bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute Kidney Injury Associated with Combination Antimicrobial Therapy in the Medical Information Mart for Intensive Care (MIMIC) III Database
Authors: Rutter W Cliff , Burgess David S 
Published: October 2017

Abstract

Background
Increased acute kidney injury (AKI) incidence is linked with coadministration of vancomycin (VAN) and piperacillin-tazobactam (TZP) in the general hospital population when compared with VAN and cefepime (FEP); however, this phenomenon was not found in critically ill patients.

Methods
Patients receiving VAN in combination with FEP or TZP for at least 48 hours during an intensive care unit stay were included in this retrospective review. AKI was defined with the Risk, Injury, Failure, Loss, and End-stage (RIFLE) criteria. Exposure to common nephrotoxins was captured within 24 hours of combination therapy initiation through the entire treatment window. Basic descriptive statistics were performed, along with bivariable and multivariable logistic regression models of AKI odds.

Results
In total, 2230 patients were included, with 773 receiving FEP+VAN and 1457 receiving TZP+VAN. The groups were well balanced at baseline in most covariates, with the exception of hepatorenal syndrome diagnosis (TZP+VAN 1.4% vs. FEP+VAN 0.3%, P = 0.02) and vasopressor exposure (TZP+VAN 26.2% vs 21.5%, P = 0.01) being more common in the TZP+VAN group. Patients in the FEP+VAN group had a higher underlying severity of disease (Charlson comorbidity index [CCI] 2.7 vs. 2.3, P =0.0002). AKI incidence was higher in the TZP+VAN cohort (35.1% vs. 26.5%, P = 0.00004), with each stratification of the RIFLE criteria being higher. The time until onset of AKI was similar between groups (TZP+VAN median 1 [0–3] days vs. FEP+VAN 1 [0–4] days, P =0.2). After multivariable logistic regression, TZP+VAN therapy was associated with an adjust odds ratio (aOR) of AKI of 1.54 (95% confidence interval [CI] 1.25–1.89) compared with FEP+VAN. Other variables associated with increased odds of AKI included: age &gt;= 65, duration of antibiotic therapy, higher baseline renal function, sepsis, endocarditis, hepatorenal syndrome, thiazide diuretic exposure, and increased CCI.

Conclusion
Treatment with TZP+VAN is associated with significant increases in AKI incidence among critically ill patients, independent of other risks for AKI.

Disclosures
All authors: No reported disclosures.
Impact of Vancomycin-Associated Acute Kidney Injury on Patient Outcomes in MRSA Bacteremia
Authors: Luther Megan , Timbrook Tristan , Lopes Vrishali , Caffrey Aisling , LaPlante Kerry 
Published: October 2017

Abstract

Background
Acute kidney injury (AKI) is a well-known adverse effect of vancomycin. Varying degrees and causes of AKI have demonstrated different effects on patient outcomes. Since AKI with vancomycin is typically reversible, we investigated how AKI associated with vancomycin therapy impacts patient mortality and time to discharge.

Methods
Unique patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and who received at least one dose of vancomycin were identified in a national Veterans Affairs cohort from January 1, 2002 to October 14, 2015. Patients with a history of dialysis in the previous year and those with AKI on admission were excluded. AKI was defined according to RIFLE criteria, as an increase in serum creatinine (SCr) of 0.5 mg/dL or 1.5× from the admission SCr, on a day they received vancomycin. Patient characteristics including demographics and comorbidities defined by ICD9 codes were compared between groups. Effect estimates for inpatient mortality were determined with a backward stepwise logistic regression model in SAS 9.2. For patients without inpatient mortality, time to discharge was analyzed using Wilcoxon rank-sum test.

Results
There were 7691 included patients with MRSA bacteremia, and 23.8%&#x2028;(n = 1830) developed AKI during therapy. Mean age was 66.7 (±12) years and 97.8% (n = 7525) were male. Patients with AKI were more likely to have congestive heart failure, diabetes, chronic kidney disease, and to be admitted to the intensive care unit (all P &lt; 0.001). Overall inpatient mortality was 17.7% (n = 1361). The crude odds of inpatient mortality were 67% higher in patients with AKI. In the adjusted model, AKI was an independent predictor of mortality (OR 1.19, 95% CI 1.02–1.40, P &lt; 0.03). Median (IQR) time to discharge was 11 (6–19) days without AKI and 18 (11–31) days with AKI (P &lt; 0.0001).

