Central Blood Cultures Research Articles

The Harm of Inappropriate Central Line Blood Cultures in Clinical Practice

This case report describes a 57-year-old man with end-stage kidney disease who was receiving hemodialysis through a tunneled central venous catheter and had severe hyperkalemia that prompted admission for emergent hemodialysis.

Disseminated Nocardia nova in a child with relapsed acute lymphoblastic leukemia: a case report

BackgroundNocardiosis is a rare infection that typically results from inhalation of or inoculation with Nocardia organisms. It may cause invasive disease in immunocompromised patients. This case describes nocardiosis with bacteremia and pulmonary involvement in a child with a hematologic malignancy.Case presentationA boy with testicular relapsed acute lymphoblastic leukemia with marrow involvement presented with sudden onset of fever, body aches, headaches, chills, and moderate respiratory distress during continuation 2 chemotherapy. Radiographic imaging demonstrated consolidation and ground glass opacities in bilateral lower lungs. Central line blood cultures grew Nocardia nova complex, prompting removal of the central line and initiation of triple therapy with imipenem-cilastatin, linezolid, and trimethoprim-sulfamethoxazole with rapid improvement of symptoms. Antibiotic susceptibilities showed a multidrug-susceptible isolate. The patient is anticipated to remain on trimethoprim-sulfamethoxazole for at least 12 months.ConclusionsIn an immunocompromised child, blood cultures, chest imaging, and head imaging can aid in the diagnosis of disseminated nocardiosis. Long-term antibiotic therapy is necessary, guided by the organism and simplified with the results of antimicrobial susceptibility testing.

A multi-national survey of experience and attitudes towards managing catheter related blood stream infections for home parenteral nutrition

Catheter-related bloodstream infection (CRBSI) is the most common complication of home parenteral nutrition (HPN) in patients with chronic intestinal failure (CIF). The aim of this study was to assess the broad range of practices of international multi-disciplinary teams involved in the care of this complication occurring in CIF patients. An online questionnaire was designed and distributed to members of the European Society for Clinical Nutrition and Metabolism (ESPEN) and distributed to colleagues involved in managing patients with CIF. A total of 47 responses were included from centers across 21 countries. The centers had been delivering HPN for a median 21 years (IQR 11-35) and were actively following a median 58 patients (27-120) per center for benign CIF in 80% of cases (67-95). Tunneled catheters were the most common type of central venous catheters (CVC), representing 70% (47-86) of all CVC in use. For the management of CRBSI, written procedures were provided in 87% of centers. First measures included simultaneous central and peripheral blood cultures (90%), stopping HPN infusion (74%), and administrating an antibiotic lock and systemic antibiotics (44%). Immediate removal of the CVC was more likely in case of fungal infection (78%), Staphylococcus aureus (53%), or in case of PICC catheter (52%) (all p<0.01). After the first CRBSI, 80% of centers used preventive CVC locks (taurolidine in 84% of cases, p<0.001). We observed a large heterogeneity in practices regarding preparation, duration, reaspiration, and volume of CVC locks, and monitoring of CRBSI (timing of blood cultures, radiological work-up). In this international survey of HPN expert centers, we observed a significant consensus regarding the initial management of CRBSI and the use of secondary preventive CVC locks, while areas of variation exist. Management of CRBSI may be improved with clearer recommendations based on the micro-organism and the type of CVC, including PICC lines which are increasingly used yet insufficiently studied in HPN patients.

Comparison Between Peripheral and Central Blood Cultures in Pediatric Oncology Patients With Blood Stream Infections.

