Outpatient Parenteral Antimicrobial Therapy Program Research Articles

Quantifying the Time to Administer Outpatient Parenteral Antimicrobial Therapy: A Missed Opportunity to Compensate for the Value of Infectious Diseases.

Outpatient parenteral antimicrobial therapy (OPAT) relies on substantial uncompensated provider time. In this study of a large academic OPAT program, the median amount of unbilled OPAT management time was 27 minutes per week, per OPAT course. These data should inform benchmarks in pursuing novel payment approaches for OPAT.

Outpatient Parenteral Antimicrobial Therapy in a Safety Net Hospital: Opportunities for Improvement.

Outpatient parenteral antimicrobial therapy (OPAT) is a safe and cost-effective transitional care approach administered via different delivery models. No standards exist for appropriate OPAT program staffing. We examined outcomes of patients receiving OPAT via different care models to identify strategies to improve safety while reducing health care overuse. Retrospective demographic, clinical, and outcome data of patients discharged with OPAT were reviewed in 2 periods (April-June 2021 and January-March 2022; ie, when staffing changed) and stratified by care model: self-administered OPAT, health care OPAT, and skilled nursing facility OPAT. Of 342 patients, 186 (54%) received OPAT in 2021 and 156 (46%) in 2022. Hospital length of stay rose from 12.4 days to 14.3 in 2022. In a Cox proportional hazards regression model, visits to the emergency department (ED) within 30 days of OPAT initiation (hazard ratio, 1.76; 95% CI, 1.13-2.73; P = .01) and readmissions (hazard ratio, 2.34; 95% CI, 1.22-4.49; P = .01) increased in 2022 vs 2021, corresponding to decreases in OPAT team staffing. Higher readmissions in the 2022 cohort were for reasons unrelated to OPAT (P = .01) while readmissions related to OPAT did not increase (P = .08). In a well-established OPAT program, greater health care utilization-length of stay, ED visits, and readmissions-were seen during periods of higher staff turnover and attrition. Rather than blunt metrics such as ED visits and readmissions, which are influenced by multiple factors besides OPAT, our findings suggest the need to develop OPAT-specific outcome measures as a quality assessment tool and to establish optimal OPAT program staffing ratios.

Dalbavancin as an alternative to traditional outpatient parenteral antimicrobial therapy for deep gram-positive infections - an observational, retrospective review.

Treatment of invasive gram-positive infections in complex patient populations is challenging. Dalbavancin, approved for skin and soft tissue infections, offers advantages in this setting due to its long half-life and infrequent dosing. However, less is known about the outcomes of off-label dalbavancin for deeper infections. The objective of this study is to examine the feasibility and outcomes of patients with complex gram-positive infections treated with dalbavancin as an alternative to standard outpatient parenteral antimicrobial therapy (OPAT). We conducted a multicenter, retrospective review of adult patients managed within an OPAT program with intravenous dalbavancin for off-label indications. Adult patients were included if they had treatment details and follow-up documented between January 2020 and June 2023. Details of dalbavancin use including indications for prescription were captured. Outcomes of interest included 90-day infection recurrence, prosthesis retention rates, 90-day mortality, and adverse medication events. In all, 61 patients received dalbavancin, mostly as sequential therapy. Twenty-three percent received dalbavancin strictly in the outpatient setting. Dalbavancin was used primarily for hardware (fracture, spine, or joint), native bone or joint, and complicated soft tissue infections. The predominant pathogen was Staphylococcus aureus (61%). Dalbavancin was frequently prescribed as a two-dose 1500 mg regimen (49%) due to persistent infection (23%), difficult line access (30%), difficulty achieving therapeutic vancomycin levels (18%), or substance abuse history (18%). Overall, six patients (10%) had infection recurrence and no patients died during the follow-up period. Three of eight patients with hardware retention had infection recurrence. Adverse effects were minimal and mostly self-limiting. Dalbavancin is an efficacious and safe alternative to standard OPAT, especially in those with barriers to traditional long-term intravenous antibiotics. Improved outcomes may be achieved with hardware removal. Dalbavancin may facilitate early discharge or prevent hospitalizations. Comparative studies of standard OPAT regimens versus dalbavancin are needed.

Stability Studies of Antipseudomonal Beta Lactam Agents for Outpatient Therapy.

