Tropheryma whipplei detected by metagenomic next-generation sequencing in bronchoalveolar lavage fluid

Whipple's disease is a chronic systemic infectious disease that mainly affects the gastrointestinal tract. In some cases, Tropheryma whipplei can cause infection at the implant site or even throughout the body. In this study, we collected alveolar lavage fluid samples from patients with Tropheryma whipplei from 2020 to 2022, and retrospectively analyzed the clinical data of Tropheryma whipplei positive patients. Patient's past history, clinical manifestations, laboratory examinations, chest CT findings, treatment, and prognosis were recorded. 16 BALFs (70/1725, 4.0 %) from 16 patients were positive for Tropheryma whipplei. 8 patients were male with an average age of 50 years. The main clinical symptoms of patients included fever (9/16), cough (7/16), dyspnea (7/16), and expectoration (5/16), but neurological symptoms and arthralgia were rare. Cardiovascular and cerebrovascular diseases were the most common comorbidity (n=8). The main laboratory characteristics of the patient are red blood cell count, hemoglobin, total protein and albumin below normal levels (11/16), and/or creatinine above normal levels(14/16). Most chest computed tomography mainly show focal or patchy heterogeneous infection (n=5) and pleural effusion (n=8). Among the 6 samples, Tropheryma whipplei was the sole agent, and Klebsiella pneumoniae was the most common detected other pathogens. Metagenomic next-generation sequencing technology has improved the detection rate and attention of Tropheryma whipplei. Further research is needed to distinguish whether Tropheryma whipplei present in respiratory samples is a pathogen or an innocent bystander.

Beta-lactamase dependent and independent evolutionary paths to high-level ampicillin resistance

The incidence of beta-lactam resistance among clinical isolates is a major health concern. A key method to study the emergence of antibiotic resistance is adaptive laboratory evolution. However, in the case of the beta-lactam ampicillin, bacteria evolved in laboratory settings do not recapitulate clinical-like resistance levels, hindering efforts to identify major evolutionary paths and their dependency on genetic background. Here, we used the Microbial Evolution and Growth Arena (MEGA) plate to select ampicillin-resistant Escherichia coli mutants with varying degrees of resistance. Whole-genome sequencing of resistant isolates revealed that ampicillin resistance was acquired via a combination of single-point mutations and amplification of the gene encoding beta-lactamase AmpC. However, blocking AmpC-mediated resistance revealed latent adaptive pathways: strains deleted for ampC were able to adapt through combinations of changes in genes involved in multidrug resistance encoding efflux pumps, transcriptional regulators, and porins. Our results reveal that combinations of distinct genetic mutations, accessible at large population sizes, can drive high-level resistance to ampicillin even independently of beta-lactamases.

Prompt antimicrobial therapy and source control on survival and defervescence of adults with bacteraemia in the emergency department: the faster, the better

BACKGROUND

Bacteraemia is a critical condition that generally leads to substantial morbidity and mortality. It is unclear whether delayed antimicrobial therapy (and/or source control) has a prognostic or defervescence effect on patients with source-control-required (ScR) or unrequired (ScU) bacteraemia.

METHODS

The multicenter cohort included treatment-naïve adults with bacteraemia in the emergency department. Clinical information was retrospectively obtained and etiologic pathogens were prospectively restored to accurately determine the time-to-appropriate antibiotic (TtAa). The association between TtAa or time-to-source control (TtSc, for ScR bacteraemia) and 30-day crude mortality or delayed defervescence were respectively studied by adjusting independent determinants of mortality or delayed defervescence, recognised by a logistic regression model.

RESULTS

Of the total 5477 patients, each hour of TtAa delay was associated with an average increase of 0.2% (adjusted odds ratio [AOR], 1.002; P < 0.001) and 0.3% (AOR 1.003; P < 0.001) in mortality rates for patients having ScU (3953 patients) and ScR (1524) bacteraemia, respectively. Notably, these AORs were augmented to 0.4% and 0.5% for critically ill individuals. For patients experiencing ScR bacteraemia, each hour of TtSc delay was significantly associated with an average increase of 0.31% and 0.33% in mortality rates for overall and critically ill individuals, respectively. For febrile patients, each additional hour of TtAa was significantly associated with an average 0.2% and 0.3% increase in the proportion of delayed defervescence for ScU (3085 patients) and ScR (1266) bacteraemia, respectively, and 0.5% and 0.9% for critically ill individuals. For 1266 febrile patients with ScR bacteraemia, each hour of TtSc delay respectively was significantly associated with an average increase of 0.3% and 0.4% in mortality rates for the overall population and those with critical illness.

CONCLUSIONS

Regardless of the need for source control in cases of bacteraemia, there seems to be a significant association between the prompt administration of appropriate antimicrobials and both a favourable prognosis and rapid defervescence, particularly among critically ill patients. For ScR bacteraemia, delayed source control has been identified as a determinant of unfavourable prognosis and delayed defervescence. Moreover, this association with patient survival and the speed of defervescence appears to be augmented among critically ill patients.

Evaluation of clinical characteristics and risk factors associated with Chlamydia psittaci infection based on metagenomic next-generation sequencing

INTRODUCTION

Psittacosis is a zoonosis caused by Chlamydia psittaci, the clinical manifestations of Psittacosis range from mild illness to fulminant severe pneumonia with multiple organ failure. This study aimed to evaluate the clinical characteristics of Chlamydia psittaci infection diagnosed based on metagenomic next-generation sequencing(mNGS), as well as the risk factors affecting the progress of Chlamydia psittaci infection, in order to improve the effect of therapeutics.

METHODS

We retrospectively analyzed the clinical data of patients infected with chlamydia psittaci in the First Affiliated Hospital of Nanchang University from January 2021 to December 2021. The patient's past medical history, clinical manifestations, laboratory examinations, chest CT results, treatment status, and prognosis data were collected. we also investigated both the pathogenic profile characteristics and the lower respiratory tract microbiota of patients with Chlamydia psittaci pneumonia using mNGS.

RESULTS

All cases of Chlamydia psittaci in our research have been confirmed by mNGS. Among 46 cases of Chlamydia psittaci pneumonia, Poultry exposure was reported in 35 cases. In severe cases of Chlamydia psittaci pneumonia, Neutrophils, Procalcitonin (PCT), Lactate Dehydrogenase (LDH), Hydroxybutyrate Dehydrogenase (HBDH), Creatine Kinase Isoenzymes-B (CK-MB) and D-Dimer levels were remarkably higher than that of non-severe cases, except for lymphocytes (all P < 0.05). Chest CT scans showed Bilateral (77.8%), multiple lobar lungs (85.2%), pleural effusions (44.4%) involvement in those suffering from severe Chlamydia psittaci pneumonia, whereas its incidence was 0%, 21.1% and 10.5% in non-severe patients, respectively (P < 0.05). Multivariate analysis revealed that higher lymphocyte concentrations (OR 0.836, 95% CI 0.714-0.962, P = 0.041) were the only protective factor for survival. mNGS results indicated that 41.3% of patients (19/46) had suspected coinfections with a coinfection rate of 84.2% (16/19) in the severe group, much higher than that in the non severe group (p < 0.05). No significantly different profiles of lower respiratory tract microbiota diversity were found between non severe group and severe group.

CONCLUSION

A history of poultry exposure in patients can serve as an important basis for diagnosing Chlamydia psittaci pneumonia, and patients with severe Chlamydia psittaci pneumonia are more likely to develop elevated inflammatory biomarkers as well as elevated cardiac markers. Higher lymphocyte concentrations are protective factors associated with severe C. psittaci pneumonia. The higher proportion of patients with coinfections in our study supports the use of mNGS for comprehensive early detection of respiratory infections in patients with C. psittaci pneumonia.

