Positive BCx Research Articles

The Yield, Safety, and Cost-effectiveness of Decreasing Repeat Blood Cultures Beyond 48 Hours in a Pediatric Hematology-Oncology Unit.

Clear recommendations are needed on when repeat blood cultures (BCxs) in hospitalized children with cancer should be obtained. We reviewed all BCx obtained on the Hematology-Oncology Unit at Riley Hospital for Children, regardless of reason for patient admission or neutropenia status, between January 2015 and February 2021. Patients with positive BCx within 48 hours of initial cultures, history of stem cell transplant, or admitted to the intensive care unit were excluded. Medical records of patients with new positive BCx drawn >48 hours after initial BCx were reviewed. Seven (1.2%) hospitalization episodes grew new pathogens, or commensals treated as pathogens, on cultures beyond 48 hours. All patients with new, true pathogens were hemodynamically unstable or had recurrent fever when the new positive BCx was obtained. Twenty-three (4.0%) hospitalization episodes had contaminant cultures beyond 48 hours, with 74 (5.4%) of 1362 BCx collected beyond 48 hours being contaminated, resulting in an additional cost of $210,519 from increased length of stay. In conclusion, repeat BCx beyond 48 hours in pediatric hematology-oncology patients with negative initial cultures are low yield and costly. Repeat BCx can be safely and cost-effectively ceased after 48 hours of negative cultures in hemodynamically and clinically stable patients.

1340. Yield of Repeat Blood Cultures beyond 48 Hours after Negative Initial Cultures in Patients Hospitalized on a Pediatric Hematology/Oncology Unit

Abstract Background Repeat blood cultures (BCxs) beyond 48 hours are often obtained despite negative initial BCxs in hospitalized pediatric hematology/oncology patients. This study seeks to determine the yield of repeat BCxs after negative initial cultures in these patients and to characterize new positive BCxs beyond 48 hours and the clinical contexts in which they were obtained. Methods A retrospective review utilizing MedMined Inc. Data Mining Surveillance database was conducted on all BCxs obtained on hospitalized patients on the pediatric hematology/oncology unit at Riley Hospital for Children in Indianapolis, IN from January 2015 to February 2021. Exclusion criteria are shown in Fig. 1. Patient episodes in which a new pathogen (or commensal treated by the primary team as a pathogen) was identified on a repeat BCx more than 48 hours after negative initial BCxs were further investigated via electronic medical record review. Results A total of 1,362 BCx sets were obtained beyond 48 hours in 792 patient hospitalizations, resulting in 303 positive BCxs (Fig. 2). Of these positive cultures, 193 were the same pathogen cultured on day 0 and 74 were contaminant cultures (in 4.0% (23/573) of patient hospitalizations without a positive BCx before 48 hours). Only 36 (2.6%) of positive BCxs beyond 48 hours were determined to be new pathogens, or commensals treated as pathogens, that were not cultured before 48 hours, corresponding to seven patient hospitalizations (1.2% (7/573) of patient hospitalizations without a positive BCx before 48 hours). The majority (6/7) of these patients were neutropenic and on broad spectrum antibiotics when the new positive BCxs were obtained. Fever pattern was prolonged in one patient and recurrent in six. No deaths occurred in these seven patients. All patients with new, true pathogens on BCxs beyond 48 hours (n=5) were either hemodynamically unstable (n=3) or had clinical changes (n=2, mucositis, diarrhea) the day the new positive BCx was drawn. Conclusion The yield of repeat BCxs beyond 48 hours in hospitalized pediatric hematology/oncology patients with negative initial BCxs is low, while the associated costs are high. Repeat BCxs beyond 48 hours after negative initial cultures need not be obtained in febrile patients that remain hemodynamically stable and without clinical changes. Disclosures Cassandra S. Prather, MD, Eli Lilly and Company: Spouse is employed by Eli Lilly and Company. Spouse owns stock in the company.|Eli Lilly and Company: Stocks/Bonds.