Current guidelines for fever in children with cancer recommend obtaining blood cultures from all lumens of the central venous catheter (CVC) and to consider a concurrent peripheral blood culture. We assessed the characteristics of blood stream infections (BSI) in oncology children and compared central and peripheral pathogen growth. A prospective, computerized surveillance of BSI in children treated at the oncology unit between May 2014 and July 2020. The growth of the same organism within a month was considered a single episode, ≥2 organisms in the same culture were defined as different episodes. Only children with concomitant cultures, drawn at presentation before initiation of antibiotics were included in the comparison between CVC and peripheral cultures. A total of 139 episodes in 81 children (with implanted Port-A-catheters) were considered true BSI. Of the 94/139 (67.6%) cases where a central and peripheral culture were concomitantly obtained, 52/94 (55.3%) had positive central/peripheral cultures that grew the same organism, 31/94 (33.0%) had positive central cultures only, and 11/94 (11.7%) had positive peripheral cultures only. In 3/94 cases, the organisms that grew from the CVC were not identical to those from the peripheral site. Four of 52 (7.7%) of the same positive central/peripheral pathogens had different susceptibility testing results. Higher CVC removal rates were observed when both peripheral and CVC cultures were positive ( P =0.044). Overall, 11.7% of BSI episodes were identified only by peripheral culture and 7.7% of paired organisms did not share the same susceptibility test results which emphasizes the importance of a peripheral culture in managing fever in oncology children.

1777. Shorter Versus Longer Antibiotic Durations for Coagulase-Negative Staphylococcus Catheter-Related Bloodstream Infections and Potential Impact on Antimicrobial Stewardship in a County Hospital

Abstract Background Coagulase negative Staphylococcus (CoNS) is a common cause of catheter-related bloodstream infection (CRBSI). Current guidelines are to provide 10-14 days (d) of antibiotics (abx) plus lock abx in the absence of catheter removal, and if the catheter has been removed, 5-7 d after removal. Olive View UCLA-Medical Center (Sylmar, CA) is an academic county hospital, serving the medical needs of the underserved community. The purpose of this study was to evaluate differences in treatment (tx) durations for CoNS CRBSI on clinical outcomes and evaluate the potential impact on antimicrobial stewardship. Methods Single center retrospective chart review from January 2018 to December 2021 on all central line-obtained blood cultures (Bcx) positive for CoNS. Exclusion criteria included suspected contamination or no abx tx, invasive CoNS infection, and concomitant infection treated with abx that have activity against CoNS. Duration of abx tx was divided into two groups: &amp;gt;10 d vs ≤10 d with or without catheter removal and &amp;gt;7 d vs ≤7 d post catheter removal. Primary outcomes assessed were recurrence of CoNS CRBSI within 90 d and 30 d hospital readmission. Secondary outcomes included hospital length of stay (LOS), 30 d all-cause mortality, and days of Bcx positivity. Groups were compared using Wilcoxon rank-sum for continuous variables and Fisher’s exact for categorical variables using Stata (Version 15). Results 153 positive CoNS central line Bcx were screened, 40 met study inclusion. 37 received vancomycin as initial abx with a median total tx duration of 13.5 d [IQR 8-14] and 9 d [IQR 6-13.5] after line removal. 22 (55%) received total abx duration of &amp;gt;10 d and 18 (45%) received total abx duration of ≤10 d. Baseline characteristics were similar between &amp;gt;10 d and ≤10 d (table 1). There was no significant difference in primary and secondary outcomes, respectively, between &amp;gt;10 d and ≤10 d (table 2). After catheter removal, there were no significant differences in outcomes whether antibiotics were continued for &amp;gt;7 d (n=18) vs ≤7 d (n=15) (table 3). Table 1:Baseline CharacteristicsTable 2:Outcomes according to days of therapyTable 3:Outcomes post catheter removal days of therapy Conclusion Abx tx duration of ≤10 d compared with &amp;gt;10 d for CoNS CRBSI did not result in differences in 90 d recurrence and 30 d readmission. Shorter courses of tx for CoNS CRBSI should be considered as a target for antimicrobial stewardship to minimize antibiotic exposure. Disclosures All Authors: No reported disclosures.

Practice update to optimise the performance and interpretation of blood cultures: 2022

Blood cultures are an important diagnostic and antibiotic stewardship tool to aid in treatment, monitoring and prognosis of patients with infection. This guideline is intended to update our 2010 guideline on the optimal use of blood cultures. Since then, there have been significant changes to the definitions of sepsis, guidance on the number of blood cultures recommended per draw, central and peripheral line blood cultures, advances in mitigating culture contamination, updates on the indications for blood cultures, and guidance on performance of follow-up cultures.