Conclusion
Vancomycin-associated AKI is associated with increased inpatient mortality and longer time to discharge. Further research is needed to compare clinical outcomes for other groups of patients, and to determine the impact of monitoring interventions to improve safety and decrease AKI.

Disclosures
A. Caffrey, Merck: Grant Investigator, Grant recipient The Medicines Company: Grant Investigator, Grant recipient Pfizer: Grant Investigator, Grant recipient K. LaPlante, Merck: Grant Investigator, Grant recipient Pfizer: Grant Investigator, Grant recipient Cempra: Scientific Advisor, Consulting fee The Medicines Company: Grant Investigator, Grant recipient Allergan: Scientific Advisor, Consulting fee Bard/ Davol: Scientific Advisor, Consulting fee Ocean Spray: Grant Investigator and Scientific Advisor, Consulting fee and Grant recipient Zavante: Scientific Advisor, Consulting fee Achaogen: Scientific Advisor, Consulting fee
National Cohort Study of Preoperative Bacteriuria, Surgical Prophylaxis, and Postoperative Outcomes
Authors: GallegosSalazar Jaime , Strymish Judith , Branch-Elliman Westyn , Itani Kamal , O’Brien William , Gupta Kalpana 
Published: October 2017

Abstract

Background
Despite recommendations against screening urine for bacteriuria prior to non-urological surgery, it is still a common practice. If the urine culture (Ucx) is positive, clinicians often feel compelled to give targeted therapy or expand the peri-operative prophylaxis (PPX) regimen to cover the urinary organism. Large multicenter studies are lacking. We aimed to evaluate rates and results of preoperative urine screening and postoperative outcomes among a national cohort of surgical patients.

Methods
All patients who underwent cardiac, orthopedic implant, or vascular surgery within the national VA health care system during the period from 10/1/08–9/30/13 and had the PPX regimen manually validated were included. Rates of positive Ucx and wound cultures during the 90-day post-operative period were compared between patients with and without pre-operative bacteriuria. Among patients with a positive pre-op urine culture the association between activity of surgical PPX and positive post-op cultures was evaluated.

Results
N = 78,810 surgeries were evaluated (21,889 cardiac, 46,565 orthopedic implant, 10,356 vascular). A pre-op Ucx was performed in 26% (Fig); of these, 6.6% were positive and 852 (63%) received PPX active against the uropathogen. Positive pre-op Ucx was associated with higher rates of positive post-op Ucx and wound cultures (Fig). Among patients who received active PPX, post-op Ucx was positive in 46% compared with 39% who received inactive PPX. The rate of post-op wound cultures was not different between patients who received active (25%) vs. inactive (24%) PPX. The pre-op and post-op organisms were the same in 117/221 (52.9%) Ucx and 17/104 (16.3%) wound cultures, respectively. PPX activity did not affect the match rate.

Conclusion
This is the largest, multicenter study demonstrating no difference in post-op urine and wound cultures in patients receiving active vs. inactive surgical PPX for pre-op bacteriuria. Prevalence of bacteriuria was similar to other surgical populations. Limitations include predominantly male population and need for further characterization of pre-op antibiotic therapy and UTI and SSI outcomes.

Disclosures
All authors: No reported disclosures.
Susceptibility Trends of Urinary Tract Infections Over a 15 Year Period on a University Campus
Authors: Hoffmann Wesley , Donnelley Monica , Ferguson Thomas 
Published: October 2017

Abstract

Background
Acute uncomplicated cystitis (AUC) is one of the most common infections for which antimicrobials are prescribed. Despite IDSA AUC guideline recommendations, prescribing practices are varied throughout the US. Per IDSA recommendations, nitrofurantoin (NTF), fosfomycin, and trimethoprim/sulfamethoxazole (TMP/SMX) are all considered first line therapy for AUC, however there is concern of resistance to some of these agents. Quality improvement activity at the University of California, Davis Student Health Center (UCDSHC) has made prescribing NTF preferred for acute cystitis since 2001 as TMP/SMX has community resistance rates of ~20%. Ciprofloxacin is the second line agent at UCDSHC.

Methods
UCDSHC reviewed all urine cultures and susceptibilities for clinical and epidemiologic purposes. Susceptibility results were gathered from the UCDSHC microbiology laboratory from 2001–2016. Prescribing data was obtained from UCDSHC under diagnosis codes consistent with cystitis or UTI to demonstrate antibiotic prescribing trends. Susceptibilities were evaluated over the 15-year time period (2001–2016). TMP/SMX, FQ’s, and NTF were the primary agents evaluated in this study.

