Utility of peripheral blood cultures in patients with cancer and suspected blood stream infections: a systematic review

Usefulness of Peripheral Blood Cultures in Children With Cancer and Episodes of Fever and Neutropenia

BACKGROUND

The collection of blood cultures (BC) is key for guiding antimicrobial therapy in children with febrile neutropenia (FN), more than 90% have central venous catheters (CVC). There is no consensus on the need for peripheral BC over central BC in this population. The aim of this study was to determine the contribution of peripheral BC over central BC in the diagnosis of bloodstream infections in children with FN.

METHODS

Descriptive, retrospective study, episodes of FN recorded prospectively in 6 hospitals in Santiago, Chile, from 2016 to 2021. Central and peripheral BC were drawn upon admission. All episodes with at least one (+) BC were allocated to one of these groups: consistent (+) BC, inconsistent (+) BC, only CVC (+) BC and only peripheral (+) BC. The volume of the samples was recorded.

RESULTS

The analysis included 241 episodes of FN with at least one (+) BC. The median age was 7.2 years, 51% were female, 84% had hematological cancer and 98% had episodes of high-risk FN. Of a total of 241 episodes, 135 (56%) had consistent (+) BC, 13 (5%) had inconsistent (+) BC, 35 (15%) had only CVC (+) BC and 58 (24%) had only peripheral (+) BC. There were no significant differences in the volume of the samples between central and peripheral BC.

CONCLUSIONS

The proportion of bloodstream infections detected only through peripheral BC was 24%, higher than previously reported, not due to sample volume. We recommend obtaining peripheral as well CVC BC in children with FN.

A multi-pronged approach to improve blood culture diagnostics in different clinical departments: a single-centre experience

PURPOSE

Blood culture (BC) diagnostics are influenced by many factors. We performed a targeted interdisciplinary analysis to analyse effects of various measures on BC diagnostics performance.

METHODS

A diagnostic stewardship initiative was conducted at two intervention and two control wards in a German tertiary level hospital. The initiative comprised staff training on the correct indications and sampling for BC, implementation of information cards, labels to identify the collection site, regular BC bottle feedback including the number of bottles, filling volumes and identified pathogens; and the use of a specific sampling device (BD Vacutainer®). Before and after the interventions, two three-month measurement periods were performed, as well as a one-month follow-up period to assess the sustainability of the conducted measures.

RESULTS

In total, 9362 BC bottles from 787 patients were included in the analysis. The number of BCs obtained from peripheral venous puncture could be increased at both intervention wards (44.0 vs. 22.2%, 58.3 vs. 34.4%), while arterial sampling could be reduced (30.6 vs. 4.9%). A total of 134 staff members were fully trained. The intervention led to a considerable increase in BC knowledge (from 62.4 to 79.8% correct answers) with differences between the individual professional groups. Relevant reduced contamination rates could be detected at both intervention wards.

CONCLUSIONS

As knowledge on the correct BC sampling and strategies to reduce contamination varies considerably between clinical departments and healthcare professionals, a targeted training should be adapted to the specific needs of the individual professional groups. An additional filling device is not necessary.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Hilab System Device in an Oncological Hospital: A New Clinical Approach for Point of Care CBC Test, Supported by the Internet of Things and Machine Learning

The complete blood count (CBC) is a highly requested test that is generally restricted to centralized laboratories, which are limited by high cost, being maintenance-demanding, and requiring costly equipment. The Hilab System (HS) is a small, handheld hematological platform that uses microscopy and chromatography techniques, combined with machine learning (ML) and artificial intelligence (AI), to perform a CBC test. This platform uses ML and AI techniques to add higher accuracy and reliability to the results besides allowing for faster reporting. For clinical and flagging capability evaluation of the handheld device, the study analyzed 550 blood samples of patients from a reference institution for oncological diseases. The clinical analysis encompassed the data comparison between the Hilab System and a conventional hematological analyzer (Sysmex XE-2100) for all CBC analytes. The flagging capability study compared the microscopic findings from the Hilab System and the standard blood smear evaluation method. The study also assessed the sample collection source (venous or capillary) influences. The Pearson correlation, Student t-test, Bland-Altman, and Passing-Bablok plot of analytes were calculated and are shown. Data from both methodologies were similar (p > 0.05; r ≥ 0.9 for most parameters) for all CBC analytes and flagging parameters. Venous and capillary samples did not differ statistically (p > 0.05). The study indicates that the Hilab System provides humanized blood collection associated with fast and accurate data, essential features for patient wellbeing and quick physician decision making.

