McHugh, Jack

Abstract Background Due to extensive protein binding, use of ceftriaxone in the setting of hypoalbuminemia may result in suboptimal drug exposure via higher concentrations of unbound drug resulting in increased volume of distribution and increased drug clearance. We aimed to evaluate the impact of hypoalbuminemia on clinical success among hospitalized adults with obesity who were treated with ceftriaxone for a bacterial infection. Methods This retrospective review included adult inpatients with weight > 100 kg or body mass index (BMI) > 40 who received ceftriaxone 2 grams intravenously every 12 hours for at least 72 hours for one of the following indications: bloodstream infection, pneumonia, urinary tract infection, non-enterococcal endocarditis, skin and soft tissue infection, or bone and joint infection. The primary outcome was clinical success, a composite of clinical cure and microbiologic cure. Clinical cure was defined as resolution of signs and symptoms compatible with active infection without need to change or extend antibiotic therapy due to inadequate effect of ceftriaxone. Microbiologic cure was defined as negative repeat sterile site cultures, if applicable. Secondary outcomes included length of stay, mortality, and 30-day readmission. Outcomes were analyzed with Mann-Whitney U tests, Pearson’s chi-squared tests, and Fisher’s exact tests (α level = 0.05). Results 137 patients were included, 34 of whom had a serum albumin ≤ 2.5 g/dL. Patients were predominantly white (94.2%) and male (69.3%) with a median BMI of 48.6 (Table 1). Clinical success, a composite of clinical and microbiologic cure, was achieved in 76.5% and 92.2% (p = 0.013) of those with and without hypoalbuminemia, respectively. Clinical cure was significantly more common among those without hypoalbuminemia (93.2%) as compared to those with hypoalbuminemia (76.5%) (p = 0.007). Death during hospitalization was more common (14.7% vs. 0%, p < 0.001) and median length of stay was longer (14 vs. 9 days, p = 0.009) in the hypoalbuminemia group. No difference was seen in 30-day readmission (23.5% vs. 11.7%, p = 0.089). Conclusion Hypoalbuminemia was associated with a lower rate of clinical success among patients with obesity who were treated with ceftriaxone 2 grams every 12 hours. Disclosures Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Advisor/Consultant|Gilead Sciences: Board Member|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria

Abstract Background Native joint septic arthritis (NJSA) is diagnosed by synovial fluid analysis to evaluate for evidence of infection but may be definitively established by a positive gram stain or culture. Antibiotics given prior to synovial fluid sampling have been described to alter cell count, gram stain, and culture results and are conventionally deferred until after arthrocentesis to optimize diagnostic yield. However, there is limited data on the impact of preoperative antibiotic therapy on operative culture yield in the diagnosis of NJSA. Methods Following IRB approval, we reviewed medical records of adults diagnosed with NJSA who underwent surgical intervention at Mayo Clinic facilities from January 2012 to December 2021. The effect of preoperative antibiotic therapy on operative culture yield was evaluated through a paired analysis of preoperative and operative cultures results utilizing logistic regression along with generalized estimating equations (GEE) to account for correlations of multiple measurements on the same subject. Results A total of 299 patients with NJSA of 321 joints with the accompanying characteristics who underwent surgery met study criteria (Table 1). Joint distribution, microbiology, and antibiotic administration are outlined in Table 2. Among those treated with preoperative antibiotics, there was a significant decrease in yield between preoperative and operative cultures (68.0% to 57.1%, p < .0001), whereas in patients without preoperative antibiotic exposure, there was an increase in yield (60.9% to 67.4%, p = 0.244; Figure 1). Logistic regression analysis revealed that preoperative antibiotic exposure was more likely to decrease operative culture yield as compared to non-exposure (change, -10.9% vs. +6.5%; p = .006). Secondary analyses restricted to individuals who received preoperative antibiotics revealed that an increasing number of doses and earlier administration of initial antibiotic therapy were associated with lower rates of operative culture yield (Figure 2). Joint distribution, diagnostic/microbiologic, and antibiotic administration characteristics of 321 joints in 299 patients with native joint septic arthritis Composite Image 1: Figure 1, 2a/2b Figure 1: Change in Preoperative and Operative Culture Yield with Antibiotic Exposure Figure 2: Effect of Antibiotic Doses and Timing of Therapy on Predicted Probability of Operative Culture Positivity Conclusion In patients with NJSA, preoperative antibiotic exposure resulted in a significant decrease in microbiologic yield of operative cultures as compared to patients in which antibiotic therapy was held prior to obtaining operative cultures. Disclosures Brandon J. Yuan, M.D., American Association of Orthopaedic Surgeons: Board Member|DePuy, A Johnson & Johnson Company: Advisor/Consultant|Mid America Orthopaedic Association: Board Member|Stryker: Advisor/Consultant Gina A. Suh, M.D., Adaptive Phage Therapeutics: Grant/Research Support|Adaptive Phage Therapeutics: IP royalties|Phagelux: Grant/Research Support Aaron J. Tande, M.D., Musculoskeletal Infection Society: Board Member|Wolters Kluwer Health - Lippincott Williams & Wilkins: Publishing royalties, financial or material support

