Impact of model-informed precision dosing on achievement of vancomycin exposure targets in pediatric patients with cystic fibrosis

BACKGROUND

Vancomycin is commonly used to treat acute pulmonary exacerbations in pediatric patients with cystic fibrosis (CF) and a history of methicillin-resistant Staphylococcus aureus. Optimizing vancomycin exposure during therapy is essential and area under-the-curve (AUC)-guided dosing is now recommended. Model-informed precision dosing (MIPD) utilizing Bayesian forecasting is a powerful approach that can support AUC-guided dose individualization. The objective of the current study was to examine the impact of implementing an AUC-guided dose individualization approach supported via a MIPD clinical decision support (CDS) tool on vancomycin exposure, target attainment rate, and safety in pediatric patients with CF treated with vancomycin during clinical care.

METHODS

A retrospective chart review was performed in patients with CF at a single children's hospital comparing pre- and post-implementation of a MIPD approach for vancomycin supported by a cloud-based, CDS tool integrated into the electronic health record (EHR). In the pre-MIPD period, vancomycin starting doses of 60 mg/kg/day (<13 years) or 45 mg/kg/day (≥13 years) were used. Dose adjustment was guided by therapeutic drug monitoring (TDM) with a target trough 10-20 mg/L. In the post-MIPD period, starting dose and dose adjustment were based on the MIPD CDS tool predictions with a target 24 h AUC (AUC24 ) 400-600 mg*h/L. Exposure and target achievement rates were retrospectively calculated and compared. Rates of acute kidney injury (AKI) were also compared.

RESULTS

Overall, 23 patient courses were included in the pre-MIPD period and 21 patient courses in the post-MIPD period. In the post-MIPD period, an individualized MIPD starting dose resulted in 71% of patients achieving target AUC24 compared to 39% in the pre-MIPD period (p < 0.05). After the first TDM and dose adjustment, target AUC24 achievement was also higher post-MIPD versus pre-MIPD (86% vs. 57%; p < 0.05). AKI rates were low and similar between periods (pre-MIPD 8.7% vs. post-MIPD 9.5%; p = 0.9).

CONCLUSION

An MIPD approach implemented within a cloud-based, EHR-integrated CDS tool safely supported vancomycin AUC-guided dosing and resulted in high rates of target achievement.

949. Impact of Antimicrobial Stewardship Pharmacist Participation in Pediatric Infectious Diseases Rounds on Prospective Audit and Feedback Recommendations

Background

Prospective audit and feedback (PAF) is a core strategy of antimicrobial stewardship programs (ASPs). To improve communication of PAF recommendations to the inpatient pediatric infectious diseases (ID) consult service, the ASP pharmacists at our hospital were integrated into ID rounds. The purpose of this study was to assess the impact of ASP pharmacy participation in ID rounds on the rate of ASP recommendations.

Methods

Prior to implementation of the ASP pharmacist rounding service, the ASP pharmacist did not routinely attend rounds or communicate PAF recommendations directly to the ID consult service. Starting 1/3/22, the ASP pharmacists had daily (M-F) in-person discussions with the ID team regarding their patients’ antimicrobials. Audits performed between 1/4/21-12/30/21 and 1/3/22-4/29/22 on patients with an ID consult were included in the non-rounding cohort (NRC) and rounding cohort (RC), respectively. We compared PAF recommendation rates, characteristics, and acceptance rates between the two cohorts.

Results

There was an increase in PAF recommendation rate in the RC compared to NRC (188/485 [39%] vs 359/1234 [29%], p < 0.001). Antibiotics were the antimicrobial category mostly likely to have a recommendation and the rate of antibiotic PAF recommendations was higher in the RC compared to the NRC (132/341 [39%] vs. 271/934 [29%], p = 0.001) (Table 1). The most common recommendation types in both cohorts were to optimize the antimicrobial dose and antimicrobial discontinuation. Recommendations were more frequently communicated to the ID team in the RC compared to NRC (125/188 [66%] vs. 107/359 [30%], p < 0.001). The recommendation acceptance rate was similar between the two cohorts (159/188 [85%] RC vs. 290/359 [81%] NRC, p = 0.29).

