599. Association between Vancomycin AUC and Clinical Failure in Patients with Streptococcal Bacteremia

Background

Vancomycin (VAN) is an efficacious therapy against Streptococcus. VAN area under the curve to minimum inhibitory concentration (AUC/MIC) is the preferred monitoring strategy for serious methicillin-resistant S. aureus infections but is not well elucidated for other bacterial pathogens such as Streptococcus.

Methods

This was a retrospective cohort study evaluating adult inpatients with streptococcal bacteremia treated with VAN definitive therapy from Jan 1, 2011 to Sept 30, 2021 at a tertiary care academic medical center. VAN AUC was retrospectively calculated using Bayesian software (ClinCalc). The primary outcome was treatment failure, defined as a composite of recurrent or persistent streptococcal bacteremia, 60-day all-cause readmission, or 60-day all-cause mortality. Secondary outcomes included time to bacteremia clearance, hospital length of stay (LOS), and nephrotoxicity. Data collected included demographics; comorbidities; severity of illness; streptococcal species and source; VAN initial trough and duration; and clinical outcomes. Classification and regression tree analysis (CART) was conducted to identify the AUC threshold predictive of clinical failure. Wilcoxon rank sum, Chi Square, or Fisher’s exact tests were utilized as appropriate to compare groups stratified by the CART-identified AUC threshold.

Results

Forty-six patients met inclusion criteria during the study timeframe. Eleven patients had a VAN AUC < 329 of which 8 (73%) experienced clinical failure, while 35 patients had a VAN AUC > 329 of which 12 (34%) experienced clinical failure (p=0.04). No significant differences in baseline or clinical characteristics were identified between groups. Median VAN initial trough was higher in the VAN AUC > 329 group (13.2 vs 6.2, p< 0.001). Median hospital LOS was longer in the VAN AUC > 329 group (15 vs 8 days, p=0.05) while median time to bacteremia clearance (29 vs 25 hrs, p=0.15) and nephrotoxicity incidence (13% vs 4%, p=1) were not significantly different.

Conclusion

Vancomycin AUC < 329 was predictive of clinical failure in patients with streptococcal bacteremia. Larger studies are needed before VAN AUC monitoring can be recommended for implementation in the management of streptococcal bacteremia.

Disclosures

All Authors: No reported disclosures.

Evidence Based Scarce Resource Allocation During the COVID-19 Pandemic: A Case Study of Bamlanivimab Administration in the Emergency Department

Background: Patients presenting for emergency department (ED) evaluation may be appropriate for treatment with monoclonal antibodies for mild to moderate COVID-19. While many sites have implemented infusion centers for these agents, EDs will continue to evaluate these patients where appropriate identification and efficient infusion of eligible patients is critical. Objectives: Patients receiving bamlanivimab in the EDs of an academic medical center are described. The primary objective was to describe operational metrics and secondary objectives reported clinical outcomes. Methods: Patients receiving bamlanivimab and discharged from the ED were included from November 16, 2020 to January 16, 2021 in the retrospective, observational cohort. Primary outcome was adherence to institutional criteria. Secondary outcomes included ED visit metrics, clinical characteristics, and return visits within 30 days. Risk factors for return visits were assessed with regression. Results: One hundred nineteen patients were included. Most (71%) were diagnosed with COVID-19 during the ED visit and median symptom duration was 3(IQR 2-5) days. Median number of risk factors for progression to severe disease was 2 (IQR 1-2). Thirty percent had a documented abnormal chest x-ray. Institutional criteria adherence was 99.2%. Median time from ED room to bamlanivimab was 4 (IQR 3.1-5.2) hours. Thirty patients had return visit within 30 days; 19 were COVID-19 related. Two multivariable regression models were analyzed for COVID-19 related return visit. Characteristics on ED presentation were considered in Model I: male gender (OR 3.01[0.97-9.31]), age (per 10 years) (OR 1.49[1.05-2.12]), African-American race (OR 3.46[1.09-11.06]), and symptom duration (per day) (OR 1.34[1.05-1.73]). Model II included labs and imaging acquired in ED. In Model II, age (per 10 years) (OR 1.52[1.07-2.16]) and abnormal CXR (OR 5.74[1.95-16.9]) were associated with COVID-19 related return visits. Conclusions: Administration of bamlanivimab to ED patients can be done efficiently, with the potential to reduce COVID-19 related return visits. Age and abnormal imaging were independent predictors of COVID-19 return visits.

