Antimicrobial Prophylaxis Regimens Research Articles

Actual opportunistic ocular surface microflora and its sensitivity to antimicrobials and bacteriophages in patients with cataracts

Background: Species of opportunistic microflora often are the pathogenic agents that causes endophthalmitis in cataract surgery. Frequently microorganisms are characterized by resistance to several antimicrobial medicaments, which limits the ability to choose an effective agent. This problem requires a detailed study and monitoring of the sensitivity of ocular surface microflora. Aim: To study the species composition of the ocular surface microflora patients before phacoemulsification and to evaluate the antimicrobial activity of antimicrobial medicaments including antiseptics and bacteriophages. Materials and methods: A total of 60 patients were examined before phacoemulsification. The sensitivity to antimicrobial medicaments and bacteriophages was determined of microorganisms isolated from three loci (conjunctival cavity, eyelid margin, lacrimal ducts). Results: Among all microorganisms isolated, there was a significant prevalence of Staphylococcus epidermidis — 48,4 %. Almost all antiseptics showed high antimicrobial activity. All staphylococci cultures were sensitive to staphylococcal bacteriophage number 2. The smallest proportion of resistant microorganisms to antimicrobial medicaments used in ophthalmology was registered in the group of aminoglycosides. Conclusions: Antimicrobial activity of the investigated medicaments was different among different bacterial species. The sensitivity of microflora changes over time, therefore it is appropriate to carry out periodic monitoring and adjust antimicrobial prophylaxis regimens based on the results received.

Postoperative outcomes after receipt of ertapenem antimicrobial prophylaxis for colon surgery: a multicenter retrospective cohort study.

To evaluate postoperative outcomes among patients undergoing colon surgery who receive perioperative prophylaxis with ertapenem compared to other antibiotic regimens. Multicenter retrospective cohort study among adults undergoing colon surgery in seven hospitals across three health systems from 1/1/2010 to 9/1/2015. Generalized linear mixed logistic regression models were applied to assess differential odds of select outcomes among patients who received perioperative prophylaxis with ertapenem compared to other regimens. Postoperative outcomes of interest included surgical site infection (SSI), Clostridioides difficile infection (CDI) and clinical culture positivity for carbapenem-resistant Enterobacteraciae (CRE). Inverse probability weights were applied to account for differing covariate distributions across ertapenem and non-ertapenem groups. A total of 2,109 patients were included for analysis. The odds of postoperative SSI was 1.56 times higher among individuals who received ertapenem than among those receiving other perioperative antimicrobial prophylaxis regimens in our cohort (46 [3.5%] vs 20 [2.5%]; IPW-weighted OR 1.56, [95% CI, 1.08-2.26], P = .02). No statistically significant differences in odds of postoperative CDI (24 [1.8%] vs 16 [2.0%]; IPW-weighted OR 1.07 [95% CI, .68-1.68], P = .78) were observed between patients who received ertapenem prophylaxis compared to other regimens. Clinical CRE culture positivity was rare in both groups (.2%-.5%) and did not differ statistically. Ertapenem use for perioperative prophylaxis was associated with increased odds of SSI among patients undergoing colon surgery in our study population, though no differences in CDI or clinical CRE culture positivity were identified. Further study and replication of these findings are needed.

Variation of Practice in Prophylactic Protocol to Reduce Prosthetic Joint Infection in Primary Hip and Knee Arthroplasty: A National Survey in the United Kingdom.