Outpatient parenteral antimicrobial therapy (OPAT) is a useful treatment strategy against Pseudomonas aeruginosa and other multidrug-resistant bacteria. However, it is hindered by the lack of stability data for the administration of antibiotics under OPAT conditions. Our objective was to investigate the stability of nine antipseudomonal and broad-spectrum beta lactam antibiotics (aztreonam, cefepime, cefiderocol, ceftazidime, ceftazidime/avibactam, ceftolozane/tazobactam, meropenem, meropenem/vaborbactam, and piperacillin/tazobactam) to allow the spread of OPAT programs. All the antibiotics were diluted in 500 mL 0.9% sodium chloride and stored at 4, 25, 32, and 37 °C for 72 h in two different devices (infusion bags and elastomeric pumps). The solutions were considered stable if the color, clearness, and pH remained unchanged and if the percentage of intact drug was ≥90%. All the antimicrobials remained stable 72 h under refrigerated conditions and at least 30 h at 25 °C. At 32 °C, all the antibiotics except for meropenem and meropenem/vaborbactam remained stable for 24 h or more. At 37 °C, only aztreonam, piperacillin/tazobactam, cefepime, cefiderocol, and ceftolozane/tazobactam were stable for at least 24 h. The stability results were the same in the two devices tested. All the antibiotics studied are actual alternatives for the treatment of antipseudomonal or multidrug-resistant infections in OPAT programs, although the temperature of the devices is crucial to ensure antibiotic stability.

2208. Ten years of the Irish National Outpatient Parenteral Antimicrobial Therapy (OPAT) Registry Data

Abstract Background The Irish Outpatient Parenteral Antimicrobial Therapy (OPAT) programme, a national centrally administered outpatient antibiotic provision service was established in 2013 within the public hospital system and is operated by the Health Service Executive (HSE). Ireland is relatively unique in having a nationally coordinated OPAT programme with complete summary data since its establishment. Here we describe the programme usage over ten years and show the data can be used to identify important trends in national antimicrobial usage, including stewardship issues, with relevant lessons for other OPAT centres. Methods Using data extracted from the national electronic portal we describe summary statistics from January 2013 to December 2022 (10 years). Results Over the ten-year period 17,559 OPAT episodes were facilitated across 42 healthcare institutions. These episodes represented 14,955 unique care episodes with the remainder being extensions or changes to active episodes. 12388 episodes were home OPAT delivered by a healthcare worker versus 5170 self OPAT where patients were taught to self-administer the antimicrobials. The median OPAT duration of therapy was 14 days with an average of 19.9 days. The median age of a referred patient was 59 years with an average age of 56 years. The top five diagnoses of osteomyelitis, abscesses, cellulitis, bacteraemia, and pyelonephritis accounted for 53% of all referrals. 81.5% of patients were prescribed a single antimicrobial, 17.9% two agents and 0.6% three. Four antibiotics – ceftriaxone, daptomycin, cefazolin and flucloxacillin continuous infusion account of 59% of the 44 different antimicrobials prescribed via the programme. Five of the 42 healthcare institutions accounted for 57.25% of all OPAT prescriptions. The number of beds in a hospital was not the strongest predictor of OPAT usage. The total number of bed days saved in the 10-year period was 292,860. Conclusion Within a health system operating on 11,171 beds available per day, for a population of just over 5 million people, with an average daily running cost of €878 per acute bed, the National OPAT programme has already contributed to significant bed day and consequent financial savings. Starting an infectious diseases clinical service significantly increases OPAT utilisation rates. ID Specialist appointed to centre for first time in 2021 Disclosures All Authors: No reported disclosures

688. Risk of Clostridioides difficile Infection and Antibiotic Associated Diarrhea in Patients Receiving Outpatient Parenteral Antimicrobial Therapy

