Educational intervention as an effective step for reducing blood culture contamination: a prospective cohort study

American Society for Microbiology evidence-based laboratory medicine practice guidelines to reduce blood culture contamination rates: a systematic review and meta-analysis

SUMMARYBlood cultures (BCs) are one of the critical tests used to detect bloodstream infections. BC results are not 100% specific. Interpretation of BC results is often complicated by detecting microbial contamination rather than true infection. False positives due to blood culture contamination (BCC) vary from 1% to as high as >10% of all BC results. False-positive BC results may result in patients undergoing unnecessary antimicrobial treatments, increased healthcare costs, and delay in detecting the true cause of infection or other non-infectious illness. Previous guidelines from the Clinical and Laboratory Standards Institute, College of American Pathologists, and others, based on expert opinion and surveys, promoted a limit of ≤3% as acceptable for BCC rates. However, the data supporting such recommendations are controversial. A previous systematic review of BCC examined three practices for reducing BCC rates (venipuncture, phlebotomy teams, and pre-packaged kits). Subsequently, numerous studies on different practices including using diversion devices, disinfectants, and education/training to lower BCC have been published. The goal of the current guideline is to identify beneficial intervention strategies to reduce BCC rates, including devices, practices, and education/training by providers in collaboration with the laboratory. We performed a systematic review of the literature between 2017 and 2022 using numerous databases. Of the 11,319 unique records identified, 311 articles were sought for full-text review, of which 177 were reviewed; 126 of the full-text articles were excluded based on pre-defined inclusion and exclusion criteria. Data were extracted from a total of 49 articles included in the final analysis. An evidenced-based committee's expert panel reviewed all the references as mentioned in Data Collection and determined if the articles met the inclusion criteria. Data from extractions were captured within an extraction template in the US Agency for Healthcare Research and Quality's Systematic Review Data Repository (https://srdr.ahrq.gov/). BCC rates were captured as the number of events (contaminated samples) per arm (standard practice versus improvement practice). Modified versions of the National Heart, Lung, and Blood Institute Study Quality Assessment Tools were used for risk of bias assessment (https://www.nhlbi.nih.gov/health-topics/study-quality-assessment-tools). We used Grading of Recommendations, Assessment, Development and Evaluations to assess strength of evidence. There are several interventions that resulted in significant reduction in BCC rates: chlorhexidine as a disinfectant for skin preparation, using a diversion device prior to drawing BCs, using sterile technique practices, using a phlebotomy team to obtain BCs, and education/training programs. While there were no substantial differences between methods of decreasing BCC, our results indicate that the method of implementation can determine the success or failure of the intervention. Our evidence-based systematic review and meta-analysis support several interventions to effectively reduce BCC by approximately 40%-60%. However, devices alone without an education/training component and buy-in from key stakeholders to implement various interventions would not be as effective in reducing BCC rates.

Effectiveness of A Nurse-Led Multimodal Intervention in Preventing Blood Culture Contamination: A Before-and-After Study

Blood culture is crucial for accurate and timely bacteremia diagnosis and guide antibiotic therapy. However, during culture sampling, contamination can occur, resulting in misdiagnosis, unnecessary antibiotic exposure, and prolonged hospitalization. This before-and-after intervention study aimed to evaluate the effectiveness of a multimodal intervention in preventing blood culture contamination. The study was conducted in a 170-bed hospital in Portugal and included a total of 23,566 blood cultures. Contamination rates were assessed in two phases: Phase 1 (before intervention, month 0) included 10,928 cultures, and Phase 2 (after intervention, month 6) included 12,638 cultures. During the study period, a multimodal intervention targeting the nursing staff was implemented, consisting of training actions, guideline updates, regular data monitoring and feedback, and introduction of a blood culture pack. Following the intervention, blood culture contamination decreased from 6.8% (Phase 1) to 3.9% (Phase 2). A comparative analysis revealed that the risk of contamination before the intervention was nearly four times higher in first culture, OR = 3.97 (CI 2.86-5.49). Our findings suggest that the multimodal intervention enhanced nurses' adherence to recommended practices, resulting in a reduced risk of blood culture contamination, earlier identification of infectious agents, and improved accuracy of antibiotic therapy.