Prosthetic joint infection (PJI) has an enormous physiological and psychological burden on patients. Surgeons rightly wish to minimise this risk. It has been shown that a standardised, evidence-based approach to perioperative care leads to better patient outcomes. A review of current practice was conducted using a cross-sectional survey among surgeons at multiple centers nationwide. An 11-question electronic survey was circulated to hip and knee arthroplasty consultants nationally via the BOA (British Orthopaedic Association) e-newsletter. The respondents included 56 consultants working across 19 different trusts. Thirty-four (60.7%) screen patients for asymptomatic bacteriuria (ASB) preoperatively, with 19 (55.9%) would treating with antibiotics. Fifty-six (100%) screen for methicillin-resistant Staphylococcus aureus and treat if positive. Only 15 (26.8%) screen for methicillin-sensitive S. aureus (MSSA) or empirically eradicate. Zero (0%) routinely catheterise patients perioperatively. Forty-one (73.2%) would give intramuscular or intravenous gentamicin for a perioperative catheterisation. All surgeons use laminar flow theatres. Twenty-six (46.4%) use only an impervious gown, 6 (10.7%) exhaust pipes, and 24 (42.3%) surgical helmet system. Five different antimicrobial prophylaxis regimens are used 9 (16.1%) cefuroxime, 2 (3.6%) flucloxacillin, 19 (33.9%) flucloxacillin and gentamicin, 10 (17.9%) teicoplanin, 16 (28.6%) teicoplanin and gentamicin. Twenty-two (39.3%) routinely give further doses. ASB screening, treatment and intramuscular gentamicin for perioperative catheterisation is routinely practiced despite no supporting evidence base. MSSA screening and treatment is underutilised. Multiple antibiotic regimens exist despite little variation in organisms in PJI. Practice varies between surgeons and centers, we should all be practicing evidence-based medicine.

“A breach in the protocol for no good reason”: a surgical antimicrobial prophylaxis experience in an Ethiopian academic medical center

BackgroundAn appropriately administered surgical antimicrobial prophylaxis decreases the rate of surgical site infections. Although evidence-based clinical practice guidelines have been published on surgical antimicrobial prophylaxis, the rate of adherence to the protocol and the impact of extending antimicrobial prophylaxis postoperatively is yet to be well elucidated.MethodA total of general surgery and vascular surgery patients with clean and clean contaminated wound undergoing elective surgical procedures were included in the study. The rate of surgical antimicrobial prophylaxis utilization, the proportion of patients whom had their antimicrobial prophylaxis extended beyond 24 h and the rate of surgical site infections across groups were evaluated.ResultsThe surgical antimicrobial prophylaxis utilization rate was 90.5%. Of these patients, 12.6% were unnecessarily administered with antibiotics. An “extended” antibiotics administration beyond 24 h after the surgery was found in 40.2%. Gastrointestinal and hepato-pancreatico-biliary surgery patients had 7.9-fold rate of “extended” surgical antimicrobial prophylaxis beyond 24 h, AOR 7.89 (95% CI 3.88–20.715.62, p value < 0.0001). The overall rate of surgical site infection was 15(6.8%). The “extended” regimen of prophylactic antibiotics had no effect on the rate of surgical site infections.ConclusionLess than half of the patients included here had surgical antimicrobial prophylaxis regimen in accordance with the existing guidelines. The most common protocol violation was noted as extension of antimicrobial prophylaxis for more than 24 h after surgery. The extension of antimicrobial prophylaxis did not decrease the rate of surgical site infections, reaffirming the evidence that prophylactic extension of surgical antimicrobial prophylaxis is unnecessary.

Optimal timing for antimicrobial prophylaxis to reduce surgical site infections: a retrospective analysis of 531 patients

It has been revealed that the administration of an antimicrobial prophylaxis (AP) reduces the rate of surgical site (SSI) following colorectal cancer surgery. Nevertheless, the optimal timing of this medication remains unclear. The aim of this study was to determine more precisely the optimal time for administering antibiotics and to see if this could reduce the number of possible surgical site infections. The files of individuals who underwent colorectal cancer surgery at the University Hospital Brandenburg an der Havel (Germany) between 2009 and 2017 were analyzed. Piperacillin/tazobactam, cefuroxime/metronidazole and mezlocillin/sulbactam were administered as AP regimens. Timing of AP was obtained. The primary objective was the rate of SSIs based on CDC criteria. Multivariate analysis took place to identify risk factors for SSIs. A total of 326 patients (61.4%) received an AP within 30 min, 166 (31.3%) between 30 and 60 min, 22 (4.1%) more than 1 h before surgery, and 15 (2.8%) after surgery. In 19 cases (3.6%) a SSI occurred during hospital stay. A multivariate analysis did not identify AP timing as a risk factor for the occurrence of SSIs. With significance, more surgical site occurrences (SSO) were diagnosed when cefuroxime/metronidazole was given. Our results suggest that AP with cefuroxime/metronidazole is less effective in reducing SSO compared with mezlocillin/sulbactam and tazobactam/piperacillin. We assume that the timing of this AP regimen of < 30 min or 30–60 min prior to colorectal surgery does not impact the SSI rate.

