Risk factors for readmission among patients receiving outpatient parenteral antimicrobial therapy: a retrospective cohort study

Current practices and challenges of outpatient parenteral antimicrobial therapy: a narrative review

Extended hospitalization for infection management increases inpatient care costs and the risk of healthcare-associated adverse events, including infections. The growing global demand for healthcare, the diminishing availability of hospital beds and an increasing patient preference for care within their own home have been the primary drivers of the expansion of hospital-in-the-home programmes. Such programmes include the use of IV antimicrobials in outpatient settings, known as outpatient parenteral antimicrobial therapy (OPAT). However, OPAT practices vary globally. This review article aims to describe the current OPAT practices and challenges worldwide. OPAT practice begins with patient evaluation and selection using eligibility criteria, which requires collaboration between the interdisciplinary OPAT team, patients and caregivers. Depending on care requirements, eligible patients may be enrolled to various models of care, receiving medication by healthcare professionals at outpatient infusion centres, hospital clinics, home visits or through self-administration. OPAT can be used for the management of many infections where an effective oral treatment option is lacking. Various classes of parenteral antimicrobials, including β-lactams, aminoglycosides, glycopeptides, fluoroquinolones and antifungals such as echinocandins, are used globally in OPAT practice. Despite its benefits, OPAT has numerous challenges, including complications from medication administration devices, antimicrobial side effects, monitoring requirements, antimicrobial instability, patient non-adherence, patient OPAT rejection, and challenges related to OPAT team structure and administration, all of which impact its outcome. A negative outcome could include unplanned hospital readmission. Future research should focus on mitigating these challenges to enable optimization of the OPAT service and thereby maximize the documented benefits for the healthcare system, patients and healthcare providers.

Effectiveness and safety of a disposable elastomeric continuous infusion pump for outpatient parenteral antimicrobial therapy (OPAT) in a UK setting

We evaluated the effectiveness and safety of continuous antimicrobial infusion using a disposable elastomeric device in an outpatient parenteral antimicrobial therapy (OPAT) setting. We conducted a retrospective analysis of all patients who received either flucloxacillin (n = 131 episodes) or piperacillin/tazobactam (n = 301 episodes) as continuous infusion via elastomeric devices over 5 years (January 2018-December 2022) at a tertiary referral hospital in Derbyshire, UK. Overall, 81 adverse events were recorded in 77 (18%; 77/432) patient-episodes. Most adverse events were vascular access-related (59%; 4.6 events per 1000 OPAT-days), including one line-related infection (0.2%; 0.1 events per 1000 OPAT-days). 165 (38%) patient-episodes experienced at least one incident of incomplete infusion. Successful outcome (cure or improvement) occurred in 364 (84%) episodes. Our findings suggest that elastomeric infusion pumps are safe and effective for administering selected antimicrobial agents in OPAT. However, close monitoring of patients and the device are essential to ensure optimal delivery of prescribed therapy.

Creation and Validation of an Automated Registry for Outpatient Parenteral Antibiotics

Existing outpatient parenteral antibiotic therapy (OPAT) registries are resource intensive, and OPAT programs struggle to produce objective data to show the value of their work. We describe the building and validation of an automated OPAT registry within our electronic medical record and provide objective data on the value of the program. Variables and outcomes include age, sex, race, ethnicity, primary insurance payor, antibiotic names, infection syndromes treated, discharge disposition, 30-day all-cause readmission and death rates, complications, and an estimate of the hospital days saved. Records for 146 OPAT episodes were reviewed manually to validate the registry. Data were displayed in a dashboard within the electronic medical record. Over the 4-year time frame, our registry collected 3956 unique patients who completed 4710 episodes (approximately 1200 episodes per year). A total of 400 complications during OPAT were identified. All variables had an accuracy of >90% on validation. The OPAT program resulted in a reduction in hospital length of stay by 88 820 days, or roughly 22 000 days per year. We intend our registry to serve as a blueprint for similar OPAT programs with limited administrative resources. Wider application of our system would allow for easier aggregation and comparisons of OPAT practice and address the lack interinstitutional standardization of OPAT data and outcomes.

