Studying Biofilm and Clinical Issues in Orthopedics

The association between biofilm-forming microorganisms and prosthetic joint infection influences all aspect of management including approaches to diagnosis, management and prevention. This article will provide an overview of new anti-biofilm strategies for management of prosthetic joint infection

Preface

As this is the first Supplement produced by JAC-Antimicrobial Resistance (JAC-AMR) we thought it would be helpful for readers for us to briefly outline our vision and intention for these Supplements. (extract

Closing the gap in surveillance and audit of invasive mold diseases for antifungal stewardship using machine learning

Clinical audit of invasive mold disease (IMD) in hematology patients is inefficient due to the difficulties of case finding. This results in antifungal stewardship (AFS) programs preferentially reporting drug cost and consumption rather than measures that actually reflect quality of care. We used machine learning-based natural language processing (NLP) to non-selectively screen chest tomography (CT) reports for pulmonary IMD, verified by clinical review against international definitions and benchmarked against key AFS measures. NLP screened 3014 reports from 1 September 2008 to 31 December 2017, generating 784 positives that after review, identified 205 IMD episodes (44% probable-proven) in 185 patients from 50,303 admissions. Breakthrough-probable/proven-IMD on antifungal prophylaxis accounted for 60% of episodes with serum monitoring of voriconazole or posaconazole in the 2 weeks prior performed in only 53% and 69% of episodes, respectively. Fiberoptic bronchoscopy within 2 days of CT scan occurred in only 54% of episodes. The average turnaround of send-away bronchoalveolar galactomannan of 12 days (range 7-22) was associated with high empiric liposomal amphotericin consumption. A random audit of 10% negative reports revealed two clinically significant misses (0.9%, 2/223). This is the first successful use of applied machine learning for institutional IMD surveillance across an entire hematology population describing process and outcome measures relevant to AFS. Compared to current methods of clinical audit, semi-automated surveillance using NLP is more efficient and inclusive by avoiding restrictions based on any underlying hematologic condition, and has the added advantage of being potentially scalable

Multicentre stepped-wedge cluster randomised controlled trial of an antimicrobial stewardship programme in residential aged care: protocol for the START trial.

INTRODUCTION: Antimicrobial resistance is a growing global health threat, driven by increasing inappropriate use of antimicrobials. High prevalence of unnecessary use of antimicrobials in residential aged care facilities (RACFs) has driven demand for the development and implementation of antimicrobial stewardship (AMS) programmes. The Stepped-wedge Trial to increase antibiotic Appropriateness in Residential aged care facilities and model Transmission of antimicrobial resistance (START) will implement and evaluate the impact of a nurse-led AMS programme on antimicrobial use in 12 RACFs. METHODS AND ANALYSIS: The START trial will implement and evaluate a nurse-led AMS programme via a stepped-wedge cluster randomised controlled trial design in 12 RACFs over 16 months. The AMS programme will incorporate education, aged care-specific treatment guidelines, documentation forms, and audit and feedback strategies that will target aged care staff, general practitioners, pharmacists, and residents and their families. The intervention will primarily focus on urinary tract infections, lower respiratory tract infections, and skin and soft tissue infections. RACFs will transition from control to intervention phases in random order, two at a time, every 2 months, with a 2-month transition, wash-in period. The primary outcome is the cumulative proportion of residents within each facility prescribed an antibiotic during each month and total days of antibiotic use per 1000 occupied bed days. Secondary outcomes include the number of courses of systemic antimicrobial therapy, antimicrobial appropriateness, antimicrobial resistant organisms, Clostridioides difficile infection, change in antimicrobial susceptibility profiles, hospitalisations and all-cause mortality. Analyses will be conducted according to the intention-to-treat principle. ETHICS AND DISSEMINATION: Ethics approval has been granted by the Alfred Hospital Human Research Ethics Committee (HREC/18/Alfred/591). Research findings will be disseminated through peer-reviewed publications, conferences and summarised reports provided to participating RACFs. TRIAL REGISTRATION NUMBER: NCT03941509

