Early versus late pre-intensive care unit admission broad spectrum antibiotics for severe sepsis in adults

Evaluation of ultra-rapid susceptibility testing of ceftolozane-tazobactam by a flow cytometry assay directly from positive blood cultures

The urgent need for rapid antimicrobial susceptibility is broadly apparent from government reports to the lay press. Accordingly, we developed a flow-cytometry assay (FCM) for evaluating ceftolozane-tazobactam (C/T) susceptibility directly on blood cultures (BC) requiring < 2 h from flag positivity to report. The protocol was optimized with C/T-susceptible and C/T-resistant gram-negative bacilli inoculated in BC aerobic bottles (Becton-Dickinson, USA), and afterward optimized for different C/T concentrations (1/4, 2/4, 4/4, and 8/4 mg/L) for 1 h incubation (37 °C), followed by FCM and software analysis. Fluorescent membrane permeability and membrane potential dyes were comparatively used to detect early cell lesions using the CytoFLEX cytometer (Beckman-Coulter, USA). Repeatability, reproducibility, and stability of the assay up to 48 h after BC positivity were determined. Internal validation was performed in spiked BC bottles with 130 Enterobacterales and 32 Pseudomonas aeruginosa isolates from Porto University (Portugal), including 13 ATCC isolates. Additionally, 64 gram-negative bacilli recovered from positive BC at Ramon y Cajal Hospital (Madrid, Spain) were tested. Categorical agreement (CA) and analytical errors were calculated comparing FCM with broth microdilution results. Only the membrane potential dyes clearly distinguished CT-susceptible and CT-resistant isolates. Excellent repeatability, reproducibility, and inter-method concordance was observed. Overall, CA was 99.1% using EUCAST criteria with 2 major errors and 98.7% with CLSI criteria with 2 major and 1 minor errors. A new, accurate, and ultra-rapid FCM (< 2 h) for testing C/T susceptibility gave accurate results and would expand current FCM antimicrobial susceptibility assay.

Antimicrobial resistance of bacteraemia in the emergency department of a German university hospital (2013-2018): potential carbapenem-sparing empiric treatment options in light of the new EUCAST recommendations

Background

This study investigated predominant microorganisms causing community-onset bacteraemia at the medical emergency department (ED) of a tertiary-care university hospital in Germany from 2013 to 2018 and their antimicrobial susceptibility patterns.

Methods

Antimicrobial resistance patterns in patients with positive blood cultures presenting to an internal medicine ED were retrospectively analysed.

Results

Blood cultures were obtained at 5191 of 66,879 ED encounters, with 1013 (19.5%) positive results, and true positive results at 740 encounters (diagnostic yield, 14.3%). The most frequently isolated relevant microorganisms were Enterobacterales (n = 439, 59.3%), Staphylococcus aureus (n = 92, 12.4%), Streptococcus pneumoniae (n = 34, 4.6%), Pseudomonas aeruginosa (n = 32, 4.3%), Streptococcus pyogenes (n = 16, 2.2%), Enterococcus faecalis (n = 18, 2.4%), and Enterococcus faecium (n = 12, 1.6%). Antimicrobial susceptibility testing revealed a high proportion of resistance against ampicillin-sulbactam in Enterobacterales (42.2%). The rate of methicillin-resistant Staphylococcus aureus was low (0.4%).

Piperacillin-tazobactam therapy provided coverage for 83.2% of all relevant pathogens using conventional breakpoints. Application of the new European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations increased the percentage of susceptible isolates to high-dose piperacillin-tazobactam to 92.8% (p < 0.001). Broad-spectrum carbapenems would only cover an additional 4.8%. The addition of vancomycin or linezolid extended coverage by just 1.7%.

Conclusions

Using an ureidopenicillin-beta-lactamase inhibitor combination at the high dose suggested by the new EUCAST recommendations provided nearly 93% coverage for relevant pathogens in patients with suspected bloodstream infection in our cohort. This might offer a safe option to reduce the empiric use of carbapenems. Our data support the absence of a general need for glycopeptides or oxazolidinones in empiric treatment.

Ceftolozane/tazobactam for the treatment of complicated intra-abdominal and urinary tract infections: current perspectives and place in therapy

The current prevalence of infections caused by multidrug-resistant (MDR) organisms is a global threat, and thus, the development of new antimicrobial agents with activity against these pathogens is a healthcare priority. Ceftolozane-tazobactam (C/T) is a new combination of a cephalosporin with a β-lactamase inhibitor that shows excellent in vitro activity against a broad spectrum of Enterobacteriaceae and Pseudomonas aeruginosa, including extended spectrum β-lactamase-producing (ESBL) strains and MDR or extensively drug-resistant (XDR) P. aeruginosa. In phase III randomized clinical trials, C/T demonstrated similar efficacy to meropenem for the treatment of complicated intra-abdominal infections (cIAIs) and superior efficacy to levofloxacin for the treatment of complicated urinary tract infections (cUTIs), including pyelonephritis. The drug is generally safe and well tolerated and its PK/PD profile is very favorable. Observational studies with C/T have revealed good efficacy for the treatment of different types of infection caused by MDR or XDR P. aeruginosa, including some that originated from the digestive or urinary tracts. The place of C/T in therapy is not well defined, but its use could be recommended in a carbapenem-sparing approach for the treatment of infections caused by ESBL-producing strains or for the treatment of infections caused by P. aeruginosa if there are no other more favorable therapeutic options. Further clinical experience is needed to position this new antimicrobial drug for the empirical treatment of cIAIs or cUTIs.