Impact of Paired Central and Peripheral Blood Cultures in Children With Cancer.

Children with cancer require central venous access which carries risk for line-related infections. The necessity of peripheral and central blood cultures is debated for those with fevers. We evaluated and described results for first episode of paired blood cultures from children with cancer who have a central venous line using retrospective database. Blood culture results, laboratory data, and medical outcomes were included. Descriptive analyses of blood culture results and clinical data were performed. There were 190 episodes of paired positive blood cultures with 167 true positive episodes. Of the true positive episodes, 104 (62.3%) were positive in both central and peripheral cultures, 42 (25.1%) were positive in central only cultures, and 21 (12.6%) were positive in peripheral cultures only. Intensive care unit admission within 48 hours after blood cultures (n=33) differed significantly: 28.7% for both central and peripheral, 10% for central only, and 0% for peripheral only (P=0.009). Central line removal (n=34) differed by type of positivity but was not significant: 22.1% for both central and peripheral, 23.8% for central only, and 4.8% for peripheral only (P=0.15). Peripheral blood cultures provided important medical information yet had differences in short-term clinical outcomes. Further evaluation of medical decision making is warranted.

Culture Ordering for Patients with New-onset Fever: A Survey of Pediatric Intensive Care Unit Clinician Practices.

Accurate assessment of infection in critically ill patients is vital to their care. Both indiscretion and under-utilization of diagnostic microbiology testing can contribute to inappropriate antibiotic administration or delays in diagnosis. However, indiscretion in diagnostic microbiology cultures may also lead to unnecessary tests that, if false-positive, would incur additional costs and unhelpful evaluations. This quality improvement project objective was to assess pediatric intensive care unit (PICU) clinicians' attitudes and practices around the microbiology work-up for patients with new-onset fever. We developed and conducted a self-administered electronic survey of PICU clinicians at a single institution. The survey included 7 common clinical vignettes of PICU patients with new-onset fever and asked participants whether they would obtain central line blood cultures, peripheral blood cultures, respiratory aspirate cultures, cerebrospinal fluid cultures, urine cultures, and/or urinalyses. Forty-seven of 54 clinicians (87%) completed the survey. Diagnostic specimen ordering practices were notably heterogeneous. Respondents unanimously favored a decision-support algorithm to guide culture specimen ordering practices for PICU patients with fever (100%, N = 47). A majority (91.5%, N = 43) indicated that a decision-support algorithm would be a means to align PICU and consulting care teams when ordering culture specimens for patients with fever. This survey revealed variability of diagnostic specimen ordering practices for patients with new fever, supporting an opportunity to standardize practices. Clinicians favored a decision-support tool and thought that it would help align patient management between clinical team members. The results will be used to inform future diagnostic stewardship efforts.

Taurolidine lock in the treatment of colonization and infection of totally implanted venous access devices in cancer patients.

Taurolidine lock is known to be effective in preventing catheter-related infections in a variety of venous access devices, including long term venous access devices for chemotherapy. Though, literature about the use of taurolidine for treating catheter colonization or catheter-related blood stream infection is scarce. We have retrospectively reviewed the safety and efficacy of 2% taurolidine lock for treatment of catheter-colonization and of catheter-related bloodstream infection in cancer patients with totally implanted venous access devices. Diagnosis of colonization or catheter-related infection was based on paired peripheral and central blood cultures, according to the method of Delayed Time to Positivity. We recorded 24 cases of catheter-related infection and two cases of colonization. Taurolidine lock-associated with systemic antibiotic therapy-was successful in treating all cases of catheter-related infection, with disappearance of clinical symptoms, normalization of laboratory values, and eventually negative blood cultures. Taurolidine lock was also safe and effective in treating device colonization. No adverse effect was reported. In our retrospective analysis, 2% taurolidine lock was completely safe and highly effective in the treatment of both catheter-colonization and catheter-related bloodstream infection in cancer patients with totally implanted venous access devices.