Antimicrobial Stewardship in the ICU

Increasing rates of infection and multidrug-resistant pathogens, along with a high use of antimicrobial therapy, make the intensive care unit (ICU) an ideal setting for implementing and supporting antimicrobial stewardship efforts. Overuse of antimicrobial agents is common in the ICU, as practitioners are challenged daily with achieving early, appropriate empiric antimicrobial therapy to improve patient outcomes. While early antimicrobial stewardship programs focused on the financial implications of antimicrobial overuse, current goals of stewardship programs align closely with those of critical care providers-to optimize patient outcomes, reduce development of resistance, and minimize adverse outcomes associated with antibiotic overuse and misuse such as acute kidney injury and Clostridioides difficile-associated disease. Significant opportunities exist in the ICU for critical care clinicians to support stewardship practices at the bedside, including thoughtful and restrained initiation of antimicrobial therapy, use of biomarkers in addition to rapid diagnostics, Staphylococcus aureus screening, and traditional microbiologic culture and susceptibilities to guide antibiotic de-escalation, and use of the shortest duration of therapy that is clinically appropriate. Integration of critical care practitioners into the initiatives of antimicrobial stewardship programs is key to their success. This review summarizes key components of antimicrobial stewardship programs and mechanisms for critical care practitioners to share the responsibility for antimicrobial stewardship.

535. Comparison of Outcomes in Patients Positive for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection After Monoclonal Antibody Therapy (MAT) with Bamlamivimab or Casirivimab-Imdevimab

Background

Limited options currently exist for treatment of patients diagnosed with symptomatic coronavirus 2019 (COVID-19). Monoclonal antibody therapy (MAT) has been investigated as a therapeutic option for symptomatic COVID-19 patients in the outpatient setting at high-risk for progression to severe disease based on emergency use authorization (EUA) criteria. No published studies have compared outcomes for patients treated with different MAT for COVID-19.

Methods

This was a single-center, retrospective cohort study at The Ohio State University Wexner Medical Center to compare COVID-19-related emergency room (ER) visits, admissions, and mortality at 30 days after MAT infusion for adult patients with symptomatic SARS-CoV-2 between November 16, 2020 and February 2, 2021 who received bamlanivimab versus those who received casirivimab-imdevimab. Statistical analysis used logistic regression analysis to determine the odds ratio (OR) to evaluate the relationship between patient characteristics, MAT, and outcomes.

Results

The cohort included 943 patients with SARS-CoV-2 who received MAT, including 658 patients who received bamlanivimab and 285 who received casirivimab-imdevimab. Outcome results between patients who received bamlanivimab and casirivimab-imdevimab showed no statistically significant difference seen in the number of COVID-19 related ER visits (3.2% vs 3.5%, p = 0.80), hospital admissions (4.6% vs 2.8%, p = 0.21), or mortality (0.5% vs 0.7%, p = 0.63). Multivariate analysis showed no statistically significant difference in outcomes between the groups when accounting for potential confounders. As reflected in the Table, chronic lymphocytic leukemia (CLL), gender, and asthma were associated with increased COVID-19 related ER visit within 30 days of infusion and age, chronic obstructive pulmonary disease, CLL, and lupus were associated with increased risk for COVID-19 related admission within 30 days of infusion. Age and obesity with body mass index greater than 35 mg/kg² were associated with increased risk for COVID-19 related mortality at 30 days.

Conclusion

COVID-19 related outcomes were similar when comparing patients with COVID-19 treated with bamlanivimab versus those treated with casirivimab-imdevimab.

Disclosures

Mohammad Mahdee Sobhanie, M.D., Regeneron (Scientific Research Study Investigator)Regeneron (Scientific Research Study Investigator, Was a sub-investigator for Regeneron 2066 and 2069) Carlos Malvestutto, M.D., Lilly (Scientific Research Study Investigator)Regeneron Inc. (Scientific Research Study Investigator)ViiV Healthcare (Advisor or Review Panel member)

307. Predictors of Respiratory Bacterial Co-Infection in Hospitalized COVID-19 Patients

Background

COVID-19 pneumonia can be indistinguishable from other infectious respiratory etiologies, so providers are challenged with deciding whether empiric antibiotics should be prescribed to hospitalized patients with SARS-CoV-2. This study aimed to evaluate predictors of respiratory bacterial co-infections (RBCI) in hospitalized patients with COVID-19.

Methods

Retrospective study evaluating COVID-19 inpatients from Feb 1, 2020 to Sept 30, 2020 at a tertiary academic medical center. Patients with RBCI were matched with three COVID-19 inpatients lacking RBCI admitted within 7 days of each other. The primary objectives of this study were to determine the prevalence of and identify variables associated with RBCI in COVID-19 inpatients. Secondary outcomes included length of stay and mortality. Data collected included demographics; inflammatory markers; bacterial culture/antigen results; antibiotic exposure; and COVID-19 severity. Wilcoxon rank sum, Chi Square tests, or Fisher’s exact tests were utilized as appropriate. A multivariable logistic regression (MLR) model was conducted to identify covariates associated with RBCI.