912. Impact of Rapid Identification and Stewardship Intervention on Coagulase-negative Staphylococcus Bloodstream Infection (BSI)

Abstract Background Coagulase-negative staphylococci (CoNS) are commonly isolated from blood cultures (BCx). Most do not require treatment (tx), yet antibiotics are frequently initiated. Workup of CoNS BSI consumes significant resources. We aimed to demonstrate the safety and efficacy of an early algorithm-based rapid diagnostic testing (RDT) plus antimicrobial stewardship (ASP) intervention. Methods BCx with CoNS were captured in 3 time periods to represent pre-RDT, RDT-only, and RDT+ASP. GenMark ePlex RDT was implemented for all Gram-positive BCx, identifying S. epidermidis and other non-aureus/lugdunensis Staphylococcal species. Results were called to ASP in both RDT-only and RDT+ASP periods. In the latter, a prospective algorithm was implemented to standardize ASP recommendations (Fig 1) for cases classified as simple, uncomplicated, and complicated BSI. The primary outcome was receipt of < 24h of antibiotic tx. Safety outcomes included rates of recurrent BSI and hospital readmission. Results 184 patients were included (Fig 2). The median age was 62, 54% were male, and the median Charlson comorbidity index was 5. 41% had a central venous catheter at time of BSI. Overall, 67%, 19%, and 12% of cases were classified as simple, uncomplicated, or complicated BSI, respectively (Fig 3). BSI class and patient demographics did not vary between periods. During pre- and post-RDT periods, median days of antibiotic tx did not vary significantly for patients with simple BSI (1.1 vs 1.2). In contrast, median days of tx were reduced to 0 (P=0.005) for simple BSI in the RDT+ASP period. Overall, 54% of patients with CoNS BSI received < 24h of tx in RDT+ASP time period compared to 34% (P=0.009) in the combined pre-RDT and RDT-only periods. Tx was entirely avoided in 28% of CoNS BSI cases in the RDT+ASP period compared to 16.5% of cases in other periods (P=0.07). 7 cases classified as simple were reclassified as uncomplicated or complicated after further work up. Rates of recurrent BSI and 30-day readmission were comparable across time periods. Conclusion Our algorithm-based ASP + RDT intervention reduced antibiotic tx for CoNS BSI, an effect not realized with RDT alone. These data attest to the safety and efficacy of early ASP intervention for patients with CoNS BSI identified by RDTs at the time of positive BCx. Disclosures J Ryan Bariola, MD, Infectious Disease Connect: Salary support|Merck: Grant/Research Support Tina Khadem, PharmD, Infectious Disease Connect: Salary support|Merck: Grant/Research Support Brian Potoski, PharmD, BCPS-AQ ID, Merck Group: Grant/Research Support Ryan K. Shields, PharmD, MS, Infectious Disease Connect: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Roche: Grant/Research Support.

The Sepsis Bundle Effect: An Evaluation of Culture Results and Utilization in Pediatric Appendicitis.

Sepsis prevention pathways, which often include blood and urine cultures, are common in children's hospitals. Fever and tachycardia, signs often seen in patients with appendicitis, frequently trigger these pathways. We hypothesized that cultures were frequently obtained in children with appendicitis. We conducted a single-center retrospective cohort study evaluating children with image-confirmed appendicitis from 4/1/2019 to 10/1/2020, coinciding with the initiation of sepsis prevention pathways. Factors associated with culture acquisition, as well as culture results, treatment, and outcomes were evaluated. Six hundred and fifty eight children presented with acute appendicitis during the 1.5-year period, with a median age of 10.67 years (interquartile range (IQR) 8.17-14.08). Cultures were obtained in 22.9%, including blood culture (BCx) in 8.1% and urine culture (UCx) in 17.9%. Culture acquisition decreased by 17.6% after sepsis protocol initiation. Blood culture acquisition correlated with fever (P = .003) and younger age (P = .03), whereas the attainment of BCx and UCx was associated with female sex (P = .04, P < .0001), complicated appendicitis (P = .0001, P = .03), and unknown diagnosis (P < .0001, P < .0001). There were five positive UCx (4.24%); however, all remained asymptomatic despite a short antibiotic duration dictated by institutional appendicitis protocol. The one positive BCx (1.89%) was suspected contamination and not treated. The findings of this cohort suggest a low incidence of positive culture as well as lack of impact on clinical management in image-proven appendicitis and the initiation of a sepsis bundle without automatic culture acquisition may result in decreased culture attainment.

