department were included. Based on in vitro susceptibility, antibiotic therapy was scored as appropriate or inappropriate. Primary outcome was 30-day mortality. To control for confounding, we performed conventional multivariable logistic regression and propensity score methods. Additionally, we performed an analysis in a more homogeneous subgroup (i.e. antibiotic monotherapy).

Results

We included 1.039 patients, 729 (70.2%) received appropriate therapy. Overall 30-day mortality was 10.4%. Appropriately treated patients had more unfavorable characteristics, indicating more severe illness. Despite adjustments, we found no association between appropriate therapy and mortality. For the antibiotic monotherapy subgroup (n = 449), patient characteristics were more homogeneous. Within this subgroup, appropriate therapy was associated with lower mortality (Odds Ratios [95% Confidence Intervals] ranging from: 0.31 [0.14; 0.67] to 0.40 [0.19; 0.85]).

Conclusions

Comparing heterogeneous treatment groups distorts associations despite use of common methods to prevent bias. Consequently, conclusions of such observational studies should be interpreted with care. If possible, future investigators should use our method of attempting to identify and analyze the most homogeneous treatment groups nested within their study objective, because this minimizes residual confounding.

Effect of infectious disease consultation on mortality and treatment of patients with candida bloodstream infections: a retrospective, cohort study

BACKGROUND

Candida bloodstream infection is associated with high mortality. Infectious disease consultation improves outcomes in several infections, including Staphylococcus aureus and cryptococcosis, as well as multidrug-resistant organisms. We aimed to examine the association between infectious disease consultation and differences in management with mortality in candida bloodstream infections.

METHODS

In this retrospective, single-centre cohort study, we reviewed the medical charts of all patients admitted to Barnes-Jewish Hospital (St Louis, MO, USA), a tertiary referral centre, aged 18 years or older with candida bloodstream infection from 2002 to 2015. We collected data for demographics, comorbidities, predisposing factors, all-cause mortality, antifungal use, central-line removal, and ophthalmological and echocardiographic evaluation to assess 90-day all-cause mortality between individuals with and without an infectious disease consultation. For the survival analysis we used Cox proportional hazards model with inverse weighting by propensity score to assess the effects of infectious disease consultation on mortality and differences in management.

FINDINGS

Between Jan 1, 2002, and Dec 31, 2015, of 1794 patients assessed for eligibility, we analysed 1691 patients with candida bloodstream infection; 776 (45·9%) who had an infectious disease consultation and 915 (54·1%) who did not have an infectious disease consultation. All 1691 patients were included in the analysis. None were missing data. Most underlying comorbidities were evenly distributed between groups. 90-day mortality was lower in the infectious disease consultation group than in patients who did not receive an infectious disease consultation (29% [222/776] vs 51% [468/915]; p<0·0001). In the model with inverse weighting by the propensity score, infectious disease consultation was associated with a hazard ratio of 0·81 (95% CI 0·73-0·91; p<0·0001) for mortality. In the consultation group, median duration of antifungal therapy was longer (18 [IQR 14-35] vs 14 [6-20] days; p<0·0001) and central-line removal (587 [76%] of 776 vs 538 [59%] of 915; p<0·0001), echocardiography use (442 [57%] of 776 vs 305 [33%] of 915; p<0·0001), and ophthalmological examination (412 [53%] of 776 vs 160 [17%] of 915; p<0·0001) were more frequently done. Fewer patients in the infectious disease consultation group were not treated (13 [2%] of 776 vs 128 [14%] of 915; p<0·0001).

INTERPRETATION

Patients with candida bloodstream infection receiving an infectious disease consultation have lower mortality. This finding might be attributable to these individuals receiving a higher number of non-pharmacological, evidence-based interventions and lower amounts of non-treatment. These data suggest that an infectious disease consultation should be an integral part of clinical care of patients with candida bloodstream infection.

FUNDING

Astellas Global Development Pharma, Washington University Institute of Clinical and Translational Sciences, and the Agency for Healthcare Research and Quality.

The soluble mannose receptor (sMR/sCD206) in critically ill patients with invasive fungal infections, bacterial infections or non-infectious inflammation: a secondary analysis of the EPaNIC RCT

Background

Invasive fungal infections (IFI) are difficult to diagnose, especially in critically ill patients. As the mannose receptor (MR) is shed from macrophage cell surfaces after exposure to fungi, we investigate whether its soluble serum form (sMR) can serve as a biomarker of IFI.