CNS: Central nervous system; IV: Intravenous; NRC: Non-rounding cohort; PAF: Prospective audit and feedback; PO: Per os, oral; RC: Rounding cohort; SSTI: Skin and soft tissue infection; UTI: Urinary tract infection.

Conclusion

Implementation of a pediatric ASP pharmacist rounding service increased the PAF recommendation rate and improved recommendation communication with the pediatric ID consult service. Participation in rounds may better inform ASP pharmacist PAF recommendations. Future studies describing the potential benefit to the ID team by having an ASP pharmacist present on rounds are warranted. ASPs should consider formal integration of ASP pharmacists as part of the ID consult service to further improve the quality of antimicrobial prescribing.

Disclosures

All Authors: No reported disclosures.

159. Characterization of Suboptimal Discharge Antimicrobial Prescriptions and Effect of Inpatient Audit and Feedback on Quality of Antimicrobial Prescribing

Background

Approximately 30% of children are discharged from the hospital with an antimicrobial prescription; nearly a third of these prescriptions are suboptimal. Although the best approach to antimicrobial stewardship of discharge prescriptions remains uncertain, prospective audit and feedback (PAF) has improved inpatient antimicrobial use. We aimed to identify and characterize suboptimal discharge antimicrobial prescribing and assess the impact of inpatient PAF on the quality of discharge antimicrobial prescribing at a free-standing children’s hospital.

Methods

A retrospective review of enteral discharge antimicrobial prescriptions between 12/1/20-5/31/21 and parenteral antimicrobial prescriptions sent to our hospital’s infusion pharmacy between 3/1/21-5/31/21 was performed to determine if suboptimal or not. A prescription was determined to be suboptimal if the antimicrobial choice, dose, frequency, duration, formulation, or indication was not consistent with institutional and/or national guidelines. Data collection included the antimicrobial, indication, and prescribing medical service. Prescriptions were evaluated for a corresponding inpatient PAF for the same drug and indication and then stratified based on inpatient PAF completion.

Results

A total of 1192 discharge prescriptions for 698 unique patients over 834 hospital encounters were reviewed. Overall, 243 (20%) prescriptions were identified as suboptimal; reasons were duration (16%), dose (8%), frequency (5%), or antimicrobial choice, formulation, or route (≤1%). Prescriptions for cephalexin had the highest rate of suboptimal prescribing (80/167, 48%), followed by amoxicillin-clavulanate (89/203, 44%). A corresponding inpatient PAF was identified for 675 (57%) of discharge antimicrobial prescriptions. Inpatient PAF prior to discharge resulted in fewer suboptimal discharge prescriptions for the same antimicrobial (8% vs. 36%, p < 0.001).

Conclusion

Antimicrobial prescribing at inpatient discharge was suboptimal in 1 of every 5 prescriptions. Inpatient PAF was associated with improved antimicrobial prescribing at hospital discharge. Antimicrobial stewardship programs should continue to explore ways to capture and intervene on antimicrobials prescribed at discharge.

Disclosures

Hayden T. Schwenk, MD, MPH, Nothing to disclose

Multicenter Interim Guidance on Use of Antivirals for Children With Coronavirus Disease 2019/Severe Acute Respiratory Syndrome Coronavirus 2

BACKGROUND

Although coronavirus disease 2019 (COVID-19) is a mild infection in most children, a small proportion develop severe or critical illness. Data describing agents with potential antiviral activity continue to expand such that updated guidance is needed regarding use of these agents in children.

METHODS

A panel of pediatric infectious diseases physicians and pharmacists from 20 geographically diverse North American institutions was convened. Through a series of teleconferences and web-based surveys, a set of guidance statements was developed and refined based on review of the best available evidence and expert opinion.

RESULTS

Given the typically mild course of COVID-19 in children, supportive care alone is suggested for most cases. For children with severe illness, defined as a supplemental oxygen requirement without need for noninvasive or invasive mechanical ventilation or extracorporeal membrane oxygenation (ECMO), remdesivir is suggested, preferably as part of a clinical trial if available. Remdesivir should also be considered for critically ill children requiring invasive or noninvasive mechanical ventilation or ECMO. A duration of 5 days is appropriate for most patients. The panel recommends against the use of hydroxychloroquine or lopinavir-ritonavir (or other protease inhibitors) for COVID-19 in children.