Abstract Background Native joint septic arthritis (NJSA) of the wrist is a rare condition, with published literature suggesting an incidence of approximately 1.5% among patients presenting with acute painful and swollen wrist. The aim of this study was to investigate the characteristics, management, and outcomes of wrist NJSA at our institution. Methods We conducted a retrospective study of all adults diagnosed with wrist NJSA who underwent surgical intervention at Mayo Clinic facilities from January 2012 to December 2021. The diagnosis was confirmed based on clinical presentation, synovial fluid white blood cell count, and aspiration or operative cultures. Results A total of 557 patients developed NJSA during the study period, of whom 55 (9.9%) were diagnosed with wrist NJSA, median age was 63, with the associated demographics (Table 1). 12 (21.8%) had a history of antecedent trauma or procedure, 11 (20%) had synchronous joint infections, and 22 (40%) had positive blood cultures. The median synovial white blood cell count was 94,050/mm3 (IQR 51,920 – 139,941 /mm3). Crystals were detected in 5 patients (8.8%). Additional diagnostic data are available in Table 2. Open debridement was performed in 35 (61.4%) patients, and the rest underwent arthroscopy. Positive Gram stain results were detected in the preoperative synovial fluid of 12 (21.8%) cases. The most common pathogen isolated was Staphylococcus aureus in 13 (24%) of cases. The median duration of antimicrobial therapy was 31 days (IQR 26 – 45 days). There was no statistically significant difference in the incidence of complications between patients who underwent open debridement and those who underwent arthroscopy (Table 3). The most common complication of both groups was compromised range of motion of the wrist joint. Conclusion Native wrist septic arthritis comprised 9.9 % of all NJSA during the study period. Concomitant bacteremia and synchronous joint infections were common, highlighting the importance of obtaining blood cultures and comprehensive joint exam in this setting. Crystals and Gram stains were detected in 10 % and 22% of cases, respectively. These findings should not rule out NJSA. Decreased range of motion was common complication, affecting 21% of all cases. Disclosures Gina A. Suh, M.D., Adaptive Phage Therapeutics: Grant/Research Support|Adaptive Phage Therapeutics: IP royalties|Phagelux: Grant/Research Support Aaron J. Tande, M.D., Musculoskeletal Infection Society: Board Member|Wolters Kluwer Health - Lippincott Williams & Wilkins: Publishing royalties, financial or material support Brandon J. Yuan, M.D., American Association of Orthopaedic Surgeons: Board Member|DePuy, A Johnson & Johnson Company: Advisor/Consultant|Mid America Orthopaedic Association: Board Member|Stryker: Advisor/Consultant