Results

Seven hundred thirty-five patients were hospitalized with COVID-19 during the study period. Of these, 82 (11.2%) had RBCI. Fifty-seven of these patients met inclusion criteria and were matched to three patients lacking RBCI (N = 228 patients). Patients with RBCI were more likely to receive antibiotics [57 (100%) vs. 130 (76%), p < 0.0001] and for a longer cumulative duration [19 (13-33) vs. 8 (4-13) days, p < 0.0001] compared to patients lacking RBCI. The MLR model revealed risk factors of RBCI to be admission from SNF/LTAC/NH (AOR 6.8, 95% CI 2.6-18.2), severe COVID-19 (AOR 3.03, 95% CI 0.78-11.9), and leukocytosis (AOR 3.03, 95% CI 0.99-1.16).

Conclusion

Although RBCI is rare in COVID-19 inpatients, antibiotic use is common. COVID-19 inpatients may be more likely to have RBCI if they are admitted from a SNF/LTAC/NH, have severe COVID-19, or present with leukocytosis. Early and prompt recognition of RBCI predictors in COVID-19 inpatients may facilitate timely antimicrobial therapy while improving antimicrobial stewardship among patients at low risk for co-infection.

Disclosures

All Authors: No reported disclosures

Implementation of an antimicrobial stewardship program in a veterinary medical teaching institution

Widespread use of antimicrobials in human and veterinary medicine drives the emergence and dissemination of resistant bacteria in human, animal, and environmental reservoirs. The AVMA and FDA Center for Veterinary Medicine have both taken public positions emphasizing the importance of incorporating antimicrobial stewardship in veterinary clinical settings; however, a model for implementing a comprehensive antimicrobial stewardship program in veterinary practice is not readily available. In 2015, The Ohio State University College of Veterinary Medicine began developing a veterinary antimicrobial stewardship program modeled on existing programs in human health-care institutions and the 7 core elements of a successful hospital antimicrobial stewardship program, as defined by the CDC. The program includes comprehensive antimicrobial use guidelines, active environmental surveillance, and enhanced infection control procedures in The Ohio State University Veterinary Medical Center, along with routine monitoring and reporting of antimicrobial prescribing practices and antimicrobial susceptibility patterns of common pathogens isolated from patients and the hospital environment. Finally, programs have been developed to educate clinicians, staff, and students on antimicrobial resistance and appropriate antimicrobial prescribing practices. The antimicrobial stewardship program has been designed to help clinicians and students confidently make judicious antimicrobial use decisions and provide them with actionable steps that can help them act as strong stewards while providing the best care for their patients. This report describes our program and the process involved in developing it, with the intent that the program could serve as a potential model for other veterinary medical institutions.

Effectiveness of fidaxomicin versus oral vancomycin in the treatment of recurrent clostridioides difficile

WHAT IS KNOWN AND OBJECTIVE

The 2017 IDSA/SHEA Clinical Practice Guidelines for Clostridioides difficile infection (CDI) recommend treating recurrent episodes with fidaxomicin or oral vancomycin, but there is little evidence to support one strategy over another, particularly beyond the first recurrence. The aim of this study was to compare clinical outcomes in patients with recurrent CDI treated with vancomycin vs. fidaxomicin.

METHODS

This retrospective study evaluated inpatients with recurrent CDI treated with vancomycin or fidaxomicin between 1 January 2013 and 1 May 2019. The primary outcome was CDI recurrence. Secondary outcomes included re-infection, treatment failure, infection-related length of stay (IRLOS) and in-hospital all-cause mortality (IHACM). The Wilcoxon rank-sum test, Pearson's chi-square test or Fisher's exact test was utilized, as appropriate. A multivariable logistic regression (MLR) model was used to estimate the adjusted odds ratio and 95% confidence interval assessing recurrence while adjusting for confounding variables. A survival analysis was also conducted.

RESULTS

135 patients met the inclusion criteria (35 fidaxomicin vs. 100 vancomycin). There was no difference in CDI recurrence [7 (20%) fidaxomicin vs. 11 (11%) vancomycin, p = 0.18]; this persisted in the MLR model (OR: 0.85 [95% CI 0.27-2.7]) and survival analysis (p = 0.1954). Additionally, there was no difference in re-infection rate (p = 0.73), treatment failure (p = 0.13), IRLOS (p = 0.19) or IHACM (p = 0.65).

WHAT IS NEW AND CONCLUSION

This represents the first analysis of CDI recurrence that included patients with >2 prior episodes of CDI. The study found no difference in additional recurrences when patients were treated with oral vancomycin vs fidaxomicin for recurrent CDI. However, the current study is limited by the small sample size available for inclusion. Prospective randomized studies with larger sample sizes are needed to confirm this study's conclusions.

722. Effectiveness of Fidaxomicin versus Oral Vancomycin in the Treatment of Recurrent Clostridioides difficile

Background

The 2017 IDSA/SHEA clinical practice guidelines for Clostridioides difficile infection (CDI) recommend treating recurrent episodes with fidaxomicin or oral vancomycin, but there is little evidence to support one strategy over another, particularly beyond the first recurrence. The aim of this study was to compare clinical outcomes in patients with recurrent CDI treated with vancomycin vs. fidaxomicin.