Blood plasma metagenomic next-generation sequencing for identifying pathogens of febrile neutropenia in acute leukemia patients

To investigate the value of metagenomic next-generation sequencing (mNGS) in acute leukemia (AL) patients with febrile neutropenia (FN). We retrospectively reviewed 37 AL patients with FN and compared the results of mNGS with blood culture (BC) and the clinical features of the mNGS-positive group and the mNGS-negative group. A total of 14 detected pathogens were the final clinical diagnosis, of which 9 strains were detected only by mNGS and 5 strains were detected by both mNGS and BC. The top pathogens were Klebsiella pneumoniae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. A total of 67.57% (25/37) were bacterial infections, and 2.7% (1/37) were fungal or viral infections. The diagnostic positivity rate of mNGS (25/37, 67.6%) was significantly higher than that of BC (7/37, 18.9%), and the difference was statistically significant (p < 0.05). Then, we explored the clinical distinction between the mNGS-positive group and the mNGS-negative group, and 3 features were filtered, including lymphocyte count (LY), creatinine levels (Cr), and white blood cell count (WBC). Our study demonstrated that early implementation of mNGS can effectively improve the efficacy of pathogen detection in AL patients with FN. The higher diagnostic positivity rate and the ability to detect additional pathogens compared to BC made mNGS a valuable tool in the management of infectious complications in this patient population. Furthermore, the identified clinical features associated with mNGS results provided additional insights for the clinical indication of infection in AL patients with FN.

Antibiotic Therapy Strategies for Treating Gram-Negative Severe Infections in the Critically Ill: A Narrative Review

INTRODUCTION

Not enough data exist to inform the optimal duration and type of antimicrobial therapy against GN infections in critically ill patients.

METHODS

Narrative review based on a literature search through PubMed and Cochrane using the following keywords: "multi-drug resistant (MDR)", "extensively drug resistant (XDR)", "pan-drug-resistant (PDR)", "difficult-to-treat (DTR) Gram-negative infection," "antibiotic duration therapy", "antibiotic combination therapy" "antibiotic monotherapy" "Gram-negative bacteremia", "Gram-negative pneumonia", and "Gram-negative intra-abdominal infection".

RESULTS

Current literature data suggest adopting longer (≥10-14 days) courses of synergistic combination therapy due to the high global prevalence of ESBL-producing (45-50%), MDR (35%), XDR (15-20%), PDR (5.9-6.2%), and carbapenemases (CP)/metallo-β-lactamases (MBL)-producing (12.5-20%) Gram-negative (GN) microorganisms (i.e., Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumanii). On the other hand, shorter courses (≤5-7 days) of monotherapy should be limited to treating infections caused by GN with higher (≥3 antibiotic classes) antibiotic susceptibility. A general approach should be based on (i) third or further generation cephalosporins ± quinolones/aminoglycosides in the case of MDR-GN; (ii) carbapenems ± fosfomycin/aminoglycosides for extended-spectrum β-lactamases (ESBLs); and (iii) the association of old drugs with new expanded-spectrum β-lactamase inhibitors for XDR, PDR, and CP microorganisms. Therapeutic drug monitoring (TDM) in combination with minimum inhibitory concentration (MIC), bactericidal vs. bacteriostatic antibiotics, and the presence of resistance risk predictors (linked to patient, antibiotic, and microorganism) should represent variables affecting the antimicrobial strategies for treating GN infections.

CONCLUSIONS

Despite the strategies of therapy described in the results, clinicians must remember that all treatment decisions are dynamic, requiring frequent reassessments depending on both the clinical and microbiological responses of the patient.

Plazomicin against Multidrug-Resistant Bacteria: A Scoping Review

Plazomicin is a next-generation semisynthetic aminoglycoside antibiotic that can be used to treat infections by multi-resistant bacteria. It is effective against many bacteria-producing carbapenemases or other specific hydrolases. This scoping review aims to define the role acquired by plazomicin from its approval by the FDA (US Food and Drug Administration) in 2018 to the present day. Furthermore, we aim to provide a base for a future meta-analysis. This project was conducted following the recommendations presented in the PRISMA extension for scoping reviews and the JBI Manual for Evidence Synthesis. Among 901 potentially engaging citations, 345 duplicates were removed, and only 81 articles were selected for the analysis. According to the data analysis, plazomicin has been used to treat urinary tract infections, bloodstream infections, and ventilation-associated pneumonia. The pathogens killed included multi-resistant E. coli, K. pneumoniae, A. baumannii, P. aeruginosa, and S. aureus. Plazomicin can be a manageable, valid non-beta-lactam alternative for treating multi-resistant bacteria infections.

Continuous Piperacillin-Tazobactam Infusion Improves Clinical Outcomes in Critically Ill Patients with Sepsis: A Retrospective, Single-Centre Study

Continuous infusion of beta-lactam antibiotics has emerged as an alternative for the treatment of sepsis because of the favourable pharmacokinetics of continuous infusion. This study aimed to evaluate the survival benefits of continuous vs. intermittent infusion of piperacillin-tazobactam in critically ill patients with sepsis. We retrospectively conducted a single-centre study of continuous infusion vs. intermittent infusion of piperacillin-tazobactam for adult patients who met the Sepsis-3 criteria and were treated at a medical ICU within 48 h after hospitalisation between 1 May 2018 and 30 April 2020. The primary outcome was mortality at 28 days. A total of 157 patients (47 in the continuous group and 110 in the intermittent group) met the inclusion criteria for evaluation. The 28-day mortality rates were 12.8% in the continuous group and 27.3% in the intermittent group (p = 0.07). However, after adjustment for potential covariables, patients in the continuous group (12.8%) showed significantly lower mortality at 28 days than those in the intermittent group (27.3%; adjusted hazard ratio (HR), 0.31; 95% confidence interval (CI), 0.13-0.79; p = 0.013). In sepsis patients, continuous infusion of piperacillin-tazobactam may confer a benefit regarding the avoidance of mortality at 28 days compared with intermittent infusion.

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.

Prognostic Effects of Inappropriate Empirical Antimicrobial Therapy in Adults With Community-Onset Bacteremia: Age Matters

Background

Studies have reported the effects of delayed administration of appropriate antimicrobial therapy (AAT) on the short-term prognosis of patients with bloodstream infections; however, whether there is an age-related difference in these effects remains debated.

Methods

In this 4-year multicenter case-control study, patients with community-onset bacteremia were retrospectively categorized into the "middle-aged" (45-64 years), "old" (65-74 years), and "very old" (≥75 years) groups. Two methods were adopted to investigate the prognostic effects of delayed AAT in each age group. First, its effects were, respectively, investigated, after adjustment for the independent predictors of 30-day mortality. Second, patients in each age group were matched by the closest propensity-score (PS), which was calculated by independent predictors of mortality; the survival curves and Pearson chi-square tests were adopted to disclose its effects in each PS-matching group.

Results

Each hour of delayed AAT resulted in an average increase in the 30-day crude mortality rate of 0.2% (P = 0.03), 0.4% (P < 0.001), and 0.7% (P < 0.001) in middle-aged (968 patients), old (683), and very old (1,265) patients, after, respectively, adjusting the independent predictors of mortality in each group. After appropriate PS-matching, no significant proportion differences in patient demographics, bacteremia characteristics, severity of bacteremia and comorbidities, and 15-day or 30-day crude mortality rates were observed between three matched groups (582 patients in each group). However, significant differences in survival curves between patients with delayed AAT > 24 or >48 h and those without delayed administration were demonstrated in each age group. Furthermore, the odds ratios of 30-day mortality for delayed AAT > 24 or >48 h were 1.73 (P = 0.04) or 1.82 (P = 0.04), 1.84 (P = 0.03) or 1.95 (P = 0.02), and 1.87 (P = 0.02) or 2.34 (P = 0.003) in the middle-aged, old, and very old groups, respectively. Notably, the greatest prognostic impact of delayed AAT > 24 or >48 h in the very old group and the smallest impact in the middle-aged group were exhibited.

Conclusion

For adults (aged ≥45 years) with community-onset bacteremia, the delayed AAT significantly impacts their short-term survival in varied age groups and the age-related differences in its prognostic impact might be evident.

Analysis of Prognostic Risk Factors of Bloodstream Infections in Beijing Communities: A Retrospective Study from 2015 to 2019

Objective

This study intends to investigate the prognostic risk factors of bloodstream infection in Beijing.

Methods

This study is a clinical retrospective study. Four hundred forty-six patients with community-onset bloodstream infections (COBSI), admitted to the emergency department and inpatient department of Beijing Jishuitan Hospital from January 1, 2015, to December 31, 2019, were selected as the main research objects. According to whether the patient survives for 100 days or not, 363 cases were in the survival group, and 83 cases were in the death group. By analyzing the clinical data of the two groups of patients, the epidemiology, clinical characteristics, bacterial resistance, and risk factors affecting the prognosis of the patients were analyzed.

