An agent-based model on antimicrobial de-escalation in intensive care units: Implications on clinical trial design

Antimicrobial de-escalation refers to reducing the spectrum of antibiotics used in treating bacterial infections. This strategy is widely recommended in many antimicrobial stewardship programs and is believed to reduce patients' exposure to broad-spectrum antibiotics and prevent resistance. However, the ecological benefits of de-escalation have not been universally observed in clinical studies. This paper conducts computer simulations to assess the ecological effects of de-escalation on the resistance prevalence of Pseudomonas aeruginosa-a frequent pathogen causing nosocomial infections. Synthetic data produced by the models are then used to estimate the sample size and study period needed to observe the predicted effects in clinical trials. Our results show that de-escalation can reduce colonization and infections caused by bacterial strains resistant to the empiric antibiotic, limit the use of broad-spectrum antibiotics, and avoid inappropriate empiric therapies. Further, we show that de-escalation could reduce the overall super-infection incidence, and this benefit becomes more evident under good compliance with hand hygiene protocols among health care workers. Finally, we find that any clinical study aiming to observe the essential effects of de-escalation should involve at least ten arms and last for four years-a size never attained in prior studies. This study explains the controversial findings of de-escalation in previous clinical studies and illustrates how mathematical models can inform outcome expectations and guide the design of clinical studies.

Efficacy and safety of a structured de-escalation from antipseudomonal β-lactams in bloodstream infections due to Enterobacterales (SIMPLIFY): an open-label, multicentre, randomised trial

BACKGROUND

De-escalation from broad-spectrum to narrow-spectrum antibiotics is considered an important measure to reduce the selective pressure of antibiotics, but a scarcity of adequate evidence is a barrier to its implementation. We aimed to determine whether de-escalation from an antipseudomonal β-lactam to a narrower-spectrum drug was non-inferior to continuing the antipseudomonal drug in patients with Enterobacterales bacteraemia.

METHODS

An open-label, pragmatic, randomised trial was performed in 21 Spanish hospitals. Patients with bacteraemia caused by Enterobacterales susceptible to one of the de-escalation options and treated empirically with an antipseudomonal β-lactam were eligible. Patients were randomly assigned (1:1; stratified by urinary source) to de-escalate to ampicillin, trimethoprim-sulfamethoxazole (urinary tract infections only), cefuroxime, cefotaxime or ceftriaxone, amoxicillin-clavulanic acid, ciprofloxacin, or ertapenem in that order according to susceptibility (de-escalation group), or to continue with the empiric antipseudomonal β-lactam (control group). Oral switching was allowed in both groups. The primary outcome was clinical cure 3-5 days after end of treatment in the modified intention-to-treat (mITT) population, formed of patients who received at least one dose of study drug. Safety was assessed in all participants. Non-inferiority was declared when the lower bound of the 95% CI of the absolute difference in cure rate was above the -10% non-inferiority margin. This trial is registered with EudraCT (2015-004219-19) and ClinicalTrials.gov (NCT02795949) and is complete.

FINDINGS

2030 patients were screened between Oct 5, 2016, and Jan 23, 2020, of whom 171 were randomly assigned to the de-escalation group and 173 to the control group. 164 (50%) patients in the de-escalation group and 167 (50%) in the control group were included in the mITT population. 148 (90%) patients in the de-escalation group and 148 (89%) in the control group had clinical cure (risk difference 1·6 percentage points, 95% CI -5·0 to 8·2). The number of adverse events reported was 219 in the de-escalation group and 175 in the control group, of these, 53 (24%) in the de-escalation group and 56 (32%) in the control group were considered severe. Seven (5%) of 164 patients in the de-escalation group and nine (6%) of 167 patients in the control group died during the 60-day follow-up. There were no treatment-related deaths.

INTERPRETATION

De-escalation from an antipseudomonal β-lactam in Enterobacterales bacteraemia following a predefined rule was non-inferior to continuing the empiric antipseudomonal drug. These results support de-escalation in this setting.