Abstract Background Achromobacter spp. are important pathogens that are most frequently implicated in opportunistic infections, especially in patients with chronic lung disease, malignancy, and solid organ or hematopoietic stem cell transplantations. They commonly cause pneumonia, bacteremia, and device-associated infections. Intrinsic and acquired resistance mechanisms usually complicate treatment. Further characterization of the changing antibiotic susceptibilities and clinical manifestations of Achromobacter spp. are needed to improve clinical practice. Methods We performed a retrospective review of Achromobacter isolates from 2013 to 2023 in the Mayo Clinic Enterprise with available antimicrobial susceptibility testing (AST) data. Variables included sample source, collection date, and AST by agar dilution with susceptibility defined according to Clinical and Laboratory Standards Institute (CLSI) breakpoints. Samples were categorized into quartiles based on collection date and grouped into source types (respiratory, genitourinary, etc.) and AST. Results A total of 1,506 patients were identified with a total of 1,546 unique Achromobacter spp. isolates from 2013 - 2023. The most common species was A. xylosoxidans, encompassing 40.1% of all isolates (Table 1). Respiratory samples (sputum, bronchoalveolar lavage) were the most common source (57.5%), followed by musculoskeletal and soft tissue (16.4%), genitourinary (12.2%), and oropharyngeal sources (10.3%). AST from 2013 to 2023 showed persistent high levels of resistance to aztreonam and tetracycline, with stable susceptibility to piperacillin-tazobactam, trimethoprim-sulfamethoxazole, and carbapenems (Table 2). Over our 10-year analysis, there was increased resistance to aminoglycosides, fluoroquinolones, ceftazidime, and cefepime.Table 1.Achromobacter Species Identification and Isolate Percentage (%) Stratified by Year Table 1 lists the Achromobacter species identified stratified by the year each sample was collected. Each value represents the number of isolates that were identified as the listed Achromobacter species, with "Achromobacter sp." indicating an isolate without species identification. Percentages of species are listed in parentheses (%). Sample totals are listed in the right column.Table 2.Antibiotic Susceptibility of All Tested Achromobacter Isolates (Percentage of Susceptible Isolates) Table 2 lists antibiotics by class, stratified by year that Achromobacter isolates were tested. Each value is the total number of isolates tested for antimicrobial susceptibility, followed by the percentage of susceptible isolates in parentheses (%). Total isolates tested and overall susceptibility percentage is also listed over the 10-year period. Conclusion Achomobacter continues to be a clinically significant organism with a complex resistance profile. Our dataset shows a significant prevalence of non-respiratory and non-genitourinary samples, in addition to increasing resistance over many antibiotic classes. Our data suggests that piperacillin-tazobactam, imipenem, and minocycline are appropriate empiric regiments for Achromobacter. Disclosures All Authors: No reported disclosures

Abstract Background Eosinopenia has previously been studied as a predictor of bacteremia and sepsis, and has been identified as a marker of increased mortality in critically ill patients. To date, one study has examined changes in eosinophil count during bacterial infection, noting quicker normalization of eosinophil count versus traditional markers of inflammation, whereas no studies have examined eosinophil count recovery as a predictor of blood stream clearance. Methods We conducted a multicenter, retrospective cohort study of adult patients diagnosed with Staphylococcus aureus bacteremia (SAB) between January 2018 and December 2019 at Mayo Clinic campuses. Patients with eosinopenia on the date of the first positive blood culture were selected for further analysis. Eosinopenia was defined as an eosinophil count < 0.03 x10(9)/L. Eosinophil count recovery was defined as the first subsequent date where an eosinophil count ≥0.03 x10(9)/L was recorded. Clearance of SAB was defined as negative blood cultures at 48 hours on two consecutive days, and the date of clearance was defined as the date of first negative blood culture. Results A total of 213 cases of SAB were identified where an eosinophil count was obtained on date of first positive blood culture. Of these cases, 132 (62.0%) had eosinopenia at time of diagnosis. Data related to count recovery was available for 90 patients, with associated characteristics for this cohort detailed in Table 1. S. aureus isolates were oxacillin susceptible in 91.1% (82/90) of cases. The median time to clearance of bacteremia was 2.7 days (IQR 1.8-4.7 days), and the median time to eosinophil count recovery was 2.0 days (IQR 2.0-3.0 days). Data related to timing of eosinophil count recovery are presented in Table 2. Resolution of eosinopenia occurred within 48 hours of bloodstream clearance in 79/90 (87.8%) of cases and preceded or occurred within 48 hours of blood culture clearance in 88/90 (97.8%) of cases. Conclusion Eosinopenia is a common finding at time of diagnosis of SAB, and recovery of eosinophil count is suggestive of imminent clearance of blood cultures. Disclosures All Authors: No reported disclosures