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

Background

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.

Objectives

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).

Methods

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.

Results

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.

Conclusion

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.

Prolonged use of linezolid in bone and joint infections: a retrospective analysis of adverse effects

OBJECTIVES

Antibiotic treatment for bone and joint infections generally lasts for 6 weeks or longer. Linezolid may be a good option for treating bone and joint infections, but there is an increased risk of potential serious adverse drug events (ADEs) when used for more than 28 days. The aim of this study was to obtain detailed information on the type and time to occurrence of the patient-reported ADEs, the dynamics of haematopoiesis over time, and the reasons for early discontinuation of linezolid when used for an intended maximum duration of 12 weeks.

METHODS

This single-centre retrospective study was conducted at the Sint Maartenskliniek in The Netherlands. Patients were included if they were planned to use linezolid for more than 28 days. The main reason for discontinuation of linezolid, the ADE according to the Naranjo score, and the time to occurrence of ADEs were analysed.

RESULTS

Among 78 patients, drug toxicity led to early discontinuation of linezolid in 11 (14%) patients before and nine (12%) after 28 days of therapy. The median treatment duration was 42 days. Gastrointestinal intolerance (42%) and malaise (32%) were the most common ADEs. In 75% of the cases the ADE occurred within 28 days of therapy. Sixty-seven patients were able to continue linezolid beyond 28 days, 87% of whom completed therapy as scheduled. Severe cytopenia, according to the Common Terminology Criteria for Adverse events (CTCA), was observed in four patients and was reversible after discontinuation of linezolid. One patient suffered optic neuropathy related to linezolid use.

CONCLUSIONS

Linezolid could be considered an alternative option to the current standard of IV glycopeptides for the treatment of bone and joint infection for up to 12 weeks. If patients pass the first 28 days of therapy, the likelihood of successful completion of therapy is high with a low risk of serious ADEs.

Patient safety outcomes for continuous infusion vancomycin as outpatient parenteral antimicrobial therapy

BACKGROUND

Administration of vancomycin as a continuous infusion has been associated with reduced nephrotoxicity. Given limited published experience with continuous infusion vancomycin in outpatient parenteral antimicrobial therapy (OPAT) programs, we reviewed outcomes from our center.

METHODS

This was a retrospective, single-center study of adult patients receiving vancomycin OPAT as continuous or intermittent infusion for an intended treatment duration of at least 7 days. The primary outcome was time to nephrotoxicity with continuous versus intermittent infusion vancomycin while on OPAT; additional outcomes included time to any vancomycin-associated adverse event, time to 60-day death or readmission, and time to 60-day emergency department encounter. Proportional hazards modeling was used to identify variables independently associated with outcomes, as well as assess the strength of association of continuous infusion with each outcome.

RESULTS

Four-hundred ninety-two patients were included: 118 treated with continuous and 374 with intermittent vancomycin infusion. Continuous infusion was not associated with lower rates of nephrotoxicity compared to intermittent infusion (adjusted hazard ratio (aHR) 0.72, 95% CI: 0.35-1.50). There were no advantages of continuous over intermittent infusion in the rates of any adverse event (aHR 0.93, 95% CI: 0.56-1.53), 60-day death or readmission (aHR 1.04, 95% CI: 0.68-1.61), or 60-day emergency department encounter (aHR 1.17, 95% CI: 0.68-1.99). Vancomycin area under the concentration-time curve (AUC) at discharge was the only modifiable factor identified that was independently associated with patient safety outcomes.

CONCLUSION

There was no appreciable benefit of continuous infusion vancomycin on outpatient safety outcomes. AUC-centered dosing approaches warrant further investigation as strategies to improve vancomycin safety in OPAT programs.