Abstract Background The colonic microbiome plays a critical role in resisting the ingrowth of pathogenic microbes like Clostridioides difficile (C. difficile). Disruption of the microbiome by antibiotics is known to cause antibiotic-associated diarrhea (AAD) and C. difficile infection (CDI). Outpatient parenteral antimicrobial therapy (OPAT) reduces hospital length of stay and exposure to healthcare-associated pathogens which may decrease the incidence of CDI. Previous studies that compared patients who received metronidazole for non-CDI indications with those who did not found a reduction in CDI among patients who received metronidazole. The aim was to study the incidence of AAD and CDI in the OPAT patient population and compare the incidence rate between patients who received oral metronidazole for non-CDI indications with those who did not. Methods We retrospectively reviewed a cohort from our facility's OPAT program. We included adult patients (18 years or older) discharged to home or skilled nursing facility (SNF) on OPAT over a 2-year time span, regardless of diagnosis. Pregnant patients, patients with active CDI before starting OPAT, and those who were receiving an associated CDI treatment were excluded. Antibiotic-associated diarrhea was defined as 3 or more loose or watery stools per day with negative CDI testing or spontaneous improvement after stopping antibiotics. Community-onset and healthcare facility–associated CDI (CO-HCFA CDI) was defined as 3 or more watery stools per day with a positive stool C. difficile diagnostic test in the community or within the first 3 days of readmission, provided the diagnosis was made less than 4 weeks since discharge from a healthcare facility. Demographics of Patients Discharged on OPAT. Patients selected between June 1, 2018 and June 2020, grouped by whether or not they developed Clostridioides difficile infection (CDI). SD= standard deviation; Q1= 1st quartile; Q3= 3rd quartile. Results Of the 617 charts that met inclusion criteria, 31 had AAD and 3 had CO-HCFA CDI. Incidence of CO-HCFA CDI was < 1%; < 1 per 1000 person-day and incidence of AAD was 5.02%. The protective role of metronidazole could not be studied due to the rarity of CDI in this study. Patients with positive CDI after initiation of OPAT and associated characteristics. Conclusion Although our study was not able to answer our initial question when comparing the effect of metronidazole within OPAT groups and rates of CDI, our data is promising for showing low rates of CDI in patients receiving OPAT. This study demonstrates the putative benefits of OPAT with reduced CDI incidence regardless of use of anti-CDI drugs. Disclosures Tirdad Zangeneh, DO, AiCuris: Grant/Research Support

2206. Using Day-Level Registry Data on Patients in OPAT to Assess Heterogeneous Patterns of Time-Varying Antimicrobial Exposure and Unplanned Stopping across Multiple Infection Diagnoses, 2015-2022

Abstract Background Patients receiving outpatient parenteral antimicrobial therapy (OPAT) are often medically complex and require carefully tailored treatments to address severe and often concomitant infections. Methods We conducted a cohort study of patients enrolled in the University of North Carolina Medical Center OPAT program between March 2015 and December 2022 (2358 OPAT courses among 2072 unique patients). Patients were followed from OPAT regimen initiation (day 0) until observed treatment stop date, based on a grace period of 5 days to confirm discontinuation. Using hierarchical and mutually exclusive categorization schema, we classified patients into 1 of 10 infection diagnosis groups (Figure 1A), and classified all observed antibiotic cocktails (64 distinct antimicrobial medications comprising 520 distinct cocktails) into 18 treatments (Figure 1B). For each patient, we assessed their planned OPAT duration to classify their observed discontinuation as “planned,” “unanticipated early stop,” or “unanticipated prolonged treatment.” Stratified by infection diagnosis and treatment classifications, we used stacked bar charts to describe treatment heterogeneity, and Aalen-Johansen-based cumulative incidence curves to estimate occurrence of each type of discontinuation amid competing events. Results The cohort was 59.7% male with median age 56 years (IQR 45-66); the most common infection diagnosis was osteomyelitis +/- diabetic foot infection (28.1%, Figure 1A). Medication exposures were heterogeneous within and across infection diagnoses (Figure 1A and 1B). Median planned OPAT duration was 36 days (middle 90% 15-44). Overall cumulative incidence of unanticipated early discontinuation was 11.9%; overall incidence of unanticipated prolonged treatment was 22.9% (Figure 2). Conclusion Day-level data on medication use in this registry provided evidence of heterogeneity in medication exposure and unplanned discontinuation from OPAT, within and across infection diagnoses. These data highlight the need for multi-layered ascertainment of medication exposure, microorganisms, and infection diagnosis in this medically complex patient population to inform surveillance for adverse effects and comparative effectiveness research for post-discharge antibiotic treatment. Disclosures Asher J. Schranz, MD, MPH, WoltersKluwer: Honoraria Alan C. Kinlaw, PhD, MSPH, Genentech: Grant/Research Support

Pediatric Outpatient Parenteral Antimicrobial Therapy (OPAT): Experience of Families During Implementation of the Program

