Reducing blood culture contamination in community hospital emergency departments: a multicenter evaluation of a quality improvement intervention

BD Chloraprep™ ("2 % chlorhexidine with 70 % isopropyl alcohol") versus povidone iodine plus alcohol, for prevention of blood culture contamination at children: An investigator-initiated, open-label, single centre, randomized controlled trial

INTRODUCTION

One of the important problems that lower the diagnostic value of blood culture is contamination with skin organisms. The povidone-iodine, alcohol, and chlorhexidine gluconate alcohol are used for disinfection prior to blood sampling for culture.

METHODS

The investigator-initiated, open label, single centre, randomised trial compared blood culture contamination rates between two groups of patients in which using a povidone iodine skin-preparation process with the contamination rate for using "2 % chlorhexidine with 70 % isopropyl alcohol" skin-disinfection. The patients who required sampling for blood cultures were included in the study and study period was from 15 March 2023 to 15 July 2023.

RESULTS

A total of 400 blood cultures were obtained during the study, including 133 in the study group and 267 in the control group. In the total blood cultures, 11.75 % (n = 47) had microorganism isolation. Among them 39 (9.75 %) were contaminants and 8 (2 %) of them were true pathogens. The contaminant microorganisms were as following; 34 coagulase-negative Staphylococci, 3 Micrococcus spp, and 2 Streptococci viridans. The blood culture contamination rate in the study group was 5.3 % (n = 7) and 12.0 % (n = 32) in the control group, and significantly lower in the study group (p = 0.033). There is no significant difference regarding skin related side effects between two groups.

CONCLUSIONS

This study, showed that 2 % chlorhexidine gluconate in 70 % isopropyl alcohol is more efficacious in children than 10 % povidone-iodine preparations for disinfecting the skin prior to blood specimen collection for prevention of blood culture contamination.

Effectiveness of Multimodal Intervention to Improve Blood Culture Collection in a Tertiary Care Hospital

Introduction and methods Blood culturing has become one of the backbone investigations for septicemia, fever of unknown origin, etc. This study was conducted to test the effect of multimodal interventions on the practical skills of healthcare workers (HCWs), raise awareness regarding the importance of aseptic blood culture collection practices, and increase compliance with the specific steps to be followed. Hence, this current interventional study was aimed at comparing the rate of isolation of contaminants grown among the blood culture specimens, assessing the knowledge, attitude, and practice (KAP) of HCWs collecting the blood culture specimen on various aspects of sample collection, educating the nursing staff regarding blood sample collection using a structured, pre-formed checklist, and emphasizing best practices for blood culture collection. All of the study's objectives were successfully met within the time frame specified. Using a pre-formed checklist and a Google form for KAP analysis eased the calculation. Results On analysis, the blood culture contamination rate in the pre-interventional phase dropped drastically from 6.16% to 3.03% in the post-interventional phase. The educational sessions conducted are a paramount reason for the reduction in the contamination rate. The HCWs were the least compliant towards the eighth step in the checklist (regarding palpation of skin); however, that too increased from 66.93% and 64.51% to a whopping 82.25% and 83.06%, respectively, with a chi-square value of 0.03 and a p-value of 0.85 (not significant). Conclusion Implementation of interventional studies as an audit like this in tertiary care hospitals can result in a significant reduction in blood culture contamination rates and can also improve the compliance of HCWs with blood culture protocols. This, in turn, can overall improve the effectiveness of blood culture (BC) testing and reduce mortality and morbidity in tertiary care hospitals. Further research can be conducted to brainstorm more methods to increase the compliance of HCWs. Better monitoring strategies can also be set to ensure low contamination rates. Additionally, some other methods can be derived to locate the source of contamination within the hospital environment and thus eliminate it. Similar interventions can be conducted for a longer duration of time to further reduce the blood culture contamination rate below 3% (as per the recommendations).

A Quality Improvement Initiative on Reducing Blood Culture Contamination in the Emergency Department

INTRODUCTION

Contaminated blood cultures may have detrimental effects on patients, the organization, and antimicrobial stewardship. Patients in the emergency department may need blood cultures collected before antimicrobial therapy. Contaminated blood culture samples may contribute to prolonged hospital stay and also are associated with delayed or unnecessary antimicrobial therapy. This initiative aims to improve the emergency department's blood culture contamination rate that will eventually benefit the patients who will receive timely and proper antimicrobial therapy, and benefit the organization fiscally.

METHODS

This quality improvement initiative used the Define-Measure-Analyze-Improve-Control (DMAIC) process. The organization targets blood culture contamination rate of ≤2.5%. Control charts were used to study how blood culture contamination rate changed over time. In 2018, a workgroup was formed to work on this initiative. Improved site disinfection using 2% Chlorhexidine gluconate cloth before the standard procedure of blood culture sample collection was initiated. Chi squared test of significance was used to compare blood culture contamination rates 6 months before and during feedback intervention as well as contamination rate from source of blood draw.