Clinical decision rule for obtaining peripheral blood cultures in febrile oncology patients

BACKGROUND

The utility of peripheral blood cultures in pediatric oncology patients presenting with fever is controversial. A recent systematic review showed that about one in 40 bloodstream infections (BSIs) would be missed if only central venous line (CVL) cultures are obtained.

OBJECTIVE

To derive a clinical decision rule for obtaining peripheral blood cultures in pediatric oncology patients presenting to a pediatric emergency department (PED) with fever and a CVL.

DESIGN/METHOD

A retrospective chart review was performed on pediatric oncology patients referred to the PED for fever while on therapy. Logistic regression with a random intercept was used to determine independent predictors of BSI and generate a prediction model for obtaining peripheral blood cultures. The decision rule was generated from the best performance as measured by a receiver operator curve. Bootstrapping analysis was performed for internal validation.

RESULTS

Predictors that were significant and independently associated with positive peripheral blood cultures included vasopressor support (odds ratio [OR] 16.5, 95% confidence interval [CI]: 2.80-97.71), acute myeloid leukemia (AML) diagnosis (OR 6.9, 95% CI: 1.81-25.98), hypotension (OR 4.0, 95% CI: 1.05-15.17), mucositis (OR 8.2, 95% CI: 2.48-27.01), and maximum temperature in PED ≥39°C (OR 6.6, 95% CI: 2.36-18.20). The area under the curve (AUC) for this model was 0.90 (95% CI: 0.82-0.97) in the derivation cohort and 0.90 (95% CI: 0.81-0.98) after the internal validation.

CONCLUSIONS

We derived a clinical prediction model for deciding when to obtain peripheral blood cultures in febrile oncology patients with CVLs on active therapy. Future studies should focus on prospective and external validation of this diagnostic prediction tool.

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.

Guidance Statement for the Management of Febrile Neutropenia in Pediatric Patients Receiving Cancer-Directed Therapy in Central America and the Caribbean

PURPOSE

Our objective was to provide regionally appropriate, resource-conscious recommendations for the diagnosis and treatment of pediatric patients with febrile neutropenia.

METHODS

A multinational panel of Central American and Caribbean clinicians who deliver pediatric oncology care prioritized clinically important questions and then used the Grading of Recommendations Assessment, Development and Evaluation methodology to provide recommendations on the selected topics.

RESULTS

Twenty-two questions and 2 definitions were included in the guideline, which was intended to establish minimum care standards for pediatric patients treated in regional centers. Of all the included studies, 6.9% were conducted in low- and middle-income countries, and no studies were performed in countries represented on the panel.

CONCLUSION

The panel made recommendations on the basis of existing evidence but identified important gaps in knowledge from the region and from resource-limited settings that may affect the clinical applicability of these recommendations. These deficiencies suggest a research agenda that will enable future guidelines to be more responsive to the local context.

Optimising Antimicrobial Selection and Duration in the Treatment of Febrile Neutropenia in Children

Febrile neutropenia (FN) is a frequent complication of cancer treatment in children. Owing to the potential for overwhelming bacterial sepsis, the recognition and management of FN requires rapid implementation of evidenced-based management protocols. Treatment paradigms have progressed from hospitalisation with broad spectrum antibiotics for all patients, through to risk adapted approaches to management. Such risk adapted approaches aim to provide safe care through incorporating antimicrobial stewardship (AMS) principles such as implementation of comprehensive clinical pathways incorporating de-escalation strategies with the imperative to reduce hospital stay and antibiotic exposure where possible in order to improve patient experience, reduce costs and diminish the risk of nosocomial infection. This review summarises the principles of risk stratification in FN, the current key considerations for optimising empiric antimicrobial selection including knowledge of antimicrobial resistance patterns and emerging technologies for rapid diagnosis of specific infections and summarises existing evidence on time to treatment, investigations required and duration of treatment. To aid treating physicians we suggest the key features based on current evidence that should be part of any FN management guideline and highlight areas for future research. The focus is on treatment of bacterial infections although fungal and viral infections are also important in this patient group.