P0608 / #1034: VARIATION IN CULTURE ORDERING PRACTICES AMONG PEDIATRIC INTENSIVE CARE UNIT (PICU) CLINICIANS.

Aims & Objectives: There are no published guidelines to suggest timing of microbiology cultures for critically ill children. Using clinical vignettes, we aimed to evaluate possible variation in clinician’s ordering practices for microbiology cultures in critically ill children with fever. Methods: A team of PICU and Pediatric Infectious Disease clinicians developed a web survey based on six vignette-style clinical scenarios of PICU patients with fever to evaluate clinician ordering practices of central line blood cultures, peripheral blood cultures, respiratory aspirate cultures, urine cultures, urinalyses, and cerebrospinal fluid cultures. The survey was disseminated to PICU attending faculty, fellows, and nurse practitioners in late 2019. Survey results were coded based on the percentage of clinicians suggesting a culture/test was appropriate. Green responses had most consensus either to not order or order (0-16%, 85-100%), yellow responses had moderate consensus (17-33%, 68-84%), and red responses had least consensus (34-67%). Results: Overall response rate was 87% (n=54). The most variability in collection practices were with respiratory cultures, urine cultures, urinalyses, and cerebrospinal fluid cultures (Table 1). Peripheral blood cultures demonstrated moderate variability among clinicians in 5 of the 6 clinical scenarios. Central blood cultures had the most consensus. Clinicians unanimously supported development of a clinical decision support tool for microbiology culture specimen collection in PICU patients with new fever.Conclusions: Our survey demonstrated distinct variation in clinician ordering practices for children with fever. A clinical decision support tool that included all microbiology culture considerations for PICU patients with fever may help standardize culturing practices among PICU clinicians.

Prevalence of central venous catheter salvage in newborn with staphylococcal bloodstream infection

to establish the prevalence of salvage of central venous catheters in newborns with bloodstream infection caused by coagulase-negative staphylococci. retrospective cross-sectional study with 136 newborns admitted to the Neonatal Intensive Care Unit between 2011 and 2017. The total of 143 infection events undergoing antibiotic therapy were evaluated. among the 143 infection events, 39 catheters in which antibiotic therapy was used were saved and in 69 cases, the device was removed. Positive central blood culture and single lumen catheter were factors associated with salvage failure. The probability of salvage decreased with infections diagnosed from 15 days of using the catheter. Negative blood culture raised the chance of salvage by fourfold. the use of antibiotic therapy in the treatment of infections resulted in a low prevalence of salvage of the central venous catheter. The probability of salvage was associated with variables of the device.

A Catheter-Related Bloodstream Infection Caused by the Yeast Kodamaea ohmeri

Catheter-related bloodstream infections caused by Kodamaea ohmeri are generally not considered due to the relative scarcity of reported cases. This is a case of an 85-year-old man with poorly controlled diabetes mellitus who was initially admitted to our hospital for diabetic ketoacidosis. An internal jugular catheter was inserted as part of the initial management. A week later the patient developed a temperature spike and a yeast identified as Kodamaea ohmeri by ID 32 C (bioMérieux, France) was isolated from both his central and peripheral blood cultures. The catheter was removed and the patient was treated with fluconazole despite the organism’s relatively high minimum inhibitory concentration (2 μg/mL) to this antifungal. The fungemia resolved following a 2-weeks course of fluconazole.

Prophylactic Antibiotics for Reducing Central Line-associated Blood Stream Infection in Children with Totally Implantable Venous Access Devices.