Methods

This is a secondary analysis of the multicentre randomised controlled trial (EPaNIC, n = 4640) that investigated the impact of initiating supplemental parenteral nutrition (PN) early during critical illness (Early-PN) as compared to withholding it in the first week of intensive care (Late-PN). Serum sMR concentrations were measured in three matched patient groups (proven/probable IFI, n = 82; bacterial infection, n = 80; non-infectious inflammation, n = 77) on the day of antimicrobial initiation or matched intensive care unit day and the five preceding days, as well as in matched healthy controls (n = 59). Independent determinants of sMR concentration were identified via multivariable linear regression. Serum sMR time profiles were analysed with repeated-measures ANOVA. Predictive properties were assessed via area under the receiver operating curve (aROC).

Results

Serum sMR was higher in IFI patients than in all other groups (all p < 0.02), aROC to differentiate IFI from no IFI being 0.65 (p < 0.001). The ability of serum sMR to discriminate infectious from non-infectious inflammation was better with an aROC of 0.68 (p < 0.001). The sMR concentrations were already elevated up to 5 days before antimicrobial initiation and remained stable over time. Multivariable linear regression analysis showed that an infection or an IFI, higher severity of illness and sepsis upon admission were associated with higher sMR levels; urgent admission and Late-PN were independently associated with lower sMR concentrations.

Conclusion

Serum sMR concentrations were higher in critically ill patients with IFI than in those with a bacterial infection or with non-infectious inflammation. However, test properties were insufficient for diagnostic purposes.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2549-8) contains supplementary material, which is available to authorized users.

A prospective, multi-center study of Candida bloodstream infections in Chile

BACKGROUND

Active surveillance is necessary for improving the management and outcome of patients with candidemia. The aim of this study was to describe epidemiologic and clinical features of candidemia in children and adults in tertiary level hospitals in Chile.

METHODS

We conducted a prospective, multicenter, laboratory-based survey study of candidemia in 26 tertiary care hospitals in Chile, from January 2013 to October 2017.

RESULTS

A total of 780 episodes of candidemia were included, with a median incidence of 0.47/1,000 admissions. Demographic, clinical and microbiological information of 384 cases of candidemia, from 18 hospitals (7,416 beds), was included in this report. One hundred and thirty-four episodes (35%) occurred in pediatric patients and 250 (65%) in adult population. Candida albicans (39%), Candida parapsilosis (30%) and Candida glabrata (10%) were the leading species, with a significant difference in the distribution of species between ages. The use of central venous catheter and antibiotics were the most frequent risk factors in all age groups (> 70%). Three hundred and fifteen strains were studied for antifungal susceptibility; 21 strains (6.6%) were resistant to fluconazole, itraconazole, voriconazole, anidulafungin or micafungin. The most commonly used antifungal therapies were fluconazole (39%) and echinocandins (36%). The overall 30-day survival was 74.2%, significantly higher in infants (82%) and children (86%) compared with neonates (72%), adults (71%) and elderly (70%).

CONCLUSIONS

Our prospective, multicenter surveillance study showed a low incidence of candidemia in Chile, with high 30-day survival, a large proportion of elderly patients, C. glabrata as the third most commonly identified strain, a 6.6% resistance to antifungal agents and a frequent use of echinocandins.

Relationship Between Antimicrobial Prescribing and Antimicrobial Resistance Among UTI Patients at Buraidah Central Hospital, Saudi Arabia

Introduction:

Most of the decisions regarding diagnosis and treatment are based on laboratory test results. Urinary tract infections (UTIs) are among the most common infections in humans. The changing antimicrobial sensitivity in UTI requires appropriate antibiotics. Antimicrobial resistance is an emerging problem in the Kingdom of Saudi Arabia where the complete reversal of antimicrobial resistance is difficult due to irrational use of antibiotics.

Objectives:

This study aimed to determine the most common bacterial agents causing UTI in different seasons among patients who were admitted to Buraidah Central Hospital (BCH), Saudi Arabia. The study also evaluated the link between prescribing and resistance toward antimicrobials.

Materials and Methods:

A 6-month retrospective study was conducted among adult patients who were admitted to the inpatient department at BCH. A total of 379 files were collected from microbiological laboratory for inpatients.

Results:

Most UTI-causing bacteria prevailed in the same season. Of 15 bacterial strains, 12 were significantly correlated with 20 (of a total of 40) antibiotics that were used. Most bacteria were gram-negative. Gram-negative bacilli including Escherichia coli, Klebsiella spp., and Pseudomonadaceae and gram-positive Enterococcus faecalis were most frequently causing UTIs.

Conclusion:

Overall prevalence of antibiotic resistance was negative in bacterial isolates. However, the relationship between antimicrobial prescribing and antimicrobial resistance was significantly negative among UTI patients in BCH, Saudi Arabia.