Abstract Disclosure: S. Paknikar: None. J. McHugh: None. K. Rachmasari: None. I. Bancos: None. Introduction: Ectopic secretion of adrenocorticotropic hormone (ACTH) is a rare and severe form of Cushing Syndrome (CS) that requires an urgent specialized approach for diagnosis and management. Clinical Case: A 50-year-old woman was referred to endocrinology due to concern for CS. Over the previous year she had developed progressive weakness, edema, weight gain with abdominal fat redistribution, hypertension, and multiple compression fractures. On exam, she had a profound proximal myopathy, reported 10/10 pain along the spine, and was hypertensive (170/105 mm Hg) with normal other vitals. The patient's sodium was 141mmol/L [reference range 135-145 mmol/ L], potassium 4.1 mmol/L [3.6-5.2 mmol/L] while on spironolactone, and creatinine was 0.57 mg/dL [0.59-1.04 mg/dL]. Due to the severity of her symptoms, she was admitted to the hospital. Hormonal work up was consistent with an ACTH dependent CS: ACTH was 121pg/mL [7.2-63 pg/mL] and 24-hour urine cortisol was 645 mcg/24 hr [3.5-45 mcg/24 hr]. Workup for ACTH secreting tumor included a pituitary MRI which showed a 3 mm area of delayed enhancement in the pituitary gland, felt to be artifactual. A chest computed tomography (CT) showed a 1.3 cm low-density nodule in the right upper lobe concerning for a neuroendocrine tumor. A Gallium-68 DOTATATE Positron emission tomography/CT scan was performed and demonstrated that the nodule was highly DOTATATE avid (Krenning score of 3, scale of 0-4). These findings supported a diagnosis of ectopic CS caused by an ACTH secreting lung neuroendocrine tumor. Management of ectopic CS was twofold: addressing the underlying ACTH secreting lesion and urgent treatment of hypercortisolism and its consequences. In this case, this was achieved with CT-guided cryoablation of the right upper lobe nodule. The ACTH levels were monitored postoperatively, and when decreased (9.3pg/mL [ 7.2-63 pg/mL], glucocorticoid replacement therapy was initiated. As a result of prolonged hypercortisolism, the patient experienced multiple compression fractures and debility. Physical therapy was recommended for recovery from the compression fractures as well as proximal myopathy. Enoxaparin was initiated due to risk of venous thromboembolism from CS. From an osteoporosis standpoint, she was continued on calcium and vitamin-D supplementation and treated with weekly alendronate. Her hypertension improved allowing medication reduction. Postoperatively, she received education on adrenal insufficiency and biochemical monitoring for adrenal insufficiency recovery was implemented. Conclusion: Ectopic ACTH secreting tumors represent a rare cause of CS and effective management requires consideration of medical comorbidities to determine the approach: surgical, cryoablative, or medical therapy alone, mitigation of Cushing syndrome sequelae, and prompt recognition and treatment of glucocorticoid withdrawal. Presentation: Thursday, June 15, 2023

Blood culture-negative infective endocarditis (BCNE) is a challenging condition associated with significant morbidity and mortality. This review discusses the epidemiology, microbiology, diagnosis, and treatment of BCNE considering advancements in molecular diagnostics and increased access to cardiac surgery. BCNE can be categorized into bacterial endocarditis with sterilized blood cultures due to previous antibiotic treatment, endocarditis caused by fastidious microorganisms, and true BCNE caused by intracellular organisms that cannot be cultured using traditional techniques. Non-infectious causes such as nonbacterial thrombotic endocarditis should also be considered. Diagnostic approaches involve thorough patient history; blood and serum testing, including appropriate handling of blood cultures; serological testing; and molecular techniques such as targeted and shotgun metagenomic sequencing. Where available, evaluation of explanted cardiac tissue through histopathology and molecular techniques is crucial. The therapy for BCNE depends on the likely causative agent and the presence of prosthetic material, with surgical intervention often required.