Results

A total of 446 pathogenic bacteria were isolated in this study, including 324 Gram-negative (G-) bacteria (72.6%), 121 Gram-positive (G+) bacteria (27.1%). The results of the study showed that there were significant differences in MDR, initial antibiotic use, solid tumor, CKD, septic shock, acute liver injury, AKI, central venous catheter, urinary catheter, blood replacement therapy, invasive operation, and use of three or more antibiotics between the two groups (p<0.05). The multiple logistic regression analysis showed that solid tumors (OR=3.339, 95% CI: (1.441, 7.734), p=0.005), combined septic shock (OR=20.729, 95% CI: (10.235, 41.982), p<0.001), indwelling catheters (OR=3.556, 95% CI: (1.538, 8.222), p=0.003) and continuous venovenous hemofiltration (CVVH, OR=19.548, 95% CI: (8.724, 35.641), p=0.003) are independent risk factors affecting the prognosis of COBSI patients. Appropriate initial antibiotic therapy is a protective factor affecting the prognosis of COBSI patients.

Conclusion

Solid tumors, combined septic shock, indwelling catheters, CVVH are independent risk factors affecting the prognosis of COBSI patients.

Prognostic Effects of Delayed Administration of Antimicrobial Therapy in Older Persons Experiencing Bacteremia With or Without Initial Sepsis Presentations

OBJECTIVES

To investigate the prognostic effects of delayed administration of appropriate antimicrobial therapy (AAT) in older persons experiencing bacteremia with and without initial sepsis syndrome, respectively.

DESIGN

A 4-year multicenter cohort study.

SETTING AND PARTICIPANTS

Older people (≥65 years of age) with community-onset bacteremia in the emergency department (ED) of 3 participating hospitals.

METHODS

Clinical data were retrospectively collected and causative microorganisms were prospectively collected for susceptibilities to determine the period of delayed AAT for each bacteremia episode. Sepsis was defined based on the Sepsis-3 criteria. A multivariable regression model was used to investigate the prognostic effects of delayed AAT, after adjusting independent determinants of 30-day mortality.

RESULTS

Of the total 2357 patients, their median (interquartile range) age was 78 (72-84) years and septic patients accounted for 48.4% (1140 patients) of the overall patients. Compared with nonseptic patients, septic individuals exhibited the shorter period of delayed AAT (median, 2.0 vs 2.5 hours; P < .001), longer hospitalization (median, 11 vs 9 days; P < .001), and higher crude mortality rates at 15 (28.9% vs 2.1%; P < .001) and 30 days (34.6% vs 4.0%; P < .001). In multivariable regression analyses, each hour of delayed AAT resulted in average increases in the 30-day crude mortality rates of 0.38% [adjusted odds ratio (AOR) 1.0038; P < .001), 0.42% (AOR 1.0042; P < .001), and 0.31% (AOR 1.0031; P = .04) among overall, septic, and nonseptic patients, respectively.

CONCLUSIONS AND IMPLICATIONS

For older persons with community-onset bacteremia, irrespective of whether or not patients experiencing initial sepsis presentations, the prognostic impacts of delayed AAT have been evidenced. Notably, because of the longer period of delayed AAT in patients without fulfilling the Sepsis-3, adopting a stricter sepsis definition and/or early bacteremia predictor to avoid delayed AAT and unfavorable prognoses in patients with bacteremia is necessary.

Blood Cultures and Appropriate Antimicrobial Administration after Achieving Sustained Return of Spontaneous Circulation in Adults with Nontraumatic Out-of-Hospital Cardiac Arrest

We aimed to determine the incidence of bacteremia and prognostic effects of prompt administration of appropriate antimicrobial therapy (AAT) on nontraumatic out-of-hospital cardiac arrest (OHCA) patients achieving a sustained return of spontaneous circulation (sROSC), compared with non-OHCA patients. In the multicenter case-control study, nontraumatic OHCA adults with bacteremia episodes after achieving sROSC were defined as case patients, and non-OHCA patients with community-onset bacteremia in the emergency department were regarded as control patients. Initially, case patients had a higher bacteremia incidence than non-OHCA visits (231/2171, 10.6% vs. 10,430/314,620, 3.3%; p < 0.001). Compared with the matched control (2288) patients, case (231) patients experienced more bacteremic episodes due to low respiratory tract infections, fewer urosepsis events, fewer Escherichia coli bacteremia, and more streptococcal and anaerobes bacteremia. Antimicrobial-resistant organisms, such as methicillin-resistant Staphylococcus aureus and extended-spectrum beta-lactamase-producing Enterobacteriaceae, were frequently evident in case patients. Notably, each hour delay in AAT administration was associated with an average increase of 10.6% in crude 30-day mortality rates in case patients, 0.7% in critically ill control patients, and 0.3% in less critically ill control patients. Conclusively, the incidence and characteristics of bacteremia differed between the nontraumatic OHCA and non-OHCA patients. The incorporation of blood culture samplings and rapid AAT administration as first-aids is essential for nontraumatic OHCA patients after achieving sROSC.

Impact of antibiotic timing on mortality from Gram-negative bacteraemia in an English district general hospital: the importance of getting it right every time

OBJECTIVES

There is limited evidence that empirical antimicrobials affect patient-oriented outcomes in Gram-negative bacteraemia. We aimed to establish the impact of effective antibiotics at four consecutive timepoints on 30 day all-cause mortality and length of stay in hospital.

METHODS

We performed a multivariable survival analysis on 789 patients with Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa bacteraemias. Antibiotic choices at the time of the blood culture (BC), the time of medical clerking and 24 and 48 h post-BC were reviewed.

RESULTS

Patients that received ineffective empirical antibiotics at the time of the BC had higher risk of mortality before 30 days (HR = 1.68, 95% CI = 1.19-2.38, P = 0.004). Mortality was higher if an ineffective antimicrobial was continued by the clerking doctor (HR = 2.73, 95% CI = 1.58-4.73, P < 0.001) or at 24 h from the BC (HR = 1.83, 95% CI = 1.05-3.20, P = 0.033) when compared with patients who received effective therapy throughout. Hospital-onset infections, 'high inoculum' infections and elevated C-reactive protein, lactate and Charlson comorbidity index were independent predictors of mortality. Effective initial antibiotics did not statistically significantly reduce length of stay in hospital (-2.98 days, 95% CI = -6.08-0.11, P = 0.058). The primary reasons for incorrect treatment were in vitro antimicrobial resistance (48.6%), initial misdiagnosis of infection source (22.7%) and non-adherence to hospital guidelines (15.7%).

CONCLUSIONS

Consecutive prescribing decisions affect mortality from Gram-negative bacteraemia.

Blood Stream Infections from MDR Bacteria

BACKGROUND

Bloodstream infections (BSIs) constitute a growing public health concern, are among the most severe nosocomial pathologies, and are considered a worldwide cause of unfaithful outcomes, increasing treatment costs and diagnostic uncertainties. BSIs are one of the most frequent lethal conditions that are managed in intensive care units (ICUs). In the case of septic shock, immune deficiency, and delayed treatment, even with adequate antimicrobial therapy and/or source control, the outcomes are often unfavorable.

METHODS

this review article summarizes the epidemiological and microbiological characteristics of BSIs with a particular focus on ICU acquired BSIs (ICU-BSIs), which are usually caused by multidrug-resistant (MDR) pathogens. For this reason, their antimicrobial resistance patterns and therapeutic options have also been compiled.

RESULTS

ICU-acquired BSIs prevail in 5-7% of ICU patients. Klebsiella pneumoniae, Escherichia coli, Acinetobacter baumannii, and Pseudomonas aeruginosae are the pathogens most often responsible for MDR infections. MDR Enterobacteriaceae have seen their prevalence increase from 6.2% (1997-2000) to 15.8% (2013-2016) in recent years.

CONCLUSIONS

Considering that prevention and treatment of sepsis is nowadays considered a global health priority by the World Health Organization, it is our obligation to invest more resources into solving or reducing the spread of these unfaithful infections. It is relevant to identify patients with risk factors that make them more susceptible to BSIs, to guarantee earlier molecular or microbiological diagnoses, and more rapidly appropriate treatment by using de-escalation strategies where possible.

