Clinical outcomes of carbapenem de-escalation regardless of microbiological results: A propensity score analysis

A multicentre study to determine the in vitro efficacy of flomoxef against extended-spectrum beta-lactamase producing Escherichia coli in Malaysia

Background

The high burden of extended-spectrum beta-lactamase-producing (ESBL)-producing Enterobacterales worldwide, especially in the densely populated South East Asia poses a significant threat to the global transmission of antibiotic resistance. Molecular surveillance of ESBL-producing pathogens in this region is vital for understanding the local epidemiology, informing treatment choices, and addressing the regional and global implications of antibiotic resistance.

Methods

Therefore, an inventory surveillance of the ESBL-Escherichia coli (ESBL-EC) isolates responsible for infections in Malaysian hospitals was conducted. Additionally, the in vitro efficacy of flomoxef and other established antibiotics against ESBL-EC was evaluated.

Results

A total of 127 non-repetitive ESBL-EC strains isolated from clinical samples were collected during a multicentre study performed in five representative Malaysian hospitals. Of all the isolates, 33.9% were isolated from surgical site infections and 85.8% were hospital-acquired infections. High rates of resistance to cefotaxime (100%), cefepime (100%), aztreonam (100%) and trimethoprim-sulfamethoxazole (100%) were observed based on the broth microdilution test. Carbapenems remained the most effective antibiotics against the ESBL-EC, followed by flomoxef. Antibiotic resistance genes were identified by PCR. The blaCTX-M-1 was the most prevalent ESBL gene, with 28 isolates (22%) harbouring blaCTX-M-1 only, 27 isolates (21.3%) co-harbouring blaCTX-M-1 and blaTEM, and ten isolates (7.9%) co-harbouring blaCTX-M-1, blaTEM and blaSHV. A generalised linear model showed significant antibacterial activity of imipenem against different types of infection. Besides carbapenems, this study also demonstrated a satisfactory antibacterial activity of flomoxef (81.9%) on ESBL-EC, regardless of the types of ESBL genes.

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.

Continuation Versus De-escalation of Broad-Spectrum Antibiotic Therapy in Critically Ill COVID-19 Patients

Background

Antibiotic de-escalation (ADE) is a stewardship initiative that aims to reduce exposure to antimicrobials, thus limiting their unwanted effect, including antimicrobial resistance. Our study aims to describe the impact of ADE compared with the continuation of therapy on the outcome of critically ill coronavirus disease 2019 (COVID-19) patients.

Material and Methods

A single-center retrospective study included critically ill COVID-19 adult patients admitted between January 1, 2019 and August 31, 2021, and started on broad-spectrum antibiotics. The primary outcome was intensive care unit (ICU) mortality. In addition, other clinical outcomes were evaluated, including ICU readmissions, length of stay, and superinfection.

Results

The study included 73 patients with a mean age of 61.0 ± 19.4, and ADE was performed in 10 (13.6%) of these. In the ADE group, 8/10 (80%) cultures were positive. ICU mortality was not statistically different between ADE and continuation of therapy groups (60 vs. 41.3%, respectively, P = 0.317). Superinfection occurred in 4 (5.4%) patients. Hospital mortality, length of stay, and ICU readmission rates did not differ significantly between groups.

Conclusion

De-escalation of broad-spectrum antibiotics in critically ill covid-19 patients was not associated with higher mortality. A larger cohort is needed to confirm these findings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44229-023-00027-0.

Carbapenem prescribing at a veterinary teaching hospital before an outbreak of carbapenem-resistant Escherichia coli

OBJECTIVES

Carbapenems are a critically important class of antimicrobials used to treat infections caused by multi-drug-resistant bacteria. Following an outbreak of a carbapenemase (NDM-5)-producing strain of Escherichia coli at our veterinary institution, we opted to describe the use of carbapenems in our institution and the role that drug contraindications in patients may have played when culture and susceptibility testing identified alternative drug options.

MATERIALS AND METHODS

Medical record reviews of all cases where a carbapenem was prescribed were performed, and indications for use, timing of prescribing relative to culture and susceptibility reports, and alternative possible antimicrobial treatments were extracted. Contraindications to alternative antimicrobials were also documented.

RESULTS

Carbapenems were prescribed infrequently: from 2013 to 2018, they accounted for 0.47% of all antimicrobial prescriptions and were administered to 108 of 56,776 (0.2%) patients seen at our institution. They were prescribed empirically in slightly more than half of the patients (57.6%). Among cases where a carbapenem was prescribed after culture and susceptibility results were available, alternative antimicrobials could have been used in 68.3% of cases.

CLINICAL SIGNIFICANCE

Variability in use of these drugs within an institution highlights the need to develop well-defined use guidelines, including when to use these drugs empirically and how to safely de-escalate or choose alternative drugs guided by culture and susceptibility results.