Abstract Background Nocardia primarily infects patients who are immunocompromised or those with chronic lung disease. Although disseminated infection is widely recognized as an important prognostic factor, studies have been mixed on its impact on outcomes of nocardiosis. Methods We performed a retrospective cohort study of adults with culture-confirmed nocardiosis. Advanced infection was defined as disseminated infection, cavitary pulmonary infection, or pleural infection. The primary outcome was 1-year mortality, as analyzed by multivariable Cox regression. Results Of 511 patients with culture growth of Nocardia, 374 (73.2%) who had clinical infection were included. The most common infection sites were pulmonary (82.6%), skin (17.9%), and central nervous system (14.2%). In total, 117 (31.3%) patients had advanced infection, including 74 (19.8%) with disseminated infection, 50 (13.4%) with cavitary infection, and 18 (4.8%) with pleural infection. Fifty-nine (15.8%) patients died within 1 year. In multivariable models, disseminated infection was not associated with mortality (hazard ratio, 1.16; 95% CI, .62–2.16; P = .650) while advanced infection was (hazard ratio, 2.48; 95% CI, 1.37–4.49; P = .003). N. farcinica, higher Charlson Comorbidity Index, and culture-confirmed pleural infection were also associated with mortality. Immunocompromised status and combination therapy were not associated with mortality. Conclusions Advanced infection, rather than dissemination alone, predicted worse 1-year mortality after nocardiosis. N. farcinica was associated with mortality, even after adjusting for extent of infection. While patients who were immunocompromised had high rates of disseminated and advanced infection, immunocompromised status did not predict mortality after adjustment. Future studies should account for high-risk characteristics and specific infection sites rather than dissemination alone.

AbstractBackgroundSpecific pretransplant infections have been associated with poor posttransplant outcomes. However, the impact of pretransplant Nocardia isolation has not been studied.MethodsWe performed a retrospective study from three centers in Arizona, Florida, and Minnesota of patients with Nocardia infection or colonization who subsequently underwent solid organ or hematopoietic stem cell transplantation from November 2011 through April 2022. Outcomes included posttransplant Nocardia infection and mortality.ResultsNine patients with pretransplant Nocardia were included. Two patients were deemed colonized with Nocardia, and the remaining seven had nocardiosis. These patients underwent bilateral lung (N = 5), heart (N = 1), heart‐kidney (N = 1), liver‐kidney (N = 1), and allogeneic stem cell transplantation (N = 1) at a median of 283 (interquartile range [IQR] 152–283) days after Nocardia isolation. Two (22.2%) patients had disseminated infection, and two were receiving active Nocardia treatment at the time of transplantation. One Nocardia isolate was resistant to trimethoprim‐sulfamethoxazole (TMP‐SMX) and all patients received TMP‐SMX prophylaxis posttransplant, often for extended durations. No patients developed posttransplant nocardiosis during a median follow‐up of 1.96 (IQR 0.90–6.33) years. Two patients died during follow‐up, both without evidence of nocardiosis.ConclusionsThis study did not identify any episodes of posttransplant nocardiosis among nine patients with pretransplant Nocardia isolation. As patients with the most severe infections may have been denied transplantation, further studies with larger sample sizes are needed to better analyze any impact of pretransplant Nocardia on posttransplant outcomes. However, among patients who receive posttransplant TMP‐SMX prophylaxis, these data suggest pretransplant Nocardia isolation may not impart a heightened risk of posttransplant nocardiosis. image

Postdural puncture headache is a frequently encountered complication following procedures such as lumbar puncture, neuraxial anesthesia, or intrathecal drug delivery device implantation. It classically presents as a painful orthostatic headache that is exacerbated when a patient is upright. For treatment, patients are often started on conservative options such as hydration, caffeine, bedrest, and NSAID analgesics; however, certain patients who fail these therapies may require intervention with an epidural blood patch. The epidural blood patch remains the gold standard for treating refractory postdural puncture headache. Contraindications to epidural blood patch include severe coagulopathy, patient refusal, or infection at the intended site of entry. There are no clear consensus recommendations regarding patients with a hematological malignancy and potential risk that autologous blood may seed malignant cells into the neuraxis. In this case report, we present a patient with acute myeloid leukemia who developed a postdural puncture headache after receiving subarachnoid administration of antineoplastics. The patient was refractory to conservative therapy, prompting multidisciplinary consultation and discussion with the patient about the risks and benefits of proceeding with an epidural blood patch. Ultimately, the patient elected to proceed with the offered epidural blood patch which led to complete resolution of his painful headaches and did not cause any spread of malignant cells into his neuraxis or cerebral spinal fluid.