Implementation of an empirical antimicrobial protocol in a critical care setting: A single-center retrospective observational cohort study in bacteremic patients

In the treatment of severe infections in critical care settings, the selection of initial empirical antimicrobials affects patient outcomes and antimicrobial overuse. The application of a comprehensive treatment guidance might facilitate appropriate antimicrobial selection. Therefore, we developed such an antimicrobial guidance for use in emergency and critical care center and verified its efficacy. We retrospectively analyzed the data of 195 patients (96 patients before guidance introduction [control group] and 99 after guidance introduction [intervention group]) who were ultimately diagnosed with bacteremia to assess the effects of the guidance (the intervention). The appropriateness of the empirical therapy was greater in the intervention than in the control group (96% vs. 90%, respectively; P = 0.10). Moreover, the rate of carbapenem use was significantly lower in the intervention than in the control group (6% vs. 20%, respectively; P < 0.01). The control and intervention groups had similar 28-day survival rates of 81% and 85%, respectively; P = 0.50). These findings imply that introducing an empirical antimicrobial guidance in emergency outpatient and emergency intensive care settings could improve antimicrobial stewardship without affecting patient mortality. The data of this study can be used as a reference for establishing the study design of a large-scale prospective trial, aimed at verifying guidance efficacy.

In Vitro Activity of Plazomicin against Gram-Negative and Gram-Positive Isolates Collected from U.S. Hospitals and Comparative Activities of Aminoglycosides against Carbapenem-Resistant Enterobacteriaceae and Isolates Carrying Carbapenemase Genes

Plazomicin and comparator agents were tested by using the CLSI reference broth microdilution method against 4,825 clinical isolates collected during 2014 and 2015 in 70 U.S. hospitals as part of the ALERT (Antimicrobial Longitudinal Evaluation and Resistance Trends) program. Plazomicin (MIC₅₀/MIC₉₀, 0.5/2 μg/ml) inhibited 99.2% of 4,362 Enterobacteriaceae at ≤4 μg/ml. Amikacin, gentamicin, and tobramycin inhibited 98.9%, 90.3%, and 90.3% of these isolates, respectively, by applying CLSI breakpoints. The activities of plazomicin were similar among Enterobacteriaceae species, with MIC₅₀ values ranging from 0.25 to 1 μg/ml, with the exception of Proteus mirabilis and indole-positive Proteeae that displayed MIC₅₀ values of 2 μg/ml. For 97 carbapenem-resistant Enterobacteriaceae (CRE), which included 87 isolates carrying bla_KPC, plazomicin inhibited all but 1 isolate at ≤2 μg/ml (99.0% and 98.9%, respectively). Amikacin and gentamicin inhibited 64.9% and 56.7% of the CRE isolates at the respective CLSI breakpoints. Plazomicin inhibited 96.5 and 95.5% of the gentamicin-resistant isolates, 96.9 and 96.5% of the tobramycin-resistant isolates, and 64.3 and 90.0% of the amikacin-resistant isolates according to CLSI and EUCAST breakpoints, respectively. The activities of plazomicin against Pseudomonas aeruginosa (MIC₅₀/MIC₉₀, 4/16 μg/ml) and Acinetobacter species (MIC₅₀/MIC₉₀, 2/16 μg/ml) isolates were similar. Plazomicin was active against coagulase-negative staphylococci (MIC₅₀/MIC₉₀, 0.12/0.5 μg/ml) and Staphylococcus aureus (MIC₅₀/MIC₉₀, 0.5/0.5 μg/ml) but had limited activity against Enterococcus spp. (MIC₅₀/MIC₉₀, 16/64 μg/ml) and Streptococcus pneumoniae (MIC₅₀/MIC₉₀, 32/64 μg/ml). Plazomicin activity against the Enterobacteriaceae tested, including CRE and isolates carrying bla_KPC from U.S. hospitals, supports the development plan for plazomicin to treat serious infections caused by resistant Enterobacteriaceae in patients with limited treatment options.