Risk of venous thromboembolism in outpatient parenteral antimicrobial therapy (OPAT): A systematic review and meta-analysis

The risk of venous thromboembolism (VTE) in outpatient parenteral antimicrobial therapy (OPAT) is not fully understood and the optimal strategy for thromboprophylaxis remains unclear. This systematic review investigated the incidence of VTE in OPAT settings (PROSPERO CRD42022381523). MEDLINE, CINAHL, Emcare, Embase, Cochrane Library and grey literature were searched from earliest records to 18 January 2023. Primary studies reporting non-catheter-related VTE or catheter-related thromboembolism (CRT) events in adults who received parenteral antibiotics in home or outpatient settings were eligible. In total, 43 studies involving 23 432 patient episodes were reviewed, of which 4 studies reported non-catheter-related VTE and 39 included CRT. Based on generalised linear mixed-effects models, pooled risk estimates of non-catheter-related VTE and CRT were 0.2% [95% confidence interval (CI) 0.0-0.7%] and 1.1% [95% CI 0.8-1.5%; prediction interval (PI) 0.2-5.4%]. Heterogeneity was largely attributed to risk of bias by meta-regression (R2 = 21%). Excluding high-risk-of-bias studies, CRT risk was 0.8% (95% CI 0.5-1.2%; PI 0.1-4.5%). From 25 studies, the pooled CRT rate per 1000 catheter-days was 0.37 (95% CI 0.25-0.55; PI 0.08-1.64). These findings do not support universal thromboprophylaxis or routine use of an inpatient VTE risk assessment model in the OPAT setting. However, a high index of suspicion should be maintained, especially for patients with known risk factors for VTE. An optimised protocol of OPAT-specific VTE risk assessment should be sought.

A Bundle of the Top 10 OPAT Publications in 2022

Outpatient parenteral antimicrobial therapy (OPAT) has become more common in clinical settings. Correspondingly, OPAT-related publications have also increased; the objective of this article was to summarize clinically meaningful OPAT-related publications in 2022. Seventy-five articles were initially identified, with 54 being scored. The top 20 OPAT articles published in 2022 were reviewed by a group of multidisciplinary OPAT clinicians. This article provides a summary of the "top 10" OPAT publications of 2022.

A single centre experience of prosthetic joint infection outcomes with outpatient parenteral antimicrobial therapy

Objectives

Prosthetic joint infection (PJI) is a serious complication following arthroplasties. This study assessed the clinical outcomes, readmission rates and financial impact of PJIs treated with outpatient parenteral antimicrobial therapy (OPAT).

Methods

The study used prospectively collected data from the OPAT patient database at a tertiary care Irish hospital for PJI cases managed between 2015 and 2020. Data was analyzed using IBM-SPSS.

Results

Forty-one patients with PJIs were managed via OPAT over five years, with median age of 71.6 years. Median duration of OPAT was 32 days. Hospital readmission occurred in 34% of cases. Reasons for readmission included progression of infection in 64.3%, unplanned reoperation in 21.4% and planned admission for joint revision in 14.3%. Type 2 Diabetes Mellitus (T2DM) was found to have a statistically significant association with unplanned readmission (OR 8.5, CI 95% 1.1-67.6; p < 0.01). OPAT saved a mean of 27.49 hospital-bed days per patient. 1,127 bed days were saved in total, estimating a total savings of 963,585 euros and median savings of 26,505 euros.

Conclusions

The readmission rate observed was comparable to international data. Most readmissions were related to primary infections rather than due to OPAT-specific complications. Our main findings were that patients with PJIs can be safely managed via OPAT, and the finding of association between T2DM and increased risk of readmission.

Best practices, implementation and challenges of outpatient parenteral antimicrobial therapy: results of a worldwide survey among healthcare providers

Background

Outpatient Parenteral Antimicrobial Therapy (OPAT) is considered a patient-friendly and cost-effective practice. Patients in the OPAT service can be at risk for developing adverse events. Due to extensive variations in practice, guidelines have been developed to minimize the risks.