FUNDING

Plan Nacional de I+D+i 2013-2016 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, Spanish Network for Research in Infectious Diseases; Spanish Clinical Research and Clinical Trials Platform, co-financed by the EU; European Development Regional Fund "A way to achieve Europe", Operative Program Intelligence Growth 2014-2020.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical impact of multidisciplinary carbapenem stewardship interventions: a retrospective cohort study

BACKGROUND

Antimicrobial stewardship (AMS) program aims to optimise antimicrobial utilisation and curb antimicrobial resistance. We investigated the clinical impact of AMS among patients with carbapenem in medical wards of a tertiary hospital.

METHODS

A retrospective cohort study was conducted on hospitalised adult patients treated with carbapenem and reviewed by a multidisciplinary AMS team. We compared the clinical outcomes of accepted (n = 103) and not-accepted AMS intervention cases (n = 37). The outcomes evaluated include trends of total white blood cells (TWBC), C-reactive protein (CRP), body temperature at day-7, and clinical status at day-30 post-AMS intervention.

RESULTS

The interventions included discontinuation (50%), de-escalation (47.9%) and escalation (2.1%) of antibiotics, where the acceptance rate was 67.1%, 80.6% and 66.7%, respectively. Overall, we found no significant difference in clinical outcomes between accepted and not-accepted AMS interventions at day-7 and day-30 post-interventions. On day-7, 62.0% of patients in the accepted group showed decreased or normalised TWBC and CRP levels compared to 47.4% of the not-accepted group (p = 0.271). The mortality at day-30 (32% versus 35%, p = 0.73), discharge rate (53.4% versus 45.9%, p = 0.437), and median length of hospital stay (36.0 versus 30.0 days, p = 0.526) between the groups were comparable. The predictors of 30-day mortality in the study subjects were Charlson Comorbidity Index > 3 (OR: 2.84, 95% CI 1.28-6.29, p = 0.010) and being febrile at day-7 (OR: 4.58, 95% CI 1.83-11.5, p = 0.001).

CONCLUSION

AMS interventions do not result in significant adverse clinical impact and mortality risk.

De-escalation from Echinocandins to Azole Treatment in Critically Ill Patients with Candidemia

OBJECTIVES

This study aims to further explore the duration of echinocandins and analyze the de-escalation (DE) strategy in patients with candidemia.

METHODS

Multivariable logistic regression was used to evaluate the association between the duration of echinocandins (≤ 5-day group vs > 5-day group) and in-hospital mortality.

RESULTS

Of the 357 cases of candidemia, 200 patients (56.02%) were identified in the ≤5-day group. The ≤5-day group did not have a higher in-hospital mortality than the >5-day group in the multivariable model (odds ratio [OR] 1.536, 95% confidence interval (CI) 0.837-2.819, P-value = 0.166), and the finding was validated by the propensity score matching and inverse probability of treatment weighting models. Subgroup analyses showed that patients in the ≤5-day group without DE may have a poor prognosis (OR 4.223, 95% CI 1.773-10.055, P-value = 0.001). The patients in the ≤5-day group, with a sequential organ failure assessment (SOFA) score of ≥3 evaluated at the time of stopping echinocandins, may have a poor prognosis (OR 2.164, 95% CI 1.009-4.641, P-value = 0.047).

CONCLUSION

In critically ill adult patients with candidemia, the ≤5-day group with DE was feasible. However, the SOFA score was recommended when stopping echinocandins to ensure the safety of DE therapy.

Impact of Extended and Restricted Antibiotic Deescalation on Mortality

BACKGROUND

More data are needed about the safety of antibiotic de-escalation in specific clinical situations as a strategy to reduce exposure to broad-spectrum antibiotics. This study aims to compare the survival curve of patient de-escalated (early or late) against those not de-escalated on antibiotics, to determine the association of patient related, clinical related, and pressure sore/device related characteristics on all-cause 30-day mortality and determine the impact of early and late antibiotic de-escalation on 30-day all-cause mortality.

METHODS

This is a retrospective cohort study on patients in medical ward Hospital Kuala Lumpur, admitted between January 2016 and June 2019. A Kaplan-Meier survival curve and Fleming-Harrington test were used to compare the overall survival rates between early, late, and those not de-escalated on antibiotics while multivariable Cox proportional hazards regression was used to determine prognostic factors associated with mortality and the impact of de-escalation on 30-day all-cause mortality.