RESULTS

Blood culture contamination rates 6 months before and during feedback intervention showed significant decrease (3.52% before intervention and 2.95% after intervention; P < .05). Contamination rates differed significantly based on the source of blood culture draw (7.64% via line, 3.05% via percutaneous venipuncture, and 4.53% via other; P < .01).

DISCUSSION

Blood culture contamination rate continued to decrease with the use of a predisinfection process with 2% Chlorhexidine gluconate cloth before blood sample collection process. Practice improvement also was evident with effective feedback mechanism.

Higher nursing care level is associated with higher incidence of blood culture contamination in the emergency department: A case-control study

Background

Blood culture is critical in treating infectious diseases. This leads to unnecessary intervention, inappropriate antibiotic use, and excess cost. Few studies have tackled patient factors that could possibly affect contamination rates. This study aimed to explore the association between patients' nursing care levels and blood culture contamination.

Methods

This is a single-centered, retrospective, case-control study of adult patients whose blood culture specimens were taken in the emergency department between April 2018 and July 2019. The study was conducted in an acute care community hospital in Japan. The case group included patients with false-positive blood culture results with contamination; the control group included patients with true-positive or true-negative blood culture results without contamination. We randomly selected two control patients per case. Patients' age, gender, nursing care level, ambulance use, housing status, Glasgow Coma Scale, hospital arrival time, and puncture sites were obtained from the patients' medical charts.

Results

Of the 5130 patients, 686 patients got positive blood culture results. Of the 686 patients, 35 patients were included in the case group, and 70 were randomly selected from the noncontaminated group and included in the control. In multivariate analysis, patients with contaminated blood cultures had a higher nursing care level (adjusted odds ratio: 8.50; 95% confidence interval: 1.65-43.7; p = 0.01).

Conclusions

A higher nursing care level is associated with a higher incidence of blood culture contamination in the emergency department. Careful and appropriate procedures are required for patients with a higher nursing care level.

Compare the efficacy of recommended peripheral intravascular cannula insertion practices with a standard protocol: A randomized control trial

Background

Millions of patients admitted globally in health care setups require insertion of peripheral intravascular catheter for intravenous drugs or fluid administration. However, if proper precautions are not followed during insertion, it results in significant morbidity. This study was designed to study the efficacy and safety of recommended Centre for Disease Control and Prevention (CDC) guidelines for peripheral intravascular catheter insertion practice and its comparison with a standard insertion protocol being followed and their outcome.

Methods

Patients were randomized and catheter was inserted as recommended by CDC guideline (Group 1, n = 100) or followed standard defined steps during insertion (Group 2, n = 100).

Results

Almost double the patients had occurrence of thrombophlebitis in Group 1 (p = 0.02). No difference observed between catheter needle size and infection rates (p = 0.3). Infection rate increased significantly if second attempt is taken for insertion. The time required to insert catheter following CDC recommended protocol is less than as by standard surgical complete asepsis cleaning protocol (86.03 vs 109.40 s) (p = 0.001). Study also observed that insertion at wrist joint leads to higher incidence of thrombophlebitis. During 0-24 h, 6% (12) insertions turned positive followed by a dip during 25-48 h, 2% (5) insertions. 80% (159) insertions did not develop thrombophlebitis at the end of 72 h.

Conclusion

It is thus amply demonstrated that meticulous adherence to insertion procedure with asepsis plays an important role in decreasing intravascular catheter associated morbidity. Other parameters like needle gauge, sites of insertion, have little bearing. The time required in following standard aseptic technique is significantly more but keeping in view the benefit to the patient it is highly recommended.

Effectiveness of multimodal intervention to improve blood culture collection in the emergency department

Introduction:

The blood culture (BC) contamination was a significant problem in our hospital, especially in the emergency department (ED). The study, therefore, was undertaken to improve the BC collection in the ED.

Methods:

The study was conducted for 1 year divided into two phases of 6 months each: Preintervention phase and intervention phase (regular and phlebotomist groups). The interventions comprised implementing standard protocol for BC collection and conducting educational sessions. In preintervention and regular groups, the BCs were collected by interns and technicians, while dedicated phlebotomist did so in the phlebotomist group. Data were analyzed and interpreted for the contamination rate as well as compliance in adequate filling of the requisition form. Statistical Package for the Social Sciences (SPSS) version 22. A value of P < 0.005 was considered statistically significant, and P < 0.01 was considered statistically significant.

Results:

In the preintervention group, 13.7% of specimens were reported as contaminated which was reduced to 4.2% and 3.2% in the regular and phlebotomist group, respectively, after intervention. Compliance of health-care workers to various elements of BC collection protocol was also found to be significantly improved in the intervention phase compared to the preintervention phase (P < 0.001).

Conclusions:

Implementation of this multimodal intervention resulted in a drastic reduction in BC contamination and improvement in compliance to BC collection protocol and filling of various parameters in the BC requisition form, thus improving the overall effectiveness of BC testing. It was also noted that the contamination rate was further reduced by implementing dedicated phlebotomist.