Abstract Background Experience with ambulatory intravenous antimicrobial therapy in pediatrics is reported since 1973. This modality avoids hospitalization or helps for early discharge in a patient who, in addition to antibiotics, has no other criteria to remain hospitalized. Even though it reduces the risks and costs that hospitalization entails and allows the patient to remain inserted in his family its use is not widespread in Latin America. We report the experience of families during the implementation of outpatient parenteral antibiotic therapy (OPAT) in pediatric oncologic patients at Solca Guayaquil. Methods A pilot program for outpatient parenteral antibiotic therapy (OPAT) was started in March 2022. We included patients with a permanent central venous access (port-a-cath) who were otherwise clinical stable (afebrile > 48h, increasing absolute neutrophil count (>500 in hematologic malignancies, >100 in solid tumors), no transfusion requirement) and completed a social questionnaire described previously (SUAU C, Thelma et al) with a score > 9. Patients had follow up with pediatric infectious diseases once a week during therapy and received a certificate of completion on their last day with a QR code to complete an anonymous online survey regarding their experience with the program. Results From March to November 2022 there were 6 patients enrolled. Their mean age 9.6 years, 3 (50%) were male and mean duration of therapy 7.7 days. Response rate was 100%. Ronald Mc. Donald's house hosted 5 (83%) patients while 1 (17%) was staying at home. There was 1 (16.7%) readmission 72h after completion of the program. No disfunction of catheter, secondary infection or deaths were reported. Return to regular activities was possible for 4 (67%) of patients. The experience was considered excellent, good or average in 3(50%), 2(33%) and 1(17%) cases. Quality of care during OPAT was perceived as exceeding expectations, meeting expectations and no opinion in 2(33%), 3(50%), and 1(17%) respectively. Support received by hospital staff was pondered excellent and good in 3 (50%) each. All of the patients agreed that OPAT was better than staying admitted however 1 (17%) declared that would not take this modality again (referred as "stressful"). Conclusion The newly implemented OPAT program was perceived overall as a positive experience for patients and their families, there were no major complications. The feedback provided helped to improve the logistics of the program.

Retrospective evaluation of an intervention bundle on OPAT implementation in a large non-university hospital

ABSTRACT Objectives Optimization of outpatient parenteral antimicrobial therapy (OPAT) requires interdisciplinarity and an operational algorithm. This report retrospectively assesses the impact of a multimodal quality-enhancement intervention bundle on the implementation rate, efficacy, and safety of a home OPAT program in a Belgian large community-based hospital. Methods OPAT recipients between 1 March 2019 and 30 June 2022 were included. The OPAT trajectories were divided into pre-intervention (from 1 March 2019 to 31 October 2020) and post-intervention (from 1 November 2020 to 30 June 2022) groups. The quality-enhancement intervention bundle consisted of the involvement of an infectious disease specialist, revision and implementation of a state-of-the-art prosthetic joint infection diagnosis and treatment protocol, weekly multidisciplinary discussion of all prosthetic joint infections, revision of the OPAT algorithm, and the introduction of teicoplanin as an OPAT-convenient antimicrobial. Results Eighty-five patients were included in a total of 96 OPAT trajectories (n = 33 pre-intervention; n = 63 post-intervention). After the intervention, the number of OPAT trajectories nearly doubled. The number of patients with a recurrent infection within 6 months after OPAT completion decreased 15%. The overall 6-month mortality and readmission rates during OPAT treatment decreased 8% and 10%, respectively. Mortality during OPAT treatment did not change. These differences between pre- and post-intervention did not achieve statistical significance, despite the higher risk for complications in the post-intervention group because of increased infection complexity and required treatment duration. Conclusion Within a Belgian, single, large community-based hospital, a multimodal intervention bundle resulted in increases in OPAT implementation, infection complexity, and required treatment durations without statistically significant differences in outcomes.

Use of Ceftriaxone and Benzylpenicillin in Outpatient Parenteral Antimicrobial Therapy: Spectrum vs Cost.

The application of antimicrobial stewardship (AMS) principles may entail increased cost to allow for narrower-spectrum therapy. Prescribing benzylpenicillin (BP) and ceftriaxone (CRO) for outpatient parenteral antimicrobial therapy (OPAT) demonstrates the complex challenge of this principle. The aim of this study is to analyze the use of BP and CRO in our OPAT program, including indications and relative cost. We analyzed all adult patients in our OPAT program who received intravenous BP or CRO over 1 year. We identified a "crossover group" of patients who could have received either agent. Economic comparison was based on acquisition cost of the therapy (drug, infuser, and preparation costs). Of 105 eligible patients, 54 (51%) and 51 (49%) received BP and CRO, respectively. Forty (38%) patients were suitable for either agent; of these, the majority (n = 31, 78%) were treated with BP. Economic analysis demonstrated that the average daily cost of BP therapy was $93.76/d (AUD) vs $1.23/d for CRO. Thus, across our OPAT programs, we had an additional average cost of $92.53/patient/d to use BP instead of CRO. Program-wide the annual additional cost of using BP and thus applying this AMS strategy was $68 386.12. BP is often selected over CRO by clinicians, where possible, as recommended by the Australian guidelines; however, BP is associated with higher daily acquisition costs. More broadly, a number of narrower-spectrum agents may involve significantly higher costs than comparators; as such, the $92.53/d to prevent CRO exposure can be considered when applying other antimicrobial-substitution AMS interventions in an acute health care setting.