Evaluation and management of abnormal liver enzymes in the liver transplant recipient: When, why, and what now?

Evaluation and management of abnormal liver enzymes in the liver transplant recipient: When, why, and what now?

Adherence to Antimicrobial Prophylaxis Guidelines for Elective Surgeries Across 825 US Hospitals, 2019-2020.

There are limited US data assessing adherence to surgical antimicrobial prophylaxis guidelines, particularly across a large, nationwide sample. Moreover, commonly prescribed inappropriate antimicrobial prophylaxis regimens remain unknown, hindering improvement initiatives. We conducted a retrospective cohort study of adults who underwent elective craniotomy, hip replacement, knee replacement, spinal procedure, or hernia repair in 2019-2020 at hospitals in the PINC AI (Premier) Healthcare Database. We evaluated adherence of prophylaxis regimens, with respect to antimicrobial agents endorsed in the American Society of Health-System Pharmacist guidelines, accounting for patient antibiotic allergy and methicillin-resistant Staphylococcus aureus colonization status. We used multivariable logistic regression with random effects by hospital to evaluate associations between patient, procedural, and hospital characteristics and guideline adherence. Across 825 hospitals and 521 091 inpatient elective surgeries, 308 760 (59%) were adherent to prophylaxis guidelines. In adjusted analysis, adherence varied significantly by US Census division (adjusted OR [aOR] range: .61-1.61) and was significantly lower in 2020 compared with 2019 (aOR: .92; 95% CI: .91-.94; P < .001). The most common reason for nonadherence was unnecessary vancomycin use. In a post hoc analysis, controlling for patient age, comorbidities, other nephrotoxic agent use, and patient and procedure characteristics, patients receiving cefazolin plus vancomycin had 19% higher odds of acute kidney injury (AKI) compared with patients receiving cefazolin alone (aOR: 1.19; 95% CI: 1.11-1.27; P < .001). Adherence to antimicrobial prophylaxis guidelines remains suboptimal, largely driven by unnecessary vancomycin use, which may increase the risk of AKI. Adherence decreased in the first year of the COVID-19 pandemic.

Antimicrobial stewardship in solid organ transplant—Opportunities in the National Health Service

Antimicrobial stewardship (AMS) is an intervention, which ensures the appropriateness of antimicrobial use to avoid in part the rising problem of antimicrobial resistance and negative effects of inappropriate antimicrobial use. In the solid organ transplant (SOT) population, which is prone to a particularly high risk of infection resulting from immunosuppression and anatomical issues with each type of SOT, the need for good stewardship has never been more important. This article looks at current AMS practice in SOT units in the United Kingdom and how things could be improved in the future. The current practice of AMS alongside national antimicrobial resistance rates were reviewed using national mandatory reporting data. The background to the current practice and policies in place in the National Health Service (NHS) were also reviewed and possibilities for future approaches explored. AMS is a requirement within all NHS hospitals in the United Kingdom as per government policy. Mandatory reporting of specific bloodstream infections (BSIs) and antimicrobial consumption alongside financial incentives has been the approach nationwide. Gram-negative resistance rates in BSIs have been increasing prior to the COVID-19 pandemic. Little SOT-specific data on antimicrobial resistance exists, and the general approach to AMS in SOT units has generally modeled the national approach. Although there is a good, standardized approach to AMS in the NHS, there is a need for SOT-specific AMS approaches to be developed in the United Kingdom. More data is required on antimicrobial resistance rates, and studies are needed to investigate optimal antimicrobial prophylaxis regimens for each solid organ group. Tools to aid AMS efforts and novel treatment options for complex multiresistant infection must also be explored amongst transplant centers.

Comparison of Fluoroquinolones and Other Antibiotic Prophylaxis Regimens for Preventing Complications in Patients Undergoing Transrectal Prostate Biopsy.