Patient-specific risk factors contributing to blood culture contamination

Objective:

Contaminated blood cultures result in extended hospital stays and unnecessary antibiotic therapy. Patient-specific factors associated with blood culture contamination remain largely unexplored. Identifying patients at higher risk of blood culture contamination could alert healthcare providers to take extra precautionary measures to limit contamination in these patients, and thereby prevent associated adverse outcomes. We sought to identify patient-related factors that contribute to blood culture contamination in hospitalized patients.

Design and setting:

We conducted a secondary data analysis of a retrospective cohort study at an academic medical center.

Patients:

Study participants included 19,255 adult patients who had blood culture(s) performed during a hospital admission between June 2014 and December 2016.

Methods:

Data were analyzed to evaluate risk factors for blood culture contamination using logistic regression.

Results:

Among adult patients, we identified 464 contaminated episodes and 11,010 negative blood-culture episodes. Chronic obstructive pulmonary disease (adjusted odds ratio [AOR], 1.67; 95% confidence interval [CI], 1.20–2.34) and stay in an intensive care unit (ICU) during an admission (AOR, 1.41; 95% CI, 1.14–1.74) were associated with blood culture contamination. Other risk factors included race, body mass index, and admission from the emergency department. Subgroup analyses of patients admitted from the emergency department showed similar results.

Conclusions:

We identified patient-specific factors that increase the odds of false-positive blood cultures. By introducing mitigation strategies to limit contamination in patients with these risk factors, it may be possible to reduce the adverse clinical impact of blood culture contamination.

Risk factors and clinical outcomes associated with blood culture contamination

OBJECTIVE

To determine patient-specific risk factors and clinical outcomes associated with contaminated blood cultures.

DESIGN

A single-center, retrospective case-control risk factor and clinical outcome analysis performed on inpatients with blood cultures collected in the emergency department, 2014-2018. Patients with contaminated blood cultures (cases) were compared to patients with negative blood cultures (controls).

SETTING

A 509-bed tertiary-care university hospital.

METHODS

Risk factors independently associated with blood-culture contamination were determined using multivariable logistic regression. The impacts of contamination on clinical outcomes were assessed using linear regression, logistic regression, and generalized linear model with γ log link.

RESULTS

Of 13,782 blood cultures, 1,504 (10.9%) true positives were excluded, leaving 1,012 (7.3%) cases and 11,266 (81.7%) controls. The following factors were independently associated with blood-culture contamination: increasing age (adjusted odds ratio [aOR], 1.01; 95% confidence interval [CI], 1.01-1.01), black race (aOR, 1.32; 95% CI, 1.15-1.51), increased body mass index (BMI; aOR, 1.01; 95% CI, 1.00-1.02), chronic obstructive pulmonary disease (aOR, 1.16; 95% CI, 1.02-1.33), paralysis (aOR 1.64; 95% CI, 1.26-2.14) and sepsis plus shock (aOR, 1.26; 95% CI, 1.07-1.49). After controlling for age, race, BMI, and sepsis, blood-culture contamination increased length of stay (LOS; β = 1.24 ± 0.24; P < .0001), length of antibiotic treatment (LOT; β = 1.01 ± 0.20; P < .001), hospital charges (β = 0.22 ± 0.03; P < .0001), acute kidney injury (AKI; aOR, 1.60; 95% CI, 1.40-1.83), echocardiogram orders (aOR, 1.51; 95% CI, 1.30-1.75) and in-hospital mortality (aOR, 1.69; 95% CI, 1.31-2.16).

CONCLUSIONS

These unique risk factors identify high-risk individuals for blood-culture contamination. After controlling for confounders, contamination significantly increased LOS, LOT, hospital charges, AKI, echocardiograms, and in-hospital mortality.

Low prevalence of bloodstream infection and high blood culture contamination rates in patients with COVID-19

PURPOSE

In the management of COVID-19, knowledge is lacking on the frequency of secondary bacterial infections and on how empirical antibiotic therapy should be used. In the present study, we aimed to compare blood culture (BC) results of a COVID-19 patient cohort with two cohorts of patients without detected COVID-19.

METHODS

Using a retrospective cohort study design of patients subjected to BC in six tertiary care hospitals, SARS-CoV-2 positive patients from March 1 to April 30 in 2020 (COVID-19 group) were compared to patients without confirmed SARS-CoV-2 during the same period (control group-2020) and with patients sampled March 1 to April 30 in 2019 (control group-2019). The outcomes studied were proportion of BC positivity, clinically relevant growth, and contaminant growth.

RESULTS

In total 15,103 patients and 17,865 BC episodes were studied. Clinically relevant growth was detected in 197/3,027 (6.5%) BC episodes in the COVID-19 group compared to 717/6,663 (10.8%) in control group-2020 (p<0.0001) and 850/8,175 (10.4%) in control group-2019 (p<0.0001). Contamination was present in 255/3,027 (8.4%) BC episodes in the COVID-19 group compared to 330/6,663 (5.0%) in control group-2020 (p<0.0001) and 354/8,175 (4.3%) in control group-2019 (p<0.0001).