Sepsis: mechanisms of bacterial injury to the patient

In bacteremia the majority of bacterial species are killed by oxidation on the surface of erythrocytes and digested by local phagocytes in the liver and the spleen. Sepsis-causing bacteria overcome this mechanism of human innate immunity by versatile respiration, production of antioxidant enzymes, hemolysins, exo- and endotoxins, exopolymers and other factors that suppress host defense and provide bacterial survival. Entering the bloodstream in different forms (planktonic, encapsulated, L-form, biofilm fragments), they cause different types of sepsis (fulminant, acute, subacute, chronic, etc.). Sepsis treatment includes antibacterial therapy, support of host vital functions and restore of homeostasis. A bacterium killing is only one of numerous aspects of antibacterial therapy. The latter should inhibit the production of bacterial antioxidant enzymes and hemolysins, neutralize bacterial toxins, modulate bacterial respiration, increase host tolerance to bacterial products, facilitate host bactericidal mechanism and disperse bacterial capsule and biofilm.

Improved empirical antibiotic treatment of sepsis after an educational intervention: the ABISS-Edusepsis study

BACKGROUND

Early appropriate antibiotic treatment is essential in sepsis. We aimed to evaluate the impact of a multifaceted educational intervention to improve antibiotic treatment. We hypothesized that the intervention would hasten and improve the appropriateness of empirical antibiotic administration, favor de-escalation, and decrease mortality.

METHODS

We prospectively studied all consecutive patients with sepsis/septic shock admitted to 72 intensive care units (ICUs) throughout Spain in two 4-month periods (before and immediately after the 3-month intervention). We compared process-of-care variables (resuscitation bundle and time-to-initiation, appropriateness, and de-escalation of empirical antibiotic treatment) and outcome variables between the two cohorts. The primary outcome was hospital mortality. We analyzed the intervention's long-term impact in a subset of 50 ICUs.

RESULTS

We included 2628 patients (age 64.1 ± 15.2 years; men 64.0%; Acute Physiology and Chronic Health Evaluation (APACHE) II, 22.0 ± 8.1): 1352 in the preintervention cohort and 1276 in the postintervention cohort. In the postintervention cohort, the mean (SD) time from sepsis onset to empirical antibiotic therapy was lower (2.0 (2.7) vs. 2.5 (3.6) h; p = 0.002), the proportion of inappropriate empirical treatments was lower (6.5% vs. 8.9%; p = 0.024), and the proportion of patients in whom antibiotic treatment was de-escalated was higher (20.1% vs. 16.3%; p = 0.004); the expected reduction in mortality did not reach statistical significance (29.4% in the postintervention cohort vs. 30.5% in the preintervention cohort; p = 0.544). Gains observed after the intervention were maintained in the long-term follow-up period.

CONCLUSIONS

Despite advances in sepsis treatment, educational interventions can still improve the delivery of care; further improvements might also improve outcomes.

Improved empirical antibiotic treatment of sepsis after an educational intervention: the ABISS-Edusepsis study

BACKGROUND

Early appropriate antibiotic treatment is essential in sepsis. We aimed to evaluate the impact of a multifaceted educational intervention to improve antibiotic treatment. We hypothesized that the intervention would hasten and improve the appropriateness of empirical antibiotic administration, favor de-escalation, and decrease mortality.

METHODS

We prospectively studied all consecutive patients with sepsis/septic shock admitted to 72 intensive care units (ICUs) throughout Spain in two 4-month periods (before and immediately after the 3-month intervention). We compared process-of-care variables (resuscitation bundle and time-to-initiation, appropriateness, and de-escalation of empirical antibiotic treatment) and outcome variables between the two cohorts. The primary outcome was hospital mortality. We analyzed the intervention's long-term impact in a subset of 50 ICUs.

RESULTS

We included 2628 patients (age 64.1 ± 15.2 years; men 64.0%; Acute Physiology and Chronic Health Evaluation (APACHE) II, 22.0 ± 8.1): 1352 in the preintervention cohort and 1276 in the postintervention cohort. In the postintervention cohort, the mean (SD) time from sepsis onset to empirical antibiotic therapy was lower (2.0 (2.7) vs. 2.5 (3.6) h; p = 0.002), the proportion of inappropriate empirical treatments was lower (6.5% vs. 8.9%; p = 0.024), and the proportion of patients in whom antibiotic treatment was de-escalated was higher (20.1% vs. 16.3%; p = 0.004); the expected reduction in mortality did not reach statistical significance (29.4% in the postintervention cohort vs. 30.5% in the preintervention cohort; p = 0.544). Gains observed after the intervention were maintained in the long-term follow-up period.