To analyse the need of prophylactic antibiotic before the insertion of totally implantable venous access devices (TIVADs) in terms of preventing central line-associated blood stream infection (CLABSI) in early postoperative period in pediatric oncology patients. A cohort study. Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore from January 2005 to June 2016. A total of 645 consecutive children with malignancy, who were implanted with TIVAD, were included in the study. The data were collected retrospectively and divided into two groups on the basis of prophylactic antibiotic administration (Group A) received the antibiotic; and Group B did not receive the antibiotic. Both the groups were compared in terms of positive central blood cultures in the absence of any other clinical source of infection during the early postoperative period of 30 days. The overall infection rate was 12.54% (35 out of 279) in Group B (did not receive prophylactic antibiotic) and 11.68% (41 out of 351) in Group A (received prophylactic antibiotic) without any significant difference (p = 0.741). There was no advantage of the use of prophylactic antibiotic before TIVAD insertion in preventing early postoperative CLABSI.

Time to and differential time to blood culture positivity for assessing catheter-related yeast fungaemia: A longitudinal, 7-year study in a single university hospital.

Time to positivity (TTP) and differential time to positivity (DTTP) between central and peripheral blood cultures are commonly used for bacteraemia to evaluate the likelihood of central venous catheter (CVC)-related bloodstream infection. Few studies have addressed these approaches to yeast fungaemia. This study aimed to evaluate TTP and DTTP to assess CVC-related yeast fungaemia (CVC-RYF). We retrospectively analysed the results from 105 adult patients with incident fungaemia, with CVC removed and cultured, collected from 2010 to 2017. The bottles were incubated in a BioMérieux BacT/ALERT 3D and kept for at least 5days. Of the 105 patients included, most were oncology patients (85.7%) and had of long-term CVC (79.6%); 32 (30.5%) had a culture-positive CVC (defined as CVC-RYF) with the same species as in blood culture, and 69.5% had culture-negative CVC (defined as non-CVC-RYF, NCVC-RYF). Candida albicans represented 46% of the episodes. The median TTP was statistically different between CVC-RYF and NCVC-RYF (16.8hours interquartile range (IQR) [9.7-28.6] vs 29.4hours [IQR 20.7-41.3]; P=.001). A TTP <10hours had the best positive likelihood ratio (21.5) for CVC-RYF, although the sensitivity was only 28%. DTTP was available for 52 patients. A DTTP >5hours had a sensitivity of 100% and a specificity of 71% for CVC-RYF. Since the median TTP was 17hours and the most performing DTTP >5hours, these delays are too long to take a decision in the same operational day. More rapid methods for detecting infected catheters should be tested to avoid unnecessary CVC withdrawal.

2856. Salvaging High-Value Catheters: Antifungal Lock Therapy for Candidal Central Catheter Infections in a Pediatric Cohort

BackgroundBy IDSA guidelines, therapy for central line-associated bloodstream infections (CLABSI) due to Candida species requires catheter removal and administration of systemic antifungals. Despite this, in selected cases catheter salvage is desirable. The addition of antifungal lock therapy (ALT) has been proposed in these cases, but evidence for efficacy of this approach is limited. Here we report a retrospective analysis of ALT use for CLABSI due to Candida species at a single pediatric center.MethodsAll events of candidal CLABSI with ALT use were identified by retrospective record review between January 1, 2008 and December 31, 2018. CLABSI was defined by the growth of Candida from at least one central blood culture. Clearance was defined as a period of 48 hours with no positive cultures. Recurrence was defined as a subsequent positive blood culture with the same fungal organism either before or after line removal. Events were classified as “early removal” vs. “retained 7 days” depending on whether the line remained in place on day 7 after the first positive culture.ResultsOverall, 122 qualifying CLABSI were identified, 64 (52%) were retained 7 days or more (Table 1). Overall, 59% of CLABSI met criteria for clearance prior to line removal. Lines retained 7 days were likely to also remain in place at 28 days (72%) and had a low rate of relapse (8%) within 28 days. Lines in the early removal group had lower recurrence rates within 1 year (17% vs. 42%, P = 0.005), but this difference narrowed when considering recurrence at any time (31% vs. 47%, P = 0.1) or by Kaplan–Meier analysis (Figure 1) Additional microbiological and outcome data can be found in Tables 2 and 3.ConclusionThis retrospective analysis is the largest described cohort of antifungal locks for line salvage in a pediatric population to our knowledge. These findings highlight the advantages of line removal, with lower recurrence at 1 year. However, when line salvage with antifungal locks is attempted, retention and recurrence rates in the first month are favorable, and recurrence rates converge in the long-term, presumably because the underlying risk factors remain. While line removal remains the standard therapy for candidal CLABSI, we find that ALT-based line salvage may be a viable alternative. Disclosures All Authors: No reported Disclosures.