A Diagnostic Stewardship Intervention To Improve Blood Culture Use among Adult Nonneutropenic Inpatients: the DISTRIBUTE Study.

Interventions to optimize blood culture (BCx) practices in adult inpatients are limited. We conducted a before-after study evaluating the impact of a diagnostic stewardship program that aimed to optimize BCx use in a medical intensive care unit (MICU) and five medicine units at a large academic center. The program included implementation of an evidence-based algorithm detailing indications for BCx use and education and feedback to providers about BCx rates and indication inappropriateness. Neutropenic patients were excluded. BCx rates from contemporary control units were obtained for comparison. The primary outcome was the change in BCxs ordered with the intervention. Secondary outcomes included proportion of inappropriate BCx, solitary BCx, and positive BCx. Balancing metrics included compliance with the Centers for Medicare and Medicaid Services (CMS) SEP-1 BCx component, 30-day readmission, and all-cause in-hospital and 30-day mortality. After the intervention, BCx rates decreased from 27.7 to 22.8 BCx/100 patient-days (PDs) in the MICU (P = 0.001) and from 10.9 to 7.7 BCx/100 PD for the 5 medicine units combined (P < 0.001). BCx rates in the control units did not decrease significantly (surgical intensive care unit [ICU], P = 0.06; surgical units, P = 0.15). The proportion of inappropriate BCxs did not significantly change with the intervention (30% in the MICU and 50% in medicine units). BCx positivity increased in the MICU (from 8% to 11%, P < 0.001). Solitary BCxs decreased by 21% in the medicine units (P < 0.001). Balancing metrics were similar before and after the intervention. BCx use can be optimized with clinician education and practice guidance without affecting sepsis quality metrics or mortality.

3:45 PM Abstract No. 360 Predictors of catheter-related infections of tunneled lines in the inpatient setting

Inpatients with central venous catheters (CVCs) that show signs of local or systemic infection may undergo CVC removal followed by catheter tip culture for confirmation of catheter-related infections (CRI) and catheter-related bloodstream infections (CRBSI), as defined by positive catheter tip culture with a congruent positive blood culture. The use of this test has dwindled over the past decade, owing to factors including reimbursement penalties, poor predictive value, and increased reliance on blood cultures (BCx). We aim to develop a clinical risk calculator to reduce unnecessary removal and catheter tip culture. This IRB-approved retrospective study examined 151 patients in the inpatient setting who underwent tunneled CVC removal and tip culture. The primary outcome was the presence of CRI as defined by a positive catheter tip culture. Subgroup analysis was performed to determine which clinical factors results influenced the presence of CRI. All analyses were performed using χ2 analysis, and binary logistic regression with backward elimination. In this cohort, the median age at placement was 52 years, and median catheter-days was 98 days. Of the 151 lines removed, 32 patients (21%) had CRBSI and 43(29%) of catheter tips were culture positive. Variables predictive of CRI were gram-positive BCx prior to line removal and access site purulence (OR = 2.2 and OR = 4.0, P < 0.05). Variables that were not predictive of CRI included: fungal BCx, access site and laterality, CVC type, white count, placement indication, catheter tip location, signs of systemic infection, tenderness, and erythema. While not in the final model, CVC cultures with gram-negative organisms were related to the absence of CRIs (χ2 value = 3.6, P < 0.05). In this population, it is important to discern high-risk patients. Our model demonstrates feasibility of a risk calculator in the setting of possible CRI. When choosing a course of action, clinicians may consider removing CVCs in the presence of purulence or gram-positive BCx, and conversely, treating through non-gram positive BCx infections. Limitations of the study include cohort size and antibiotics given before cultures.