The Hypotension Period after Initiation of Appropriate Antimicrobial Administration Is Crucial for Survival of Bacteremia Patients Initially Experiencing Severe Sepsis and Septic Shock

Bacteremia is linked to substantial morbidity and medical costs. However, the association between the timing of achieving hemodynamic stability and clinical outcomes remains undetermined. Of the multicenter cohort consisted of 888 adults with community-onset bacteremia initially complicated with severe sepsis and septic shock in the emergency department (ED), a positive linear-by-linear association (γ = 0.839, p < 0.001) of the time-to-appropriate antibiotic (TtAa) and the hypotension period after appropriate antimicrobial therapy (AAT) was exhibited, and a positive trend of the hypotension period after AAT administration in the 15-day (γ = 0.957, p = 0.003) or 30-day crude (γ = 0.975, p = 0.001) mortality rate was evidenced. Moreover, for every hour delay of the TtAa, 30-day survival dropped an average of 0.8% (adjusted odds ratio [AOR], 1.008; p < 0.001); and each additional hour of the hypotension period following AAT initiation notably resulted in with an average 1.1% increase (AOR, 1.011; p < 0.001) in the 30-day crude mortality rate, after adjusting all independent determinants of 30-day mortality recognized by the multivariate regression model. Conclusively, for bacteremia patients initially experiencing severe sepsis and septic shock, prompt AAT administration might shorten the hypotension period to achieve favourable prognoses.

Surveillance of bloodstream infections in intensive care units in England, May 2016-April 2017: epidemiology and ecology

BACKGROUND

Bloodstream infections (BSIs) in patients in intensive care units (ICUs) are associated with increased morbidity, mortality and economic costs. Many BSIs are associated with central venous catheters (CVCs). The Infection in Critical Care Quality Improvement Programme (ICCQIP) was established to initiate surveillance of BSIs in English ICUs.

METHODS

A web-based data capture system was launched on 1^st May 2016 to collect all positive blood cultures (PBCs), patient-days and CVC-days. National Health Service (NHS) trusts in England were invited to participate in the surveillance programme. Data were linked to the antimicrobial resistance dataset maintained by Public Health England and to mortality data.

FINDINGS

Between 1^st May 2016 and 30^th April 2017, 84 ICUs (72 adult ICUs, seven paediatric ICUs and five neonatal ICUs) based in 57 of 147 NHS trusts provided data. In total, 1474 PBCs were reported, with coagulase-negative staphylococci, Escherichia coli, Staphylococcus aureus and Enterococcus faecium being the most commonly reported organisms. The rates of BSI and ICU-associated CVC-BSI were 5.7, 1.5 and 1.3 per 1000 bed-days and 2.3, 1.0 and 1.5 per 1000 ICU-CVC-days in adult, paediatric and neonatal ICUs, respectively. There was wide variation in BSI and CVC-BSI rates within ICU types, particularly in adult ICUs (0-44.0 per 1000 bed-days and 0-18.3 per 1000 ICU-CVC-days).

CONCLUSIONS

While the overall rates of ICU-associated CVC-BSIs were lower than 2.5 per 1000 ICU-CVC-days across all age ranges, large differences were observed between ICUs, highlighting the importance of a national standardized surveillance system to identify opportunities for improvement. Data linkage provided clinically important information on resistance patterns and patient outcomes at no extra cost to participating trusts.

Epidemiology and Prognosis of Intensive Care Unit-Acquired Bloodstream Infection

Intensive care unit–acquired bloodstream infections (ICU-BSI) are frequent and are associated with high morbidity and mortality rates. We conducted this study to describe the epidemiology and the prognosis of ICU-BSI in our ICU and to search for factors associated with mortality at 28 days. For this, we retrospectively studied ICU-BSI in the ICU of the Cayenne General Hospital, from January 2013 to June 2019. Intensive care unit–acquired bloodstream infections were diagnosed in 9.5% of admissions (10.3 ICU-BSI/1,000 days). The median delay to the first ICU-BSI was 9 days. The ICU-BSI was primitive in 44% of cases and secondary to ventilator-acquired pneumonia in 25% of cases. The main isolated microorganisms were Enterobacteriaceae in 67.7% of patients. They were extended-spectrum beta-lactamase (ESBL) producers in 27.6% of cases. Initial antibiotic therapy was appropriate in 65.1% of cases. Factors independently associated with ESBL-producing Enterobacteriaceae (ESBL-PE) as the causative microorganism of ICU-BSI were ESBL-PE carriage before ICU-BSI (odds ratio [OR]: 7.273; 95% CI: 2.876–18.392; P < 0.000) and prior exposure to fluoroquinolones (OR: 4.327; 95% CI: 1.120–16.728; P = 0.034). The sensitivity of ESBL-PE carriage to predict ESBL-PE as the causative microorganism of ICU-BSI was 64.9% and specificity was 81.2%. Mortality at 28 days was 20.6% in the general population. Factors independently associated with mortality at day 28 from the occurrence of ICU-BSI were traumatic category of admission (OR: 0.346; 95% CI: 0.134–0.894; P = 0.028) and septic shock on the day of ICU-BSI (OR: 3.317; 95% CI: 1.561–7.050; P = 0.002). Mortality rate was independent of the causative organism.

Bloodstream infections in critically ill patients: an expert statement

Bloodstream infection (BSI) is defined by positive blood cultures in a patient with systemic signs of infection and may be either secondary to a documented source or primary—that is, without identified origin. Community-acquired BSIs in immunocompetent adults usually involve drug-susceptible bacteria, while healthcare-associated BSIs are frequently due to multidrug-resistant (MDR) strains. Early adequate antimicrobial therapy is a key to improve patient outcomes, especially in those with criteria for sepsis or septic shock, and should be based on guidelines and direct examination of available samples. Local epidemiology, suspected source, immune status, previous antimicrobial exposure, and documented colonization with MDR bacteria must be considered for the choice of first-line antimicrobials in healthcare-associated and hospital-acquired BSIs. Early genotypic or phenotypic tests are now available for bacterial identification and early detection of resistance mechanisms and may help, though their clinical impact warrants further investigations. Initial antimicrobial dosing should take into account the pharmacokinetic alterations commonly observed in ICU patients, with a loading dose in case of sepsis or septic shock. Initial antimicrobial combination attempting to increase the antimicrobial spectrum should be discussed when MDR bacteria are suspected and/or in the most severely ill patients. Source identification and control should be performed as soon as the hemodynamic status is stabilized. De-escalation from a broad-spectrum to a narrow-spectrum antimicrobial may reduce antibiotic selection pressure without negative impact on mortality. The duration of therapy is usually 5–8 days though longer durations may be discussed depending on the underlying illness and the source of infection. This narrative review covers the epidemiology, diagnostic workflow and therapeutic aspects of BSI in ICU patients and proposed up-to-date expert statements.

Beneficial effects of early empirical administration of appropriate antimicrobials on survival and defervescence in adults with community-onset bacteremia

Background

Bloodstream infections are associated with high morbidity and mortality, both of which contribute substantially to healthcare costs. The effects of early administration of appropriate antimicrobials on the prognosis and timing of defervescence of bacteremic patients remain under debate.

Methods

In a 6-year retrospective, multicenter cohort, adults with community-onset bacteremia at the emergency departments (EDs) were analyzed. The period from ED arrival to appropriate antimicrobial administration and that from appropriate antimicrobial administration to defervescence was regarded as the time-to-appropriate antibiotic (TtAa) and time-to-defervescence (TtD), respectively. The primary study outcome was 30-day mortality after ED arrival. The effects of TtAa on 30-day mortality and delayed defervescence were examined after adjustment for independent predictors of mortality, which were recognized by a multivariate regression analysis.

Results

Of the total 3194 patients, a TtAa-related trend in the 30-day crude (γ = 0.919, P = 0.01) and sepsis-related (γ = 0.909, P = 0.01) mortality rate was evidenced. Each hour of TtAa delay was associated with an average increase in the 30-day crude mortality rate of 0.3% (adjusted odds ratio [AOR], 1.003; P < 0.001) in the entire cohort and 0.4% (AOR, 1.004; P < 0.001) in critically ill patients, respectively, after adjustment of independent predictors of 30-day crude mortality. Of 2469 febrile patients, a TtAa-related trend in the TtD (γ = 0.965, P = 0.002) was exhibited. Each hour of TtAa delay was associated with an average 0.7% increase (AOR, 1.007; P < 0.001) in delayed defervescence (TtD of ≥ 7 days) after adjustment of independent determinants of delayed defervescence. Notably, the adverse impact of the inappropriateness of empirical antimicrobial therapy (TtAa > 24 h) on the TtD was noted, regardless of bacteremia severity, bacteremia sources, or causative microorganisms.