CONCLUSIONS

Despite advances in sepsis treatment, educational interventions can still improve the delivery of care; further improvements might also improve outcomes.

Sepsis and septic shock: Pathogenesis and treatment perspectives

The majority of bacteremias do not develop to sepsis: bacteria are cleared from the bloodstream. Oxygen released from erythrocytes and humoral immunity kill bacteria in the bloodstream. Sepsis develops if bacteria are resistant to oxidation and proliferate in erythrocytes. Bacteria provoke oxygen release from erythrocytes to arterial blood. Abundant release of oxygen to the plasma triggers a cascade of events that cause: 1. oxygen delivery failure to cells; 2. oxidation of plasma components that impairs humoral regulation and inactivates immune complexes; 3. disseminated intravascular coagulation and multiple organs' failure. Bacterial reservoir inside erythrocytes provides the long-term survival of bacteria and is the cause of ineffectiveness of antibiotics and host immune reactions. Treatment perspectives that include different aspects of sepsis development are discussed.

From NELA to EPOCH and beyond: enhancing the evidence base for emergency laparotomy

Around 35,000 patients undergo emergency laparotomy surgery in the UK each year with an in-hospital 30-day mortality estimated as between 11 and 15 %. The recent publication of the First Patient Report of the National Emergency Laparotomy Audit (NELA) has provided a detailed description of individual hospital performance against national standards of care in emergency laparotomy in England and Wales. Although the standards used for audit purposes in NELA are based upon the best currently available evidence, none of the source data derives from randomised controlled studies. This commentary explores the evidence base for the standards evaluated by NELA and highlights recent and forthcoming studies that may substantially contribute to improving the evidence base in this area, thereby improving patient care and strengthening the validity of the NELA audit standards.

The Impact of Timing of Antibiotics on Outcomes in Severe Sepsis and Septic Shock: A Systematic Review and Meta-Analysis

OBJECTIVES

We sought to systematically review and meta-analyze the available data on the association between timing of antibiotic administration and mortality in severe sepsis and septic shock.

DATA SOURCES

A comprehensive search criteria was performed using a predefined protocol.

STUDY SELECTION

INCLUSION CRITERIA

adult patients with severe sepsis or septic shock, reported time to antibiotic administration in relation to emergency department triage and/or shock recognition, and mortality.

EXCLUSION CRITERIA

immunosuppressed populations, review article, editorial, or nonhuman studies.

DATA EXTRACTION

Two reviewers screened abstracts with a third reviewer arbitrating. The effect of time to antibiotic administration on mortality was based on current guideline recommendations: 1) administration within 3 hours of emergency department triage and 2) administration within 1 hour of severe sepsis/septic shock recognition. Odds ratios were calculated using a random effect model. The primary outcome was mortality.

DATA SYNTHESIS

A total of 1,123 publications were identified and 11 were included in the analysis. Among the 11 included studies, 16,178 patients were evaluable for antibiotic administration from emergency department triage. Patients who received antibiotics more than 3 hours after emergency department triage (< 3 hr reference) had a pooled odds ratio for mortality of 1.16 (0.92-1.46; p = 0.21). A total of 11,017 patients were evaluable for antibiotic administration from severe sepsis/septic shock recognition. Patients who received antibiotics more than 1 hour after severe sepsis/shock recognition (< 1 hr reference) had a pooled odds ratio for mortality of 1.46 (0.89-2.40; p = 0.13). There was no increased mortality in the pooled odds ratios for each hourly delay from less than 1 to more than 5 hours in antibiotic administration from severe sepsis/shock recognition.

CONCLUSION

Using the available pooled data, we found no significant mortality benefit of administering antibiotics within 3 hours of emergency department triage or within 1 hour of shock recognition in severe sepsis and septic shock. These results suggest that currently recommended timing metrics as measures of quality of care are not supported by the available evidence.

[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.

Prolonged antibiotic use induces intestinal injury in mice that is repaired after removing antibiotic pressure: implications for empiric antibiotic therapy

Metabolic profiling of urine and fecal extracts, histological investigation of intestinal ilea, and fecal metagenomics analyses were used to investigate effects of prolonged antibiotic use in mice. The study provides insight into the effects of extended empiric antibiotic therapy in humans. Mice were administered a broad-spectrum antibiotic for four consecutive days followed by oral gavage with Clostridium butyricum, an opportunistic gram-positive pathogenic bacteria commonly isolated in fecal and blood cultures of necrotizing enterocolitis patients. Metagenomics data indicated loss of bacterial diversity after 4 days on antibiotics that was restored after removing antibiotic pressure. Histological analyses indicated damage to ileal villi after antibiotic treatment that underwent repair after lifting antibiotic pressure. Metabolic profiling confirmed intestinal injury in antibiotic-treated mice indicated by increased urinary trans-4-hydroxy-l-proline, a breakdown product of collagen present in connective tissue of ileal villi that may serve as a biomarker for antibiotic-induced injury in at risk populations.