351. Antibiotic Management Decisions and Use of a Multiplex PCR Panel for Pneumonia Diagnosis Among Critically Ill Patients with COVID-19

Background Antibiotic use among patients with COVID-19 is common, exceeds the prevalence of probable bacterial co-infection, and promotes development of resistant organisms. Lack of diagnostic microbiological data may prolong empiric broad-spectrum therapy. Here we evaluate the use of the BioFire FilmArray pneumonia panel (PP), a novel rapid diagnostic test, and antibiotic decisions among intensive care unit (ICU) patients with COVID-19. Methods We conducted a retrospective review of adult ICU patients admitted with COVID-19 between January 2020 and May 2021 at an academic medical center. ICU patients who underwent bronchoscopy/bronchoalveolar lavage (BAL) with PP (PP group) were matched by age (< 65 or ≥65), BMI (< 30 or ≥30), and BAL date (within 60 days) to ICU patients who did not undergo BAL (no-BAL group). PP patients were matched by age and BMI to ICU patients who underwent BAL without PP (no-PP group). Antibiotic use was compared between groups. Chi squared analysis, t-test, and ANOVA were used for comparisons as appropriate. Results 65 patients were included; the majority were male (65%), < 65 years (86%), and had BMI ≥30 (54%) (Table 1). Only 17 no-PP matches were identified for PP patients due to infrequent BALs. Similar proportion of patients in PP and no-PP groups had organisms identified from BAL (54% vs. 47%, p=0.65). Among PP patients with a detected organism, all (n=13) had subsequent changes in antibiotic regimen ≤72 hours after BAL; 10/13 (77%) had a change targeted to detected organism and 5/13 (39%) had antibiotic narrowing. Among PP patients with no detected organism, only 4/11 (36%) had antibiotic narrowing or maintenance off antibiotics. In all groups, average antibiotic use exceeded 70% of admission duration. Table 1. Patient characteristics and antibiotic management. Abbreviations: BAL - bronchoalveolar lavage Conclusion Rapid, highly sensitive diagnostic tests have potential to guide clinical decisions and promote antibiotic stewardship among patients with severe viral pneumonia and suspected bacterial co-infection. In this descriptive analysis, antibiotic management did not differ significantly with use of PP. While most patients with detected organism on PP had targeted antibiotic changes, a negative PP did not appear to influence antibiotic narrowing. Larger studies and provider education are needed to evaluate potential of the PP for antibiotic stewardship. Disclosures Jason Zucker, MD, MS, Nothing to disclose Daniel A. Green, M.D., BioFire (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member) Deborah Theodore, MD, BioFire Diagnostics (Other Financial or Material Support, Donation of testing materials to support investigator-initiated research)

1126. Short-Course Therapy and Transition to Enteral Antibiotics for Uncomplicated Bacteremia Due to Enterobacterales Species

Background Gram-negative bacteremia historically has been treated with 10-14 days of parenteral antibiotics. However, data supporting this practice are lacking, and recent evidence shows equivalent outcomes for short-course (SC) therapy (7 days) and early (by day 5) conversion to highly bioavailable enteral (PO) antibiotics for Enterobacterales bacteremia. Methods Under a QI framework, we used PDSA cycles to reduce treatment duration and increase use of PO levofloxacin or trimethoprim-sulfamethoxazole for uncomplicated Enterobacterales bacteremia among Infectious Diseases (ID) clinicians at a children’s hospital in Boston, MA. We conducted an education session on evidence to support these practices for ID faculty and fellows in October 2020. In December 2020, we implemented standardized recommendations for a 7-day duration and early PO transition for eligible patients (≥ 3-months-old, ≤ 2 days monomicrobial bacteremia, with source control and return to baseline clinical status) that could be inserted automatically into electronic consult notes. In February 2021, we reinforced this practice to ID providers. We collected data before and after these interventions on ID recommendations and on patients’ actual antibiotic management. Results From 11/01/20 to 05/31/21, mean recommended treatment decreased from 10.6 to 9.5 days; however, mean duration received was similar (11.2 vs 11.7 days) (Figure 1). The percentage of patients for whom ID recommended PO conversion and in whom transition to PO agents by day 5 occurred increased from 27% to 37.5%. Figure 1. Change in average duration of antibiotics recommended and received, in days Conclusion Education and creation of automated standardized recommendations led to decreased recommended treatment durations and increased PO conversions for Enterobacterales bacteremia, but only modestly. This quality improvement initiative demonstrates the potential benefits of education and electronic documentation tools to facilitate evidence-based practice changes, but also highlights the difficulty in changing practice even amongst ID clinicians. Further PDSA cycles will be targeted at increasing more consistent awareness among a large ID division in addition to other stakeholders. Disclosures Gabriella S. Lamb, MD, MPH, Nothing to disclose