Stability of temocillin in outpatient parenteral antimicrobial therapy: is it a real option?

Temocillin is an interesting alternative to carbapenems for susceptible Enterobacteriaceae. Although its use in outpatient parenteral antimicrobial therapy (OPAT) programmes has generated interest, this has been hampered by the lack of stability data. The purpose of the present study was to evaluate the physical and chemical stability of temocillin at the recommended dose for its use in OPAT programmes, contained in polypropylene infusion bags or polyisoprene elastomeric devices at different temperatures, and to describe a novel LC-MS/MS developed for the quantification of temocillin. Temocillin daily dose (6 g) was diluted in 500 mL of 0.9% sodium chloride to obtain a final concentration of 12 g/L. This solution was stored at 4°C, 25°C, 32°C and 37°C for 72 h, both in polypropylene infusion bags and in polyisoprene elastomeric pumps. Physical and chemical stability were evaluated during 72 h after manufacturing. Solutions were considered stable if colour, clearness and pH remained unchanged and if the percentage of intact drug was ≥90%. Temocillin attained the chemical stability criterion of ≥90% of the original concentration for the whole experiment in both devices at 4°C, 25°C and 32°C. At 37°C, temocillin was stable for 24 h but its concentration dropped below 90% from that timepoint. No precipitation occurred and minor colour changes were observed. Temocillin is stable under OPAT conditions and it would be an appropriate candidate for the treatment of patients who can be discharged to complete therapy in an OPAT programme. For this study, an LC-MS/MS method was developed.

Feasibility of individualised patient modelling for continuous vancomycin infusions in outpatient antimicrobial therapy, a retrospective study.

The area under the curve (AUC) to minimum inhibitory concentration (MIC) ratio is proposed as a therapeutic drug-monitoring parameter for dosing vancomycin continuous infusion in methicillin-resistant Staphylococcus aureus (MRSA) infection. Individualised pharmacokinetic-pharmacodynamic (PK/PD) calculation of AUC24 may better represent therapeutic dosing than current Therapeutic Drug Monitoring (TDM) practices, targeting a Steady State Concentration of 15-25mg/L. To compare real world TDM practice to theoretical, individualised, PK/PD target parameters utilising Bayesian predictions to steady state concentrations (Css) for outpatients on continuous vancomycin infusions. A retrospective single centre study was conducted at a tertiary hospital on adult patients, enrolled in an outpatient parenteral antimicrobial therapy (OPAT) program, receiving vancomycin infusions for MRSA infection. Retrospective Bayesian dosing was modelled to target PK/PD parameters and compared to real world data. Fifteen patients were evaluated with 53% (8/15) achieved target CSS during hospitalisation, and 83% (13/15) as outpatient. Median Bayesian AUC/MIC was 613mg.h/L with CSS 25mg/L. Patients suffering an Acute Kidney Injury (33%) had higher AUC0-24/MIC values. Retrospective Bayesian modelling demonstrated on median 250mg/24h lower doses than that administered was required (R2 = 0.81) which achieved AUC24/MIC median 444.8 (range 405-460) mg.h/L and CSS 18.8 (range 16.8-20.4) mg/L. Bayesian modelling could assist in obtaining more timely target parameters at lower doses for patients receiving continuous vancomycin infusion as part of an OPAT program, which may beget fewer adverse effects. Utilisation of personalised predictive modelling may optimise vancomycin prescribing, achieving earlier target concentrations as compared to empiric dosing regimens.

EE477 Cost Evaluation of a Nurse Coordinated Outpatient Parenteral Antimicrobial Therapy (OPAT) Program

Outpatient parenteral antimicrobial therapy (OPAT) is a treatment model to provide intravenous antimicrobials for medically stable patients after hospital discharge. Our OPAT program was enhanced through the addition of a nurse specialist who provides services including treatment coordination, disease monitoring, and care communication (post-intervention group). This study aims to quantify 30 and 60-day OPAT program-related readmission rates and associated costs between pre- and post-intervention programs at an academic healthcare system from a payer’s perspective.