Methods

This was a retrospective study evaluating inpatients with recurrent CDI treated with vancomycin or fidaxomicin between January 1, 2013 and May 1, 2019. The primary outcome was CDI recurrence. Secondary outcomes included re-infection, treatment failure, infection-related length of stay (IRLOS), and in-hospital all-cause mortality (IHACM). Data collected included demographics; number of previous CDI episodes; CDI therapy; time to recurrence and re-infection; exposure to broad-spectrum antibiotics, proton pump inhibitors, and probiotics. Wilcoxon rank sum, Pearson chi-square, or Fisher’s exact tests were utilized, as appropriate. A multivariable logistic regression (MLR) model was used to estimate the adjusted odds ratio and 95% confidence interval assessing recurrence while adjusting for confounding variables. A survival analysis was also conducted.

Results

One hundred thirty-five patients met inclusion criteria (n = 35 fidaxomicin vs. n = 100 vancomycin). Of these, 42 (31%) had experienced at least 2 CDI episodes prior to their index recurrence. There was no difference in CDI recurrence [7 (20%) fidaxomicin vs. 11 (11%) vancomycin, p=0.18]; this persisted in the MLR model (OR 0.85 [95% CI 0.27-2.7]) and survival analysis (P = 0.1954). Additionally, there was no difference in re-infection rate (p=0.73), treatment failure (p=0.13), IRLOS (p=0.19), or IHACM (p=0.65).

Conclusion

Oral vancomycin and fidaxomicin are both suitable treatment options in the setting of recurrent CDI.

Disclosures

All Authors: No reported disclosures

575. Effectiveness of Short vs Long Course Perioperative Antibiotics in Lung Transplant Recipients with Donor Positive Respiratory Cultures

Background

Lung transplant recipients are at increased risk for infection in the early post-operative phase. Perioperative antibiotic (POA) practices are variable among transplant centers with sparse data regarding optimal antibiotic prophylaxis duration. This study aimed to evaluate the efficacy of short course (SC) (≤10 days) vs long course (LC) (≥11 days) POA in lung transplant patients.

Methods

This was a single-center, retrospective study of non-cystic fibrosis first time lung transplant recipients with donor positive cultures between Aug 2013 and Sept 2019. Patients who died within 14 days of transplant were excluded. Data collected included baseline characteristics, donor and recipient cultures, POA, and hospitalization details. The primary outcome was 30-day recipient freedom from donor-derived respiratory bacterial infection. Secondary outcomes included development of Clostridioides difficile infection (CDI), cumulative time on ventilator, post-op time to extubation, in-hospital all-cause mortality, and 30-day development of POA resistance. Descriptive statistics were used for analysis. Continuous variables were compared using the Wilcoxon rank sum test while categorical variables were compared using the chi-square or Fisher’s exact test. Statistical significance was defined as p< 0.05.

Results

A total of 147 patients were included (58 SC vs 89 LC). Median POA duration in the SC group was 6.5 days vs 13 days in the LC group (p< 0.0001). The primary outcome of 30-day freedom from donor-derived respiratory infection was present in 56 (97%) patients in the SC vs. 85 (96%) patients in the LC group (p= 1). There was no difference in development of CDI (p = 0.4), mortality (p = 1), or resistant organisms (p=0.28) while cumulative ventilator time and time to post-op extubation were longer in the LC group (p = 0.002 & 0.007, respectively). Methicillin-sensitive Staphylococcus aureus was the most common organism isolated from donors in the SC (23, 40%) and LC (48, 54%) groups.

Conclusion

Among lung transplant recipients with positive donor cultures, short course POA was as effective as long course in preventing donor-derived bacterial pneumonia. Further studies are needed to assess heterogeneity in POA practices and optimal duration among transplant centers.

Disclosures

Brian C. Keller, MD, PhD, CareDx, Inc. (Grant/Research Support) Bryan A. Whitson, MD, PhD, Abbott Laboratories (Consultant)TransMedics OCS (Other Financial or Material Support, Serves on the Clinical Events Committee)

Effectiveness of short vs long-course perioperative antibiotics in lung transplant recipients with donor positive respiratory cultures

Lung transplant recipients are at increased risk for infection in the early postoperative phase, thus perioperative antibiotics are employed. This retrospective study evaluated the efficacy of short- vs long-course perioperative antibiotics in lung transplant patients. Lung transplant patients with donor positive cultures between August 2013 and September 2019 were evaluated, excluding those with cystic fibrosis, death within 14 days and re-transplants. The primary outcome was 30-day freedom from donor-derived respiratory infection. A total of 147 patients were included (57 short vs 90 long-course). Median perioperative antibiotic duration was 6 days in the short-course vs 14 days in the long-course group (P < .0001). Thirty-day freedom from donor-derived respiratory infection was present in 56 (98%) patients in the short-course vs 85 (94%) patients in the long-course group (P = .41). There was no difference in development of Clostridioides difficile infections (P = .41), while cumulative ventilator time and time to post-op extubation were longer in the long-course group (P = .001 and .004, respectively). Among lung transplant recipients with positive donor respiratory cultures, short-course perioperative antibiotics were as effective as long-course antibiotics in preventing donor-derived bacterial respiratory infections.

