Sustained reductions in unnecessary antimicrobial administration and hospital Clostridioides difficile rates via stewardship in a nonacademic setting

A large community hospital sought to reduce its burden of hospital-acquired Clostridioides difficile infection (CDI). We implemented an antimicrobial stewardship program (ASP), resulting in marked reductions in unnecessary antimicrobial use, CDI rates, antimicrobial acquisition costs, with preservation of gram-negative susceptibilities. ASP programs are effective in a community setting.

132. Standardized Antimicrobial Administration Ratios to Guide Antimicrobial Stewardship in the Neonatal Intensive Care Unit: a Single Center Experience

Background Antimicrobial stewardship (AMS) is particularly challenging in the neonatal population. Both under- and overuse can negatively impact outcomes. There are limited reports of strategies to improve AMS in the neonatal population. Standardized Antimicrobial Administration Ratios (SAARs) are novel metrics of antimicrobial use, recently introduced for neonatal populations by the National Healthcare Safety Network (NHSN). We describe our experience using SAARs to guide AMS in the neonatal intensive care unit (NICU). Methods This was a retrospective study conducted from January 2020 to April 2021. A team consisting of AMS and NICU department staff identified and implemented AMS strategies. Based on a review of NICU SAAR data, a goal was set to reduce third generation cephalosporin use by encouraging aminoglycoside use when appropriate. The pre-implementation period was January 2020 to May 2020 and the post-implementation period was July 2020 to April 2021. Antibiotic use was measured as SAARs and compared between study periods. The primary outcome was the neonatal SAAR for third generation cephalosporins. Secondary outcomes included SAARs for aminoglycosides and all neonatal antibacterial agents. SAARs were compared using the NHSN Statistics Calculator. Results For third generation cephalosporins, there were 385 observed antimicrobial days (OAD) and 115 expected antimicrobial days (EAD) in the pre-implementation period compared to 597 OAD and 228 EAD in the post implementation period. This resulted in a SAAR of 3.34 and 2.62, respectively; a reduction of 22% (p < 0.001). For aminoglycosides, there were 713 OAD and 584 EAD compared to 1617 OAD and 1155 EAD. This resulted in a SAAR of 1.22 and 1.4; an increase of 15% (p = 0.002). For all neonatal antibacterial agents, there were 2716 OAD and 1739 EAD compared to 5321 OAD and 3438 EAD. This resulted in a SAAR of 1.56 and 1.55; indicating no change in use (p = 0.70). See Table 1 for results. Table 1. Antibiotic Use Conclusion While this initiative resulted in decreased use of third generation cephalosporins, this was not associated with a decrease in antibiotic use overall. Use of SAARs in the NICU may be helpful in both identifying opportunities to improve antibiotic use and monitoring antibiotic use over time. Disclosures Steven Smoke, PharmD, Karius (Advisor or Review Panel member) Shionogi (Scientific Research Study Investigator, Advisor or Review Panel member)

155. Antimicrobial Resistance Patters as a Predictor of Standardized Antimicrobial Administration Ratio: A National Correlation Study