579. Machine-Learning Based Models for Prediction of Recurrence-free Catheter Retention After ALT Treatment of CLABSI in a Pediatric Population

BackgroundDeciding whether to attempt salvage of an infected central venous catheter (CVC) can be challenging. While line removal is the definitive treatment for central-line associated bloodstream infection (CLABSI), salvage may be attempted with systemic antibiotics and antibiotic lock therapy (ALT). Weighing risk and benefit of CVC salvage is limited by uncertainty in the future viability of salvaged CVCs. If a CVC is likely to require subsequent removal (e.g., due to recurrent infection) salvage may not be beneficial, whereas discarding a viable CVC is also not desirable. Here we describe a machine learning approach to predicting outcomes in CVC salvage.MethodsEpisodes of pediatric CLABSI cleared with ALT were identified by retrospective record review between January 1, 2008 and December 31, 2018 and were defined by a single positive central blood culture of a known pathogen or two matching cultures of a possible contaminant. Clearance was defined as 48-hours of negative cultures and relapse was defined as a matching positive blood culture after clearance. Predictive models [logistic regression (LR), random forest (RF), support vector machine (SVM) and an ensemble combining the three] were used to predict recurrence-free CVC retention (RFCR) at various time points using a training and test set approach.ResultsOverall, 712 instances CLABSI cleared with ALT were identified. Demographic and microbiological data are summarized in Tables 1 and 2. Few (8%) instances recurred in the first 28 days. 58% recurred at any time within the study period. Rates of RFCR were 75%, 43%, 22% and 10% at 28, 91, 182 and 365 days. Machine learning (ML) models varied in their ability to predict RFCR (Table 3). RF models performed best overall, although no model performed well at 91 days.ConclusionML models provide an opportunity to augment clinical decision making by learning patterns from data. In this case, estimating the likelihood of useful line retention in the future could help guide informed decisions on salvage vs. removal of infected CVCs. Limitations include the heterogeneity of clinical data and the use of an outcome capturing both clinical decision making (line removal) and infection recurrence. With further model development and prospective validation, practical machine learning models may prove useful to clinicians. Disclosures All authors: No reported disclosures.

Catheter-related infections in patients with acute type II intestinal failure admitted to a national centre: Incidence and outcomes