CONCLUSIONS

Antiviral therapy for COVID-19 is not necessary for the great majority of pediatric patients. For children with severe or critical disease, this guidance offers an approach for decision-making regarding use of remdesivir.

Model-Informed Precision Dosing of Vancomycin in Hospitalized Children: Implementation and Adoption at an Academic Children's Hospital

Background

Model-informed precision dosing (MIPD) can serve as a powerful tool during therapeutic drug monitoring (TDM) to help individualize dosing in populations with large pharmacokinetic variation. Yet, adoption of MIPD in the clinical setting has been limited. Overcoming technologic hurdles that allow access to MIPD at the point-of-care and placing it in the hands of clinical specialists focused on medication dosing may encourage adoption.

Objective

To describe the hospital implementation and usage of a MIPD clinical decision support (CDS) tool for vancomycin in a pediatric population.

Methods

Within an academic children’s hospital, MIPD for vancomycin was implemented via a commercial cloud-based CDS tool that utilized Bayesian forecasting. Clinical pharmacists were recognized as local champions to facilitate adoption of the tool and operated as end-users. Integration within the electronic health record (EHR) and automatic transmission of patient data to the tool were identified as important requirements. A web-link icon was developed within the EHR which when clicked sends users and needed patient-level clinical data to the CDS platform. Individualized pharmacokinetic predictions and exposure metrics for vancomycin are then presented in the form of a web-based dashboard. Use of the CDS tool as part of TDM was tracked and users were surveyed on their experience.

Results

After a successful pilot phase in the neonatal intensive care unit, implementation of MIPD was expanded to the pediatric intensive care unit, followed by availability to the entire hospital. During the first 2+ years since implementation, a total of 853 patient-courses (n = 96 neonates, n = 757 children) and 2,148 TDM levels were evaluated using the CDS tool. For the most recent 6 months, the CDS tool was utilized to support 79% (181/230) of patient-courses in which TDM was performed. Of 26 users surveyed, > 96% agreed or strongly agreed that automatic transmission of patient data to the tool was a feature that helped them complete tasks more efficiently; 81% agreed or strongly agreed that they were satisfied with the CDS tool.

Conclusions

Integration of a vancomycin CDS tool within the EHR, along with leveraging the expertise of clinical pharmacists, allowed for successful adoption of MIPD in clinical care.

Multicenter Initial Guidance on Use of Antivirals for Children With Coronavirus Disease 2019/Severe Acute Respiratory Syndrome Coronavirus 2

BACKGROUND

Although coronavirus disease 2019 (COVID-19) is mild in nearly all children, a small proportion of pediatric patients develop severe or critical illness. Guidance is therefore needed regarding use of agents with potential activity against severe acute respiratory syndrome coronavirus 2 in pediatrics.

METHODS

A panel of pediatric infectious diseases physicians and pharmacists from 18 geographically diverse North American institutions was convened. Through a series of teleconferences and web-based surveys, a set of guidance statements was developed and refined based on review of best available evidence and expert opinion.

RESULTS

Given the typically mild course of pediatric COVID-19, supportive care alone is suggested for the overwhelming majority of cases. The panel suggests a decision-making framework for antiviral therapy that weighs risks and benefits based on disease severity as indicated by respiratory support needs, with consideration on a case-by-case basis of potential pediatric risk factors for disease progression. If an antiviral is used, the panel suggests remdesivir as the preferred agent. Hydroxychloroquine could be considered for patients who are not candidates for remdesivir or when remdesivir is not available. Antivirals should preferably be used as part of a clinical trial if available.

CONCLUSIONS

Antiviral therapy for COVID-19 is not necessary for the great majority of pediatric patients. For those rare cases of severe or critical disease, this guidance offers an approach for decision-making regarding antivirals, informed by available data. As evidence continues to evolve rapidly, the need for updates to the guidance is anticipated.