Conclusions

The delay in the TtAa was associated with an increasing risk of delayed defervescence and 30-day mortality for adults with community-onset bacteremia, especially for critically ill patients. Thus, for severe bacteremia episodes, early administration of appropriate empirical antimicrobials should be recommended.

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.

Acute kidney injury during daptomycin versus vancomycin treatment in cardiovascular critically ill patients: a propensity score matched analysis

Background

Gram-positive organisms are a leading cause of infection in cardiovascular surgery. Furthermore, these patients have a high risk of developing postoperative renal failure in intensive care unit (ICU). Some antibiotic drugs are known to impair renal function. The aim of the study was to evaluate whether patients treated for Gram-positive cardiovascular infection with daptomycin (DAP) experienced a lower incidence of acute kidney injury (AKI) when compared to patients treated with vancomycin (VAN), with comparable efficacy.

Methods

ICU patients who received either DAP or VAN, prior to or after cardiovascular surgery or mechanical circulatory support, from January 2010 to December 2012, were included in this observational retrospective cohort study. We excluded patients with end stage renal disease and antibiotic prophylaxis. The primary endpoint was the incidence of AKI within the first week of treatment. Secondary endpoints were the incidence of AKI within the first 14 days of treatment, the severity of AKI including renal replacement therapy (RRT), the rates of clinical failure (unsuccessful infection treatment) and of premature discontinuation and mortality. To minimize selection bias, we used a propensity score to compare the 2 groups. Univariate and multivariate analysis were performed to determine factors associated with AKI.

Results

Seventy two patients, treated for infective endocarditis, cardiovascular foreign body infection, or surgical site infection were included (DAP, n = 28 and VAN, n = 44). AKI at day 7 was observed in 28 (64%) versus 6 (21%) of the VAN and DAP patients, respectively (p = 0.001). In the multivariate analysis adjusted to the propensity score, vancomycin treatment was the only factor associated with AKI (Odds Ratio 4.42; 95% CI: 1.39–15.34; p = 0.014). RRT was required for 2 (7%) DAP patients and 13 (30%) VAN patients, p = 0.035. Premature discontinuation and clinical failure occurred more frequently in VAN group than in DAP group (25% versus 4%, p = 0.022 and 42% versus 12%, respectively, p = 0.027).

Conclusions

Daptomycin appears to be safer than vancomycin in terms of AKI risk in ICU patients treated for cardiovascular procedure-related infection. Daptomycin could be considered as a first line treatment to prevent AKI in high-risk patients.

Thrombocytopenia in bacteraemia and association with bacterial species

Thrombocytopenia is common in patients with invasive bacterial infections. Bacteria can activate platelets, but it is unclear if this affects platelet count. The aim of this study was to examine whether bacteraemia with Staphylococcus aureus, which readily activate human platelets, was more likely to be complicated by thrombocytopenia than bacteraemia with Escherichia coli or Streptococcus pneumoniae with different abilities to activate platelets.We compared information from 600 adult patients with community-acquired bacteraemia with S. aureus (n = 140), E. coli (n = 420) and S. pneumoniae (n = 40) in Southern Sweden, 2012, linking information on positive blood cultures from microbiological databases and medical charts. The proportion of patients with thrombocytopenia (platelet count <150 × 109/ml) was calculated. Logistic regression was used to estimate the odds ratios (OR) for thrombocytopenia according to bacterial species adjusted for confounders.The proportion of thrombocytopenia was 29% in S. aureus, 28% in E. coli and 20% in S. pneumonia bacteraemia (P = 0.50), corresponding to an OR of 1.2 (95% confidence interval 0.7-1.9) for thrombocytopenia for S. aureus as compared with E. coli or S. pneumoniae, adjusted for confounders.This study indicates that platelet activation by bacteria is not a major causative mechanism in sepsis-associated thrombocytopenia.

A nationwide survey of intravenous antimicrobial use in intensive care units in Japan

Although most patients in the intensive care unit (ICU) receive antibiotics, little is known about patterns of antibiotic use in ICUs in Japan. The objective of this study was to evaluate the pattern of antibiotic use in ICUs. A nationwide one-day cross-sectional surveillance of antibiotic use in the ICU was conducted three times between January 2011 and December 2011. All patients aged at least16 years were included. Data from 52 ICUs and 1148 patients were reviewed. There were 1028 prescriptions for intravenous antibiotics. Of 1148 patients, 834 (73%) received at least one intravenous antibiotic, and 575 had at least one known site of infection. Respiratory and intra-abdominal infections were the two most common types. Of 1028 prescriptions, 331 (34%) were for surgical or medical prophylaxis. Excluding prophylaxis, carbapenems were the most commonly prescribed agent. Infectious disease consultations, pre- and post-prescription antimicrobial stewardship, and ICU-dedicated antibiograms were available in 44%, 52%, 77%, and 21% of the ICUs, respectively. In logistic regression analysis adjusting for patient characteristics, treatment in a university hospital (adjusted odds ratio, 1.72; 95% CI, 1.05-2.84; P = 0.033) and an open ICU (adjusted odds ratio, 2.30; 95% CI, 1.02-5.17; P = 0.044) were significantly associated with greater likelihood of carbapenem use. An increase in the number of closed ICUs and more intensive care specialists may reduce carbapenem use in Japanese ICUs. Large-scale epidemiological studies of antimicrobial resistance in the ICU are needed.

Sepsis caused by bloodstream infection in patients in the intensive care unit: the impact of inactive empiric antimicrobial therapy on outcome

BACKGROUND

Sepsis is one of the leading causes of death in the UK.

AIMS

To identify the rate of inactive antimicrobial therapy (AMT) in the intensive care unit (ICU) and whether inactive AMT has an effect on in-hospital mortality, ICU mortality, 90-day mortality and length of hospital stay. A further aim was to identify risk factors for receiving inactive AMT.

METHODS

This was a retrospective observational study conducted at Glasgow Royal Infirmary ICU between January 2010 and December 2013. In total, 12,000 blood cultures were taken over this time period, of which 127 were deemed clinically significant. Multi-variate logistic regression was used to identify risk factors independently associated with mortality. Univariate analysis followed by multi-variate analysis was performed to identify risk factors for receiving inactive AMT.

RESULTS

The rate of inactive AMT was 47% (N = 60). Multi-variate analysis showed that receiving antibiotics within the first 24h of ICU admission led to reduced mortality [relative risk 1.70, 95% confidence interval (CI) 1.19-2.44]. Furthermore, it showed that severity of illness (as defined by SIRS criteria sepsis vs septic shock) increased mortality [odds ratio (OR) 9.87, 95% CI 1.73-55.5]. However, inactive AMT did not increase mortality (OR 1.07, 95% CI 0.47-2.41) or length of hospital stay (53.2 vs 69.1 days, P = 0.348). Fungal bloodstream infection was found to be a risk factor for receiving inactive AMT (OR 5.10, 95% CI 1.29-20.14).

CONCLUSION

Mortality from sepsis is influenced by multiple factors. This study was unable to demonstrate that inactive AMT had an effect on mortality in sepsis.

Continuous versus Intermittent β-Lactam Infusion in Severe Sepsis. A Meta-analysis of Individual Patient Data from Randomized Trials

RATIONALE

Optimization of β-lactam antibiotic dosing for critically ill patients is an intervention that may improve outcomes in severe sepsis.

OBJECTIVES

In this individual patient data meta-analysis of critically ill patients with severe sepsis, we aimed to compare clinical outcomes of those treated with continuous versus intermittent infusion of β-lactam antibiotics.

METHODS

We identified relevant randomized controlled trials comparing continuous versus intermittent infusion of β-lactam antibiotics in critically ill patients with severe sepsis. We assessed the quality of the studies according to four criteria. We combined individual patient data from studies and assessed data integrity for common baseline demographics and study endpoints, including hospital mortality censored at 30 days and clinical cure. We then determined the pooled estimates of effect and investigated factors associated with hospital mortality in multivariable analysis.