Our study aimed to compare the incidence of infective complications after transrectal ultrasound-guided prostate biopsy (TRUSBx) when adopting different antimicrobial prophylaxis regimens. A multi-institutional cohort of 1150 patients who underwent TRUSBx was retrospectively analyzed. Procedures were performed between 2017 and 2019 (before and after the EMA warning about the use of fluoroquinolones for the antibiotic prophylaxis of patient candidates to TRUSBx). The primary endpoint was the occurrence of infective complications, including sepsis and/or fever. The population was stratified according to the antibiotic prophylaxis adopted: fluoroquinolones (levofloxacin, ciprofloxacin, prulifloxacin), cephalosporins (cefixime, ceftriaxone) or trimethoprim/sulfamethoxazole. Univariable and multivariable binomial logistic regression models were used to assess the odds ratio (OR) with 95% confidence interval (CI) testing of the risk of infective complication after adjusting for each prebiopsy covariate. In total, 478 (41.6%) patients received fluoroquinolone-based prophylaxis. Among these, 443 (38.5%), 25 (2.2%) and 10 (0.9%) patients received levofloxacin prophylaxis, ciprofloxacin and prulifloxacin, respectively while 14.6% received cefixime, 20.7% received the comedication of ceftriaxone/fosfomycin and 23.1% received trimethoprim/sulfamethoxazole. The trimethoprim/sulfamethoxazole and fluoroquinolone regimens were significantly associated with a lower risk of infective complications (OR 0.15, 95% CI 0.03–0.48, p = 0.003 and OR 0.17, 95% CI 0.06–0.43, p < 0.001, respectively). The ceftriaxone/fosfomycin (OR 0.21, 95% CI 0.04–0.92, p = 0.04) and fluoroquinolone (OR 0.07, 95% CI 0.00–0.70, p = 0.048) prophylaxis were associated with a lower risk of infective sequelae. Fluoroquinolone-based prophylaxis was associated with a lower risk of infective complications after TRUSBx compared to other prophylaxis regimens although its clinical application was recently forbidden by European Medical Agency restrictions.

Changes in the gut bacterial communities in colon cancer surgery patients: an observational study

BackgroundColon surgery has been shown to modulate the intestinal microbiota. Our objective was to characterize these changes using state-of-the-art next generation sequencing techniques.MethodsWe performed a single-centre prospective observational cohort study to evaluate the changes in the gut microbiota, i.e., taxon distribution, before and after elective oncologic colon surgery in adult patients with different antimicrobial prophylaxis regimens (standard prophylaxis with cefuroxime/metronidazole versus carbapenems for extended-spectrum beta-lactamase-producing Enterobacterales [ESBL-E] carriers). We obtained rectal samples on the day of surgery, intraoperative luminal samples, and rectal or stoma samples 3 days after surgery. We performed metataxonomic analysis based on sequencing of the bacterial 16S rRNA gene marker. Similarities and differences between bacterial communities were assessed using Bray–Curtis similarity, visualised using principal coordinates analysis and statistically tested by PERMANOVA. Comparison of taxa relative abundance was performed using ANCOM.ResultsWe included 27 patients between March 27, 2019 and September 17, 2019. The median age was 63.6 years (IQR 56.4–76.3) and 44% were females. Most (81%) patients received standard perioperative prophylaxis as they were not ESBL carriers. There was no significant association between ESBL carriage and differences in gut microbiome. We observed large and significant increases in the genus Enterococcus between the preoperative/intraoperative samples and the postoperative sample, mainly driven by Enterococcus faecalis. There were significant differences in the postoperative microbiome between patients who received standard prophylaxis and carbapenems, specifically in the family Erysipelotrichaceae.ConclusionThis hypothesis-generating study showed rapid changes in the rectal microbiota following colon cancer surgery.

Incidence and Significance of Microbiological Results and Antimicrobial Prophylaxis in Patients Undergoing Total Pancreatectomy with Autologous Islet Cell Transplant

