Multicenter Cohort Study of Ceftaroline versus Daptomycin for Treatment of Methicillin-Resistant Staphylococcus aureus Bloodstream Infection

Background Observational data suggest ceftaroline may be effective for methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSI) but comparative data with standard of care are limited. This analysis compares the outcomes of MRSA BSI treated with ceftaroline or daptomycin. Methods Multicenter, retrospective, observational cohort study of adult patients with MRSA BSI from 2010 to 2017. Patients treated with ≥ 72 hours of ceftaroline or daptomycin were included. Those clearing BSI before study drug and those with a pneumonia source were excluded. The primary outcome was composite treatment failure, defined as 30-day mortality, BSI duration ≥ 7 days on study drug, and 60-day MRSA BSI recurrence. Inverse probability of treatment weighted risk difference in composite failure between daptomycin and ceftaroline groups was computed and 15% non-inferiority margin applied. Results Two hundred seventy patients were included; 83 ceftaroline and 187 daptomycin. Ceftaroline was non-inferior to daptomycin with respect to composite failure [39% daptomycin, 32.5% ceftaroline; weighted risk difference (95% CI) 7.0% (-5.0 – 19.0%)]. No differences between treatment groups was observed for 30-day mortality or other secondary efficacy outcomes. Creatine phosphokinase elevation was significantly more common among daptomycin patients (5.3% vs 0%, P = 0.034). Rash was significantly more common among ceftaroline patients (10.8 vs 1.1%, P = 0.001). Conclusions No difference in treatment failure or mortality was observed between MRSA BSI treated with ceftaroline or daptomycin. These data support future study of ceftaroline as a primary MRSA BSI treatment and current use of ceftaroline when an alternative to vancomycin and daptomycin is required.

185. Does an Infectious Diseases Consultation Improve Clinical Outcomes and Treatment Bundle Adherence for Enterococcal Bacteremia in a Multicenter Healthcare System?

Background Infectious diseases consultation (IDC) for Staphylococcus aureus bacteremia has a known mortality benefit, but for other gram positive bacteremias the benefit is not known. This study examined differences in outcomes for enterococcal bacteremia when management includes IDC. Methods This retrospective multicenter observational cohort study included adults with at least 1 positive blood culture with Enterococcus species. Patients who died or transferred to palliative care within 2 days of positive blood cultures were excluded. The primary outcome was a composite of clinical failure, including persistent blood cultures or fever for 5 days and in-hospital mortality. Secondary outcomes included adherence to a treatment bundle (appropriate empiric/definitive antibiotics, echocardiography (ECHO), duration of treatment, and repeat blood cultures). Results A total of 250 patients were included. IDC was obtained in 62.0% of patients. More patients in the IDC group had endocarditis (20% vs 0%, p < 0.0001) and bone and joint infections (13.5% vs 1.1%, p = 0.001), compared to more UTI (16.8% vs 39.0%, p < 0.0001) in the non-IDC group. Patients in the IDC group had more murmurs on initial exam (21.3% vs 6.3%, p = 0.002), prosthetic device (49.7% vs 27.4%, p = 0.001), and NOVA scores of ≥ 4 (40.6% vs 18.9%, p < 0.0001). Most infections were due to E. faecalis (78.4%) and most were susceptible to vancomycin and ampicillin at 90.4% and 92.4%, respectively. The composite of clinical failure occurred in 22.6% of patients with IDC and 16.8% in the non-IDC group (p=0.274). There was higher adherence to the treatment bundle in the IDC group (Figure 1). More patients in the IDC group were treated with ampicillin (47.1% vs 22.1%, p < 0.0001), and numerically more patients received treatment with vancomycin in the non-IDC group (17.4% vs 24.2%, p = 0.068). In the multivariate analysis, vasopressors were the only independent predictor of the primary outcome (OR 9.3, 95% CI 3.5-24.8, p < 0.0001). Figure 1. Adherence to treatment bundle. IDC = infectious diseases consultation, Echo = echocardiogram, * = p < 0.05 Conclusion There was no difference in rates of composite failure in patients with or without IDC; however, adherence to a treatment bundle was higher in the IDC group. IDC demonstrated stewardship benefits with regards to vancomycin usage. Disclosures All Authors: No reported disclosures

Bedding Plane Effects on Mechanical Behavior of Surrounding Rock in Mountain Tunneling