161. Evaluating the Predictive Value of Blood Culture Bottle Reporting for Coagulase Negative Staphylococci-Positive Cultures: Assessing Contamination vs. True Bacteremia

BackgroundCoagulase-negative staphylococci (CoNS) are common blood culture (BCx) contaminants, but can also be causes of true blood stream infection (BSI). As a result, the clinical interpretation of CoNS positive BCx poses a significant challenge for providers and drives unnecessary antibiotic use, extended lengths of stay, and increased hospital costs. Despite these challenges, little is known about whether the number of positive BCx bottles within a set can be used to predict contamination vs. true BSI.MethodsThis study was conducted in an 865-bed tertiary care academic medical center in Richmond, VA. A retrospective chart review of CoNS-positive BCx from October to December 2018 was performed. Data collection included patient demographics, number of positive bottles within a set (i.e., were 1 or 2 bottles positive), care setting, antibiotic use, clinical judgement of contamination, and additional workup following the positive BCx result. Polymicrobic BCx were excluded.Results50 patients (mean age 58.2 years, 60% male) with CoNS-positive BCx were included in this study. Forty (80%) of the cultures had only 1 of 2 BCx bottles positive within a set. 10 (20%) were positive from both bottles in the set. All patients were drawn in the Emergency Department and 90% were subsequently admitted to the hospital. Upon chart review, 47 (94%) and 3 (6%) of cultures were considered to be contaminants and real BSI, respectively. Of those judged to be contaminants, 10 (20%) were positive in both bottles within a set, and thus falsely suggested true BSI. Of the 3 judged to be true BSI, 2 (66%) were positive in 1 out of 2 bottles, and thus falsely suggested contamination.42 (84%) patients had repeat BCx drawn following the initial positive culture, and 26 (52%) were continued on IV antibiotics. Forty (80%) of the cultures were judged contaminants by the primary medical service, and 77% stopped antibiotics (20/26) when CoNS was identified.ConclusionThese data show that reporting the number of bottles which are positive within a set provides misleading information and should not be used to determine whether a culture result represents contamination or true BSI.Disclosures All authors: No reported disclosures.

192. Augmenting Utility of Rapid Diagnostic Testing in Treatment of Gram-Negative Bacteremia with Stewardship Intervention

BackgroundRapid diagnostic tests (RDT) can identify pathogens in bloodstream infections (BSI) in less than 24 hours. Our institution utilizes an RDT for blood cultures (BCx) that can detect various organisms and resistance determinants. A retrospective evaluation conducted in our institution calculated the negative predictive values (NPV) of various Gram-negative pathogens and susceptibility to target antimicrobials in the absence of detected resistance markers. Resultant NPV >90% for E. coli and K. pneumoniae to ceftriaxone support use of RDT with stewardship intervention for more rapid de-escalation of antimicrobial therapy in patients with resistance marker-negative BSI.MethodsIn our facility, all positive BCx are processed through RDT. In the post-intervention group, pharmacists monitored RDT results and provided recommendations. Our IRB-approved, prospective study assessed time to antimicrobial de-escalation in treatment of resistance marker-negative E. coli and K. pneumoniae BSI before (January 1 to December 31, 2018) and after Stewardship intervention (January 1 to March 31, 2019). Secondary outcomes included days of therapy (DOT) of target narrow-spectrum β-lactams, carbapenems, and non-carbapenem anti-pseudomonal (NCAP) β-lactams, length of stay (LOS), and treatment failure. Data were analyzed using the Fisher exact or Chi-square and t-test for categorical and continuous data, respectively.ResultsOf the 12,893 evaluated RDT results in the pre-intervention group and 2,238 post intervention, 41 and 12 patients met inclusion criteria, respectively. Baseline characteristics were similar in both groups. Time to de-escalation to a target agent was decreased by 24 hours after stewardship intervention (50 v 74.6 hours) (P = 0.14). There were no statistically significant differences in DOTs for target agents (5.19 v 5.25 DOT; P = 0.48), carbapenems (1.29 v 1.08 DOT; P = 0.41), or NCAP β-lactams (1.73 v 2.33; P = 0.25). Treatment failure (2 in each group; P = 0.17) and LOS (10.9 v 11.9 days; P = 0.4) were similar between groups. Protocol compliance and intervention acceptance rate was approximately 60%.ConclusionAppreciation of NPVs and utilization of stewardship intervention allowed for early de-escalation of empiric therapy in patients with resistance marker-negative E. coli and K. pneumoniae bacteremia. Disclosures All authors: No reported disclosures.