Introduction: The impact of microbiological findings in the preservation, cannulation solutions, and final islet cell product is debatable amongst providers taking care of patient undergoing total pancreatectomy with autologous islet cell-transplantation (TPAIT). It is further challenged by the lack of guidelines on the type and duration of antimicrobial prophylaxis needed. We aimed to correlate post-op infections to theses cultures and the efficacy of antimicrobial prophylaxis. Methods: Twenty-two patient’s (February 1, 2018 to August 31, 2021) microbiological data from the preservation, cannulation, and final islet cell cultures and their 60 days post-transplant infections were retrospectively analyzed. Results: Microbial cultures were positive in 5 (22.7%) patient’s preservation solution, 4 (18.2%) cannulation solution, and 6 (27.3%) final products (Table 1). Most common antimicrobial prophylaxis regimens were piperacillin/tazobactam (pip/tazo), vancomycin, and micafungin (n=9). The average duration was seven days (range: 2-10). Six patients were discharged on amoxicillin/clavulanic acid. Three patients (14%) had infections: 2 (9%) had Clostridium difficile (22 and 37 days after surgery), 1 (5%) had Candida albicans growing from the abdominal collection (59 days) with no growth in any of the isolation cultures, and 1 (5%) had Burkholderia cepacia in urine (44 days). Conclusion: Isolation procedure and final product cultures were not associated with any infections. Broad spectrum antimicrobial use intra- and post-operatively and extended oral antimicrobial therapy may have minimized the number of infectious outcomes. Consideration is warranted regarding the use of antimicrobial prophylaxis and duration as some of these agents pose a risk for C. difficile.Tabled 1EP02F-020Final Islet Cell CulturePreservation SolutionCannulation Solution1Yeast like organisms in anaerobic cultureNegativeYeast like organisms in anaerobic culture2Initially resulted as gram positive cocci with final identification as Granulicatella adiacensNegativeInitially resulted with gram negative rods in both aerobic and anaerobic cultures. Final report of Klebsiella pneumonia in the aerobic culture and Enterobacter species in anaerobic culture.3Streptococcus massiliensis from aerobic cultureNegativeNegative4Yeast like organisms in anaerobic cultureGram negative rods in aerobic and anaerobic culturesGram negative rods in aerobic and anaerobic cultures5NegativeGram positive rods in anaerobic cultureNegative6Gram positive cocci in anaerobic cultureGram negative rods in aerobic cultureNegative7Gram positive cocci in aerobic and anaerobic culturesGram negative rods in aerobic and anaerobic culturesGram negative rods in aerobic and anaerobic cultures8NegativeGram positive cocci in anaerobic cultureNegative Open table in a new tab

Cost-Effectiveness Analysis of the Prophylactic Use of Ertapenem for the Prevention of Surgical Site Infections after Elective Colorectal Surgery.

Standard surgical antimicrobial prophylaxis (SAP) regimens are less effective in preventing surgical site infections (SSIs) due to rising antimicrobial resistance (AMR) rates, particularly for patients undergoing colorectal surgery. This study aimed to evaluate whether ertapenem should be a preferred strategy for the prevention of SSIs following elective colorectal surgery compared to three standard SAP regimens: amoxicillin-clavulanate, cefoxitin, and cefazolin plus metronidazole. A cost-effectiveness analysis was conducted using decision tree models. Probabilities of SSIs and AMR-SSIs, costs, and effects (in terms of quality-adjusted life-years) were considered in the assessment of the alternative strategies. Input parameters integrated real data from the Italian surveillance system for SSIs with data from the published literature. A sensitivity analysis was conducted to assess the potential impact of the decreasing efficacy of standard SAP regimens in preventing SSIs. According to our models, ertapenem was the most cost-effective strategy only when compared to amoxicillin-clavulanate, but it did not prove to be superior to cefoxitin and cefazolin plus metronidazole. The sensitivity analysis found ertapenem would be the most cost-effective strategy compared to these agents if their failure rate was more than doubled. The findings of this study suggest ertapenem should not be a preferred strategy for SAP in elective colorectal surgery.

Reducing Broad-Spectrum Antimicrobial Use in Extracorporeal Membrane Oxygenation: Reduce AMMO Study.

The use of extracorporeal membrane oxygenation (ECMO) in critically ill adults is increasing. There are currently no guidelines for antimicrobial prophylaxis. We analyzed 7 years of prophylactic antimicrobial use across 3 time series for patients on ECMO at our institution in the development, improvement, and streamlining of our ECMO antimicrobial prophylaxis protocol. In this quasi-experimental interrupted time series analysis, we evaluated the impact of an initial ECMO antimicrobial prophylaxis protocol, implemented in 2014, on antimicrobial use and National Healthcare Safety Network-reportable infection rates. Then, following a revision and streamlining of the protocol in November 2018, we reevaluated the same metrics. Our study population included 338 intensive care unit patients who received ECMO between July 2011 and November 2019. After implementation of the first version of the protocol, we did not observe significant changes in antimicrobial use or infection rates in these patients; however, following revision and streamlining of the protocol, we demonstrated a significant reduction in broad-spectrum antimicrobial use for prophylaxis in patients on ECMO without any evidence of a compensatory increase in infection rates. Our final protocol significantly reduces broad-spectrum antimicrobial use for prophylaxis in patients on ECMO. We propose a standard antimicrobial prophylaxis regimen for patients on ECMO based on current evidence and our experience.Summary: There are no guidelines for antimicrobial prophylaxis in patients on extracorporeal membrane oxygenation (ECMO). A rational approach employing concepts of antimicrobial stewardship can drive logical antimicrobial selection for prophylaxis in patients on ECMO without adversely impacting outcomes.