1086. Antimicrobial Stewardship: From Bedside to Man’s Best Friend

Background

Antimicrobial stewardship plays an integral role in ensuring appropriate antimicrobial use in the inpatient hospital setting and is now required by The Joint Commission. Although it is well established that antimicrobial misuse and overuse has societal and ecological implications, the same regulations do not yet apply to our veterinary and agricultural counterparts.

Methods

At The Ohio State University Wexner Medical Center (OSUWMC), the Antimicrobial Stewardship Program (ASP) was created in 2007. A partnership was formed with The Ohio State University Veterinary Medical Center (OSUVMC) in 2017 and was leveraged through a pre-existing campus-wide One Health initiative. The goal was to develop a comprehensive Veterinary Hospital ASP. “The Core Elements of Hospital Antibiotic Stewardship Programs” (Centers for Disease Control and Prevention) and “The Core Principles of Antibiotic Stewardship in Veterinary Medicine” (American Veterinary Medical Association) were also referenced for guidance.

Results

Specific initiatives within the OSUVMC ASP were modeled after similar interventions in the OSUWMC including development of antibiotic use guidelines by animal type for commonly encountered infections, antimicrobial utilization tracking, antibiogram creation, and both active and passive surveillance of targeted resistant pathogens. A mobile-friendly website was created to allow providers easy access to these ASP tools. Overall antimicrobial prescriptions decreased 22.4% following the first year of program implementation. Planning is currently underway for an ASP outreach program to local veterinary practices to increase awareness of ASP and improve antimicrobial prescribing. A parallel outreach program with rural Ohio hospitals is underway at OSUWMC.

Conclusion

A comprehensive veterinary hospital ASP was successfully implemented in collaboration with OSUWMC counterparts using successful human interventions applied in the animal setting. Optimizing antimicrobial use and resistance at both sites will likely prevent resistance transmission between these geographically proximate hospitals. Sharing the details of our approach may benefit other institutions looking to expand their stewardship reach.

Disclosures

All authors: No reported disclosures.

177. Clinical Outcomes of Daptomycin vs. Anti-Staphylococcal β-Lactams in Definitive Treatment of Methicillin-Susceptible Staphylococcus aureus (MSSA) Bloodstream Infections

Background

The preferred management of patients with MSSA bacteremia includes definitive therapy with intravenous anti-staphylococcal β-lactam antibiotics. In β-lactam allergic or intolerant patients, daptomycin has been targeted as a viable alternative. The objective of this study was to assess clinical outcomes of daptomycin compared with nafcillin or cefazolin for the treatment of MSSA bacteremia.

Methods

This was a retrospective cohort study of patients hospitalized from November 1, 2011 to October 31, 2018 at The Ohio State University Wexner Medical Center with MSSA bacteremia. Patients treated with nafcillin, cefazolin or daptomycin were included with 1:1:1 random selection. The primary outcome was a composite of clinical failure, defined as a change in therapy due to persistent/worsening signs and symptoms, bacteremia recurrence or persistence, or inpatient infection-related mortality. Secondary endpoints included 30-day infection-related mortality, duration of bacteremia, 30-day all-cause mortality and adverse events (AEs) necessitating a change in therapy.

Results

Among patients with MSSA bacteremia, 162 received at least one dose of daptomycin. Of those, 29 received at least 14 days of daptomycin and/or received daptomycin as definitive therapy and thus were included in the analysis. There was no difference in the primary outcome of composite clinical failure comparing daptomycin vs. nafcillin/cefazolin (P = 0.71). In addition, no difference was observed in 30-day infection-related mortality (P = 0.51), duration of MSSA bacteremia (P = 0.9), or 30-day all-cause mortality (P = 0.64). A higher number of AEs necessitating change in therapy were seen in the daptomycin group (P = 0.0002), reflecting initial β-lactam intolerance.

Conclusion

No difference in clinical failure was identified in patients treated with daptomycin vs. nafcillin/cefazolin suggesting that daptomycin may serve as a non-inferior alternative for treatment of MSSA bacteremia. A higher number of AEs occurred in the daptomycin group indicating β-lactam intolerance as a primary indication for daptomycin therapy. Given the small sample size, subsequent studies are needed to further evaluate the use of daptomycin in the treatment of MSSA bacteremia.