Results
From 2001–2016, 3,831 E. coli and 296 S. saprophyticus isolates were evaluated, accounting for 88% of the total number of organisms. E. coli susceptibilities to NTF remained &gt;98% from 2001–2016. E. coli susceptibilities to FQ’s trended down from 99% in 2001 to 88% in 2016. E. coli susceptibilities to TMP/SMX remained stable around 80% from 2001–2016. S. saprophyticusremained highly susceptible to NTF, FQ’s, and TMP/SMX (95%, 97%, and 100% respectively at the end of the study period). In total, 12,298 prescriptions were written from 2008–20016. Eighty percent (9,875) were NTF and 17% (2,016) were FQ’s. The remaining 1% and 2% were TMP/SMX and ‘Other’, respectively.

Conclusion
After changes in prescribing practice in 2001, NTF was used in 80% of cystitis cases over 15 years and retained excellent activity against common urinary pathogens. FQ’s retained acceptable activity for empiric use for urinary tract infections, but susceptibilities trended down notably despite limited FQ use. TMP/SMX did not regain increased activity over the time period.

Disclosures
All authors: No reported disclosures.
Poor Clinical Outcomes Associated with Community-Onset Extended-Spectrum Cephalosporin-Resistant Enterobacteriaceae Urinary Tract Infections
Authors: Anesi Judith , Lautenbach Ebbing , Nachamkin Irving , Garrigan Charles , Bilker Warren , Dankwa Lois , Wheeler Mary K , Tolomeo Pam , Han Jennifer 
Published: October 2017

Abstract

Background
Urinary tract infections (UTIs) are the most common bacterial infection among adults in the community. Recent data suggest an increase in bacterial resistance to first line antibiotics used for UTI, though the impact on clinical outcomes is unclear. The objective of our study was to determine clinical outcomes associated with community-onset extended-spectrum cephalosporin-resistant (ESC-R) Enterobacteriaceae (EB) UTI.

Methods
A retrospective cohort study was conducted in a large health system from 2010 to 2013. All patients presenting to an emergency department or outpatient clinic with UTI due to EB were included. Exposed subjects were those with an EB demonstrating resistance to an ESC (ceftriaxone or ceftazidime). Unexposed subjects were those with ESC-susceptible EB UTIs and were matched to cases 1:1 based on study year. Multivariable logistic regression analyses were performed to evaluate the association between ESC-R EB UTI and 1) clinical failure (defined as ongoing symptoms, repeat positive culture, or need for additional antibiotics within 7 days); 2) inappropriate initial antibiotic therapy (IIAT) (defined as failure to receive an antibiotic to which the organism was susceptible within 48 hours of presentation).

Results
A total of 302 patients with community-onset EB UTI were included. On multivariable analyses, a UTI with an ESC-R EB was significantly associated with clinical failure (odds ratio [OR] 5.12, 95% confidence interval [CI] 2.79–9.39, P &lt; 0.01). Other variables independently associated with clinical failure included presence of pyelonephritis at the time of UTI diagnosis (OR 2.15, 95% CI 1.14–4.03, p 0.02) and infection with Citrobacter species (OR 29.56, 95% CI 4.46–195.91, P &lt; 0.01). ESC-R EB UTI was also associated with IIAT on multivariable analysis (OR 3.73, 95% CI 2.25–6.21, P &lt; 0.01).

Conclusion
Community-onset UTI due to an ESC-R EB organism is associated with a significantly increased risk of clinical failure, which may be due in part to the use of inappropriate initial antibiotic therapy. Further studies are needed to determine which patients in the community are at high risk for drug-resistant infection to help inform prompt urine culture ordering and appropriate antibiotic prescribing for ESC-R EB.

Disclosures
All authors: No reported disclosures.
Antibiotic Susceptibilities and Appropriateness of Initial Drug Selection for Community-Acquired Urinary Tract Infections (UTI) Caused by Extended-Spectrum Β-Lactamase (ESBL)-Producing Pathogens
Authors: Lee Stephen , Fish Douglas N , Barber Gerard , Barron Michelle 
Published: October 2017

Abstract

Background
Community-acquired (CA) UTI caused by ESBL-producing pathogens pose challenges related to initial antibiotic (AB) selection. Better characterization of AB susceptibilities in CA ESBL infections may improve empiric drug selection for outpatient therapy. The objectives of this study were to describe AB susceptibilities of isolates in CA ESBL UTI and provide recommendations for appropriate treatment at our institution.