Impacts and Challenges of Advanced Diagnostic Assays for Transplant Infectious Diseases

The advanced technologies described in this chapter should allow for full inventories to be made of bacterial genes, their time- and place-dependent expression, and the resulting proteins as well as their outcome metabolites. The evolution of these molecular technologies will continue, not only in the microbial pathogens but also in the context of host-pathogen interactions targeting human genomics and transcriptomics. Their performance characteristics and limitations must be clearly understood by both laboratory personnel and clinicians to ensure proper utilization and interpretation.

Guideline for the Management of Fever and Neutropenia in Children With Cancer and Hematopoietic Stem-Cell Transplantation Recipients: 2017 Update

Purpose To update a clinical practice guideline (CPG) for the empirical management of fever and neutropenia (FN) in children with cancer and hematopoietic stem-cell transplantation recipients. Methods The International Pediatric Fever and Neutropenia Guideline Panel is a multidisciplinary and multinational group of experts in pediatric oncology and infectious diseases that includes a patient advocate. For questions of risk stratification and evaluation, we updated systematic reviews of observational studies. For questions of therapy, we conducted a systematic review of randomized trials of any intervention applied for the empirical management of pediatric FN. The Grading of Recommendation Assessment, Development and Evaluation approach was used to make strong or weak recommendations and to classify levels of evidence as high, moderate, low, or very low. Results Recommendations related to initial presentation, ongoing management, and empirical antifungal therapy of pediatric FN were reviewed; the most substantial changes were related to empirical antifungal therapy. Key differences from our 2012 FN CPG included the listing of a fourth-generation cephalosporin for empirical therapy in high-risk FN, refinement of risk stratification to define patients with high-risk invasive fungal disease (IFD), changes in recommended biomarkers and radiologic investigations for the evaluation of IFD in prolonged FN, and a weak recommendation to withhold empirical antifungal therapy in IFD low-risk patients with prolonged FN. Conclusion Changes to the updated FN CPG recommendations will likely influence the care of pediatric patients with cancer and those undergoing hematopoietic stem-cell transplantation. Future work should focus on closing research gaps and on identifying ways to facilitate implementation and adaptation.

Increasing Antimicrobial Resistance Monitored in Surveillance Analysis of Blood Stream Infections in Febrile Neutropenic Pediatric Oncology Patients

BACKGROUND

Continuous surveillance of pattern of blood stream infection is necessary in febrile neutropenia (FN)especially with the recent escalating trend in the management of pediatric cancer patients towards intensified regimens and with the increase in infections caused by resistant organisms limiting the choice of antibiotics.

AIM

To monitor change in pattern of blood stream infections (BSI) in FN pediatric cancer patients.

MATERIALS AND METHODS

Surveillance of FN episodes with positive BSI was prospectively monitored and compared to a previous surveillance in the same pediatric oncology unit.

RESULTS

A total of 232 BSI positive episodes were documented in 192 patients during a 6 months period. The results of recent surveillance analysis showed an increase in intensified regimens of chemotherapy, antimicrobial resistance, fungal infections, and prolonged duration of episodes when compared to previous surveillance, with p value sof <0.001, 0.005, 0.021, and <0.001, respectively. There was an apparent decrease in the crude mortality but this was not statistically significant, to 6% in 2011 from 10 % in 2006.

CONCLUSIONS

The pattern of BSI at our institution is still inclining towards gram positive organisms but is showing a shift towards more antibiotic resistance and fungal infections.

Core outcomes and definitions for pediatric fever and neutropenia research: a consensus statement from an international panel

BACKGROUND

There are no specific recommendations for the design and reporting of studies of children with fever and neutropenia (FN). As a result, there is marked heterogeneity in the variables and outcomes that are reported and new definitions continue to emerge. These inconsistencies hinder the ability of researchers and clinicians to compare, contrast and combine results. The objective was to achieve expert consensus on a core set of variables and outcomes that should be measured and reported, as a minimum, in pediatric FN studies.

PROCEDURE

The Delphi method was used to achieve consensus among an international group of clinicians, pharmacists, researchers, and patient representatives. Four surveys focusing on (i) the identification of a core set of variables and outcomes; and (ii) definitions of these variables and outcomes, were administered electronically. Consensus was predefined as more than 80% agreement on any statement.