MEASUREMENTS AND MAIN RESULTS

We identified three randomized controlled trials in which researchers recruited a total of 632 patients with severe sepsis. The two groups were well balanced in terms of age, sex, and illness severity. The rates of hospital mortality and clinical cure for the continuous versus intermittent infusion groups were 19.6% versus 26.3% (relative risk, 0.74; 95% confidence interval, 0.56-1.00; P = 0.045) and 55.4% versus 46.3% (relative risk, 1.20; 95% confidence interval, 1.03-1.40; P = 0.021), respectively. In a multivariable model, intermittent β-lactam administration, higher Acute Physiology and Chronic Health Evaluation II score, use of renal replacement therapy, and infection by nonfermenting gram-negative bacilli were significantly associated with hospital mortality. Continuous β-lactam administration was not independently associated with clinical cure.

CONCLUSIONS

Compared with intermittent dosing, administration of β-lactam antibiotics by continuous infusion in critically ill patients with severe sepsis is associated with decreased hospital mortality.

Timing of appropriate empirical antimicrobial administration and outcome of adults with community-onset bacteremia

Background

Early administration of appropriate antimicrobials has been correlated with a better prognosis in patients with bacteremia, but the optimum timing of early antibiotic administration as one of the resuscitation strategies for severe bacterial infections remains unclear.

Methods

In a retrospective cohort study, adults with community-onset bacteremia at the emergency department (ED) were analyzed. Effects of different cutoffs of time to appropriate antibiotic (TtAa) administration after arrival at the ED on 28-day mortality were examined, after adjustment for independent predictors of mortality identified by multivariate regression analysis.

Results

Among 2349 patients, the mean (interquartile range) TtAa was 2.0 (<1 to 12) hours. All selected cutoffs of TtAa, ranging from 1 to 96 hours, were significantly associated with 28-day mortality (adjusted odds ratio (AOR), 0.54–0.65, all P < 0.001), after adjustment of the following prognostic factors: fatal comorbidities (McCabe classification), critical illness (Pitt bacteremia score (PBS) ≥4) on arrival at the ED, polymicrobial bacteremia, extended-spectrum beta-lactamase-producer bacteremia, underlying malignancies or liver cirrhosis, and bacteremia caused by pneumonia or urinary tract infections. The adverse impact of TtAa on 28-day mortality was most evident at the cutoff of 48 hours, as the lowest AOR was identified (0.54, P < 0.001). In subgroup analyses, the most evident TtAa cutoff (i.e., the lowest AOR) remained at 48 hours in mildly ill (PBS = 0; AOR 0.47; P = 0.04) and moderately ill (PBS = 1–3; AOR 0.55; P = 0.02) patients, but shifted to 1 hour in critically ill patients (PBS ≥4; AOR 0.56; P < 0.001).

Conclusions

The time from triage to administration of appropriate antimicrobials is one of the primary determinants of mortality. The optimum timing of appropriate antimicrobial administration is the first 48 hours after non-critically ill patients arrive at the ED. As bacteremia severity increases, effective antimicrobial therapy should be empirically prescribed within 1 hour after critically ill patients arrive at the ED.

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016

OBJECTIVE

To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012."

DESIGN

A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable.

RESULTS

The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions.

CONCLUSIONS

Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

The Surgical Infection Society Revised Guidelines on the Management of Intra-Abdominal Infection

BACKGROUND

Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations.

METHODS

Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council.

RESULTS

This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included.

SUMMARY

The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline.

Does appropriate empiric antibiotic therapy modify intensive care unit-acquired Enterobacteriaceae bacteraemia mortality and discharge?

BACKGROUND

Conflicting results have been found regarding outcomes of intensive care unit (ICU)-acquired Enterobacteriaceae bacteraemia and the potentially modifying effect of appropriate empiric antibiotic therapy.

AIM

To evaluate these associations while adjusting for potential time-varying confounding using methods from the causal inference literature.

METHODS

Patients who stayed more than two days in two general ICUs in England between 2002 and 2006 were included in this cohort study. Marginal structural models with inverse probability weighting were used to estimate the mortality and discharge associated with Enterobacteriaceae bacteraemia and the impact of appropriate empiric antibiotic therapy on these outcomes.

FINDINGS

Among 3411 ICU admissions, 195 (5.7%) ICU-acquired Enterobacteriaceae bacteraemia cases occurred. Enterobacteriaceae bacteraemia was associated with an increased daily risk of ICU death [cause-specific hazard ratio (HR): 1.48; 95% confidence interval (CI): 1.10-1.99] and a reduced daily risk of ICU discharge (HR: 0.66; 95% CI: 0.54-0.80). Appropriate empiric antibiotic therapy did not significantly modify ICU mortality (HR: 1.08; 95% CI: 0.59-1.97) or discharge (HR: 0.91; 95% CI: 0.63-1.32).

CONCLUSION

ICU-acquired Enterobacteriaceae bacteraemia was associated with an increased daily risk of ICU mortality. Furthermore, the daily discharge rate was also lower after acquiring infection, even when adjusting for time-varying confounding using appropriate methodology. No evidence was found for a beneficial modifying effect of appropriate empiric antibiotic therapy on ICU mortality and discharge.

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016

OBJECTIVE

To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012".

DESIGN

A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable.

RESULTS

The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions.

CONCLUSIONS

Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

How to measure the impacts of antibiotic resistance and antibiotic development on empiric therapy: new composite indices

OBJECTIVES

We aimed to construct widely useable summary measures of the net impact of antibiotic resistance on empiric therapy. Summary measures are needed to communicate the importance of resistance, plan and evaluate interventions, and direct policy and investment.

DESIGN, SETTING AND PARTICIPANTS

As an example, we retrospectively summarised the 2011 cumulative antibiogram from a Toronto academic intensive care unit.

OUTCOME MEASURES

We developed two complementary indices to summarise the clinical impact of antibiotic resistance and drug availability on empiric therapy. The Empiric Coverage Index (ECI) measures susceptibility of common bacterial infections to available empiric antibiotics as a percentage. The Empiric Options Index (EOI) varies from 0 to 'the number of treatment options available', and measures the empiric value of the current stock of antibiotics as a depletable resource. The indices account for drug availability and the relative clinical importance of pathogens. We demonstrate meaning and use by examining the potential impact of new drugs and threatening bacterial strains.

CONCLUSIONS

In our intensive care unit coverage of device-associated infections measured by the ECI remains high (98%), but 37-44% of treatment potential measured by the EOI has been lost. Without reserved drugs, the ECI is 86-88%. New cephalosporin/β-lactamase inhibitor combinations could increase the EOI, but no single drug can compensate for losses. Increasing methicillin-resistant Staphylococcus aureus (MRSA) prevalence would have little overall impact (ECI=98%, EOI=4.8-5.2) because many Gram-positives are already resistant to β-lactams. Aminoglycoside resistance, however, could have substantial clinical impact because they are among the few drugs that provide coverage of Gram-negative infections (ECI=97%, EOI=3.8-4.5). Our proposed indices summarise the local impact of antibiotic resistance on empiric coverage (ECI) and available empiric treatment options (EOI) using readily available data. Policymakers and drug developers can use the indices to help evaluate and prioritise initiatives in the effort against antimicrobial resistance.

Improving the quality of nurse-influenced patient care in the intensive care unit

BACKGROUND

Quality of care is a major focus in the intensive care unit (ICU).

AIM

To describe a nurse-initiated quality improvement (QI) project that improved the care of critically ill patients in a New Zealand tertiary ICU.

DESIGN

A framework for QI was developed and implemented as part of a practice change initiative.

METHODS

Audit data were collected, analysed and reported across seven nurse-influenced patient care standards. The seven standards were enteral nutrition delivered within 24 h of admission, timely administration of antibiotics, sedation holds for eligible patients, early mobilization and three pressure ulcer prevention strategies.

RESULTS

Comparison of audit data collected in 2014 and 2015 demonstrated improvements in five of the seven standards. Those standards with the largest practice improvements were related to the following standards: all eligible patients have enteral nutrition commenced within the first 24 h of ICU admission (3% increase); all eligible patients receive antibiotics within 30 min of prescription time (6% increase); all eligible patients have a daily sedation interruption (DSI; 24% increase); and all eligible patients are mobilized daily in their ICU stay (11% increase in percentage of patients mobilized daily).