Radiation Injury

Since the development of x-rays in the late 19th century, radiation has increasingly been used for diagnostic imaging and various industrial purposes. The human health consequences of radiation exposure can range from minor asymptomatic exposures to the development of potentially fatal acute radiation sickness depending on the characteristics of the exposure. This review provides an overview of radiation injury, including historical perspective and principles of toxicity; assessment and stabilization (bedside evaluation, supportive care, and empirical therapy); diagnosis (estimation of radiation dose, laboratory assessment, biodosimetry and bioassays, smoke inhalation, and psychiatric sequelae); treatment and disposition (hematologic acute radiation illness, countermeasures and antidotes, gastrointestinal symptoms, fluid and electrolyte management, surgical intervention, local radiation injury, psychiatric treatment, radiation exposure during pregnancy, palliative care, and disposition); and outcomes (carcinogenesis, noncancer effects). Tables include the characteristic of common radioactive isotopes, common radiation dose equations and conversions, prescribing information for colony-stimulating factors, recommended antimicrobial prophylaxis and treatment regimens, and radioisotope decorporation or blocking agents. Figures show types of ionizing radiation, comparison of radiation contamination and exposure, patterns of early lymphocyte response based on radiation dose, the relationship between time to onset of vomiting and radiation dose, and a sample body chart for documentation of radiation contamination. This review contains 5 figures, 5 tables, and 82 references. Key Words: radiation, radiation exposure, radiation sickness, diagnostic imaging, pregnancy, carcinogenesis, toxicity, acute radiation syndrome (ARS)

906. Surgical Site Infections in Children with Beta-Lactam Allergy: A Matched Cohort Study

BackgroundSurgical site infections (SSIs) are a significant cause of morbidity and mortality. The administration of appropriate pre-operative antimicrobial prophylaxis (AMP) reduces SSI risk and beta-lactam antibiotics are considered the most effective agents. Studies in adult patients found increased SSI risk in patients with documented beta-lactam allergy (BLA) due to use of second line AMP agents. The SSI risk in BLA pediatric patients is not well-described.MethodsWe conducted a retrospective matched cohort study of patients (1-19 years-old) who underwent a surgical procedure at a quaternary pediatric hospital during 2010-2017. Patients with documented BLA at the time of surgery were matched 1:1 to patients with no BLA by age at surgery, National Surgical Quality Improvement Program (NSQIP) category, surgical calendar year, and presence of complex chronic conditions (CCC). AMP by BLA status was considered appropriate if recommended by the 2013 American Society of Health-System Pharmacists (ASHP) guidelines, antibiotic class appropriate, or recommended by an infectious disease physician. McNemar’s test was used to assess differences in SSI rates and antibiotic regimen appropriate for BLA status between BLA and no BLA groups.ResultsOf the 11878 surgical procedures among 9781 patients during the study period, 1021(9%) of patients had a reported BLA and we matched 972. SSI was rare in both groups and there was no significant difference in rates (18 (1.9%) in no BLA, 17 (1.8%) in BLA, p=1.0). BLA were more likely to receive an antibiotic regimen considered inappropriate for BLA status (22%) compared to no BLA (3%) with 89% receiving a beta-lactam-containing AMP regimen (p< 0.01).ConclusionBLA was not associated with increased SSI risk in the pediatric patients studied. Interestingly, a significant proportion of children with a documented allergy received a beta-lactam for AMP. This suggests some providers recognize that allergy labels are inaccurate and may be comfortable administering beta-lactam AMP regardless of allergy status.Disclosures All Authors: No reported disclosures