1128. Antibiotic Stewardship in Nonoperative Management of Perforated Appendicitis: Oral Antibiotics Are an Alternative

Background Standard of care of nonoperative appendicitis patients involves ongoing antibiotic therapy. Yet, there is variability regarding the decision to continue outpatient parenteral antibiotic treatment (OPAT) or transition to oral (PO) antibiotics. We review antibiotic susceptibility patterns aiming to help guide antibiotic choice and reduce the need for OPAT. Methods Single center retrospective study reviewing pediatric inpatients who underwent nonoperative management of perforated appendicitis with cultures obtained during drainage by Interventional Radiology (IR). We reviewed age, ethnicity, hospitalization length, antibiotic choice, route and duration, and culture data. Results Forty-six patients underwent nonoperative medical management for appendicitis (23[50%] 5-12 year olds (yo); 16[35%] 12-< 18yo; 23[50%] Latino;13[28%] White, 11[24%] Other; 5[11%] Asian; 1[2%] Black). Thirty-eight [83%] patients went home on OPAT, 6[13%] on PO, and 2[4%] completed therapy while inpatient. Time from admission to IR drainage was 1.9 ± 2.8 days (34[75%] within 24 hours of admission, 3[8%] within 24-48, and 2[5%] within 48-72). Duration of hospital stay was 9.7 ± 4 days (PO) and 5.9 ± 2.7 days (OPAT). Duration on antibiotics was 20 ± 9.3 (PO) and 18.4 ± 4.9 days (OPAT). Labs on admission and discharge are compared in Table 1. Eight [17%] patients were readmitted due to complications, 38[83%] went home with a drain, and 20[43%] had a fecalith on CT scan. Based on culture susceptibilities of the 38 OPAT patients, 29[76%] had oral antibiotics as an option. The three most common organisms in those sent home on OPAT included Enterococcus faecalis (38[100%]), Bacteroides spp (33[87%]) and Escherichia coli (27[71%]) (Figure 1). All patients who grew Pseudomonas aeruginosa had a PO option; similarly with 93% of E. coli, 81% of α-hemolytic Streptococcus spp, and 76% of E. faecalis. Conclusion Nearly 80% of patients sent home on OPAT had PO antibiotic regimens options based on the culture results & susceptibility profiles. This data indicates that using cultures and susceptibility data can help guide antibiotic management, significantly reducing PICC line placement and likely reduce healthcare costs and complications associated with central lines. Disclosures All Authors: No reported disclosures

Effective Enteral Treatment of Antibiotic for Patient with Respiratory Failure and Septic Shock in the Intensive Care Unit

Background: Pneumonia is a lung infection involving pulmonary alveoli caused by microbes, including bacteria, viruses, and fungi. It is a major infection that causes hospitalization and death worldwide and exacts an enormous cost in economic and human terms. The study to assess clinical outcomes for a critically ill patient treated with an enteral antibiotic for bacterial pneumonia is still limited. Case: We reported a case of pneumonia from 68 years old patient that caused respiratory failure and septic shock in the intensive care unit treated by enteral antibiotic and had a good outcome. Conclusion: Pneumonia can cause respiratory failure and septic conditions. Optimum antibiotic management is one of the methods to solve this problem. The benefit of utilizing enteral antibiotics is substantial and probably appropriate in certain patients.

Fatal Case of a Contained Ruptured of the Infrarenal Aorta due to Simultaneous Primary Aortocaval Fistula and Aortoenteric Fistula

We report an extremely rare case of primary aortocaval fistula with simultaneous development of an aortoenteric fistula in a 68-year-old man. The patient developed under oral anticoagulation a spontaneous intracaval aortic rupture. An emergency intervention was performed with a covering of the fistula with an aorto-uniiliac stent graft and a femoro-femoral crossover bypass. One week later, the patient was transferred to our institution with the diagnosis of a psoas abscess and a suspected concomitant aortoenteric fistula. We performed a complete explantation of the endograft and implanted it after extensive debridement an aortobiiliac bypass, made of bovine pericardium. The postoperative course was complicated, first by bleeding from the left iliac anastomosis, and then by bleeding from the proximal aortic anastomosis. The entire graft was explanted and an axillo-femoral bypass was implanted. The patient then developed a multi-organ failure and died 3 months later. If possible, an extended surgical debridement and resection of all infected tissue with in situ reconstruction is the gold standard. However, with this therapy, there is still a high risk of reinfection. Long-term antibiotic management is mandatory.