The layered rock showed the characteristics in Mountain tunnel, Yunnan. A series of uniaxial compression tests and variable angle shear tests were carried out, and the aim was to investigate the effect of the bedding on its mechanical parameters and failure modes. The test results show that the uniaxial compressive strength, elastic modulus, and Poisson's ratio of layered rock present a U-shaped distribution with the increase in bedding orientation from 0° to 90°. All of them have a maximum when the bedding orientation is 0° and a minimum when the bedding orientation is 45°. The failure modes of layered rock can be summarized into three types: the fracture tensile failure parallel to the weak plane of bedding; the shear slip failure along bedding weak plane; and tension-shear composite failure between bedding weak plane and matrix. Based on the testing data and analysis results, it can be concluded that the layered rock specimen with different bedding orientations is an important reason for the anisotropy of mechanical parameters and failure modes.

The effect of fibre surface treatment and coupling agents to improve the performance of natural fibres in PLA composites

This paper describes work carried out to assess the effect of fibre treatments and coupling agent on the mechanical performance of PLA composites reinforced with 20 wt% fibre. The chemically-treated harakeke and hemp fibres used to produce fibre mats. Maleic anhydride (MA) grafted PLA (MA-g-PLA) was used as a coupling agent. Composites with fibre treated with silane and dicumyl peroxide (DCP) and composites using MA-g-PLA were characterised by swelling testing, scanning electron microscopy (SEM), tensile testing, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). It was found that the interfacial bonding for composites with fibres treated using silane and peroxide and composites coupled with MA-g-PLA noticeably improved supported by lower swelling indices, higher tensile strengths and lower tan δ compared to those composites with fibres treated using alkali only, with the highest tensile strength of about 11% higher obtained from composites treated with MA-g-PLA followed by silane and then peroxide. However, using silane, peroxide and MA-g-PLA as additional composite treatments increased significantly the composite failure strain by up 11, 19 and 30%, respectively for harakeke composites and by 13, 24 and 30%, respectively for hemp composites.

Results of Acetabular Microfracture in Patients undergoing FAI surgery are Strongly Correlated with Age (142)

Objectives: Full-thickness cartilage injury is not uncommon in patients undergoing primary treatment of Femoroacetabular impingement (FAI). Treatment of these lesions with microfracture is commonly performed. However, the outcomes of these procedures relative to other patients undergoing FAI surgery is not well established and the literature on this topic is limited to small, retrospective single surgeon studies. The purpose of the present study was to evaluate outcomes of patients who underwent concurrent FAI correction and acetabular microfracture and to identify predictors treatment failure. Methods: A prospective multicenter cohort study of the treatment of FAI was performed. A total of 760 hips undergoing primary FAI surgery were enrolled. Inclusion criteria were primary FAI surgery, Tonnis 0 or 1 osteoarthritis grade, and age between 16 and 55 years. A total of 61 hips underwent treatment of full-thickness acetabular cartilage lesions with microfracture, with 55 (90.2%) having follow-up greater than 1 year (mean 4.0 years). This group had a mean age of 35.0+10.1 years, BMI of 27.2+4.2, and included 81.8% (45/55) males. A comparison cohort of 492 hips undergoing primary FAI surgery without treatment of acetabular full-thickness cartilage was utilized. Baseline, intraoperative, and follow-up data was recorded including the modified Harris hip score (mHHS) and HOOS domains of pain, ADLs, sports and recreation, symptoms, and quality of life. Composite failure was characterized by reoperation [total hip arthroplasty (THA) or revision surgery] or clinical failure (failure to meet either MCID or PASS for mHHS). Age was assessed in 5 year intervals. Students t-test was used for continuous variables and chi squared were used for categorical variables. A p value less than 0.05 was considering significant. Results: Hips undergoing acetabular microfracture were more likely (compared to comparison cohort) to be male (81.8% vs. 40.9%, p<.001) older (35.0 vs. 29.9 years, p=0.001), had higher BMI (27.2 vs. 25.0, p=.001), and greater alpha angle (69.6 vs. 62.3, p<.001). In the microfracture cohort, 12.7% of patients progressed to THA (compared to 3.0% in comparison cohort, p=.001), while the rate of composite failure was similar to the comparison cohort (29.1% vs. 26.0%, p=.618). Age was highly correlated with the risk of THA and composite failure. The rate of THA for patients <35, 35-40*, and >40 years* of age was 0%, 20.0%, and 22.7% p=.016*), while the rate of composite failure in these groups was 17.4%, 20.0% and 45.5%, respectively (p=.029*). Hips greater than 35 years of age demonstrated inferior HOOS outcomes for domains of pain, ADLs, sports and recreation, QOL, and symptoms and SF-12 physical component scores(Table 1). Conclusions: The results of acetabular microfracture in patients undergoing FAI surgery at a mean follow-up of 4.0 years postoperatively are strongly correlated with age. Patients under 35 years of age demonstrate excellent outcomes with low rates of revision or progression to THA. Acetabular microfracture should have a limited to absent role in patients over the age of 40.