Objectives

In this first worldwide survey on OPAT, we explored the current OPAT services around the world, adherence to recommendations and identified best practices and challenges from different perspectives.

Methods

An e-survey was conducted and consisted of questions about demographics, characteristics of the OPAT service, role of pharmacy, future developments, and respondents' views on improvements as well as best practices.

Results

A total of 126 responses from 28 countries were included. Seventy-eight percent (78%) of the respondents stated that their facility provides antimicrobial therapy in the outpatient setting, whereas 22% did not. Forty-two percent (42%) of the hospitals with OPAT services had a specialized OPAT service, while 14% lacked specialized services and 22% had a partially specialized team in place. In facilities with a specialized OPAT service, the number of mandatory infectious disease (ID) consultations before discharge and clinical monitoring by an ID specialist or OPAT team member, the frequency of monitoring, and the availability of an OPAT registry were higher. A multidisciplinary team's presence was commonly noted as best practices. On the other hand, respondents experienced difficulties with reimbursement and lack of standardization in the screening, follow-up and monitoring of patients.

Conclusion

This survey provides a better understanding of the implementation and practices of OPAT services globally and describes best practices and the challenges from different professionals.

Successful Integration of Clinical Pharmacists in an OPAT Program: A Real-Life Multidisciplinary Circuit

Outpatient parenteral antimicrobial therapy (OPAT) programs encompass a range of healthcare processes aiming to treat infections at home, with the preferential use of the intravenous route. Although several barriers arise during the implementation of OPAT circuits, recent cumulative data have supported the effectiveness of these programs, demonstrating their application in a safe and cost-effective manner. Given that OPAT is evolving towards treating patients with higher complexity, a multidisciplinary team including physicians, pharmacists, and nursing staff should lead the program. The professionals involved require previous experience in infectious diseases treatment as well as in outpatient healthcare and self-administration. As we describe here, clinical pharmacists exert a key role in OPAT multidisciplinary teams. Their intervention is essential to optimize antimicrobial prescriptions through their participation in stewardship programs as well as to closely follow patients from a pharmacotherapeutic perspective. Moreover, pharmacists provide specialized counseling on antimicrobial treatment technical compounding. In fact, OPAT elaboration in sterile environments and pharmacy department clean rooms increases OPAT stability and safety, enhancing the quality of the program. In summary, building multidisciplinary teams with the involvement of clinical pharmacists improves the management of home-treated infections, promoting a safe self-administration and increasing OPAT patients' quality of life.

Clinical Efficacy and Safety of Vancomycin Continuous Infusion in Patients Treated at Home in an Outpatient Parenteral Antimicrobial Therapy Program

Vancomycin is commonly used in outpatient parenteral antimicrobial therapy (OPAT) of Gram-positive infections. Therapeutic drug monitoring and adverse event monitoring pose a challenge. Outcome data of vancomycin in OPAT (vOPAT) are limited. The study aim was to report the safety and efficacy of a structured vOPAT program implemented in the University Hospitals Leuven. The program provides continuous elastomeric infusion of vancomycin at home with biweekly follow-up at the outpatient clinic. Demographics, clinical, biochemical and treatment parameters, target attainment parameters and clinical outcomes were recorded. An e-survey was conducted to assess patient satisfaction. Thirty-five vOPAT episodes in 32 patients were included. During 206 follow-up consultations, 203 plasma concentration measurements were registered with a median vancomycin plasma concentration of 22.5 mg/L (range 6.6–32.0). The majority of concentrations (68.5%) were within the therapeutic range (20.0–25.0 mg/L). Adverse event rates, including drug- (5.7%) and catheter-related (5.7%) events, were low. For 32 vOPAT episodes, a clinical cure rate of 100% was observed. All patients who completed the e-survey were satisfied with their vOPAT course. These findings show that a structured vOPAT program with rigorous follow-up provides safe and effective ambulatory treatment of patients with vancomycin in continuous infusion.