Background Data on antimicrobial usage (AU) and antimicrobial resistance (AR) is submitted to the National Healthcare Safety Network (NHSN) from facilities monthly. Bacterial proportion resistant (%R) from the AR option reports proportion of isolates resistant to specific antimicrobial categories. Standardized Antimicrobial Administration Ratio (SAAR), generated under the AU option, compares observed to predicted days of antimicrobial therapy. The purpose of this study was to evaluate the association between %R and SAAR for broad-spectrum antibacterial agents predominantly used for hospital-onset infections (BSHO) and antibacterial agents predominantly used for resistant gram-positive infections (gram-pos) in adult intensive care units (ICUs) and medical-surgical wards (M/S). Methods This retrospective observational review utilized data reported to NHSN to examine the association of BSHO and gram-pos SAARs with %R for various phenotypic categories by quarter from 2017 through the second quarter of 2020. Phenotypic categories included methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecalis and faecium (VRE), extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella spp. (ESBL), and multi-drug resistant Pseudomonas aeruginosa (MDR PSA). Pearson correlations were used to quantify the associations between SAARs and %R. Results A total of 182 institutions were included for analysis. Weak, positive correlations were observed between SAAR for BSHO in ICU and M/S for MDR PSA %R and also for ESBL %R (r = 0.14 to 0.22, all p < 0.0001). For the gram-pos SAAR in ICU and M/S, there were weak positive correlations between MRSA %R and VRE %R (r = 0.20 to 0.31, all p < 0.0001). Conclusion SAARs are multifactorial, yet these results highlight that more resistant organisms may possibly be contributing to higher use of antimicrobials for facilities. Future SAAR calculations could consider incorporating resistance trends from %R within the institution for increases in AU and adjusting SAARs accordingly. Comprehension of the relationship between %R and SAAR can aid facilities with stewardship programs and understanding how resistance contributes to antibiotic usage. Disclosures Julia Moody, MS, Medline (Other Financial or Material Support, Conducted studies in which participating hospitals received contributed antiseptic product)Molnlycke (Other Financial or Material Support, Conducted studies in which participating hospitals received contributed antiseptic product)

753. Impact of COVID-19 on Healthcare Facility-Onset Clostridiodes difficile Infection

Background It is estimated that the majority of hospitalized COVID-19 patients around the world received antibiotics despite the fact that bacterial co-infections are rare. This can lead to increased antimicrobial resistance and Clostridioides difficile infections (CDI). Gastrointestinal symptoms of COVID-19 may also contribute to increased testing. The objective of this study was to assess the impact of the COVID-19 pandemic on our healthcare facility-onset (HO) CDI rates. Methods This was a retrospective cross-sectional study comparing CDI rate per 1,000 patient days, C. diff order rate per 1,000 patient days, Standardized Antimicrobial Administration Ratio (SAAR), and Standardized Infection Ratio (SIR) in the pre-COVID-19 period from January 1, 2019 to December 31, 2019 to the COVID-19 period from April 1, 2020 to March 31, 2021 at a 877-bed tertiary care hospital in Detroit, Michigan. CDI and order rates were extracted from the electronic medical record (Epic™ Bugsy). SAAR and SIR data were extracted from National Healthcare Safety Network (NHSN). Results The average CDI rate per 1,000 patient days was 4.29 pre-COVID-19 compared to 1.98 during COVID-19 with a 54% reduction, and the C. diff order rate per 1,000 patient days also decreased from 130.89 to 93.03, resulting in a 29% reduction (Figure 1). The SIR was 0.383 compared to 0.308 during COVID-19 (P-value 0.404). SAAR decreased from 1.095 to 0.945 (P-value < 0.001). However, our institution experienced three COVID-19 waves, with peaks in April 2020, November 2020 and March 2021, that correlated with high risk CDI antibiotic utilization in intensive care unit (ICU) (Figure 2). The average hand hygiene rate increased from 82% to 92%. Figure 1. Clostridioides difficile order and infection rates pre-and during COVID-19 pandemic. Figure 2. Standardized Antimicrobial Administration Ratio (SAAR) pre-and during COVID-19 pandemic. Conclusion Despite the COVID-19 pandemic, the HO-CDI and C. diff order rates and overall SAAR decreased; however, antibiotic utilization increased in the ICU during the COVID-19 waves. The overall decrease may be multifactorial and related to increased hand hygiene compliance, isolation and personal protective equipment use and overall decreased antibiotic use and C. diff orders. Disclosures Rachel Kenney, PharmD, Medtronic, Inc. (Other Financial or Material Support, spouse is an employee and shareholder)

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, fewerEscherichia 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.