CONCLUSIONS

The nursing-initiated QI project demonstrated improved ICU patient care in relation to early enteral nutrition commencement, DSIs and early and daily mobilizing.

RELEVANCE TO CLINICAL PRACTICE

The use of a nursing QI framework incorporating audit and feedback is one method of evaluating and enhancing the quality of care and improving patient outcomes. This initiative demonstrated the improved quality of nursing care for ICU patients, particularly in relation to early enteral nutrition commencement, timely antibiotics, DSIs and daily mobilizing. It is thus highly relevant to critical care nursing teams, particularly those working to create a culture where change is safe, achievable and valued.

Duration of Antimicrobial Treatment for Bacteremia in Canadian Critically Ill Patients

OBJECTIVES

The optimum duration of antimicrobial treatment for patients with bacteremia is unknown. Our objectives were to determine duration of antimicrobial treatment provided to patients who have bacteremia in ICUs, to assess pathogen/patient factors related to treatment duration, and to assess the relationship between treatment duration and survival.

DESIGN

Retrospective cohort study.

SETTINGS

Fourteen ICUs across Canada.

PATIENTS

Patients with bacteremia and were present in the ICU at the time culture reported positive.

INTERVENTIONS

Duration of antimicrobial treatment for patients who had bacteremia in ICU.

MEASUREMENTS AND MAIN RESULTS

Among 1,202 ICU patients with bacteremia, the median duration of treatment was 14 days, but with wide variability (interquartile range, 9-17.5). Most patient characteristics were not associated with treatment duration. Coagulase-negative staphylococci were the only pathogens associated with shorter treatment (odds ratio, 2.82; 95% CI, 1.51-5.26). The urinary tract was the only source of infection associated with a trend toward lower likelihood of shorter treatment (odds ratio, 0.67; 95% CI, 0.42-1.08); an unknown source of infection was associated with a greater likelihood of shorter treatment (odds ratio, 2.14; 95% CI, 1.17-3.91). The association of treatment duration and survival was unstable when analyzed based on timing of death.

CONCLUSIONS

Critically ill patients who have bacteremia typically receive long courses of antimicrobials. Most patient/pathogen characteristics are not associated with treatment duration; survivor bias precludes a valid assessment of the association between treatment duration and survival. A definitive randomized controlled trial is needed to compare shorter versus longer antimicrobial treatment in patients who have bacteremia.

A Multicenter Randomized Trial of Continuous versus Intermittent β-Lactam Infusion in Severe Sepsis

RATIONALE

Continuous infusion of β-lactam antibiotics may improve outcomes because of time-dependent antibacterial activity compared with intermittent dosing.

OBJECTIVES

To evaluate the efficacy of continuous versus intermittent infusion in patients with severe sepsis.

METHODS

We conducted a randomized controlled trial in 25 intensive care units (ICUs). Participants commenced on piperacillin-tazobactam, ticarcillin-clavulanate, or meropenem were randomized to receive the prescribed antibiotic via continuous or 30-minute intermittent infusion for the remainder of the treatment course or until ICU discharge. The primary outcome was the number of alive ICU-free days at Day 28. Secondary outcomes were 90-day survival, clinical cure 14 days post antibiotic cessation, alive organ failure-free days at Day 14, and duration of bacteremia.

MEASUREMENTS AND MAIN RESULTS

We enrolled 432 eligible participants with a median age of 64 years and an Acute Physiology and Chronic Health Evaluation II score of 20. There was no difference in ICU-free days: 18 days (interquartile range, 2-24) and 20 days (interquartile range, 3-24) in the continuous and intermittent groups (P = 0.38). There was no difference in 90-day survival: 74.3% (156 of 210) and 72.5% (158 of 218); hazard ratio, 0.91 (95% confidence interval, 0.63-1.31; P = 0.61). Clinical cure was 52.4% (111 of 212) and 49.5% (109 of 220); odds ratio, 1.12 (95% confidence interval, 0.77-1.63; P = 0.56). There was no difference in organ failure-free days (6 d; P = 0.27) and duration of bacteremia (0 d; P = 0.24).

CONCLUSIONS

In critically ill patients with severe sepsis, there was no difference in outcomes between β-lactam antibiotic administration by continuous and intermittent infusion. Australian New Zealand Clinical Trials Registry number (ACT RN12612000138886).

Bloodstream infections in the Intensive Care Unit

Bloodstream infections (BSIs) represent a common complication among critically ill patients and a leading cause of morbidity and mortality. The prompt initiation of an effective antibiotic therapy is necessary in order to reduce mortality and to improve clinical outcomes. However, the choice of the empiric antibiotic regimen is often challenging, due to the worldwide spread of multi-drug resistant (MDR) organisms with reduced susceptibility to the available broad-spectrum antimicrobials. New therapeutic strategies are 5 to improve the effectiveness of antibiotic treatment while minimizing the risk of resistance selection.

Gram-negative bacteraemia; a multi-centre prospective evaluation of empiric antibiotic therapy and outcome in English acute hospitals

Increasing antibiotic resistance makes choosing antibiotics for suspected Gram-negative infection challenging. This study set out to identify key determinants of mortality among patients with Gram-negative bacteraemia, focusing particularly on the importance of appropriate empiric antibiotic treatment. We conducted a prospective observational study of 679 unselected adults with Gram-negative bacteraemia at ten acute english hospitals between October 2013 and March 2014. Appropriate empiric antibiotic treatment was defined as intravenous treatment on the day of blood culture collection with an antibiotic to which the cultured organism was sensitive in vitro. Mortality analyses were adjusted for patient demographics, co-morbidities and illness severity. The majority of bacteraemias were community-onset (70%); most were caused by Escherichia coli (65%), Klebsiella spp. (15%) or Pseudomonas spp. (7%). Main foci of infection were urinary tract (51%), abdomen/biliary tract (20%) and lower respiratory tract (14%). The main antibiotics used were co-amoxiclav (32%) and piperacillin-tazobactam (30%) with 34% receiving combination therapy (predominantly aminoglycosides). Empiric treatment was inappropriate in 34%. All-cause mortality was 8% at 7 days and 15% at 30 days. Independent predictors of mortality (p <0.05) included older age, greater burden of co-morbid disease, severity of illness at presentation and inflammatory response. Inappropriate empiric antibiotic therapy was not associated with mortality at either time-point (adjusted OR 0.82; 95% CI 0.35-1.94 and adjusted OR 0.92; 95% CI 0.50-1.66, respectively). Although our study does not exclude an impact of empiric antibiotic choice on survival in Gram-negative bacteraemia, outcome is determined primarily by patient and disease factors.

Antimicrobial stewardship - can we afford to do without it?

Antimicrobial resistance (AMR) is a rapidly developing and alarming global threat which has been highlighted by national governments and public health bodies including the World Health Organization. The spectre of a 'post-antibiotic era' is a real possibility unless curtailing the development and spread of these organisms is given high priority. Numerous studies have shown that AMR is associated with worse outcomes for patients and higher healthcare costs. While clinical data from low and middle income countries is lacking, there is increasing evidence that the problem in these areas is as great, or even greater, than in high income nations. Of the many drivers behind the development of AMR, the most significant is selection pressure caused by antibiotic use. Antimicrobial stewardship programmes are a set of interventions that aim to ensure the judicious use of antimicrobials by preventing their unnecessary use, and by providing targeted and limited therapy in situations where they are warranted. The ultimate goal of these programmes is to provide effective antimicrobial therapy whilst safeguarding their effectiveness for future generations. Whilst they do require an initial investment, they have been shown to be an effective way of controlling antimicrobial use, and have been associated with improved patient outcomes and reduced healthcare costs.

Epidemiology, Management, and Risk-Adjusted Mortality of ICU-Acquired Enterococcal Bacteremia

BACKGROUND

Enterococcal bacteremia has been associated with high case fatality, but it remains unknown to what extent death is caused by these infections. We therefore quantified attributable mortality of intensive care unit (ICU)-acquired bacteremia caused by enterococci.

METHODS

From 2011 to 2013 we studied consecutive patients who stayed >48 hours in 2 tertiary ICUs in the Netherlands, using competing risk survival regression and marginal structural modeling to estimate ICU mortality caused by enterococcal bacteremia.