An Essay on Railway Track Bed Failure Issues, Analysis and Remedy

The polymer cures as it enters the ballast, forming a three-dimensional geo-composite reinforcing cage. Although there will be some adherence to the ballast in dry conditions, the polymer's primary job is to construct this reinforcing cage. Polymer penetration is controlled by altering the rheology of the polymer. The method is also said to include a built-in safety system, with the track reverting to a ballast state in the event of a polymer or geo-composite failure. Many of the sites were considered unmaintainable before the polymer was put. The design method was utilized to forecast track behaviour before and after treatment, allowing the most appropriate polymer rheology, polymer distribution, and loading levels to be designed in order to achieve optimum performance and confirm that the procedure worked. This method can be utilized to tackle these types of long-standing problems by displaying actual polymer application profiles at a typical important location.

Sacrocolpopexy using autologous rectus fascia: cohort study of long-term outcomes and complications

Objective: To evaluate objective and subjective outcomes of patients who underwent sacrocolpopexy using autologous rectus fascia to provide more data regarding non-mesh alternatives in pelvic organ prolapse surgery. Design: Cohort study with retrospective and prospective data. Setting: A single academic medical center. Population: Women who underwent abdominal sacrocolpopexy using autologous rectus fascia between January 2010 and December 2019 Methods: Patients were recruited for a follow-up visit including completing the Pelvic Floor Distress Inventory (PFDI) and Pelvic Organ Prolapse Quantification (POPQ) exam. Demographic and clinical characteristics were collected. Main Outcome Measures: Composite failure, anatomic failure, symptomatic failure, and retreatment. Results: During the study period, 132 women underwent sacrocolpopexy using autologous rectus fascia. Median follow-up time was 2.2 years. Survival analysis showed that composite failure was 0.8% (CI 0.1-5.9%) at 12 months, 3.5% (CI 1.1-10.7%) at 2 years, 13.2% (CI 7.0-24.3%) at 3 years, and 28.3% (CI 17.0-44.8%) at 5 years. Anatomic failure was 0% at 12 months, 1.4% (CI 0.2-9.2%) at 2 years, 3.1% (CI 0.8-12.0%) at 3 years, and 6.8% (CI 2.0-22.0%) at 5 years. Symptomatic failure rate was 0% at 12 months, 1.3% (CI 0.2-9.0%) at 2 years, 2.9% (CI 0.7-11.3%) at 3 years, and 13.1% (CI 5.3-30.3%) at 5 years. Retreatment rate was 0.8% (CI 0.1-5.9%) at 12 months and 2 years, 9.4% (CI 4.2-20.3%) at 3 years, and 13.0% (CI 6.0-27.2%) at 5 years. Conclusions: Autologous rectus fascia sacrocolpopexy may be considered a safe and effective alternative for patients who desire to avoid synthetic mesh.

Study on Deformation and Failure Characteristics of Surrounding Rock of Overlying Roadway under Upward Mining in the Deep Mine

To study the impact of mining of the lower protective layer on the deformation and failure characteristics of the upper roadway, these characteristics of an 879 gas drainage roadway were studied and analyzed during the mining of the II 1051 working face of the Zhuxianzhuang coal mine using similar simulation experiments and numerical simulation methods. The results indicate that with the continuous excavation of the working face, the range of impact of the mining stress gradually spreads and exceeds the level of the roadway. At the present time, the roadway is in a mining stress-rising area. The two sides of the roadway are sheared, and the roof and floor are under tension–shear composite failure. The floor is the most gravely damaged—the depth of its damage is 2.5 m, and the depths of damage on either side and of the roof are approximately 1–2 m. During the advancing process of the working face, the deformation of the roadway increases slowly at first, then increases sharply, and tends to be stable thereafter. The deformation of the floor is the largest, followed by those of the two sides and the roof; the values are 800, 400, and 300 mm, respectively.