RESULTS

Overall mortality rates were not significantly different when patients were not de-escalated on extended or restricted antibiotics, compared to those de-escalated early or later (p = 0.760). Variables associated with 30-day all-cause mortality were a Sequential Organ Function Assessment (SOFA) score on the day of antimicrobial stewardship (AMS) intervention and Charlson's comorbidity score (CCS). After controlling for confounders, early and late antibiotics were not associated with an increased risk of mortality.

CONCLUSION

The results of this study reinforce that restricted or extended antibiotic de-escalation in patients does not significantly affect 30-day all-cause mortality compared to continuation with extended and restricted antibiotics.

Nosocomial Infection

OBJECTIVE

The first 70 years of critical care can be considered a period of "industrial revolution-like" advancement in terms of progressing the understanding and care of critical illness. Unfortunately, like the industrial revolution's impact on the environment, advancing ICU care of increasingly elderly, immunosuppressed, and debilitated individuals has resulted in a greater overall burden and complexity of nosocomial infections within modern ICUs. Given the rapid evolution of nosocomial infections, the authors provide an updated review.

DATA SOURCES AND STUDY SELECTION

We searched PubMed and OVID for peer-reviewed literature dealing with nosocomial infections in the critically ill, as well as the websites of government agencies involved with the reporting and prevention of nosocomial infections. Search terms included nosocomial infection, antibiotic resistance, microbiome, antibiotics, and intensive care.

DATA EXTRACTION AND DATA SYNTHESIS

Nosocomial infections in the ICU setting are evolving in multiple domains including etiologic pathogens plus novel or emerging pathogens, prevalence, host risk factors, antimicrobial resistance, interactions of the host microbiome with nosocomial infection occurrence, and understanding of pathogenesis and prevention strategies. Increasing virulence and antimicrobial resistance of nosocomial infections mandate increasing efforts toward their prevention.

CONCLUSIONS

Nosocomial infections are an important determinant of outcome for patients in the ICU setting. Systematic research aimed at improving the prevention and treatment of nosocomial infections is still needed.

The Impact of Rapid Species Identification on Management of Bloodstream Infections: What's in a Name?

Bloodstream infections are a leading cause of morbidity and mortality. Molecular rapid diagnostic tests (mRDTs) are transforming care for patients with bloodstream infection by providing the opportunity to dramatically shorten times to effective therapy and speeding de-escalation of overly broad empiric therapy. However, because of the novelty of these tests which provide information regarding microbial identification and whether specific antibiotic-resistance mutations were detected, many front-line providers still delay final decisions until complete phenotypic susceptibility results are available several days later. Thus the benefits of mRDTs have been largely limited to circumstances where antimicrobial stewardship programs closely monitor these tests and intervene as soon as the results are available. We searched PubMed and Google Scholar for articles published from 1980 to 2019 using the terms antibiotic, antifungal, bacteremia, bloodstream infection, candidemia, candidiasis, children, coagulase negative staphylococcus, consultation, contamination, costs, echocardiogram, endocarditis, enterobacteriaceae, enterococcus, Gram-negative, guidelines, IDSA, immunocompromised, infectious disease or ID, lumbar puncture, meningitis, mortality, MRSA, MSSA, neonatal, outcomes, pediatric, pneumococcal, polymicrobial, Pseudomonas, rapid diagnostic testing, resistance, risk factors, sepsis, Staphylococcus aureus, stewardship, streptococcus, and treatment. With the data from this search, we aim to provide guidance to front-line providers regarding the interpretation and immediate actions to be taken in response to the identification of common bloodstream pathogens by mRDTs. In addition to antimicrobial therapy, additional diagnostic or therapeutic interventions are recommended for particular organisms and clinical settings to either determine the extent of infection or control its source. Pediatric perspectives are offered for those bloodstream pathogens for which management differs from that in adults.

Impact of infectious diseases consultation on the outcome of patients with bacteraemia

Bacteraemia or bloodstream infections (BSI) are associated with much morbidity and mortality. Management of patients with bacteraemia is complex, and the increase in immunosuppressed patients and multidrug-resistant organisms poses additional challenges. The objective of this review is to assess the available published information about the impact of different aspects of management on the outcome of patients with BSI, and, specifically, the importance of infectious diseases specialists (IDS) consultation. The impact of management by IDS on different aspects, including interpretation of newer rapid techniques, early evaluation and treatment, and follow up, are reviewed. Overall, the available data suggest that IDS intervention improves the management and outcome of patients with BSI, either through consultation or structured unsolicited interventions in the context of multidisciplinary bacteraemia programmes.