RESULTS

Among 3080 admissions, 266 events of ICU-acquired bacteremia occurred in 218 (7.1%) patients, of which 76 were caused by enterococci (incidence rate, 3.0 per 1000 patient-days at risk; 95% confidence interval [CI], 2.3-3.7). A catheter-related bloodstream infection (CRBSI) was suspected in 44 (58%) of these, prompting removal of 68% of indwelling catheters and initiation of antibiotic treatment for a median duration of 3 (interquartile range 1-7) days. Enterococcal bacteremia was independently associated with an increased case fatality rate (adjusted subdistribution hazard ratio [SHR], 2.68; 95% CI, 1.44-4.98). However, for patients with CRBSI, case fatality was similar for infections caused by enterococci and coagulase-negative staphylococci (CoNS; adjusted SHR, 0.91; 95% CI, .50-1.67). Population-attributable fraction of mortality was 4.9% (95% CI, 2.9%-6.9%) by day 90, reflecting a population-attributable risk of 0.8% (95% CI, .4%-1.1%).

CONCLUSIONS

ICU-acquired enterococcal bacteremia is associated with increased case fatality; however, the mortality attributable to these infections is low from a population perspective. The virulence of enterococci and CoNS in a setting of CRBSI seems comparable.

The role of antimicrobials in the treatment of sepsis and critical illness-related bacterial infections: examination of the evidence

OBJECTIVE

To appraise the evidence behind the Surviving Sepsis Campaign Guidelines on antimicrobial therapy in sepsis and evaluate relevant literature in small animal veterinary critical care.

DATA SOURCE

Electronic searches using MEDLINE and EMBASE databases.

HUMAN DATA SYNTHESIS

Current recommendations are to administer appropriate antimicrobials within 1 hour of a diagnosis of severe sepsis or septic shock. Evidence is supportive of this recommendation in septic shock but the evidence is less compelling in milder forms of critical illness-related infections. It is unclear when the administration of appropriate antimicrobials is most beneficial and when it should be considered essential. Evidence supports shorter courses of antimicrobial therapy for many infections seen in the critical care unit with the biomarkers procalcitonin and C-reactive protein helpful in guiding the duration of therapy.

VETERINARY DATA SYNTHESIS

Current evidence is lacking to support the use of early and aggressive use of antimicrobials in all patients with critical illness-related bacterial infections. Two studies failed to demonstrate improved survival in patients with pulmonary or abdominal infections administered appropriate vs inappropriate empirical antimicrobials. One study failed to show an improved survival when dogs with abdominal infections were administered antimicrobials within 1 hour vs 6 hours of diagnosis of infection. Information regarding ideal duration of antimicrobial therapy and use of biomarkers to guide therapy is currently lacking.

CONCLUSION

Clinicians should aim to administer early and appropriate antimicrobials; however, the impact this will have on patient outcome remains uncertain. The ability to administer early and appropriate antimicrobials may be considered a measure of the quality of medical practice rather than a prognostic indicator.

Treatment of bloodstream infections in ICUs

Bloodstream infections (BSIs) are frequent in ICU and is a prognostic factor of severe sepsis. Community acquired BSIs usually due to susceptible bacteria should be clearly differentiated from healthcare associated BSIs frequently due to resistant hospital strains. Early adequate treatment is key and should use guidelines and direct examination of samples performed from the infectious source. Previous antibiotic therapy knowledge, history of multi-drug resistant organism (MDRO) carriage are other major determinants of first choice antimicrobials in heathcare-associated and nosocomial BSIs. Initial antimicrobial dose should be adapted to pharmacokinetic knowledge. In general, a high dose is recommended at the beginning of treatment.

If MDRO is suspected combination antibiotic therapy is mandatory because it increase the spectrum of treatment. Most of time, combination should be pursued no more than 2 to 5 days.

Given the negative impact of useless antimicrobials, maximal effort should be done to decrease the antibiotic selection pressure. De-escalation from a broad spectrum to a narrow spectrum antimicrobial decreases the antibiotic selection pressure without negative impact on mortality. Duration of therapy should be shortened as often as possible especially when organism is susceptible, when the infection source has been totally controlled.

[First-line anti-infective treatment in sepsis]

BACKGROUND

The Surviving Sepsis Campaign strongly recommends that intravenous antibiotic therapy should be started as early as possible, ideally within the first hour of recognition of severe sepsis or septic shock. There is ample evidence that failure to initiate early antimicrobial treatment correlates with increased morbidity and mortality.

OBJECTIVES

The purpose of this work was to review the recent literature regarding optimal initial antimicrobial treatment in patients with severe sepsis and sepsis shock.

MATERIALS AND METHODS

A literature review was performed.

RESULTS

The most frequently quoted papers claiming the overriding prognostic importance of early administered antibiotics are retrospective data analyses. However, an equivalent number of studies report that a group of septic patients do not benefit from early administration of antibiotics, but can also be harmed. In these patients, watchful waiting with administration of a targeted antibiotic can be used, thus, avoiding the possible collateral damage from excessive treatment with antibiotics. Treatment with monotherapy is adequate in most cases.

CONCLUSION

The administration of antibiotics based on the local epidemiology should be initiated quickly in critically ill patients with severe sepsis and septic shock. In patients who are not in septic shock, treatment can be withheld, while awaiting further studies or clinical assessment to confirm the suspicion of infection.

Quality indicators on the use of antimicrobials in critically ill patients

Quality indicators have been applied to many areas of health care in recent years, including intensive care. However, they have not been specifically developed and validated for antimicrobial use in critically ill patients. Antimicrobials play a key role in intensive care units not only in the prognosis of each individual patient, but also in the development of resistance and changes in the flora in this setting. Evaluating the use of these agents is complex in the intensive care unit, however, because the indications vary greatly and antimicrobial treatment is often changed during admission. We designed and developed specific quality indicators regarding the use of antimicrobials in critically ill patients admitted to the intensive care unit. These indicators are proposed as a tool for application in intensive care units to detect problems in the use of antimicrobials. Future trials are needed, however, to validate these indicators in a large population over time.

Predictors of 7- and 30-day mortality in pediatric intensive care unit patients with cancer and hematologic malignancy infected with Gram-negative bacteria

Background

Infection with Gram-negative bacteria is associated with increased morbidity and mortality. The aim of this study was to evaluate the predictors of 7- and 30-day mortality in pediatric patients in an intensive care unit with cancer and/or hematologic diseases and Gram-negative bacteria infection.

Methods

Data were collected relating to all episodes of Gram-negative bacteria infection that occurred in a pediatric intensive care unit between January 2009 and December 2012, and these cases were divided into two groups: those who were deceased seven and 30 days after the date of a positive culture and those who survived the same time frames. Variables of interest included age, gender, presence of solid tumor or hematologic disease, cancer status, central venous catheter use, previous Pseudomonas aeruginosa infection, infection by multidrug resistant-Gram-negative bacteria, colonization by multidrug resistant-Gram-negative bacteria, neutropenia in the preceding seven days, neutropenia duration ≥3 days, healthcare-associated infection, length of stay before intensive care unit admission, length of intensive care unit stay >3 days, appropriate empirical antimicrobial treatment, definitive inadequate antimicrobial treatment, time to initiate adequate antibiotic therapy, appropriate antibiotic duration ≤3 days, and shock. In addition, use of antimicrobial agents, corticosteroids, chemotherapy, or radiation therapy in the previous 30 days was noted.

Results

Multivariate logistic regression analysis resulted in significant relationship between shock and both 7-day mortality (odds ratio 12.397; 95% confidence interval 1.291–119.016; p = 0.029) and 30-day mortality (odds ratio 6.174; 95% confidence interval 1.760–21.664; p = 0.004), between antibiotic duration ≤3 days and 7-day mortality (odds ratio 21.328; 95% confidence interval 2.834-160.536; p = 0.003), and between colonization by multidrug resistant-Gram-negative bacteria and 30-day mortality (odds ratio 12.002; 95% confidence interval 1.578–91.286; p = 0.016).

Conclusions

Shock was a predictor of 7- and 30-day mortality, and colonization by multidrug resistant-Gram-negative bacteria was an important risk factor for 30-day mortality.