Disclosures

All authors: No reported disclosures.

1036. Clinical impact of an antibiotic time out initiative at an academic medical center

Background

The Infectious Diseases Society of America’s guideline for implementing antibiotic (abx) stewardship recommends routine review of abx use. Several studies demonstrate antibiotic time out (ATO) programs result in de-escalation, but there is limited evidence of improved outcomes. The aim of this study was to evaluate the clinical impact of ATO.

Methods

This retrospective study included hospitalized patients at The Ohio State University Wexner Medical Center receiving abx and a documented ATO from 7/1/2017 to 6/30/2018. ATO patients were matched by infection type to abx-treated patients lacking an ATO note. Patients were excluded if they were identified as a protected population, were in the ICU at the time of ATO, had an ATO within 48 hours of discharge, cystic fibrosis, or febrile neutropenia. The primary objective was to evaluate abx optimization in patients with documented ATO vs. those without ATO. Abx optimization was defined as the selection of ideal abx based on guidelines, culture and susceptibility results, or expert opinion when undefined. Secondary outcomes included vancomycin-associated acute kidney injury (VAN-AKI), infection-related length of stay (LOS), all-cause 30-day readmission or mortality, abx days, and nosocomial C. difficile infection (CDI) rates. The Student t-test/Fisher’s exact test and Wilcoxon-rank sum were utilized as appropriate.

Results

One hundred ATO patients were compared with 100 non-ATO patients. Baseline characteristics and infection types were similar between groups. ATO resulted in improved optimization of abx selection (P = 0.05) and duration (P < 0.01), and reduced piperacillin/tazobactam (P/T) and vancomycin (VAN) utilization. No difference was observed in VAN-AKI (22 vs. 20%, P = 0.73), 30-day readmission (28 vs. 27%, P = 0.87), mortality (5 vs. 5%, P = 1), or CDI rates (6 vs. 5%, p = 0.76) in the ATO vs. non-ATO group. However, inpatient abx days (12 vs. 8, P = 0.004) and infection-related LOS (10 vs. 8, P = 0.0006) were shorter in the non-ATO group.

Conclusion

ATO improved optimization of abx selection and duration, and reduced P/T and VAN use. Despite this, clinical outcomes were not improved.

Disclosures

All authors: No reported disclosures.

Clinical Outcomes with Penicillin Versus Alternative β-Lactams in the Treatment of Penicillin-Susceptible Staphylococcus aureus Bacteremia

OBJECTIVES

To identify the impact of penicillin versus alternative β-lactams on clinical outcomes in patients with penicillin-susceptible Staphylococcus aureus (PSSA) bacteremia.

DESIGN

Retrospective cohort study.

SETTING

Academic medical center.

PATIENTS

Adult patients with PSSA bacteremia treated with a β-lactam as definitive therapy.

MEASUREMENTS

The primary outcome was a composite end point of 30-day clinical failure (change in PSSA therapy due to persistent or worsening signs and symptoms, PSSA bacteremia recurrence or persistence, and/or infection-related mortality) in patients treated with penicillin versus alternative β-lactams. Secondary outcomes included infection-related and hospital length of stay (LOS), 90-day recurrence, 90-day infection-related readmission, 30-day all-cause mortality, adverse drug events (ADEs), and 30-day change in PSSA therapy due to ADEs. A subgroup analysis comparing penicillin, nafcillin, and cefazolin was also conducted.

MAIN RESULTS

For the 122 patients who were included, the most common definitive therapies were nafcillin (37%), cefazolin (29%), and penicillin (21%). No difference was found in 30-day clinical failure (4% vs 11%, p=0.46), infection-related LOS (12 days vs 11 days, p=0.39), hospital LOS (12.5 days vs 12 days, p=0.69), 90-day recurrence (p=1.00), 90-day infection-related readmission (p=1.00), or 30-day all-cause mortality (p=0.45) between penicillin and other β-lactams. The prevalence of ADEs was different among penicillin, nafcillin, and cefazolin (p=0.049), with nafcillin requiring more changes in therapy (p=0.005).

CONCLUSIONS

Definitive therapy with penicillin had similar efficacy compared with alternative β-lactams for the treatment of PSSA bacteremia. However, nafcillin was associated with more ADEs requiring a change in therapy.

Risk of acute kidney injury in critically ill surgical patients with presumed pneumonia is not impacted by choice of methicillin-resistant staphylococcus aureus therapy

Background

Vancomycin and linezolid are standard treatment options for nosocomial methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. While acute kidney injury (AKI) is commonly attributed to vancomycin, existing data has not definitely confirmed vancomycin as an independent risk factor for AKI.

Aims

This study aimed to quantify the incidence of AKI in Surgical Intensive Care Unit (ICU) patients receiving empiric vancomycin or linezolid for nosocomial pneumonia and to identify risk factors for AKI with a focus on MRSA antibiotic therapy.