Outpatient parenteral antimicrobial therapy (OPAT) in a safety-net hospital: Opportunities for improvement

Background: Parkland Health is a 900-bed safety-net hospital that serves Dallas County, Texas. It has an OPAT program in which patients are managed via self-administration (S-OPAT), home-health/hemodialysis (H-OPAT), and skilled nursing facilities (SNF-OPAT). We evaluated the reasons for unscheduled emergency department (ED) visits by patients in these groups to identify strategies to decrease unexpected healthcare utilization and to improve safety. Methods: We performed a retrospective chart review of all adult patients discharged from Parkland Health on OPAT between April and June 2021. Demographic, medical, and healthcare utilization information, including the date and reason of first unscheduled ED visit after discharge, was collected utilizing a standardized instrument. The institutional review board approved this study. Results: In total, 184 patients were discharged with OPAT. Among them, 32% were female and 55% identified as Hispanic; 41% were non-English speakers, and 45% were treated for a musculoskeletal infection. Among all OPAT models of care, 43.4% were S-OPAT patients, 31.5% were H-OPAT patients, and 25% were SNF-OPAT patients (Table 1). The groups differed, and fewer African Americans received H-OPAT. Also, 45% were being treated for musculoskeletal infections and were more likely to be discharged with H- or SNF-OPAT. In addition, 41% were being treated for endovascular infections and 21.7% were being treated for genitourinary infections. The total length of stay in the hospital was longer for SNF-OPAT patients and shorter for S-OPAT patients (Table 2). Among 184 OPAT patients, 41 patients (22.2%) had an ED visit: 17.3% SNF-OPAT patients, 27.6% H-OPAT patients, and 21.3% S-OPAT patients (Table 2). ED visits were attributed to intravenous (IV) access–related problems (12 of 41, 29.0%), worsening of known infection (3 of 41, 7.3%), and abnormal blood test results (2 of 41, 4.9%). Also, 24 ED visits (58%) were not related to underlying infection or OPAT. However, when examined by the OPAT care model, 41% of ED visits among S-OPAT patients, 20% among H-OPAT visits, and 25% among SNF-OPAT visits were related to IV access issues. Among S-OPAT ED visits pertaining to IV access, 71% were for minor issues such as dressing changes or line occlusion or malfunction. Conclusions: One-fifth of OPAT patients had an unscheduled ED visit, of whom 20%–41% had issues with IV access. Many of these visits could be avoided with enhanced outreach to patients discharged with OPAT and improved ambulatory capabilities to provide standard services related to maintenance of IV access.Disclosures: None

Heterogeneous OPAT regimens within and across infection diagnoses: Day-level medication use patterns among 2072 OPAT patients

Background: Patients receiving outpatient parenteral antimicrobial therapy (OPAT) are often medically complex and require carefully tailored treatments to address severe and often concomitant infections. Our objective was to illustrate the heterogeneity in antimicrobials used for patients in OPAT, within and across infection diagnosis groups. Methods: We abstracted electronic health record data regarding day-level treatment into a registry of 2,358 OPAT courses (n = 2,072 unique patients) treated in the University of North Carolina Medical Center OPAT program during 2015–2022 (total, 11,861 person weeks; average, 7 OPAT weeks per patient). We classified infection diagnoses into 10 hierarchical or mutually exclusive categories (eg, bacteremia only, diabetic foot infection (DFI) only, osteomyelitis only) (Fig., vertical axes). Accounting for 64 antimicrobial medications and 520 cocktails administered for at least 1 patient day in our OPAT registry, we also defined 18 hierarchical or mutually exclusive classifications of treatment (eg, “daptomycin alone” or “daptomycin and any other antibiotic(s)” (Fig. key). We conducted 2 stratified analyses to describe the heterogeneity across infection diagnoses with respect (1) to medications used at OPAT initiation (patient as unit of analysis) and (2) to medications used throughout OPAT (person time as unit of analysis, allowing for differential OPAT course to other treatment classifications during follow-up). We present stacked bar charts to visualize the intersection between infection diagnosis and treatment group. Results: Among patients in this OPAT registry, 34.6% had osteomyelitis and/or DFI, 4.8% had bacteremia, and 44.6% had multiple infections (Fig. 1). The most common medications in initial OPAT regimens were vancomycin (30.8% of OPAT patients), ceftriaxone (15.0%), and daptomycin (10.9%). We observed overall similarity between the distribution of treatment groups at initiation compared to cumulative person-time during the OPAT course (Figs. 1 and 2). However, we observed heterogeneity in medications by infection diagnosis (Figs. 1 and 2); for example, vancomycin was used in 39% of osteomyelitis cases but only 14% for endocarditis (Fig. 2). For several infection groups (eg, osteomyelitis, DFI, multiple infections, “other” single infections), no treatment classification exceeded 20% use (Figs. 1 and 2). Conclusions: Day-level data on medication use in this monitored registry of patients provided evidence of heterogeneity in the types of medications used throughout treatment in OPAT, which varies within and across infection diagnoses. These data highlight the need for multilayered ascertainment of medication exposure in this medically complex patient population to inform surveillance for adverse effects and guide comparative effectiveness research for postdischarge antibiotic treatment.Disclosures: None