Epidemiology, diagnosis, treatment and cost of orthopaedic device infections

© 2012 Dr. Trisha Nicole PeelOrthopaedic device infections are an uncommon complication of surgery occurring in 1-3% of patients undergoing arthroplasty. The rate of infection is higher in patients undergoing tumour endoprosthesis insertion as limb salvage surgery for treatment of bone and soft tissue tumours, estimated at up to 20% of patients. These infections have distressing consequences for patients including prolonged hospitalisation, multiple operations and prolonged treatment with broad-spectrum antibiotics. In addition, these infections are associated with significant healthcare costs, with US estimates predicting the cost of treating prosthetic joint infections in USA will exceed US$1.6 billion by 2020. The number of patients undergoing prosthetic joint surgery is increasing and, relative to the number of arthroplasties performed, the number of infections is also increasing. However, there is a paucity of literature examining prosthetic joint infections in Australian patients. In addition, the epidemiology and management of infections in tumour endoprosthesis infections has not been well described. This thesis has investigated the epidemiology, ecology, management approaches and costs of orthopaedic device infections in a cohort of Victorian patients. Specifically, the thesis examined three main cohorts; patients with arthroplasty infections managed at SVHM, patients with bone and soft tissue tumours undergoing tumour endoprosthesis insertion and patients with arthroplasty infections managed across 10 centres in Victoria, Australia. The organisms encountered and the management approaches differed from world-wide practices. In particular, methicillin resistant Staphylococcus was a major cause of infections in both the arthroplasty and tumour endoprosthesis populations. Importantly, this thesis has questioned the appropriateness of surgical antibiotic prophylaxis given the high rate of methicillin resistant Staphylococcus isolated in this cohort. This thesis demonstrated that complications involving the surgical wound were an important factor in the development of arthroplasty and tumour endoprosthesis infections. In addition, the risk factors for infection differed with the joint replaced; obesity was an independent predictor of infection in the hip arthroplasty patients, whereas the presence of a drain tube was protective against knee arthroplasty infections. The management approaches to infection in Victorian hospital differed to current literature. Debridement and retention of the prosthesis was the favoured treatment modality and entailed multiple arthrotomies and rifampicin combination therapy. This thesis examined the cost treating prosthetic joint infection with debridement and retention of the prosthesis demonstrating the cost of infection adds approximately$50,000 to the cost of primary arthroplasty. Finally this thesis examined the utility of multiplex PCR for the diagnosis of prosthetic joint infections. This thesis raised questions about the role for multiplex PCR, in particular application of this test in a commercial laboratory. This thesis adds significantly to current understanding of these infections in Australia. Future research is required to establish Australia-wide prosthetic joint infection registries for ongoing review of epidemiology and management approaches. Audit tools to consistently and objectively document wound complications need to be developed and assessed in orthopaedic patients. Finally research in strategies to prevent orthopaedic prosthetic device infections, including assessment of surgical antibiotic prophylaxis, should be undertaken

Randomised Controlled Trials of Alcohol-Based Surgical Site Skin Preparation for the Prevention of Surgical Site Infections: Systematic Review and Meta-Analysis

(1) Background: Surgical site skin preparation is an important approach to prevent postoperative wound infections. International guidelines recommend that alcohol-based combinations be used, however, the optimal combination remains uncertain. This study compares the effectiveness of alcohol-based chlorhexidine and alcohol-based iodophor for surgical site skin preparation for prevention of surgical site infections (SSIs). (2) Methods: Randomised controlled trials comparing alcohol-based interventions for surgical site skin preparation were included. The proportion of SSIs was compared using risk ratios (RR) with 95% confidence intervals (95% CI). The meta-analysis was performed with a fixed effect model using Mantel-Haenszel methods. As an a priori subgroup analysis SSI risk was examined according to different surgical procedural groups. (3) Results: Thirteen studies were included (n = 6023 participants). The use of chlorhexidine-alcohol was associated with a reduction in risk of SSIs compared with iodophor-alcohol (RR 0.790; 95% CI 0.669, 0.932). On sub-group analysis, chlorhexidine-alcohol was associated with a reduction in SSIs in caesarean surgery (RR 0.614; 95% CI 0.453, 0.831) however, chlorhexidine-alcohol was associated with an increased risk of SSI in bone and joint surgery (RR 2.667; 95% CI 1.051, 6.765). When excluding studies at high risk of bias on sensitivity analysis, this difference in alcohol-based combinations for bone and joint surgery was no longer observed (RR 2.636; 95% CI 0.995, 6.983). (4) Conclusions: The use of chlorhexidine-alcohol skin preparations was associated with a reduced risk of SSI compared to iodophor-alcohol agents. However, the efficacy of alcohol-based preparation agents may differ according to the surgical procedure group. This difference must be interpreted with caution given the low number of studies and potential for bias, however, it warrants further investigation into the potential biological and clinical validity of these findings