Materials and Methods

A retrospective cohort analysis of surgical ICU patients who received at least 48 h of vancomycin or linezolid for pneumonia was performed. Patients who received vancomycin were compared to those who received linezolid with a primary endpoint of AKI as defined by the risk/injury/failure/loss/end-stage renal disease (RIFLE) criteria. A modified RIFLE criteria assessing only changes in serum creatinine was also used.

Results

One hundred one patients were evaluated (63 vancomycin and 38 linezolid). AKI occurred in 51 (81.0%) and 32 (84.2%) patients in the vancomycin and linezolid groups (P = 0.79), respectively. Using the modified RIFLE criteria, AKI occurred in 19 (30.2%) and 14 (36.8%) patients in the vancomycin and linezolid groups (P = 0.448). After adjustment for age, diabetes mellitus, Charlson comorbidity index, and concomitant nephrotoxins, there was no difference in risk of AKI between groups (P = 0.773).

Conclusions

Patients who received empiric vancomycin or linezolid for nosocomial pneumonia experienced high, but similar rates of AKI. The results suggest MRSA antibacterial therapy in this setting may not be independently indicative of AKI risk, rather the risk is likely multifactorial.

Impact of a Cost Visibility Tool in the Electronic Medical Record on Antibiotic Prescribing in an Academic Medical Center

BACKGROUND

Studies evaluating the impact of passive cost visibility tools on antibiotic prescribing are lacking.

OBJECTIVE

The objective of this study was to evaluate whether the implementation of a passive antibiotic cost visibility tool would impact antibiotic prescribing and decrease antibiotic spending.

METHODS

An efficiency and effectiveness initiative (EEI) was implemented in October 2012. To support the EEI, an antibiotic cost visibility tool was created in June 2013 displaying the relative cost of antibiotics. Using an observational study of interrupted time series design, 3 time frames were studied: pre EEI, post EEI, and post cost visibility tool implementation. The primary outcome was antibiotic cost per 1,000 patient days. Secondary outcomes included case mix index (CMI)-adjusted antibiotic cost per 1,000 patient days and utilization of the cost visibility tool.

RESULTS

Initiation of the EEI was associated with a $4,675 decrease in antibiotic cost per 1,000 patient days (P = .003), and costs continued to decrease in the months following EEI (P = .009). After implementation of the cost visibility tool, costs remained stable (P = .844). Despite CMI increasing over time, adjustment for CMI had no impact on the directionality or statistical significance of the results.

CONCLUSION

Our study demonstrated a significant and sustained decrease in antibiotic cost per 1,000 patient days when focused medication cost reduction efforts were implemented, but passive cost visibility tool implementation was not associated with additional cost reduction. Antibiotic cost visibility tools may be of most benefit when prior medication cost reduction efforts are lacking or when an active intervention is incorporated.

Nephrotoxicity Risk Factors and Intravenous Vancomycin Dosing in the Immediate Postoperative Period Following Antibiotic-Impregnated Cement Spacer Placement

BACKGROUND

Several case reports have documented acute kidney injury (AKI) attributable to antibiotic-impregnated cement (AIC) spacers.

OBJECTIVES

To identify AKI risk factors among patients who underwent AIC placement and determine whether vancomycin-AIC placement affects systemic vancomycin dosing.

METHODS

Phase 1 was a case-control study to identify AKI risk factors among patients who underwent AIC placement. Cases experienced AKI; controls had unchanged renal function. Phase 2 was a retrospective cohort study. Patients who received ≥72 hours of intravenous (IV) vancomycin were divided into 2 groups according to whether they underwent vancomycin-AIC placement. Primary outcome was number of vancomycin dosing changes.

RESULTS

Phase 1: Among 26 cases and 74 controls AKI risk factors on univariate and multivariable analysis included exposure to angiotensin-converting-enzyme (ACE) inhibitor exposure within 7 days of AIC placement (42% vs 20%, P = 0.03) and piperacillin-tazobactam within 7 days following AIC placement (31% vs 12%, P = 0.03). Phase 2: Among 53 patients who underwent vancomycin-AIC placement and 104 who underwent another surgery type, vancomycin was adjusted more frequently in patients who underwent vancomycin-AIC placement (28% vs 15%, P = 0.06).

CONCLUSIONS

Among patients who undergo AIC placement with vancomycin and/or tobramycin, exposure to ACE inhibitors and piperacillin-tazobactam are associated with increased risk of AKI in the immediate postoperative period. No empirical adjustments to IV vancomycin dosing are necessary in patients undergoing vancomycin-AIC placement.