CONCLUSION

In COVID-19 patients, the prevalence of bloodstream bacterial infection is low and the contamination rate of BC is high. This knowledge should influence guidelines regarding blood culture sampling and empirical antibiotic therapy in COVID-19 patients.

Use of interrupted time series methods in the evaluation of health system quality improvement interventions: a methodological systematic review

BACKGROUND

When randomisation is not possible, interrupted time series (ITS) design has increasingly been advocated as a more robust design to evaluating health system quality improvement (QI) interventions given its ability to control for common biases in healthcare QI. However, there is a potential risk of producing misleading results when this rather robust design is not used appropriately. We performed a methodological systematic review of the literature to investigate the extent to which the use of ITS has followed best practice standards and recommendations in the evaluation of QI interventions.

METHODS

We searched multiple databases from inception to June 2018 to identify QI intervention studies that were evaluated using ITS. There was no restriction on date, language and participants. Data were synthesised narratively using appropriate descriptive statistics. The risk of bias for ITS studies was assessed using the Cochrane Effective Practice and Organisation of Care standard criteria. The systematic review protocol was registered in PROSPERO (registration number: CRD42018094427).

RESULTS

Of 4061 potential studies and 2028 unique records screened for inclusion, 120 eligible studies assessed eight QI strategies and were from 25 countries. Most studies were published since 2010 (86.7%), reported data using monthly interval (71.4%), used ITS without a control (81%) and modelled data using segmented regression (62.5%). Autocorrelation was considered in 55% of studies, seasonality in 20.8% and non-stationarity in 8.3%. Only 49.2% of studies specified the ITS impact model. The risk of bias was high or very high in 72.5% of included studies and did not change significantly over time.

CONCLUSIONS

The use of ITS in the evaluation of health system QI interventions has increased considerably over the past decade. However, variations in methodological considerations and reporting of ITS in QI remain a concern, warranting a need to develop and reinforce formal reporting guidelines to improve its application in the evaluation of health system QI interventions.

Using Machine Learning to Predict Bacteremia in Febrile Children Presented to the Emergency Department

Blood culture is frequently used to detect bacteremia in febrile children. However, a high rate of negative or false-positive blood culture results is common at the pediatric emergency department (PED). The aim of this study was to use machine learning to build a model that could predict bacteremia in febrile children. We conducted a retrospective case-control study of febrile children who presented to the PED from 2008 to 2015. We adopted machine learning methods and cost-sensitive learning to establish a predictive model of bacteremia. We enrolled 16,967 febrile children with blood culture tests during the eight-year study period. Only 146 febrile children had true bacteremia, and more than 99% of febrile children had a contaminant or negative blood culture result. The maximum area under the curve of logistic regression and support vector machines to predict bacteremia were 0.768 and 0.832, respectively. Using the predictive model, we can categorize febrile children by risk value into five classes. Class 5 had the highest probability of having bacteremia, while class 1 had no risk. Obtaining blood cultures in febrile children at the PED rarely identifies a causative pathogen. Prediction models can help physicians determine whether patients have bacteremia and may reduce unnecessary expenses.

Blood culture contamination in the emergency department: An integrative review of strategies to prevent blood culture contamination

BACKGROUND

Blood culture collection remains the gold standard to diagnose bacteraemia. Current evidence suggests that the emergency department (ED) often has blood culture contamination (BCC) rates above the recommended 3%, contributing to increased hospital length of stay, unnecessary or inappropriate antimicrobial treatment, and increased economic burden. The aim of this review is to identify effective strategies to improve blood culture collection in EDs to decrease contamination rates and improve patient safety.

METHODS

An integrative literature review methodology was utilised to conduct a structured search of contemporary literature using CINAHL, Embase, Medline, Pubmed and Scopus databases. All eligible literature was screened with those included in the final review collated and appraised using a quality assessment tool.

RESULTS

Eleven reports were included in the final review, which identified bundled approaches, education and feedback, equipment and technique, and stakeholder engagement as strategies that improve BCC rates in the ED.

CONCLUSIONS

All studies reported a reduction in BCC rates regardless of the strategies implemented. A bundled approach yielded the most significant results and was identified to be practical, inexpensive, and adaptable. Further research focusing on specific aspects of a bundled approach may be beneficial to understand which strategies are most effective.

Effect of a bundle-approach intervention against contamination of blood culture in the emergency department

BACKGROUND

To prevent contamination when taking blood culture, there are various effective interventions. Whether there is greater efficacy by using a combination of these interventions has not been widely evaluated.

METHODS

Our six-element intervention bundle aimed to prevent contamination of blood culture in our emergency department (ED). Elements were: use of 1% chlorhexidine alcohol, alcohol wiping, hand hygiene, using sterile gloves, using holed sterile cover, and selection of upper extremities as the site of venipuncture. We compared the contamination rate of blood culture between the pre- and the post-intervention periods among all cases with two or more blood cultures taken in our ED. We also evaluated the rate of patients receiving vancomycin among all those transferred to the hospital from the ED.