RESULTS

There were forty-five survey participants and the response rate ranged between 84 and 96%. There was consensus on eight core variables and 10 core outcomes that should be collected and reported in all studies of children with FN. Consensus definitions were identified for all of the core outcomes.

CONCLUSION

Using the Delphi method, expert consensus on a set of core variables and outcomes, and their corresponding definitions, was achieved. These core sets represent the minimum that should be collected and reported in all studies of children with FN. This will promote collaboration and ensure consistency and comparability between studies.

Importance of blood cultures from peripheral veins in pediatric patients with cancer and a central venous line

BACKGROUND

When an infection is suspected in a child with cancer and a central venous line (CVL), cultures are often only obtained from the CVL and not from a peripheral vein (PV). This study was undertaken to evaluate the importance of concomitant blood cultures from the CVL and a PV.

PROCEDURE

Clinical data and the results of all cultures taken concomitantly from the CVL and a PV were registered prospectively in children admitted with fever from April 2008 to December 2012 at the Department of Pediatrics at Aarhus University Hospital Skejby.

RESULTS

During the study period 654 paired cultures obtained from the CVL and from a PV within two hour of each other were included. A true bloodstream infection (BSI) was registered in 112 episodes. In 20 (17%) out of 112, true BSI growth of a microorganism was detected only in the culture from a PV including seven cases of Escherichia coli and three cases of Staphylococcus aureus. In 52 episodes the same microorganism was cultured from both the CVL and a PV. Twenty-four of these episodes were classified as catheter-related bloodstream infections (CRBSI) using differential time to positivity. In total, 64 (57%) of all true BSI were defined as CRBSI.

CONCLUSIONS

Blood cultures should be obtained from a PV in addition to cultures from CVL at the onset of fever in pediatric patients with cancer in order to maximize the findings of true BSIs. The frequency of CRBSI may be over-estimated if blood cultures are drawn from CVL only.

Prognostic factors for mortality with fungal blood stream infections in patients with hematological and non-hematological malignancies

Background:

This single center retrospective analysis was undertaken to identify the incidence, clinical impact, and prognostic factors for mortality associated with fungal blood stream infections (BSI) in cancer patients.

Materials and Methods:

One hundred and twenty four patients had 169 episodes of fungal BSI. Incidence has not changed over a 10 year period but non albicans candida species are the predominant fungal isolates. Mortality with fungal BSI was significantly higher than that with other microbial agents. Risk of mortality was associated with renal dysfunction and Candida albicans as the isolate. Type of chemotherapy, patient characteristics, and neutrophil count did not influence the mortality following fungal BSI.

Conclusion:

Fungal BSI is rare and the incidence has not changed in this hospital. Mortality associated with fungal BSI is high. Risk score at the time of developing fungal BSI has prognostic potential to identify patients with higher risk of mortality associated with fungal BSI.

How many sources should be cultured for the diagnosis of a blood stream infection in children with cancer?

Blood stream infection (BSI) in a child with cancer is a life-threatening condition while blood cultures (BCs) play a crucial role for the diagnosis. The current practice of obtaining a BC from all sources--peripheral vein, central venous catheter (CVC), all lumens--is controversial and therefore in this study, our aim was to evaluate the utility of obtaining BCs from all these available sources. A retrospective study of BC sets obtained from all newly diagnosed patients with malignancy was conducted. A total number of 633 BC sets from 123 boys and 88 girls (median age: 5 5/12 years) were evaluated during infection episodes from January 1, 2005, to August 31, 2010. Among these cases, 134 were classified as true BSI (21%), 468 as non-BSI, and 31 as false-positive. In 64 cases, the results from peripheral and CVC sources were discordant: 57 catheter positive-peripheral negative and seven catheter negative-peripheral positive. Consequently, seven out of 134 true BSIs (5.2%) would not have been identified if only a BC from a CVC had been obtained. Moreover, if no BCs from all lumens had been obtained we would have missed up to 25% of true-positive BSIs. In the same way, if BCs from all sources had not been drawn we would not have detected up to 52% of true-positive BSIs.

CONCLUSION

Obtaining BCs during an infection episode from all sources in a child with cancer is still mandatory.