The management of intestinal failure (IF) requires safe and sustained delivery of parenteral nutrition (PN). The long-term maintenance of central venous catheter (CVC) access is therefore vital, with meticulous catheter care and salvage of infected CVCs being of prime importance. CVC-related infection and loss of intravenous access are important causes of morbidity and mortality in IF. Avoidance, prompt recognition and appropriate management of CVC-related infections are crucial components of IF care. However, there are few, if any, data on the occurrence of CVC-related infections in patients with acute, type 2, IF managed on a dedicated IF unit and no data on the salvage outcomes of infected CVCs in this group of patients. This is a retrospective observational study conducted between January 2011 and July 2017. All patients with acute, type 2 IF newly admitted to a national U.K. IF unit (IFU) during these dates were included. All patients admitted to the unit with a CVC in place underwent immediate 'screening' paired central and peripheral blood cultures on arrival before the CVC was used for any infusate. A prospectively maintained database was used to record all confirmed catheter-related blood stream infections (BSI)/colonisations, demographic and clinical data. Diagnosis of catheter-related BSI/colonisation was based on quantitative and qualitative analysis of paired central and peripheral blood cultures. A standardized 10-14-day catheter salvage treatment protocol involving antibiotic and urokinase CVC locks and systemic antibiotic administration was used to salvage any infected or colonised CVCs, as appropriate. The CVC was not used for PN until successful salvage had been confirmed by negative blood cultures drawn 48h after antibiotic completion. The development of a subsequent catheter-related BSI was recorded for all patients, both during the remaining in-patient stay on the IFU and after discharge home on PN. Of the 509 patients with type 2 IF admitted to the IFU during the study period, 341 (54% female; mean age 54.6 (range 16-86 years)) had an indwelling CVC that had been placed in the referring hospital. Surgical complications and mesenteric ischaemia were the most common underlying disease aetiologies. Sixty-five of 341 (19.1%) patients had an infected/colonised CVC on the initial screening set of blood cultures. A successful CVC salvage rate of 91% was achieved in this cohort after antibiotic therapy. The subsequent in-patient catheter-related BSI rate for those admitted with a CVC (n=341) on the IFU was 0.042 per 1000 catheter days, over a total of 23,548 in-patient catheter days. Two hundred and seventy nine of 341 patients were discharged on home PN (HPN); with a subsequent catheter-related BSI rate on HPN of 0.22 per 1000 catheter days (mean duration of HPN=778 catheter days (range:)) over a follow-up period of 216,944 out-patient catheter days. There was no increased risk of HPN-related catheter-related BSI (p=0.09) or mortality (p=0.4) in those admitted with an infected CVC. This is the first study to report catheter-related BSI/colonisation rates and salvage outcomes in patients with type 2 IF newly admitted to a dedicated IF Unit. We report that nearly one-fifth of all patients were referred with evidence of a catheter related BSI/colonisation; despite this, successful catheter salvage is possible and, with stringent CVC care, an extremely low subsequent catheter related BSI rates can be achieved and maintained during in-patient stay on a dedicated IF Unit and after discharge on HPN. These data provide novel evidence to support ESPEN recommendations that patients with type 2 IF are managed on a dedicated IF Unit.

Differential time to positivity of central and peripheral blood cultures is inaccurate for the diagnosis of Staphylococcus aureus long-term catheter-related sepsis

Differential time to positivity of cultures of blood drawn simultaneously from central venous catheter and peripheral sites is widely used to diagnose catheter-related bloodstream infections without removing the catheter. However, the accuracy of this technique for some pathogens, such as Staphylococcus aureus, is debated in routine practice. In a 320-bed reference cancer centre, the charts of patients with at least one blood culture positive for S.aureus among paired blood cultures drawn over a six-year period were studied retrospectively. Microbiological data were extracted from the prospectively compiled database of the microbiology unit. Data concerning the 149 patients included were reviewed retrospectively by independent physicians blinded to the absolute and differential times to positivity, in order to establish or refute the diagnosis of catheter-related sepsis. Due to missing data, 48 charts were excluded, so 101 cases were actually analysed. The diagnosis was established in 62 cases, refuted in 15 cases and inconclusive in the remaining 24 cases. For the 64 patients with both central and peripheral positive blood cultures, the differential positivity time was significantly greater for patients with catheter-related bloodstream infections due to S.aureus (P<0.02). However, because of the high number of false-negative cases, the classic cut-off limit of 120 min showed 100% specificity but only 42% sensitivity for the diagnosis of catheter-related bloodstream infection due to S.aureus. These results strongly suggest that despite its high specificity, the differential time to positivity may not be reliable to rule out catheter-related bloodstream infection due to S.aureus.

Bloodstream Infections in Patients With Intestinal Failure Presenting to a Pediatric Emergency Department With Fever and a Central Line.