1136. Antifungal Prescribing Patterns among Hospitalized Children in the United States: Are There Opportunities for Antifungal Stewardship?

Background

Antifungal stewardship may help reduce the toxicity, cost, and emergence of resistance related to inappropriate antifungal use. A better understanding of antifungal prescribing patterns, particularly in high-risk, high-utilization populations, is needed to guide appropriate stewardship interventions. We analyzed antifungal prescribing characteristics, including the indications for use and differences between oncology/bone marrow transplant (Onc/BMT) and non-Onc/BMT patients, using a multi-center national cohort of hospitalized children.

Methods

We analyzed antifungal prescribing data from 32 hospitals that participated in the SHARPS Antibiotic Resistance, Prescribing, and Efficacy among Children (SHARPEC) study, a point prevalence survey conducted quarterly between June 2016 and December 2017. We included inpatients <18 years of age with an active order for a systemic antifungal agent and evaluated the patient and antifungal characteristics. In the Onc/BMT group, we classified antifungal prescribing by indication and compared the proportion of antifungal prescriptions in each category based on antifungal class, route of administration, and use of combination therapy.

Results

Six percent (2,095/34,927) of patients received a total of 2,207 antifungal prescriptions. Fifty-eight percent (1,291/2,207) of antifungal prescriptions were for Onc/BMT patients. Among patients prescribed an antifungal, those with an Onc/BMT diagnosis were older, received broader-spectrum agents, and were more likely to receive combination therapy (Table 1). The majority of antifungal use in the Onc/BMT group was for prophylaxis, with significant variation in the rate and choice of prophylactic antifungal prescribing across hospitals (Figure 1). Combination antifungal use was common among Onc/BMT patients receiving targeted therapy (Table 2).

Conclusion

The majority of antifungal use among hospitalized children is for patients with an Onc/BMT diagnosis and the patterns of antifungal utilization in this population appear to differ significantly from non-Onc/BMT patients. Based on the variation observed in this nationwide cohort, potential stewardship targets include the rate and type of antifungal prophylaxis and the use of combination therapy in Onc/BMT patients.

Disclosures

All authors: No reported disclosures.

1149. Reducing Piperacillin/Tazobactam Use in Children with Acute Perforated Appendicitis

Background

Children with perforated appendicitis have more frequent complications compared with nonperforated appendicitis. Existing data suggest broad-spectrum antibiotics are not superior to narrow-spectrum antibiotics for this condition. In an effort to safely decrease broad-spectrum antibiotic use at our hospital, we evaluated the impact of an antimicrobial stewardship program (ASP) intervention on the use of piperacillin/tazobactam (PT) and clinical outcomes in children with perforated appendicitis.

Methods

Single-center, retrospective cohort study of children ≤ 18 years with perforated appendicitis who underwent primary appendectomy. Children with primary nonoperative management or interval appendectomy were excluded. Prior to the intervention, children at our hospital routinely received PT for perforated appendicitis. An electronic health record (EHR)-integrated guideline that recommended ceftriaxone and metronidazole for perforated appendicitis was released on July 1, 2017 (Figure 1). We compared PT utilization, measured in days of therapy (DOT) per 1,000 patient-days, and clinical outcomes before and after the intervention.

Results

A total of 74 children with perforated appendicitis were identified: 23 during the pre-intervention period (June 1, 2016 to June 30, 2017) and 51 post-intervention (July 1, 2017 to September 30, 2018). Thirty-three patients (45%) were female and the median age was 8 years (IQR: 5–11.75 years). Post-intervention rate of guideline compliance was 84%. PT use decreased from 556 DOT per 1000 patient-days to 131 DOT per 1000 patient-days; incidence rate ratio of 0.24 (95% CI: 0.16–0.35), post-intervention vs. pre-intervention. There was no statistically significant difference in duration of intravenous antibiotics, total antibiotic duration, postoperative length of stay (LOS), total LOS, ED visits/readmission, or surgical site infection (SSI) between pre- and post-intervention periods (Table 1).

Conclusion

An EHR-integrated ASP intervention targeting children with perforated appendicitis resulted in decreased broad-spectrum antibiotic use with no statistically significant difference in clinical outcomes. Larger, multicenter trials are needed to confirm our findings.