Antimicrobial de-escalation in critically ill patients: a position statement from a task force of the European Society of Intensive Care Medicine (ESICM) and European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Critically Ill Patients Study Group (ESGCIP)

BACKGROUND

Antimicrobial de-escalation (ADE) is a strategy of antimicrobial stewardship, aiming at preventing the emergence of antimicrobial resistance (AMR) by decreasing the exposure to broad-spectrum antimicrobials. There is no high-quality research on ADE and its effects on AMR. Its definition varies and there is little evidence-based guidance for clinicians to use ADE in the intensive care unit (ICU).

METHODS

A task force of 16 international experts was formed in November 2016 to provide with guidelines for clinical practice to develop questions targeted at defining ADE, its effects on the ICU population and to provide clinical guidance. Groups of 2 experts were assigned 1-2 questions each within their field of expertise to provide draft statements and rationale. A Delphi method, with 3 rounds and an agreement threshold of 70% was required to reach consensus.

RESULTS

We present a comprehensive document with 13 statements, reviewing the evidence on the definition of ADE, its effects in the ICU population and providing guidance for clinicians in subsets of clinical scenarios where ADE may be considered.

CONCLUSION

ADE remains a topic of controversy due to the complexity of clinical scenarios where it may be applied and the absence of evidence to the effects it may have on antimicrobial resistance.

Extended spectrum β-lactamase producing enterobacteriaceae: carbapenem sparing options

Introduction: Carbapenems have an important place in our antibiotic armamentarium and have been trusted to effectively treat infections caused by ESBL-producing Enterobacteriaceae for many years. However, the utility of carbapenems has been compromised by the emergence of resistance especially in Enterobacteriaceae. Therefore, carbapenem-sparing alternative antibiotics are of extreme importance in clinical practice.Areas covered: We reviewed studies addressing currently available antibiotic options used as both empiric and definitive therapy for the treatment of infections due to ESBL-producing Enterobacteriaceae published in the PubMed/MEDLINE, Web of Science and Scopus databases without any date restriction. Current treatment alternatives included beta-lactam/beta-lactamase inhibitor combinations, cefepime, cephamycins, fluoroquinolones, aminoglycosides, fosfomycin, pivmecillinam, temocillin and, various oral alternative agents. We also summarized the clinical and molecular epidemiology, early prediction methods and impact of initial empirical therapy and de-escalation approach for ESBL-producing Enterobacteriaceae infections.Expert opinion: The current literature would endorse the carbapenem utilization for patients with severe and high inoculum-high risk infections. However, for milder infections particularly for urinary tract infections, various carbapenem-sparing antibiotics can be considered in selected cases. For infections including easily drainable intra-abdominal infections and catheter-related infections in which catheter removal is readily available more reliable data are needed to recommend non-carbapenem antibiotics confidently.

Direct Measurement of Performance: A New Era in Antimicrobial Stewardship

For decades, the performance of antimicrobial stewardship programs (ASPs) has been measured by incidence rates of hospital-onset Clostridioides difficile and other infections due to multidrug-resistant bacteria. However, these represent indirect and nonspecific ASP metrics. They are often confounded by factors beyond an ASP’s control, such as changes in diagnostic testing methods or algorithms and the potential of patient-to-patient transmission. Whereas these metrics remain useful for global assessment of healthcare systems, antimicrobial use represents a direct metric that separates the performance of an ASP from other safety and quality teams within an institution. The evolution of electronic medical records and healthcare informatics has made measurements of antimicrobial use a reality. The US Centers for Disease Control and Prevention’s initiative for reporting antimicrobial use and standardized antimicrobial administration ratio in hospitals is highly welcomed. Ultimately, ASPs should be evaluated based on what they do best and what they can control, that is, antimicrobial use within their own institution. This narrative review critically appraises existing stewardship metrics and advocates for adopting antimicrobial use as the primary performance measure. It proposes novel formulas to adjust antimicrobial use based on quality of care and microbiological burden at each institution to allow for meaningful inter-network and inter-facility comparisons.