Previous small studies have found a high occurrence of bloodstream infections (BSIs) in patients with intestinal failure, and these rates are higher than reported rates in other pediatric populations with central lines. The primary study objective was to describe the occurrence of BSIs in patients with intestinal failure who present to the pediatric emergency department (ED) with fever. This 5-year retrospective chart review included febrile patients with intestinal failure and central lines who presented to the Children's Hospital of Pittsburgh ED between 2006 and 2011. Each febrile episode was analyzed at the visit level. During the study, 72 patients with 519 febrile episodes were identified. Central blood cultures were obtained in 93% (480/519) of episodes and 69% (330/480) were positive. Of all BSIs, 38% (124/330) were polymicrobial, 32% (105/330) were a single gram-positive organism, 25% (84/330) were a single gram-negative organism, and 5% (17/330) were a single fungal organism. Of the bacterial pathogens, 48% (223/460) were gram-negative. Overall, 60% were enteric organisms. Pediatric patients with intestinal failure and central lines have a high occurrence of BSIs with 69% of cultures positive in this study of ED febrile episodes. In contrast to reports in other populations with central lines, BSI occurrence in patients with intestinal failure and fever is higher and larger proportions are gram-negative and enteric organisms. For these patients, we recommend central and peripheral blood cultures, empiric broad spectrum antibiotics targeting gram-negative and enteric organisms, and hospital admission.

The value of differential time to positivity of blood cultures in diagnosis of catheter-related bloodstream infection in patients with solid tumors in intensive care unit

To determine the value of differential time to positivity (DTTP) of blood culture for the diagnosis of catheter-related bloodstream infection (CRBSI) in patients with solid tumors in intensive care unit (ICU). A retrospective study was conducted. 615 pairs of peripheral vein blood cultures and instantaneous catheter tip blood culture of 615 patients admitted to ICU of Tianjin Medical University Cancer Institute and Hospital were collected from August 2011 to March 2014. The DTTP method and (or) semi quantitative culture of catheter tip were compared. CRBSI was diagnosed when both cultures were positive for the same microorganism and DTTP≥2 hours (120 minutes). The result of this procedure was compared with that of organism obtained using the semi quantitative culture of blood at catheter tip with ≥15 cfu. Based on the clinical diagnosis, the reliability of two kinds of laboratory examination was compared for the diagnosis of CRBSI by plotting receiver operator characteristic curve (ROC curve). The result of 615 cases suspected of having CRBSI were analyzed during the study period. Of these, 440 episodes were excluded because cultures were negative for blood obtained through peripheral vein and central vein. Eight episodes were excluded because only peripheral vein blood culture was positive and 57 episodes were excluded because of only central vein blood culture was positive, 68 pairs of blood cultures were excluded due to the presence of multiple catheters and repeated blood withdrawals. Two cases of polymicrobial cultures were excluded from the final analysis due to the difficulty in determining the time of positive result for each individual microorganism. Ten cases in 42 cases of suspected cases of CRBSI were excluded from analysis because catheter was not removed, therefore culture from catheter tip could not be obtained. Using the DTTP method, 14 out of 17 CRBSI cases were diagnosed with DTTP≥120 minutes, while 3 cases were missed; the semi quantitative catheter tip culture was positive in 13 cases, and in 4 cases it was neglected. In 2 cases of CRBSI it was missed by both methods. The area under the ROC curve (AUC) of DTTP, catheter tip culture and the combination method was 0.912, 0.882 and 0.941 for diagnosis of CRBSI, respectively. Validity values for the diagnosis of CRBSI for DTTP were: sensitivity 82.35%, specificity 92.31%, positive predictive value 93.33% and negative predictive value 80.00%, and they were higher than those of the catheter tip culture method only (76.47%, 84.62%, 86.67% and 73.33%). The specificity and positive predictive CRBSI combination of the two methods in the diagnosis value were up to 100%, the sensitivity (88.24%) and negative predictive value (86.67%) was also increased, but no significant differences were found with DTTP method (χ2=0.00, P=1.00; χ2=0.00, P=0.98; χ2=0.00, P=0.98; χ2=0.00, P=0.98). DTTP can be a valid method recommended for CRBSI diagnosis in critically ill patients with acceptable sensitivity, good specificity as well as positive predictive value. DTTP combined with other clinical symptoms can not only avoid unnecessary catheter withdrawal, but it also can help obtain the optimal treatment time and strategy.