In Vitro Development of a New Sponge-Based Delivery System for Intracanal Antimicrobial Administration in Endodontic Treatment

This study aimed to evaluate the in vitro performance of collagen-based sponges as a drug delivery system for intracanal antimicrobial administration. Four groups of loaded collagen-based sponges (A, 0.3% w/v amoxicillin trihydrate: potassium clavulanate (4:1); B, 0.03% w/v chlorhexidine gluconate [CHX]; C, 0.3% w/v amoxicillin trihydrate: potassium clavulanate (4:1) and 0.03% w/v CHX; D, 1% w/v amoxicillin trihydrate: potassium clavulanate (4:1) and 0.03% w/v CHX) were designed. Release kinetics were tested in vitro on cultures in Petri dishes, and the effect on bacterial biofilms was studied ex vivo on 114 extracted human single-rooted teeth. Biofilm formation was tested by scanning electron microscopy (SEM). Collagen sponges containing amoxicillin and chlorhexidine showed a time-sustained antimicrobial effect in vitro and were also able to destroy mature biofilms ex vivo. This datum was validated by means of SEM-based study of E. faecalis and S. aureus biofilms.

Impact of Prescriptionauditing and Intervention of Infectious Diseases Specialist on The Use of Antimicrobials in Intensive Care Units

Background: Antimicrobials are among the most prescribed drugs in ICUs, where the use of these drugs is approximately 10 times greater than that of other wards. Even so, it is observed that between 30 to 60% of antimicrobial prescriptions performed in these units are unnecessary or inadequate. Thus, surveillance of antimicrobial prescription is a first and essential step to identify potential overuse or misuse, which could be the target of interventions for antimicrobial administration.Methods: This is an observational, analytical, and prospective study conducted in two adult intensive care units (ICU 1 = surgical and ICU 2 = clinic), with 27 beds each. The study period was divided into pre-intervention (January to June 2019) and post-intervention (July to December 2019).Results: Overall, in the pre- and post-intervention period, 91.4% and 90.0%, respectively, of patients received at least one antimicrobial agent. The most frequently prescribed antimicrobial classes were carbapenems (PRE = 26.0% vs POST = 24.9%; p = 0.245) followed by glycopeptides (PRE = 21.0% vs POST = 18.6%; p = 0.056). Overall, there was a significant reduction in the duration of therapy (PRE = 727 LOT / 1000pd vs POST = 680 LOT / 1000pd; p = 0.028). The highest rates regarding the time of use of antimicrobials were observed for carbapenems, followed by glycopeptides, with significant reductions in the time of exposure of glycopeptides and polymyxin B, and significant increases for penicillins, and tigecycline.Conclusions: In general, the intervention of infectious diseases specialistsin intensive care units had a limited impact on the results evaluated. This may be due to the short period analyzed. Therefore, it is important to monitor the impact of these changes in the long term, drawing a more accurate assessment of the effectiveness of an intervention, with the implementation of active feedback.

Application of Standardized Antimicrobial Administration Ratio as a Motivational Tool within a Multi-Hospital Healthcare System

The standardized antimicrobial administration ratio (SAAR) is a novel antimicrobial stewardship metric that compares actual to expected antimicrobial use (AU). This prospective cohort study examines the utility of SAAR reporting and inter-facility comparisons as a motivational tool to improve overall and broad-spectrum AU within a three-hospital healthcare system. Transparent inter-facility comparisons were deployed during system-wide antimicrobial stewardship meetings beginning in October 2017. Stakeholders were advised to interpret the results to foster competition and incorporate SAAR data into focused antimicrobial stewardship interventions. Student’s t-test was used to compare mean SAARs in the pre- (July 2017 through October 2017) and post-intervention periods (November 2017 through June 2019). The mean pre-intervention SAARs for hospitals A, B, and C were 0.69, 1.09, and 0.60, respectively. Hospital B experienced significant reductions in SAAR for overall AU (from 1.09 to 0.83; p < 0.001), broad-spectrum antimicrobials used for hospital-onset infections (from 1.36 to 0.81; p < 0.001), and agents used for resistant gram-positive infections in the intensive care units (from 1.27 to 0.72; p < 0.001) after the interventions. The alignment of the SAAR across the health-system and sustained reduction in overall and broad-spectrum AU through implementation of inter-facility comparisons demonstrate the utility in the motivational application of this antimicrobial use metric.