RESULTS

During the pre- and post-intervention periods, 460 and 450 cases were included in analysis, respectively. Contamination of blood culture occurred in 29 pre-intervention cases (6.3%) and five post-interventional cases (1.1%) (relative risk 0.18, 95% confidence interval 0.07 to 0.45; P < 0.001). After bundle implementation, there was significant increase in adherence to using 1% chlorhexidine alcohol, alcohol wiping, hand hygiene, and using holed sterile covers. Among patients admitted to hospital, fewer patients received vancomycin during the post-intervention period than in the pre-intervention period (5.4% vs. 3.2%, P = 0.03).

CONCLUSIONS

Our intervention bundle dramatically reduced the contamination rate when drawing blood culture in our ED.

Practical Guidance for Clinical Microbiology Laboratories: A Comprehensive Update on the Problem of Blood Culture Contamination and a Discussion of Methods for Addressing the Problem

In this review, we present a comprehensive discussion of matters related to the problem of blood culture contamination. Issues addressed include the scope and magnitude of the problem, the bacteria most often recognized as contaminants, the impact of blood culture contamination on clinical microbiology laboratory function, the economic and clinical ramifications of contamination, and, perhaps most importantly, a systematic discussion of solutions to the problem. We conclude by providing a series of unanswered questions that pertain to this important issue.

National surveys on 15 quality indicators for the total testing process in clinical laboratories of China from 2015 to 2017

Background As effective quality management tools, quality indicators (QIs) are widely used in laboratory medicine. This study aimed to analyze the results of QIs, identify errors and provide quality specifications (QSs) based on the state-of-the-art. Methods Clinical laboratories all over China participated in the QIs survey organized by the National Health Commission of People' Republic of China from 2015 to 2017. Most of these QIs were selected from a common model of QIs (MQI) established by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). All participants were asked to submit general information and original QIs data through a medical quality control data collection system. The results of QIs were reported in percentages and sigma, except turnaround time (TAT) which was measured in minutes. The 25th, 50th and 75th percentiles were, respectively, calculated as three levels of QSs, which were defined starting from the model proposed during the 1st Strategic Conference of the EFLM on "Defining analytical performance 15 years after the Stockholm Conference on Quality Specification in Laboratory Medicine". Results A total of 76 clinical laboratories from 25 provinces in China continuously participated in this survey and submitted complete data for all QIs from 2015 to 2017. In general, the performance of all reported QIs have improved or at least kept stable over time. Defect percentages of blood culture contamination were the largest in the pre-analytical phase. Intra-laboratory TAT was always larger than pre-examination TAT. Percentage of tests covered by inter-laboratory comparison was relatively low than others in the intra-analytical phase. The performances of critical values notification and timely critical values notification were the best with 6.0σ. The median sigma level of incorrect laboratory reports varied from 5.5σ to 5.7σ. Conclusions QSs of QIs provide useful guidance for laboratories to improve testing quality. Laboratories should take continuous quality improvement measures in all phases of total testing process to ensure safe and effective tests.

Joint EFLM-COLABIOCLI Recommendation for venous blood sampling

This document provides a joint recommendation for venous blood sampling of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for Preanalytical Phase (WG-PRE) and Latin American Working Group for Preanalytical Phase (WG-PRE-LATAM) of the Latin America Confederation of Clinical Biochemistry (COLABIOCLI). It offers guidance on the requirements for ensuring that blood collection is a safe and patient-centered procedure and provides practical guidance on how to successfully overcome potential barriers and obstacles to its widespread implementation. The target audience for this recommendation are healthcare staff members directly involved in blood collection. This recommendation applies to the use of a closed blood collection system and does not provide guidance for the blood collection with an open needle and syringe and catheter collections. Moreover, this document neither addresses patient consent, test ordering, sample handling and transport nor collection from children and unconscious patients. The recommended procedure is based on the best available evidence. Each step was graded using a system that scores the quality of the evidence and the strength of the recommendation. The process of grading was done at several face-to-face meetings involving the same mixture of stakeholders stated previously. The main parts of this recommendation are: 1) Pre-sampling procedures, 2) Sampling procedure, 3) Post-sampling procedures and 4) Implementation. A first draft of the recommendation was circulated to EFLM members for public consultation. WG-PRE-LATAM was also invited to comment the document. A revised version has been sent for voting on to all EFLM and COLABIOCLI members and has been officially endorsed by 33/40 EFLM and 21/21 COLABIOCLI members. We encourage professionals throughout Europe and Latin America to adopt and implement this recommendation to improve the quality of blood collection practices and increase patient and workers safety.

Critical factors in the recovery of pathogenic microorganisms in blood

BACKGROUND

The critical factors for optimal recovery of microbial pathogens from blood are not only the basis for how we perform blood cultures on a daily basis, but are also important for development of all current blood-culture systems. Because much of this research was conducted and published between 1975 and 2010 there is a general sense that many physicians and scientists may not be familiar with it, but it is critical for performing and interpreting blood cultures.