1877. Discrepant Susceptibilities Have Minimal Impact on Antibiotic Prescribing for Patients With Two or More Blood Cultures Positive for Coagulase-Negative Staphylococci

BackgroundCoNS are common blood culture (BCx) contaminants resulting in unnecessary antibiotic therapy. Species reporting of CoNS is now possible in many medical centers due to new technology. When CoNS are isolated from multiple BCx, factors such as different susceptibility patterns and/or different species might suggest contamination. The purpose of this study was to characterize antibiotic usage attributable to CoNS positive BCx and to determine whether reporting of CoNS species could help reduce unnecessary antibiotics.MethodsInpatients from January to June 2017 at our institution were screened retrospectively. During the study period, CoNS species were not reported (except S. lugdunensis). Patients (patients) ≥18 years old with ≥1 BCx positive for CoNS were included. Patients who were neutropenic, treated with staphylococcal antibiotics (SAbx) for a non-CoNS infection, or treated for CoNS with an antibiotic other than the defined SAbx were excluded. Patients were categorized into pre-defined groups: single positive BCx(Group 1), ≥2 positive BCx with different (Group 2) or same (Group 3) susceptibilities. A random sample of patients was screened until 50 Group 1 patients met study criteria. Additional data were collected on all remaining Group 2 and 3 patients in the study period, including species name obtained from laboratory database. The primary outcome was attributable use of SAbx among patients in each group. Additional analyses were performed to compare the use of SAbx among Groups 2 and 3.ResultsOne hundred two patients were included. In the random sample (n = 76), 34% had ≥2 positive BCx. S. epidermidis was isolated more frequently in Groups 2 and 3 than in Group 1 (69% vs. 52%, P = 0.03). 74% of patients received at least 1 SAbx (97% vancomycin). Attributable use of SAbx was greater among Groups 2 and 3 (P < 0.001, figure). Differing susceptibilities occurred in 24/52 (46%) patients but did not impact SAbx use (P = 0.57 for DOTs, P = 0.35 for DDDs). Seventeen (33%) of patients with ≥2 positive BCxhad different species.ConclusionSignificantly more SAbx were prescribed when ≥2 BCx were positive for CoNS. Since differences in susceptibilities has little effect, future studies should evaluate the impact of reporting CoNS species on appropriate antibiotic prescribing. *P < 0.001 for Group 1 vs. 2 and Group 1 vs. 3 (DOTs and DDDs). P = NS for Group 2 vs. 3.Disclosures All authors: No reported disclosures.

Can Fetal Umbilical Venous Blood Be a Reliable Source for Admission Complete Blood Count and Culture in NICU Patients?

Background: Minimizing initial neonatal blood draws and their associated pain is important. The placenta has ample fetal blood that is otherwise discarded; obtaining admission laboratory evaluations from fetal umbilical venous blood (FUVB) may provide a suitable alternative. Objective: We hypothesized that obtaining an aerobic bacterial blood culture (BCX) and a complete blood count with manual differential (CBC/diff) from FUVB is feasible and yields results comparable to those obtained directly from the neonate. Study Design: BCX and CBC/diff were attempted on paired samples from FUVB (in the delivery room) and neonatal blood (shortly after NICU admission) of 110 patients. The paired t test, Pearson’s correlation coefficient (R), and multivariable linear regression were used for data analysis. Results: Positive BCXs were found in 9 of 108 FUVB samples compared to 1 of 91 neonatal samples. Three out of 9 FUVB cultures were true pathogens, including 2 Escherichia coli and 1 viridans group streptococcus, all with negative corresponding paired neonatal cultures. There was 1 positive neonatal BCX, E. coli, with a negative paired FUVB culture. Neonatal hemoglobin (Hb), platelets (PLT), and white blood cells (WBC) all significantly (p < 0.0001) correlated with the paired FUVB samples (R = 0.50, 0.49, and 0.84, respectively). Hb, PLT, and WBC values were clinically comparable but statistically higher in neonatal blood (the differences were 2.3 g/dL, 30,000 cells/μL, and 2,800 cells/μL, respectively; p < 0.007 for all comparisons). Conclusions: FUVB is suitable for obtaining CBC/diff. FUVB is an appropriate second source for BCX as it yields additional true pathogens. Our findings may support the presence of “culture-negative sepsis” in some neonates.