Liquid chromatography-tandem mass spectrometry for the quantification of moxifloxacin, ciprofloxacin, daptomycin, caspofungin, and isavuconazole in human plasma

A simple and precise ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous analysis of five anti-infective agents used to treat severe infections [three antibiotics (daptomycin, moxifloxacin, ciprofloxacin) and two antifungals (isavuconazole, caspofungin)] in human plasma. Sample preparation was based on protein precipitation with ice cold methanol. All five agents were analyzed with the corresponding isotopically labeled internal standards. All analytes were detected in multiple reactions monitoring (MRM) using API 4000 triple-quadrupole mass spectrometer with electrospray (ESI) source operating in positive mode. The calibration curves were linear over the selected ranges (r > 0.99). The method is precise and accurate with a total run time of 5.5 min. Accuracy of all target analytes ranged between 95.9-116.6%, measured with an imprecision of less than 10.8%. The lower limit of quantification was 1.25 mg/L for caspofungin, 0.3125 mg/L for isavuconazole, 3.125 mg/L for daptomycin, 0.075 mg/L for ciprofloxacin, and 0.1875 mg/L for moxifloxacin. The successful application of the method in patient samples proved its suitability for the medical surveillance of antimicrobial therapy in intensive care units as well as to other pharmacokinetic studies.

Evaluation of Candida bloodstream infection and antifungal utilization in a tertiary care hospital

BACKGROUND

Candida bloodstream infections carry a significant mortality risk, justifying the importance of adequate antifungal therapy. This study describes trends in antifungal consumption using the Defined Daily Dose (DDD) and Days of Therapy (DOT) metrics, identifies the microbiological profile, the time to initiation of empirical therapy, the adjustment after positive blood culture results for Candida, and the impact on in-hospital mortality rate in patients with candidemia.

METHODS

An analysis of antifungal consumption from 2008 to 2016, and of candidemia cases from 2012 to 2016 was carried out in a private tertiary hospital.

RESULTS

A total of 11,273 admissions were identified with a prescription for at least one type of antifungal therapy. Fluconazole was the most prescribed antifungal drug in terms of general consumption. Through the DDD and DOT metrics, we observed that over time, there was an increase in the consumption of liposomal amphotericin B, micafungin and voriconazole. Candida albicans was the most isolated species in blood cultures. Regarding candidemia, we analyzed samples from 115 patients. Empirical therapy was started within 24 h of blood culture in 44.3% of the cases, and in 81.7% of the cases, the antifungal was deemed to be adequate based in antifungal susceptibility testing, both of which were not associated with the in-hospital mortality rate.

CONCLUSIONS

Our study reinforces the importance of monitoring the consumption of antifungal agents, which helps in proposing actions that lead to their rational use and, consequently, reduces the appearance of resistant strains.

7 versus 14 days of antibiotic treatment for critically ill patients with bloodstream infection: a pilot randomized clinical trial

Background

Shorter-duration antibiotic treatment is sufficient for a range of bacterial infections, but has not been adequately studied for bloodstream infections. Our systematic review, survey, and observational study indicated equipoise for a trial of 7 versus 14 days of antibiotic treatment for bloodstream infections; a pilot randomized clinical trial (RCT) was a necessary next step to assess feasibility of a larger trial.

Methods

We conducted an open, pilot RCT of antibiotic treatment duration among critically ill patients with bloodstream infection across 11 intensive care units (ICUs). Antibiotic selection, dosing and route were at the discretion of the treating team; patients were randomized 1:1 to intervention arms consisting of two fixed durations of treatment – 7 versus 14 days. We recruited adults with a positive blood culture yielding pathogenic bacteria identified while in ICU. We excluded patients with severe immunosuppression, foci of infection with an established requirement for prolonged treatment, single cultures with potential contaminants, or cultures yielding Staphylococcus aureus or fungi. The primary feasibility outcomes were recruitment rate and adherence to treatment duration protocol. Secondary outcomes included 90-day, ICU and hospital mortality, relapse of bacteremia, lengths of stay, mechanical ventilation and vasopressor duration, antibiotic-free days, Clostridium difficile, antibiotic adverse events, and secondary infection with antimicrobial-resistant organisms.

Results

We successfully achieved our target sample size (n = 115) and average recruitment rate of 1 (interquartile range (IQR) 0.3–1.5) patient/ICU/month. Adherence to treatment duration was achieved in 89/115 (77%) patients. Adherence differed by underlying source of infection: 26/31 (84%) lung; 18/29 (62%) intra-abdominal; 20/26 (77%) urinary tract; 8/9 (89%) vascular-catheter; 4/4 (100%) skin/soft tissue; 2/4 (50%) other; and 11/12 (92%) unknown sources. Patients experienced a median (IQR) 14 (8–17) antibiotic-free days (of the 28 days after blood culture collection). Antimicrobial-related adverse events included hepatitis in 1 (1%) patient, Clostridium difficile infection in 4 (4%), and secondary infection with highly resistant microorganisms in 10 (9%). Ascertainment was complete for all study outcomes in ICU, in hospital and at 90 days.

Conclusion

It is feasible to conduct a RCT to determine whether 7 versus 14 days of antibiotic treatment is associated with comparable 90-day survival.