OBJECTIVES

To review the critical factors in the laboratory recovery and isolation of pathogenic microorganisms in blood.

SOURCES

Literature review of published papers, select reviews and updated guidelines.

CONTENT

This review focuses on the critical factors that affect the recovery isolation of pathogenic microorganisms from individuals with bloodstream infections. Contemporary blood-culture systems, and current methods for blood-culture collection, have been designed to incorporate these critical factors so as to optimize recovery and isolation of pathogens while minimizing contamination.

IMPLICATIONS

It is important for microbiologists and practitioners to understand how and why these critical factors affect current blood-culture practices to improve patient management. Future research should emphasize which of these critical factors will still play a role in the era of molecular diagnostic tests, which will no longer be relevant, and which new critical factors have yet to be defined.

Best Practices of Blood Cultures in Low- and Middle-Income Countries

Bloodstream infections (BSI) have a substantial impact on morbidity and mortality worldwide. Despite scarcity of data from many low- and middle-income countries (LMICs), there is increasing awareness of the importance of BSI in these countries. For example, it is estimated that the global mortality of non-typhoidal Salmonella bloodstream infection in children under 5 already exceeds that of malaria. Reliable and accurate diagnosis of these infections is therefore of utmost importance. Blood cultures are the reference method for diagnosis of BSI. LMICs face many challenges when implementing blood cultures, due to financial, logistical, and infrastructure-related constraints. This review aims to provide an overview of the state-of-the-art of sampling and processing of blood cultures, with emphasis on its use in LMICs. Laboratory processing of blood cultures is relatively straightforward and can be done without the need for expensive and complicated equipment. Automates for incubation and growth monitoring have become the standard in high-income countries (HICs), but they are still too expensive and not sufficiently robust for imminent implementation in most LMICs. Therefore, this review focuses on "manual" methods of blood culture, not involving automated equipment. In manual blood cultures, a bottle consisting of a broth medium supporting bacterial growth is incubated in a normal incubator and inspected daily for signs of growth. The collection of blood for blood culture is a crucial step in the process, as the sensitivity of blood cultures depends on the volume sampled; furthermore, contamination of the blood culture (accidental inoculation of environmental and skin bacteria) can be avoided by appropriate antisepsis. In this review, we give recommendations regarding appropriate blood culture sampling and processing in LMICs. We present feasible methods to detect and speed up growth and discuss some challenges in implementing blood cultures in LMICs, such as the biosafety aspects, supply chain and waste management.

The effectiveness of interventions to reduce peripheral blood culture contamination in acute care: a systematic review protocol

BACKGROUND

Blood cultures are an integral part of the diagnosis of bacteremia in unwell patients. The treatment of bacteremia involves the rapid and accurate identification of the causative agent grown from the blood cultures collected. Contamination of blood cultures with non-pathogenic microbes such as skin commensals causes false positive results and subsequent unnecessary and potentially harmful interventions. While guidelines for blood culture quality recommend no more than 2-3% contamination rate, rates up to 12% are reported in the literature. There have been a number of methods proposed to reduce the contamination of blood cultures, including educational interventions, changing of skin cleansing preparations and introduction of blood culture collection packs in acute care settings. This protocol outlines methods to identify and evaluate interventions to reduce blood culture contamination in the acute care setting.

METHODS

The reviewers will conduct a systematic search of literature in CINHAL, PubMed, EMBASE and the Cochrane Central register of controlled trials. Unpublished works will be identified in ProQuest Dissertations and Theses. Articles will be assessed for relevance based on their title and abstract. Remaining relevant citations will have their full text retrieved and assessed against eligibility criteria. All studies that meet the eligibility criteria will have their methodological quality appraised. Assessments for relevance and methodological quality will be conducted independently by two reviewers. If appropriate, data will be analysed using the Mantel-Haenszel method under a random effects model. Heterogeneity of the studies will be assessed using the I 2 and chi-squared statistic. Meta-analysis will be attempted if the data is suitable.

DISCUSSION

This review will identify and summarise the interventions previously described in the literature aimed at reducing peripherally collected blood culture contamination rates in acute care. These findings have the potential to lead to multifaceted interventions based on previous evidence to reduce blood culture contamination in the acute setting. Reductions in the proportion of contaminated blood cultures have the potential to save money, unrequired treatment (particularly antimicrobials) and hospital bed days.

SYSTEMATIC REVIEW REGISTRATION

In accordance with guidelines outlined in the PRISMA-P methodology, this protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on December 8, 2017, and last updated on January 4, 2018 (registration number CRD42017081650).

Adverse Economic Impact Associated With Blood Culture Contamination in a Pediatric Emergency Department

BACKGROUND

Blood culture contamination (BCC) leads to unnecessary interventions including hospitalization, antibiotic administration and additional laboratory tests. Previous studies in adults revealed that BCC was associated with unnecessary financial expenditures. However, information pertaining to the pediatric population is limited. Therefore, we investigated the details of the adverse economic impact associated with BCC in a pediatric emergency department (ED) in Japan.