Dogma without Data: A Clinical Decision-Making Tool for Postoperative Blood Cultures

Bacteremia is a worrisome postoperative complication and blood cultures (BCx) are often nondiagnostic. We previously reported a 4 per cent overall yield of positive cultures in postoperative patients. To reduce unnecessary testing, we present a predictive model to identify patients in whom growth of pathogens is unlikely and provide a clinical decision-making guide. Retrospective analysis of nonpregnant patients ≥18 years who had BCx within 10 days postoperatively was performed. Generalized linear mixed models identified clinical predictors of high- and low-yield cultures. A clinical algorithm was created using significant predictors, and positive predictive value, negative predictive value, sensitivity, and specificity calculated. Among 1759 BCx, hypotension, maximum temperature ≥101.5°F within 24 hours of culture, and culture collected after postoperative day (POD) two were statistically significant predictors of positive cultures. Forty nine per cent of BCx were sent ≤ POD 2, and <1 per cent of these were positive. When all three criteria were met, the probability of a positive culture increased to 17 per cent. When absent, the probability of a negative culture was 99 per cent. When applied to the initial data set, the model resulted in 85 per cent reduction of cultures with 9 per cent yield of positive cultures. Drawing BCx based on a single predictor is inadequate. Reducing the number of cultures reflexively ordered within the first two POD could significantly reduce the number of unnecessary BCx. Several clinical features identified patients most likely to have positive BCx within the first 10 POD and could reduce unnecessary BCx. This model should be validated in an independent, prospective cohort.

Consequences of Implementing a "Better" Blood Culture System.

Blood cultures (BCx) are the gold standard for diagnosing blood stream infections. However, contamination remains a challenge and can increase cost, hospital days, and unnecessary antibiotic use. National goals are to keep overall BCx contamination rates to ≤3%. Our healthcare system recently moved to a BCx system with better organism recovery, especially for gram-negative, fastidious, and anaerobic bacteria. The study objectives were to determine the benefits/consequences of implementing a more sensitive blood culture system, specifically on contamination rates. The electronic health record was queried for all BCx obtained within our tertiary-care health system from April 2015 to October 2016. Cultures were divided into those obtained 12 months before and six months after the new system was introduced. A positive BCx was defined as one with any growth. Contaminated BCx were defined as those showing coagulase-negative Staphylococcus, Corynebacterium, Bacillus, Micrococcus, or Propionibacterium acnes. Cultures with Staphylococcus aureus, Klebsiella pneumoniae, or Escherichia coli were said to contain a true pathogen. Results based on hospital location of blood drawing also were determined. A total of 20,978 blood cultures were included, 13,292 before and 7,686 after the new system was introduced. With the new system, positive BCx rates increased from 7.5% to 15.7% (p < 0.001). Contaminants increased from 2.3% to 5.4% (p < 0.001), and pathogens increased from 2.5% to 5.8% (p < 0.001). Contaminated BCx increased significantly in the surgical/trauma intensive care unit (STICU), emergency department (ED), and medical ICU (MICU), while pathogen BCx increased on the surgical floor, ED, and MICU. A new blood culture system resulted in significant increases in the rates of positive, contaminated, and pathogen BCx. After the new system, multiple hospital units had contamination rates >3%. These data suggest that a "better" BCx system may not be superior regarding overall infection rates. More research is needed to determine the impact of identifying more contaminants and pathogens with the new system.

Clinical Predictors of Positive Postoperative Blood Cultures.

To define clinical features of surgical patients in whom postoperative blood cultures are likely to identify pathogens. Bacteremia is a worrisome postoperative complication and blood cultures (BCx) are routinely used for evaluation of postoperative bacteremia, but are costly and not always diagnostic. Better methods are needed to select patients in whom BCx identify pathogens. We reviewed records of patients ≥18 years old with BCx drawn ≤10 days after surgery in 2013 seeking independent predictors of positive cultures by simple and multiple logistic regression models with statistical significance at α = 0.05. Of 1804 BCx, excluding contaminants yielded 1780 cultures among 746 patients for analysis. The yield was low, with only 4% identifying potential pathogens. Positive BCx were most common after cardiac, ear/nose/throat, obstetric, and urologic procedures [odds ratio (OR) =10.3, P < 0.001 vs low-yield procedures: eg, gynecologic, neurosurgical, plastic surgical, podiatric, transplant]. Cultures more often grew pathogens when drawn in association with higher peak temperature (Tmax, P = 0.001) and longer interval from procedure to Tmax (P = 0.001). Antibiotic therapy at time of culture reduced yield (2.9% with vs 5.5% without antibiotics, P = 0.007). Multivariable logistic regression analysis found antibiotics at culture, procedure specialty, Tmax, and postoperative timing of Tmax were associated with blood culture results. Ordering blood cultures based on fever or another single predictor inconsistently identifies pathogens. Our dataset, the largest available, identify clinical predictors in the first 10 postoperative days to guide identification of patients with bacteremia.