Trial registration

ClinicalTrials.gov, identifier: NCT02261506. Registered on 26 September 2014.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2474-1) contains supplementary material, which is available to authorized users.

Potential Adverse Effects of Broad-Spectrum Antimicrobial Exposure in the Intensive Care Unit

Background

The potential adverse effects of empiric broad-spectrum antimicrobial use among patients with suspected but subsequently excluded infection have not been fully characterized. We sought novel methods to quantify the risk of adverse effects of broad-spectrum antimicrobial exposure among patients admitted to an intensive care unit (ICU).

Methods

Among all adult patients admitted to ICUs at a single institution, we selected patients with negative blood cultures who also received ≥1 broad-spectrum antimicrobials. Broad-spectrum antimicrobials were categorized in ≥1 of 5 categories based on their spectrum of activity against potential pathogens. We performed, in serial, 5 cohort studies to measure the effect of each broad-spectrum category on patient outcomes. Exposed patients were defined as those receiving a specific category of broad-spectrum antimicrobial; nonexposed were all other patients in the cohort. The primary outcome was 30-day mortality. Secondary outcomes included length of hospital and ICU stay and nosocomial acquisition of antimicrobial-resistant bacteria (ARB) or Clostridium difficile within 30 days of admission.

Results

Among the study cohort of 1918 patients, 316 (16.5%) died within 30 days, 821 (42.8%) had either a length of hospital stay >7 days or an ICU length of stay >3 days, and 106 (5.5%) acquired either a nosocomial ARB or C. difficile. The short-term use of broad-spectrum antimicrobials in any of the defined broad-spectrum categories was not significantly associated with either primary or secondary outcomes.

Conclusions

The prompt and brief empiric use of defined categories of broad-spectrum antimicrobials could not be associated with additional patient harm.

CD101, a long-acting echinocandin, and comparator antifungal agents tested against a global collection of invasive fungal isolates in the SENTRY 2015 Antifungal Surveillance Program

CD101 is a novel echinocandin with exceptional chemical stability and long-acting pharmacokinetics. The activity of CD101 and comparators was evaluated using CLSI broth microdilution methods against 713 invasive fungal isolates, including 589 Candida spp. (6 species), 14 C. neoformans, 97 A. fumigatus and 13 A. flavus species complex collected worldwide during 2015. All C. tropicalis, C. krusei and C. dubliniensis, 99.7% of C. albicans and 98.3% of C. glabrata were inhibited by ≤0.12 µg/mL of CD101, and these isolates were susceptible/wild type to other echinocandins using CLSI clinical breakpoint and epidemiological cutoff value (ECV) interpretive criteria. C. parapsilosis displayed higher MIC values (range 0.25-2 µg/mL), but similar results were observed for other echinocandins. One C. glabrata and one C. albicans with CD101 MIC value at 1 and 0.25 µg/mL possessed F625S and S645P alterations on FKS1, respectively. These isolates also displayed elevated MIC values for at least one clinically available echinocandin. Fluconazole resistance was noted for 6.6% of C. glabrata and 3.6% C. parapsilosis. Echinocandins had limited activity against C. neoformans. CD101 activity against A. fumigatus and A. flavus (MEC ≤0.03 µg/mL) was comparable to other echinocandins (MEC ≤0.03 µg/mL). These moulds had MIC values below ECVs for the mould-active azoles. CD101 was as active as other echinocandins against common fungal organisms recovered from invasive fungal infections. The extended half-life profile is very desirable as less frequent dosing of this agent should facilitate shorter and more cost-effective hospital stays, improve compliance for outpatients, and provide more convenient outpatient prophylaxis.

Collapse of the Microbiome, Emergence of the Pathobiome, and the Immunopathology of Sepsis

The definition of sepsis has been recently modified to accommodate emerging knowledge in the field, while at the same time being recognized as challenging, if not impossible, to define. Here, we seek to clarify the current understanding of sepsis as one that has been typically framed as a disorder of inflammation to one in which the competing interests of the microbiota, pathobiota, and host immune cells lead to loss of resilience and nonresolving organ dysfunction. Here, we challenge the existence of the idea of noninfectious sepsis given that critically ill humans never exist in a germ-free state. Finally, we propose a new vision of the pathophysiology of sepsis that includes the invariable loss of the host's microbiome with the emergence of a pathobiome consisting of both "healthcare-acquired and healthcare-adapted pathobiota." Under this framework, the critically ill patient is viewed as a host colonized by pathobiota dynamically expressing emergent properties which drive, and are driven by, a pathoadaptive immune response.