METHODS

This study was a retrospective, observational study. We collected data on blood cultures performed in patients 18 years of age in a pediatric ED. Medical records of patients with positive blood cultures were reviewed, and the information regarding adverse events related to BCC was extracted. Medical costs related to BCC were estimated from the data.

RESULTS

In total, 13,139 sets of blood cultures were performed from April 2013 to June 2016, and 141 cases (1.1%) of BCC were identified. Among these, 106 patients (75%) experienced at least 1 adverse event associated with BCC. The total medical cost due to BCC was 4,076,713 Japanese yen. Multifaceted approaches targeting ED physicians including lectures on optimal blood collection methods and monthly feedback on BCC rates were effective in reducing the BCC rate and its related costs.

CONCLUSIONS

Interventions associated with BCC were common and accounted for significant adverse economic impact on pediatric patients. Regular education and monitoring were effective in reducing BCC and its related costs.

Consequences of Implementing a "Better" Blood Culture System

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

How to: accreditation of blood cultures' proceedings. A clinical microbiology approach for adding value to patient care

BACKGROUND

Quality assurance and quality management are driving forces for controlling blood culture best practices but should not be disconnected from the end-point target, i.e. patient value.

AIMS

This article is intended to help microbiologists implement blood culture accreditation that is actually beneficial to patient management.

SOURCES

Experience from a nationwide taskforce for promoting quality assurance and competence in clinical microbiology laboratories, guidelines on blood culture.

CONTENT

Experience in blood culture accreditation according to International standard ISO 15189 standards is provided in this review, with a particular focus on critical points that are specific to blood culture (e.g. excluding strain identification or antimicrobial susceptibility testing). Blood culture test method verification is based on risk analysis, and evaluation of the test method's performance is based on the literature review and suppliers' data. In addition, blood culture performance relies largely on the quality of its pre-analytical phase, and the test method should be monitored based on key performance indicators such as the volume of blood cultured, the contamination rate and time to transportation. Other critical key indicators include the rate of false-positive signals, the rate of positive blood cultures, the ecology associated with positive results, and the timely communication of the results to the ward during the post-analytical phase. Finally, a critical analysis of quality controls and of the tools needed to improve blood culture monitoring in the future is provided.

IMPLICATION

Appropriate quality assurance should focus on patient value rather than technical details to provide an appropriate clinical service.

Impact of bacteremia prediction rule in CAP: Before and after study

OBJECTIVE

In cases of community acquired pneumonia (CAP), it has been known that blood cultures have low yields and rarely affect clinical outcomes. Despite many studies predicting the likelihood of bacteremia in CAP patients, those results have been rarely implemented in clinical practice, and use of blood culture in CAP is still increasing. This study evaluated impact of implementing a previously derived and validated bacteremia prediction rule.

METHODS

In this registry-based before and after study, we used piecewise regression analysis to compare the blood culture rate before and after implementation of the prediction rule. We also compared 30-day mortality, emergency department (ED) length of stay, time-interval to initial antibiotics after ED arrival, and any changes to the antibiotics regimen as results of the blood cultures. In subgroup analysis, we compared two groups (with or without the use of the prediction rule) after implementation period, using propensity score matching.

RESULTS

Following the implementation, the blood culture rate declined from 85.5% to 78.1% (P=0.003) without significant changes in 30-day mortality and antibiotics regimen. The interval to initial antibiotics (231min vs. 221min, P=0.362) and length of stay (1019min vs. 954min, P=0.354) were not significantly changed. In subgroup analysis, the group that use the prediction rule showed 25min faster antibiotics initiation (P=0.002) and 48min shorter length of stay (P=0.007) than the group that did not use the rule.

CONCLUSION

Implementation of the bacteremia prediction rule in CAP patients reduced the blood culture rate without affecting the 30-day mortality and antibiotics regimen.

Diagnostic Yield of Timing Blood Culture Collection Relative to Fever

BACKGROUND

Conventional practice involves obtaining a blood culture during or immediately after a fever to increase diagnostic yield. There are no data to support this practice in children.

METHODS

Retrospective single-center case-control study of children (0-18 years) who had blood cultures performed as part of routine care. Cases had an a priori defined pathogen isolated from blood culture (n = 410) and were age-matched with contemporaneous controls with a sterile blood culture (n = 410). The predictive value of fever (before and after blood culture), C-reactive protein and hematologic indices were analyzed by multivariate regression and area under the receiver operating characteristic curves (AUCs) in neonatal, general pediatric and pediatric oncology patients.