Sustained Improvements in Antimicrobial Therapy and Clinical Outcomes following a Pharmacist-Led Antimicrobial Stewardship Intervention: Uncontrolled Before–After Study

Our antimicrobial pharmacist-led intervention included: (a) a structured review of antibiotic prescriptions; (b) educating prescribers on antimicrobial therapy; (c) monthly reporting of department-level rates of blood sampling for culture. Daily review began in May 2018 and was discontinued after 10 months; however, the other interventions were conducted throughout the study period. This study aimed to evaluate the sustained impact of pharmacist’s interventions on antimicrobial therapy and clinical outcomes between the baseline (May–December 2017), intervention (May–December 2018), and post-intervention (May–December 2019) periods. The rate of blood culture collections before starting antipseudomonal agent therapy was significantly increased from the baseline to post-intervention periods (71% vs. 85%, p < 0.001). Antipseudomonal agent therapy was more frequently de-escalated in the post-intervention period than in the baseline period (73% vs. 54%, p = 0.038). Total use of antipseudomonal agents was reduced from the baseline to intervention periods and persisted during the post-intervention period (50.5 vs. 41.8 and 42.6 DDD per 1000 patient-days, p = 0.016 and p = 0.022, respectively). During the study period, there were significant reductions in the incidence of hospital-acquired Clostridioides difficile infection (1.12, 0.54, and 0.51 per 10,000 patient-days, respectively, p = 0.031) and 30-day mortality with bacteremia (19%, 18%, and 12%, respectively, p = 0.005). Our pharmacist-led interventions sustainably achieved appropriate antimicrobial therapy and improved clinical outcomes.

Discontinuation of Glycopeptides in Patients with Culture Negative Severe Sepsis or Septic Shock: A Propensity-Matched Retrospective Cohort Study

Implementation of antibiotic stewardship is difficult in patients with sepsis because of severity of disease. We evaluated the impact of glycopeptide discontinuation (GD) in patients with culture negative severe sepsis or septic shock who received glycopeptides as initial empiric antibiotic therapy at admission. We conducted a single center retrospective cohort study between January 2010 and March 2018. GD was defined as discontinuation of initial empiric glycopeptides on availability of culture results, revealing the absence of identified pathogens. In 92 included patients, the leading causes of sepsis were pneumonia (34.8%) and intra-abdominal infection (23.9%); 28-day mortality and overall mortality were 14% and 21%, respectively. Glycopeptides were discontinued in 42/92 patients. After propensity score matching, baseline characteristics were not significantly different between the GD and non-GD (GND) groups. GND was associated with development of acute kidney injury (OR 5.54, 95% CI 1.49–20.6, P = 0.011). GD did not increase the 7-day, 14-day, and 28-day mortality compared with GND. The length of hospital stay was shorter in the GD group than in GND group (16.33 ± 17.11 vs. 25.05 ± 14.37, P = 0.082), though not statistically significant. GD may be safe and reduce adverse events of prolonged antibiotic use in patients with culture negative severe sepsis or septic shock receiving glycopeptides as initial empiric antibiotic therapy.

Impact of antimicrobial de-escalation on mortality: a literature review of study methodology and recommendations for observational studies

Introduction: The safety of de-escalation of empirical antimicrobial therapy is largely based on observational data, with many reporting protective effects on mortality. As there is no plausible biological explanation for this phenomenon, it is most probably caused by confounding by indication.Areas covered: We evaluate the methodology used in observational studies on the effects of de-escalation of antimicrobial therapy on mortality. We extended the search for a recent systematic review and identified 52 observational studies. The heterogeneity in study populations was large. Only 19 (36.5%) studies adjusted for confounders and four (8%) adjusted for clinical stability during admission, all as a fixed variable. All studies had methodological limitations, most importantly the lack of adjustment for clinical stability, causing bias toward a protective effect.Expert opinion: The methodology used in studies evaluating the effects of de-escalation on mortality requires improvement. We depicted all potential confounders in a directed acyclic graph to illustrate all associations between exposure (de-escalation) and outcome (mortality). Clinical stability is an important confounder in this association and should be modeled as a time-varying variable. We recommend to include de-escalation as time-varying exposure and use inverse-probability-of-treatment weighted marginal structural models to properly adjust for time-varying confounders.

Antimicrobial de-escalation as part of antimicrobial stewardship in intensive care: no simple answers to simple questions-a viewpoint of experts

Antimicrobial de-escalation (ADE) is defined as the discontinuation of one or more components of combination empirical therapy, and/or the change from a broad-spectrum to a narrower spectrum antimicrobial. It is most commonly recommended in the intensive care unit (ICU) patient who is treated with broad-spectrum antibiotics as a strategy to reduce antimicrobial pressure of empirical broad-spectrum therapy and prevent antimicrobial resistance, yet this has not been convincingly demonstrated in a clinical setting. Even if it appears beneficial, ADE may have some unwanted side effects: it has been associated with prolongation of antimicrobial therapy and could inappropriately be used as a justification for unrestricted broadness of empirical therapy. Also, exposing a patient to multiple, sequential antimicrobials could have unwanted effects on the microbiome. For these reasons, ADE has important shortcomings to be promoted as a quality indicator for appropriate antimicrobial use in the ICU. Despite this, ADE clearly has a role in the management of infections in the ICU. The most appropriate use of ADE is in patients with microbiologically confirmed infections requiring longer antimicrobial therapy. ADE should be used as an integral part of an ICU antimicrobial stewardship approach in which it is guided by optimal specimen quality and relevance. Rapid diagnostics may further assist in avoiding unnecessary initiation of broad-spectrum therapy, which in turn will decrease the need for subsequent ADE.