902. Selection of Antibiotics for Prophylaxis of Left Ventricular Assist Device Surgical Infections: More is Not More

BackgroundSurgical site infections (SSI) for implantation of left ventricular assist devices (LVADs) are associated with high mortality. Updated guidance from the International Society for Heart and Lung Transplant recommends that SSI prophylaxis regimens target Staphylococcus spp and recommend against broad regimens targeting gram-negatives and fungi. The purpose of this study was to compare outcomes between patients that received broad or narrow antimicrobial prophylaxis regimens after a change in institutional protocol.MethodsThis single center retrospective study included adult patients who underwent LVAD implantation between January 2015 and September 2019. Patients were excluded if post-surgical care was managed at an outside facility, were treated for an active infection at the time of implantation, or underwent re-implantation within 90 days. The narrow spectrum group consisted of patients that received cefazolin, vancomycin or both, while the broad spectrum group consisted of patients that received an anti-pseudomonal beta-lactam plus vancomycin ± other antibiotics. Data was compared using t-test or Wilcoxon rank sum test, Chi-Square test, or Fisher’s Exact. Cox-proportional hazards models and log-rank tests were used for survival analysis.ResultsA total of 104 patients were included, with 39 and 65 patients receiving narrow and broad spectrum prophylaxis, respectively. There was no difference in the primary outcome of SSI rate between the narrow and broad antimicrobial prophylaxis groups at 30 days (7.7% vs 7.7%, p=1.00) and 1 year (18.0% vs 18.5%, p=1.00) respectively. Secondary outcomes of time to mortality (HR 0.45, 95% CI 0.15-1.36, logrank P=0.15), time to first infection (HR 0.68, 95% CI 0.26-1.8, logrank P=0.44), or the composite outcome of mortality or infection (HR 0.55, 95% CI 0.24-1.23, logrank P=0.14) were not different between the groups. The majority of infections were due to gram-positive bacteria (73%), most commonly methicillin susceptible S. aureus (36%).Time to Mortality Time to First Infection Composite Outcome (Time to First Infection or Death) ConclusionThis study supports the use of narrow spectrum antimicrobial prophylaxis in LVAD implantation. These results highlight an opportunity to improve antibiotic use in LVAD implantation.Disclosures All Authors: No reported disclosures

Intraoperative Bacterial Contamination and Activity of Different Antimicrobial Prophylaxis Regimens in Primary Knee and Hip Replacement.

Surgical antimicrobial prophylaxis (SAP) is important for the prevention of prosthetic joint infections (PJIs) and must be effective against the microorganisms most likely to contaminate the surgical site. Our aim was to compare different SAP regimens (cefazolin, cefuroxime, or vancomycin, alone or combined with gentamicin) in patients undergoing total knee (TKA) and hip (THA) arthroplasty. In this preclinical exploratory analysis, we analyzed the results of intraoperative sample cultures, the ratio of plasma antibiotic levels to the minimum inhibitory concentrations (MICs) for bacteria isolated at the surgical wound and ATCC strains, and serum bactericidal titers (SBT) against the same microorganisms. A total of 132 surgical procedures (68 TKA, 64 THA) in 128 patients were included. Cultures were positive in 57 (43.2%) procedures (mostly for coagulase-negative staphylococci and Cutibacterium spp.); the rate was lower in the group of patients receiving combination SAP (adjusted OR 0.475, CI95% 0.229–0.987). The SAP regimens evaluated achieved plasma levels above the MICs in almost all of intraoperative isolates (93/94, 98.9%) and showed bactericidal activity against all of them (SBT range 1:8–1:1024), although SBTs were higher in patients receiving cefazolin and gentamicin-containing regimens. The potential clinical relevance of these findings in the prevention of PJIs remains to be determined.

Meta-analysis of the efficacy of ertapenem in preventing SSIs after elective colorectal surgery