Disclosures

All authors: No reported disclosures.

265. Identification of Solid-Organ Transplant Antimicrobial Stewardship Opportunities in Pediatric Liver Transplant Patients

Background

Through the prospective audit with feedback program, postoperative antimicrobial use for pediatric liver transplant was observed to extend beyond the recommended 24 hours for surgical site infection (SSI) prophylaxis. Bacterial infections in the immediate post-transplant period represent significant risk in pediatric liver-transplant recipients, including SSI. We describe our posttransplant antimicrobial (PTA) utilization in the largest pediatric liver transplant center to determine opportunities for the antimicrobial stewardship program (ASP).

Methods

All children who underwent a liver transplant between January 1, 2017 and September 30, 2017 at our institution were included. Antimicrobials initiated within 14 days posttransplant were captured, presence of fever within 14 days, positive microbiologic data within 30 days, and massive transfusion protocol (MTP) status were collected. The primary endpoint was duration of PTA. Clinical factors associated with PTA use >48 hours were evaluated.

Results

Thirty-eight children underwent a liver transplant during the study period and 29 (76%) received a broad-spectrum Gram-negative (GN) antibiotic for > 48 hours posttransplant. Half of the patients received vancomycin and 15 (40%) received an antifungal posttransplant. Fever occurred in 21 (55%) of patients with a median onset of 1 day; 3 (8%) patients had a culture-proven posttransplant bacterial infection, with no resistant Gram-positive organisms identified. Eight patients (21%) met MTP and received PTA for ≥7 days and none had a positive bacterial culture. No differences were detected in fever or culture proven posttransplant infection between patients who received ≤48 hours of GN antibiotics compared with those who received >48 hours.

Conclusion

The majority of children received PTA beyond 48 hours which was not attributable to prolonged posttransplant fevers or positive cultures. We identified ASP opportunities, including limiting GN antibiotics to 48 hours posttransplant, eliminating empiric vancomycin, restricting antifungals to MTP only, and limiting MTP PTA to 5 days.

Disclosures

All authors: No reported disclosures.

263. Effect of Microbiologic Data on Prospective Audit and Feedback Recommendations

Background

Prospective audit and feedback (PAF) is an effective method of antimicrobial stewardship. Given the time-intensive nature of PAF and low rates of intervention, understanding predictors of PAF recommendation and acceptance is imperative. Prior studies have not examined the impact of microbiologic data on the rate of PAF recommendation or recommendation acceptance. We evaluated whether antimicrobials prescribed for patients with positive microbiologic culture data were more or less likely to have a PAF recommendation and whether the presence of culture data impacted recommendation acceptance.

Methods

All PAF audits on antibiotic and antifungal medications for patients admitted to Lucile Packard Children’s Hospital Stanford between April 18, 2017 and April 17, 2018 were included. The PAF program included all pediatric units and injectable antimicrobials active for >48 hours. PAF documentation was completed in the electronic health record and included the presence or absence of positive microbiologic culture data. Our primary outcome was a comparison of PAF recommendation rate based on the presence or absence of positive culture data. We also evaluated whether there were differences in the recommendation acceptance rate and the type of recommendation based on the presence or absence of positive culture data.

Results

Of the 3,250 audits performed during the study period, 802 (25%) had positive cultures at the time of audit documentation. Of the 802 audits with positive cultures, 299 resulted in a recommendation compared with 824 of the 2,448 audits without positive cultures (37% vs. 34%, P = 0.07). PAF recommendations were more likely to be followed when positive culture data were present at the time of audit (80% vs. 73%, P = 0.03). The most common recommendation in the presence of positive culture data was to change the antimicrobial (27%) while the most common recommendation in the absence of positive culture data was to stop the antimicrobial (30%).

Conclusion

The presence of positive microbiologic culture data did not impact the PAF recommendation rate. However, recommendations were more likely to be followed when there was concurrent positive culture data. This highlights the importance of obtaining culture data to direct antimicrobial therapy.

Disclosures

All authors: No reported disclosures.