Impact of formulary restriction with prior authorization by an antimicrobial stewardship program

In an era of increasing antimicrobial resistance and few antimicrobials in the developmental pipeline, many institutions have developed antimicrobial stewardship programs (ASPs) to help implement evidence-based (EB) strategies for ensuring appropriate utilization of these agents. EB strategies for accomplishing this include formulary restriction with prior authorization. Potential limitations to this particular strategy include delays in therapy, prescriber pushback, and unintended increases in use of un-restricted antimicrobials; however, our ASP found that implementing prior authorization for select antimicrobials along with making a significant effort to educate clinicians on criteria for use ensured more appropriate prescribing of these agents, hopefully helping to preserve their utility for years to come.

Is the "low-hanging fruit" worth picking for antimicrobial stewardship programs?

A new antimicrobial stewardship program can be overwhelmed at the breadth of interventions and education required to conduct a successful program. The expression "low-hanging fruit," in reference to stewardship, refers to selecting the most obtainable targets rather than confronting more complicated management issues. These targets include intravenous-to-oral conversions, batching of intravenous antimicrobials, therapeutic substitutions, and formulary restriction. These strategies require fewer resources and less effort than other stewardship activities; however, they are applicable to a variety of healthcare settings, including limited-resource hospitals, and have demonstrated significant financial savings. Our stewardship program found that staged and systematic interventions that focus on obvious areas of need, that is, low hanging fruit, provided early successes in our expanded program with a substantial cumulative cost savings of $832,590.

Peramivir pharmacokinetics in two critically ill adults with 2009 H1N1 influenza A concurrently receiving continuous renal replacement therapy

STUDY OBJECTIVE

To determine the pharmacokinetics of intravenous peramivir-an investigational neuraminidase inhibitor for the treatment of 2009 H1N1 infection or nonsubtypable influenza A thought to be the 2009 H1N1 virus-in patients concurrently receiving continuous renal replacement therapy (CRRT).

DESIGN

Pharmacokinetic analysis.

SETTING

Critical care unit at a university-affiliated hospital.

PATIENTS

Two critically ill women with 2009 H1N1 influenza A treated with compassionate-use intravenous peramivir administered as a daily infusion of 600 mg over 30 minutes while receiving continuous venovenous hemodiafiltration (CVVHDF), a form of CRRT.

MEASUREMENTS AND MAIN RESULTS

Plasma samples were collected from the two patients before and 30 minutes after the fourth (first patient) and ninth (second patient) peramivir infusion to estimate minimum (C(min)) and maximum (C(max)) plasma concentrations, respectively. Two additional postinfusion concentrations were measured from each patient to estimate noncompartmental pharmacokinetic parameters of peramivir while receiving CVVHDF. In the two patients, respectively, C(min) was 2170 and 251 ng/ml, C(max) was 18,400 and 20,300 ng/ml, area under the plasma concentration-time curve from 0-24 hours (AUC(0-24)) was 178,000 and 94,400 ng·hour/ml, drug clearance was 56 and 106 ml/minutes, and plasma half-life was 7.6 and 3.7 hours. The volume of distribution adjusted for ideal body weight at steady state was 0.51 and 0.54 L/kg, respectively.

CONCLUSION

The first patient had a slower peramivir plasma clearance compared with the second patient, but both patients had higher peramivir clearances as calculated from AUC(0-24) than those predicted by CRRT. Thus, the dosage of intravenous peramivir was appropriate in these patients. Additional pharmacokinetic data are needed to confirm these results and help guide dosing in patients receiving various forms of CRRT.

Nutritional intervention and growth in children with chronic renal failure

OBJECTIVE

To assess whether improving energy intake by tube feeding could prevent growth failure and improve growth rates in children with congenital renal failure.

DESIGN

Prospective descriptive study.

SETTING

Renal Units, Royal Alexandra Hospital for Children, and Westmead Hospitals.

PATIENTS

All children with advanced chronic renal disease (glomerular filtration rate < 30 mL/min/1.73 m2) between 1992 and 1994.

INTERVENTION

Tube feeding was commenced if height or weight standard deviation score (SDS) was below the normal range (> -2 SDS) or when height SDS was decreasing and oral intake was not meeting energy requirements. Energy requirements were calculated for median weight for chronological age and sex to provide for catch-up growth.

MAIN OUTCOME MEASURES

Growth rate was measured by comparing height and weight SDS at the beginning and end of the study period. Normal growth rate is defined as no change in SDS over time, whereas catch-up growth is defined as an increase in SDS over time.

RESULTS

Seven children, mean age 0.6 +/- 0.7 years, with advanced renal failure (mean glomerular filtration rate = 17 mL/min/1.73 m2) caused by congenital renal hypoplasia/dysplasia were studied. All subjects were eventually tube fed for a mean time of 18. 6 +/- 4.5 months. There was no significant change in height SDS (-0. 9 to -1.1) or weight SDS (-0.4 to -0.2).

CONCLUSION

Optimizing nutritional intake by tube feeding children with advanced chronic renal failure from an early age resulted in no decline in growth rate; however, catch-up growth was not achieved.