Abstract Background The efficacy of standard surgical antimicrobial prophylaxis (SAP) regimens in preventing surgical site infections (SSIs) after colorectal surgery is declining, along with rising rates of intestinal colonization with antimicrobial resistant (AMR) Enterobacteriaceae and Bacteroides spp. Ertapenem has been approved by the FDA and EMA for SAP in this context, however it has not been used extensively for this indication out of concern for increasing carbapenem-resistance rates. A limited number of studies have investigated the efficacy of ertapenem in preventing SSIs after colorectal surgery, comparing ertapenem with different agents or combinations of agents. Methods A systematic review was conducted following the PRISMA checklist. PubMed, Embase and Cochrane databases were searched for studies measuring the efficacy of ertapenem in preventing SSIs following elective colorectal procedures. Studies were considered eligible if they reported extractable data on the proportion of SSIs and/or on the proportion of AMR pathogens isolated from SSIs. Data from all ertapenem study arms were extracted. A random effects meta-analysis was performed to estimate the overall proportion of SSI. Results Of 1109 identified studies, 5 met the inclusion criteria and were included in the meta-analysis, totalling 3176 participants. The pooled proportion of SSI was 0.10 (95% CI 0.05-0.18; I2=96%; τ2=0.6323; p ≤ 0.01). Only one study reported data on carbapenem resistance: out of 124 isolates from 30 patients, 1 gram negative carbapenem-resistant isolate was identified. Conclusions The pooled proportion of SSI using ertapenem as SAP found in this study is in line with the proportion of SSI using standard SAP found by a recent meta-analysis (Gandra, 2019). According to this analysis, the benefit of ertapenem does not outweigh the risk of further promoting AMR, although results should be interpreted with caution due to the high heterogeneity among included studies. Key messages According to this study, the efficacy of ertapenem in preventing surgical site infections after elective colorectal surgery is comparable to the efficacy of standard surgical antibiotic prophylaxis. The emergence of carbapenem resistance after surgical prophylaxis with ertapenem should be further investigated through longer term studies before widespread use for this indication.

Erythromycin compared to amoxicillin and azithromycin for antimicrobial prophylaxis for preterm premature rupture of the membranes: a retrospective study

Antimicrobial prophylaxis is widely recommended for pregnant women who have preterm premature rupture of the membranes. Erythromycin prophylaxis was used during an initial period (control) and then changed to intravenous amoxicillin for 48 h, followed by 5 days of oral amoxicillin along with a single dose of azithromycin (case). Healthcare records were reviewed retrospectively. The primary outcome was latency (between membrane rupture and delivery) and the secondary outcomes were mode of delivery, maternal high dependency unit (HDU) admission, and several laboratory parameters. There were 78 women in the case group (amoxicillin and azithromycin) and controls were selected on a 1:1 ratio. There was no statistically significant difference between cases and controls with respect to group B Streptococcus or E.coli carriage, previous preterm birth, assissted fertility and parity. No babies had a positive blood culture with Group B Streptococcus. There was a longer latency to delivery for those prescribed amoxicillin and azithromycin (median = 5.5 days), compared with controls on erythromycin (median = 2 days, p < .001). There was no difference in the mode of delivery or maternal HDU admission. Given the potential sequelae of preterm birth, this warrants further prospective investigation in a randomised control trial. IMPACT STATEMENT What is already known on this subject? Antimicrobial prophylaxis is recommended for women who have preterm premature rupture of the membranes (PPROM). It has been shown to increase latency of delivery. However there are different regimens recommended in North America (amoxicillin and a macrolide) and the United Kingdom (macrolide monotherapy). What do the results of this study add? This study has shown that in our population, women who were prescribed the PPROM regimen of amoxicillin with azithromycin had a longer median latency from time of rupture of membranes to delivery, than women in a historical control group who were prescribed erythromycin monotherapy. What are the implications of these findings for clinical practice and/or further research? This retrospective study has shown that there may be a difference in latency between different antimicrobial prophylaxis regimens for PPROM. A randomised control trial, with sufficient patient numbers, is needed to determine the best regimen for prophylaxis, and would allow harmonisation of international guidelines.

A Systematic Review of Antibiotic Prophylaxis for Delayed Sternal Closure in Children.

Antibiotic prophylaxis following delayed sternal closure in pediatric cardiac surgery is not standardized. We systematically reviewed relevant literature published between 1990 and 2019 to aid future trial design. Patient characteristics, antimicrobial prophylaxis regimens, and postoperative incidence of infection were collected. Twenty-eight studies described 36 different regimens in over 3,000 patients. There were 11 single-drug regimens and 25 multidrug regimens. Cefazolin-only was the most common regimen (9/36, 25%). The overall incidence of surgical site infection was 7.5% (217/2,910 patients) and bloodstream infection was 7.4% (123/1,667 patients). In the 2010s, multidrug regimens were associated with a significantly lower incidence of both surgical site infections (4.6% vs. 20%, P < .001) and bloodstream infections (6.0% vs. 50%, P < .001) compared to single-drug regimens.