Stability of Ampicillin plus Ceftriaxone Combined in Elastomeric Infusion Devices for Outpatient Parenteral Antimicrobial Therapy.

Currently, ampicillin plus ceftriaxone (AC) is one of the preferred treatments for Enterococcus faecalis infective endocarditis. However, there is a lack of stability data for the combination of both drugs in elastomeric devices, so the inclusion of AC in Outpatient Parenteral Antimicrobial Therapy (OPAT) programs is challenging. The objective of the study was to determine the stability of AC in elastomeric pumps when stored at 8 ± 2 °C, 25 ± 2 °C, 30 ± 2 °C and 37 ± 2 °C using LC-MS/MS. The combination was diluted in 0.9% sodium chloride and the final concentrations were ampicillin 24 g/L plus ceftriaxone 8 g/L. Physical and chemical stability were evaluated at 12, 20, 24, 36 and 48 h after preparation. Stability was met at each time point if the percentage of intact drug was ≥90% of its respective baseline concentration and color and clearness remained unchanged. The drug combination was stable for 48 h when it was kept at 8 ± 2 °C. At 25 ± 2 °C and 30 ± 2 °C, they were stable for 24 h of storage. At 37 ± 2 °C, the stability criterion was not met at any time point. These results prove that AC could be included in OPAT programs using elastomeric infusion devices for the treatment of E. faecalis infections.

Impact of a Dedicated Outpatient Parenteral Antimicrobial Therapy Program on Peripherally Inserted Central Catheter Removal at a Large Academic Medical Center

Abstract Background Outpatient parenteral antimicrobial therapy (OPAT) is a strategy to administer parenteral antibiotics in the outpatient setting through a vascular access device, such as a peripherally inserted central catheter (PICC). Prompt PICC removal after OPAT completion can minimize potential complications of phlebitis, catheter-associated infections, and venous thrombosis. There is no literature evaluating the impact of a dedicated OPAT clinic on PICC removal. Methods This was a single-center, retrospective observational study. Patients 18 years or older discharged on OPAT were included. In March 2018, Grady Health System implemented a multidisciplinary OPAT clinic. The pre-OPAT clinic group included patients referred from January 1, 2017, through March 31, 2018, and the post-OPAT clinic group included patients referred from April 1, 2018, through June 30, 2019. The primary outcome was the rate of documented PICC removal before and after implementation of a dedicated OPAT clinic. Secondary outcomes included difference in rates and reasons for emergency department (ED) visits and readmissions, and difference in rates of OPAT follow-up visits between the 2 groups. The PICC removal rates were fitted in linear regression models for pre- and post-OPAT clinic groups, and the slopes of the 2 regression models were compared. Results A total of 450 patients were included: 230 and 220 in the pre- and post-OPAT clinic groups, respectively. In the pre-OPAT group, 180 patients (73.8%) had a documented PICC removal compared with 213 patients (86.6%) in the post-OPAT group (P < 0.001). There were significantly more patients who visited the ED for a PICC-related reason in the pre-OPAT clinic group (62 vs 44, P = 0.006). Conclusions The proportion of patients with documented PICC removal increased and the proportion of patients with a PICC-related ED visit decreased after the establishment of a dedicated OPAT clinic.

Outpatient parenteral antimicrobial therapy with continuous infusion of meropenem: A retrospective analysis of three years of clinical experience