Relationship of fluconazole prophylaxis with fungal microbiology in hospitalized intra-abdominal surgery patients: a descriptive cohort study.

IntroductionHistorically, Candida albicans has represented the most common cause of candidemia. However, the proportion of bloodstream infections due to non-albicans Candida species has increased. Because of the risk for candidemia in intra-abdominal surgical patients, some experts advocate the use of fluconazole prophylaxis. The impact of this practice on the distribution of Candida species isolated in breakthrough fungal infections in this population is unknown. We examined the association of fluconazole prophylaxis with the distribution of Candida species in intra-abdominal surgery patients.MethodsWe retrospectively identified cases with a positive blood culture (BCx) for Candida among hospitalized adult intra-abdominal surgery patients between July 2005 and October 2012. Distribution of Candida species isolated represented our primary endpoint. Qualifying surgical cases were determined based on a review of discharge International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Patients receiving low-dose fluconazole prior to the positive BCx with a known indication for prophylaxis including neutropenia, ICU exposure or history of organ transplantation were classified as prophylaxis. Appropriateness of fungal treatment was determined by the timing and selection of antifungal agent based on fungal isolate.ResultsAmong 10,839 intra-abdominal surgery patients, 227 had candidemia. The most common Candida species isolated was C. albicans (n = 90, 39.6%) followed by C. glabrata (n = 81, 35.7%) and C. parapsilosis (n = 38, 16.7%). Non-albicans Candida accounted for 57.7% of isolates among the 194 non-prophylaxis patients and 75.8% among the 33 prophylaxis patients (P = 0.001). C. glabrata, the most common non-C. albicans species, was more prevalent than C. albicans in persons given prophylaxis, but not in those without prophylaxis. A total of 63% of those with candidemia were treated inappropriately based on the timing and selection of antifungal administration.ConclusionsSelection pressure from fluconazole prophylaxis in at-risk surgical patients may be associated with a drift toward fluconazole-resistant species in subsequent candidemia. Tools are needed to guide appropriate treatment through the prompt recognition and characterization of candidemia.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-014-0590-1) contains supplementary material, which is available to authorized users.

Impact of Positive Preoperative Surveillance Blood Cultures From Chronic Indwelling Catheters in Cadaveric Intestinal Transplant Recipients

Recurrent bloodstream infections are a common indication for intestinal transplantation (ITx). Often, clinical symptoms may be absent in the setting of bacteremia, especially in patients with chronic liver disease. This study investigated the incidence and impact of positive blood cultures (BCx) obtained from central venous catheters used for total parenteral nutrition (TPN) in asymptomatic patients immediately prior to cadaveric ITx. Of 13 consecutive patients transplanted between November 2003 and November 2004, 12 underwent preoperative surveillance BCx with four positives (33%). Isolates included Staphylococcus epidermidis ( n = 2), methicillin-resistant Staphylococcus aureus, and Citrobacter freundii. All four patients with positive BCx displayed liver dysfunction at the time of transplant (≥ grade 2 fibrosis, total bilirubin >8.0 g/dL), three of whom were inpatients. In contrast, only three of eight nonbacteremic patients showed liver disease of comparable severity. Liver dysfunction and inpatient status at the time of transplant appear to predict positive blood cultures. Postoperative length of stay and time on the ventilator were significantly longer among bacteremic as compared with nonbacteremic patients, but there were no differences in intraoperative blood use, time to total parenteral nutrition independence, or operative time between bacteremic and nonbacteremic patients. Our study showed that occult bacteremia in asymptomatic pre-intestinal transplant patients was not uncommon and may increase postoperative morbidity. Preemptive removal of long-term central venous catheters should be considered prior to ITx.