Methods
Adult patients with CA ESBL UTI (cystitis) from 2009 through 2013 were retrospectively matched 1:1 with a control group of non-ESBL CA UTI based on age within 5 years, gender, and organism. The primary outcome in this phase of the study was description of AB susceptibilities in CA ESBL UTI vs. controls. Secondary outcomes were comparison of appropriate initial AB therapy (defined as concordance of initial AB with in vitro susceptibilities) and development of recommendations for initial antibiotics for CA UTI.

Results
Eighty-five patients were matched into each of the ESBL and non-ESBL CA UTI groups. E. coli was the pathogen in 94% of ESBL UTIs and 96% of controls. Patients with ESBL UTI most often received ceftriaxone or oral β-lactam (BL, 31%), fluoroquinolone (FQ, 27%), trimethoprim/sulfamethoxazole (TMP/SMX, 14%), or nitrofurantoin (NF, 14%); controls were similar. Besides non-carbapenem BLs, ESBL producers were significantly more resistant to FQs (78% resistant), NF (16%), TMP/SMX (60%), gentamicin (33%), and doxycycline (78%) vs. controls (P &lt; 0.01 for each). Ertapenem and amikacin had 100% and 96% susceptibility, respectively. Initial AB were discordant in 64% of ESBL UTI vs. 14% of controls (OR 11.0, 95% CI 5.0–24.3; P &lt; 0.0001). FQs and TMP/SMX were discordant in 83% and 42% of ESBL UTI, respectively, while NF was concordant in 100% of patients with ESBL UTI and 89% of controls.

Conclusion
Patients with CA ESBL UTI were significantly more likely to receive inappropriate initial AB therapy. Although ESBL-producing strains were resistant to multiple AB classes, NF retained activity against 84% of ESBL isolates and was associated with appropriateness of initial therapy in 100% of patients with ESBL UTI. Nitrofurantoin is an appropriate oral option for treatment of CA UTI, even in patients with ESBL infection.

Disclosures
D. N. Fish, Merck & Co.: Grant Investigator, Research grant M. Barron, Merck & Co.: Grant Investigator, Research grant
Significance of Prior Culture History for Predicting Urinary Tract Infection Caused by Multi-drug Resistant Enterobacteriaceae
Authors: Bohan Jefferson , Remington Richard , Madaras-Kelly Karl 
Published: October 2017

Abstract

Background
Extended-spectrum β-lactamase (ESBL) -producing E. coli, Klebsiella spp., and Proteus spp. (EKP), that cause urinary tract infections (UTI) are resistant to first-line therapies (e.g., ceftriaxone). Prediction of UTI caused by ESBL-producing organisms is important for selection of empirical therapy. The objective was to develop a prediction model to identify UTI caused by ceftriaxone (CRO)-resistant EKP and compare the model to other commonly cited predictive models (Tumbarello M et al. AAC Jul 2011; Johnson SW et al. ICHE Apr 2013).

Methods
A single-center, matched, case–control of Veterans Affairs (VA) outpatients with a positive (≥10^4 CFU/mL) urine culture was conducted. Patients were excluded if they had no UTI diagnosis or documented symptoms, age &lt;18, transfer from another hospital, or a significant urine culture result. Cases were defined as any patient with a CRO-resistant EKP; controls were matched 4:1 to cases based on incident density (≤ 30 days) by random selection. Logistic regression and receiver operator curves were used to develop and assess models.

Results
One hundred subjects were included in the analysis. Demographics were similar except for age [Case 73.5 years (13.7); Control 64.5 years (15.2); P = 0.02] and history of CRO-resistant EKP in last 6 months (Case 40%; Control 0%; P &lt; 0.01). Predictor variables in the final model (Likelihood Ratio 44.2, P &lt; 0.01) included history of CRO-resistant EKP in last 6 months (131.5, 12.2–18308.0), cephalosporin use in past 60 days (12.7, 1.9–94.5), residence in a skilled nursing or assisted living facility (8.0, 1.6–40.5), and hospitalization in last 6 months (OR 3.0, 95% CI 0.7–12.5). In the VA population, the other models predicted significantly although less accurately (Figure 1).

Conclusion
Prior cephalosporin use, hospitalization, and residence were important predictors of UTI caused by CRO-resistant EKP; however, prior history of CRO-resistant EKP was the most important predictor. A Model that included prior culture results predicted CRO-resistant UTIs better than other commonly cited models that do not contain prior ESBL history. Prior culture data should be considered when selecting empirical antibiotics for UTI. Validation in a larger cohort is warranted.