RESULTS

One thousand one hundred seventy-two (6.7%) of 17,607 blood cultures were positive, of which 410 (35%) cultured pathogen(s). Three hundred and twenty four (79%) cases and 275 (67.1%) controls had a fever (≥37.5°C) during the 12 hours pre- or post-collection. Fever 2-6 hours before a blood culture was neither sensitive nor specific for predicting bacteremia in neonatal or pediatric patients and marginally predictive in oncology patients (AUC 0.59-0.63). Cultures obtained 2-6 hours before fever were nonpredictive in neonates (AUC 0.56-0.59), marginally predictive in pediatric patients (AUC 0.64-0.67) and moderately predictive in oncology patients (AUC 0.70). C-reactive protein was marginally predictive in neonates (AUC 0.60). Hematologic indices were nonpredictive in all groups.

CONCLUSIONS

Fever before obtaining blood culture was neither sensitive nor specific for culture positivity; timing of pediatric blood cultures relative to fever is unimportant. Bacteremia precedes a fever, but this is of limited clinical applicability.

Multidisciplinary team review of best practices for collection and handling of blood cultures to determine effective interventions for increasing the yield of true-positive bacteremias, reducing contamination, and eliminating false-positive central line-associated bloodstream infections

BACKGROUND

A literature search was conducted using keywords for articles published in English from January 1990 to March 2015. Using criteria related to blood culture collection and handling, the search yielded 101 articles. References used also included Microbiology Laboratory standards, guidelines, and textbook information.

RESULTS

The literature identified diverse and complex issues surrounding blood culture practices, including the impact of false-positive results, laboratory definition of contamination, effect on central line-associated bloodstream infection (CLABSI) reporting, indications for collecting blood cultures, drawing from venipuncture sites versus intravascular catheters, selection of antiseptics, use of needleless connectors, inoculation of blood culture bottles, and optimizing program management in emergency departments, education, and implementation of bundled practice initiatives.

CONCLUSION

Hospitals should optimize best practice in the collection, handling, and management of blood culture specimens, an often overlooked but essential component in providing optimal care of patients in all settings and populations, reducing financial burdens, and increasing the accuracy of reportable CLABSI. Although universal concepts exist in blood culture practices, some issues require further research to determine benefit. Institutions undertaking a review of their blood culture programs are encouraged to use a checklist that addresses elements that encompass the research contained in this review.

Factors Associated with Blood Culture Contamination in the Emergency Department: Critical Illness, End-Stage Renal Disease, and Old Age

Background

Blood culture contamination in emergency departments (ED) that experience a high volume of patients has negative impacts on optimal patient care. It is therefore important to identify risk factors associated with blood culture contamination in EDs.

Methodology/Principal Findings

A prospectively observational study in a university-affiliated hospital were conducted between August 2011 and December 2012. Positive monomicrobial and negative blood cultures drawn from adult patients in the ED were analyzed to evaluate the possible risk factors for contamination. A total of 1,148 positive monomicrobial cases, 391 contamination cases, and 13,689 cases of negative blood culture were identified. Compared to patients with negative blood cultures, patients in triage levels 1 and 2 (Incidence Rate Ratio, IRR = 2.24), patients with end-stage renal disease (ESRD) (IRR = 2.05), and older patients (IRR: 1.02 per year) were more likely to be associated with ED blood culture contamination.

Conclusions/Significance

Critical patients (triage levels 1 and 2), ESRD patients, and older patients were more commonly associated with blood culture contamination in the ED. Further studies to evaluate whether the characteristics of skin commensals contribute to blood culture contamination is warranted, especially in hospitals populated with high-risk patients.

Cost analysis of strategies to reduce blood culture contamination in the emergency department: sterile collection kits and phlebotomy teams

OBJECTIVE

Blood culture collection practices that reduce contamination, such as sterile blood culture collection kits and phlebotomy teams, increase up-front costs for collecting cultures but may lead to net savings by eliminating downstream costs associated with contamination. The study objective was to compare overall hospital costs associated with 3 collection strategies: usual care, sterile kits, and phlebotomy teams.

DESIGN

Cost analysis.

SETTING

This analysis was conducted from the perspective of a hospital leadership team selecting a blood culture collection strategy for an adult emergency department (ED) with 8,000 cultures drawn annually.

METHODS

Total hospital costs associated with 3 strategies were compared: (1) usual care, with nurses collecting cultures without a standardized protocol; (2) sterile kits, with nurses using a dedicated sterile collection kit; and (3) phlebotomy teams, with cultures collected by laboratory-based phlebotomists. In the base case, contamination rates associated with usual care, sterile kits, and phlebotomy teams were assumed to be 4.34%, 1.68%, and 1.10%, respectively. Total hospital costs included costs of collecting cultures and hospitalization costs according to culture results (negative, true positive, and contaminated).

RESULTS

Compared with usual care, annual net savings using the sterile kit and phlebotomy team strategies were $483,219 and $288,980, respectively. Both strategies remained less costly than usual care across a broad range of sensitivity analyses.

CONCLUSIONS

EDs with high blood culture contamination rates should strongly consider evidence-based strategies to reduce contamination. In addition to improving quality, implementing a sterile collection kit or phlebotomy team strategy is likely to result in net cost savings.