IntroductionData regarding outpatient parenteral antimicrobial therapy (OPAT) with continuous infusion of meropenem (CIM) remain scarce and controversial. We aimed to analyze its outcomes. MethodsWe conducted a retrospective analysis of a cohort of patients who received OPAT with CIM during a three-year period at a single center in northwest Spain. Demographics, clinical data and OPAT outcomes were recorded. ResultsSince January 2017–December 2019, 34 patients received 35 OPAT episodes with CIM. The median age was 75 years, and 18 (51.4%) had a Charlson comorbidity index>2. Twelve (34.3%) had respiratory infection, 11 (31.4%) urinary tract infection, and 12 (34.3%) other infections. Twenty-one (60%) received a dose of 6g/day, and 27 (77.1%) received combined antibiotic therapy. The duration of OPAT with CIM was 10 median days. Pseudomonas aeruginosa was the most frequently (34.3%) isolated microorganism and 10 (28.6%) infections were polymicrobial. During OPAT and hospital at home unit admission, 4 (11.4%) patients had any adverse reaction that required CIM withdrawal, 2 (5.7%) were readmitted, and 3 (8.8%) died (2 infection-related deaths). After 30 days from discharge 6 (18.8%) of 32 not-censored patients had unplanned readmissions (2 infection-related), 6 (18.8%) developed recurrence (3 relapses, 3 reinfections) and 1 (3.1%) died (none-infection-related death). Twenty-three (71.9%) of these 32 patients did not experience unplanned readmission, recurrence or death. ConclusionCIM can be an option to be administrated in OPAT programs in selected patients. Further studies are warranted to increase evidence regarding its use, and to externally validate our findings.

Decreased hospital readmissions after programmatic strengthening of an outpatient parenteral antimicrobial therapy (OPAT) program.

To determine whether a structured OPAT program supervised by an infectious disease physician and led by an OPAT nurse decreased hospital readmission rates and OPAT-related complications and whether it affected clinical cure. We also evaluated predictors of readmission while receiving OPAT. A convenience sample of 428 patients admitted to a tertiary-care hospital in Chicago, Illinois, with infections requiring intravenous antibiotic therapy after hospital discharge. In this retrospective, quasi-experimental study, we compared patients discharged on intravenous antimicrobials from an OPAT program before and after implementation of a structured ID physician and nurse-led OPAT program. The preintervention group consisted of patients discharged on OPAT managed by individual physicians without central program oversight or nurse care coordination. All-cause and OPAT-related readmissions were compared using the χ2 test. Factors associated with readmission for OPAT-related problems at a significance level of P < .10 in univariate analysis were eligible for testing in a forward, stepwise, multinomial, logistic regression to identify independent predictors of readmission. In total, 428 patients were included in the study. Unplanned OPAT-related hospital readmissions decreased significantly after implementation of the structured OPAT program (17.8% vs 7%; P = .003). OPAT-related readmission reasons included infection recurrence or progression (53%), adverse drug reaction (26%), or line-associated issues (21%). Independent predictors of hospital readmission due to OPAT-related events included vancomycin administration and longer length of outpatient therapy. Clinical cure increased from 69.8% before the intervention to 94.9% after the intervention (P < .001). A structured ID physician and nurse-led OPAT program was associated with a decrease in OPAT-related readmissions and improved clinical cure.

Risk of Treatment Failure for Prosthetic Joint Infections: Retrospective Chart Review in an Outpatient Parenteral Antimicrobial Therapy Program.

Prosthetic joint infections (PJIs) are a major complication of total joint replacement surgeries. Treatment includes surgical intervention with prolonged courses of IV antibiotics in outpatient parenteral antimicrobial therapy (OPAT) programs. The risk of PJI treatment failure is high and may be associated with various clinical factors. To determine the rate of PJI treatment failure and to identify potential risk factors for failure in patients admitted to an OPAT program. A retrospective chart review was conducted for adult patients with PJI admitted to an OPAT program between July 1, 2013, and July 1, 2019. Treatment courses were deemed to have failed according to predetermined criteria. χ2 tests and multiple linear regression were used to examine associations of comorbidities, pathogens, and antimicrobial regimens with treatment failure. In total, 100 patients associated with 137 PJI treatment courses in the OPAT program were included. Of these, 28 patients accounted for 65 of the treatment courses. Methicillin-susceptible Staphylococcus aureus was the most frequently isolated pathogen (31/137 or 22.6% of treatment courses). Patient comorbidities included body mass index of at least 30 kg/m2 (58% of patients) and diabetes (41% of patients). The overall rate of treatment failure was 56.2% (77/137 treatment courses). Selected risk factors associated with treatment failure or success were diabetes (50.9% versus 29.8%; odds ratio [OR] 4.03, 95% confidence interval [CI] 1.38-12.88, p = 0.013) and depression (32.1% versus 14.9%; OR 5.02, 95% CI 1.30-22.89, p = 0.025). The overall rate of PJI treatment failure in the study population was high. Patients with diabetes and depression experienced higher incidences of failure. Future investigations of comprehensive PJI management should be considered to ensure successful treatment and to minimize excessive use of health care resources.