Microbiological Characteristics and Surgical Management of Animal-Bite-Related Oral & Maxillofacial Injuries: A Single Center’s Experience

The objective of the current study is to retrospectively evaluate animal-bite injuries and to gain insight into the epidemiology, accident consequences and treatment concept of these accidents in oral and maxillofacial surgery. Data of patients, who were admitted January 2015 and April 2021, were retrospectively evaluated regarding the patients’ characteristics (age, gender), facial distribution of substance defects/partial amputations, duration of hospitalization, operation treatments and antibiotic treatments. Data of 75 patients were included. Patients were bitten by dogs (n = 69.92%), cats (n = 4) and horses (n = 2). Lower eyelid/cheek complex was the most affected region (n = 37, 32.74%). Most of the patients between 0 and 3 years had to be operated on under general anesthesia (p = 0.011), while most of the adults could be operated on under local anesthesia (p = 0.007). In the age group 0–12 years, 30 patients (68%) were operated on under general anesthesia. Ampicillin/Sulbactam (48%) was the antibiotic most used. Antibiotics were adjusted after wound swabs in case of wound infections or critical wound conditions. This means that resistant antibiotics were stopped, and sensitive antibiotics were used. Structured surgical and antibiotic management of animal-bite wounds in the maxillofacial region is the most important factor for medical care to avoid long-term aesthetic consequences. Public health actions and policies under the leadership of an interdisciplinary committee could improve primary wound management, healing outcome and information status in the general population.

Prospective Evaluation of Antibiotic Management in Ureteral Stent and Nephrostomy Interventions

<b><i>Introduction:</i></b> Screening for and treating asymptomatic bacteriuria (ABU) or administering antibiotic prophylaxis is recommended during ureteral stent and nephrostomy interventions. This study investigates the frequency of postinterventional infectious complications to gain insight into the need for antibiotics. <b><i>Methods:</i></b> Between September 2016 and June 2019, 168 insertions/exchanges of ureteral stents or nephrostomies were recorded in a prospective multicenter study. Patients without a symptomatic UTI did not receive antibiotic treatment/prophylaxis. Asymptomatic patients in whom their urologist already administered an antibiotic treatment served as a comparative group. Follow-up included postinterventional complications within 30 days. Symptoms were assessed by the Acute Cystitis Symptom Score (ACSS) before and after the intervention. Predictors of increasing postinterventional symptoms were analyzed by a multivariable logistic regression model. <b><i>Results:</i></b> One hundred forty-five interventions were eligible. One hundred twenty-two (84.1%) interventions were performed without antibiotic treatment. Preinterventional ABU was detected in 54.4% and sterile urine in 22.8% (22.8% without culture). Postinterventional infectious complications did not differ between patients with versus without antibiotics. Transurethral interventions aggravate symptoms (<i>p</i> = 0.034) but do not increase infectious complications compared to percutaneous interventions. Patients without diabetes mellitus are at higher risk for increasing symptoms. <b><i>Conclusion:</i></b> Results indicate that peri-interventional antibiotic treatment may be omitted in patients without symptomatic UTI. Symptoms must be differentiated between infectious and procedure-associated origins.

Case report: appendicitis induced Staphylococcus aureus and Klebsiella pneumoniae bacteremia in a young healthy male

Background Appendicitis is one of the most frequently encountered conditions at the emergency department. Distinction is made between complicated and uncomplicated appendicitis. Complicated appendicitis may cause serious intra-abdominal infection, bacteremia, or sepsis. Emergency health providers should be highly alert to any early signs indicating such complications. Case presentation We present the case of a healthy young male with a gangrenous appendicitis, who received antibiotics and underwent appendectomy. Blood cultures showed unequivocal Staphylococcus aureus and concomitant Klebsiella pneumoniae bacteremia requiring prolonged antibiotic treatment and further diagnostic evaluation. Conclusions Although rare, appendicitis can cause Staphylococcus aureus and Klebsiella pneumoniae bacteremia with extensive implications for workup and antibiotic management. Our case stresses the importance of obtaining cultures in patients with suspicion of bacteremia given its consequences for clinical management.