Disclosures
All authors: No reported disclosures.
Percutaneous Nephrostomy Tube-related Infections
Authors: El Haddad Hanine , Viola George , Jiang Ying , Raad Issam , Rolston Kenneth V , Szvalb Ariel 
Published: October 2017

Abstract

Background
Percutaneous nephrostomy tubes (PCN) are indicated for relief of urinary tract obstruction. These devices are prone to mechanical and infectious complications. The infection rate at 90 days is ±20%. Our objective was to determine whether discordant antimicrobial coverage provided prior to PCN exchange was associated with a higher rate of recurrent infection compared with those who received concordant therapy.

Methods
We retrospectively reviewed 780 patients that had undergone initial PCN placement at our institution between July 2014 and February 2017. We only included patients that had developed a definite PCN infection, subsequent PCN exchange, with a minimum 30 day post-PCN exchange follow up. We defined PCN infection as the presence of a positive urine culture (≥104 cfu/mL) plus symptoms consistent with a urinary tract infection. Recurrence was defined as a new PCN infection with the isolation of the same organism to the initial episode. Antibiotics were defined as concordant if they had activity against all organisms’ isolated based on antimicrobial susceptibilities.

Results
A total of 47 patients met our inclusion criteria. The median age of patients was 59, with 49% being male. The most common underlying tumors were urothelial (45%), cervical (17%) and prostate cancer (15%). Clinical characteristics included ureteral stents (17%), diabetes (19%), history of GU surgery (38%), and active chemotherapy at the time of PCN insertion (70%). The median time to onset of infection was 42 days. Infections were polymicrobial in 50% of the cases. The most common organisms encountered were Pseudomonas spp. (36%), Enterococcus spp. (23%) and Escherichia coli (18%). The median length of follow up of PCN tubes after exchange was 55 days. There were 12 (26%) recurrences occurring at a median time of 27 days. The provision of discordant antibiotics preceding PCN exchange was significantly associated with recurrence of infection (66.7% vs. 12.8%; P &lt; 0.002).

Conclusion
Discordant antimicrobial therapy provided during PCN exchange, in the setting of a PCN infection is associated with a higher rate of relapse. Therefore, to decrease the high rate for PCN reinfection, we propose that prior to PCN exchange secondary to infection, patients should be receiving concordant antimicrobial therapy.

Disclosures
All authors: No reported disclosures.
Characterizing Clinical Demographics, Susceptibility Patterns, and Development of Resistance in Raoultella ornitholytica Infections in Southern Virginia
Authors: Fuh Jennifer , Kouchakzadeh Katayoun , McDaniel Kori , Desai Balaji 
Published: October 2017

Abstract

Background
Raoultella ornitholytica (R. ornitholytica) is a waterborne Gram-negative bacilli increasingly found in hospitals. Multi-drug resistance has been reported, including to carbapenems. Our objective was to identify demographics of R. ornitholytica at Danville Regional Medical Center (DRMC) to determine predisposing factors to infection and potential antibiotic resistance.

Methods
Cultures positive for R. ornitholytica were identified through DRMC’s electronic medical records (EMR) from 1/2010 to 3/2017. Site of infection, concurrent infections, isolate susceptibilities, prior antibiotic exposure, and appropriateness of treatment were extracted from the EMR. Healthcare associated was defined as occurring in the hospital, nursing home, long-term acute care, or inpatient rehabilitation facility within the past 90 days. Those with diabetes, cancer, and end stage renal disease (ESRD) were qualified as immunosuppressed.

Results
Thirty-two cases were isolated, of which 20 had associated clinical data. One urine isolate was consistent with colonization. Of the 19 infections, the majority (n = 15) were urinary tract infections (UTIs) and one case each from bronchial washing, heel wound, blood culture, and vulvar lesion. Clinical demographics are shown in Figure 1. Thirteen (65%) had concurrent infections, of which 5 (26%) were co-infected with Enterococcus faecalis, one which was vancomycin resistant. Three had chronic Foley catheters, constituting 20% of the UTIs. Susceptibilities are reported in Figure 2. Prior antibiotic use is shown in Figure 3.

Conclusion
Most of the isolates from our institution were relatively sensitive, with most resistance to ampicillin. Two isolates were pansensitive, however one case was sensitive only to nitrofurantoin and ertapenem. All isolates which were resistant to cefazolin and ceftriaxone had prior exposure. The elderly and diabetics had the greatest association with infection. A majority of patients had a concurrent infection, which may suggest this as an opportunistic organism. Our findings warrant further studies to better characterize clinical associations and development of resistance in response to prior antibiotic exposure.

Disclosures
All authors: No reported disclosures.