Microbiological performance and adherence in blood culture protocols: The role of a second anaerobic bottle

Background

Bacteremia represents high rates of morbidity and mortality, especially in developing countries, highlighting the need for a diagnostic method that allows prompt and appropriate patient treatment. This study compared microbiological performance and adherence of two blood culture protocols for the diagnosis of bacteremia.

Methods

Quasi-experimental study conducted between June 2022 and February 2023. Two blood culture protocols were evaluated. Protocol 1 included two aerobic bottles and one anaerobic bottle. Protocol 2 included two aerobic and two anaerobic bottles. Protocols were analyzed in three phases: evaluation of protocol 1 (Phase 1); evaluation of protocol 1 plus educational activities for healthcare staff (Phase 2) and evaluation of protocol 2 (Phase 3).

Results

342 patients and 1155 blood culture bottles (732 aerobic and 423 anaerobic) were included. Positivity was 17.6 %, 22.8 % and 19.4 % in phases 1, 2 and 3, respectively. Among patients with bacteremia, 84.5 % had positive anaerobic bottles, with 9.9 % showing growth only in this bottle. The contamination rates were 1.9 %, 0.3 %, and 0.8 % for each phase, mainly in aerobic bottles. Median positivity time was 11 h for both bottes aerobic and anaerobic. Overall nursing adherence increased from 13.1 % in Phase 1, 25.9 % in Phase 2, and 28.1 % in Phase 3 (p = 0.009).

Conclusions

The findings indicate that adding a second anaerobic bottle does not enhance blood culture positivity. Rather than increasing bottle quantity, staff training might be a more effective approach to optimize results.

Reducing Blood Culture Contamination Rates: Introduction of a Combined Education and Skin Antisepsis Intervention

Background. Blood culture contamination (BCC) is an important quality concern in clinical microbiology as it can lead to unnecessary antimicrobial therapy in patients and increased workload for laboratory scientists. The Clinical Laboratory and Standards Institute recommend BCC rates to be <3 % and recently updated guidelines have set a new goal of 1 %. The aim of this project was to design and implement interventions to reduce BCC rates at our institution. Methods. We introduced a combined education and skin antisepsis intervention in a large Model 4 academic teaching hospital in the South of Ireland. BD ChloraPrep skin antisepsis applicators (2 % chlorhexidine gluconate/70 % isopropyl alcohol), licensed for use for blood culture specimen collection, were introduced, replacing Clinell (2 % chlorhexidine gluconate/70 % isopropyl alcohol) wipes. In addition, a multimodal education programme was designed and delivered. This consisted of a video demonstrating the recommended blood culture specimen collection technique using the new applicators as well as simulation training for all interns. The video was uploaded to the intranet as an educational resource available to all staff. Results. The interventions were implemented in July 2022 and BCC rates pre- and post-intervention were calculated. The average BCC rate for the 12 months preceding the intervention (July 2021 to July 2022) was 2.56 % with highest rates in the Emergency Department. This compared to an average rate of 2.2 % in the 12 months post-intervention (July 2022 to July 2023). In comparing the two rates the reduction in BCC rates between the two periods was not statistically significant (P=0.30). Conclusion. Overall BCC rates reduced but the difference between the two periods did not reach statistical significance. The resource-intensive nature of providing regular and timely feedback of contamination rates and the larger impact of in-person education and training over virtual modalities may explain the modest reduction. Further investments in these areas, particularly in the Emergency Department, will be necessary to further reduce rates in line with new recommendations.

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.

Development and validation of a standardized blood culture contamination definition and metric dashboard for a large health care system

OBJECTIVES

Blood culture contamination is a major problem in health care, with significant impacts on both patient safety and cost. Initiatives to reduce blood culture contamination require a reliable, consistent metric to track the success of interventions. The objective of our project was to establish a standardized definition of blood culture contamination suitable for use in a Veterans Health Administration (VHA) national data query, then to validate this definition and query. A secondary objective was to construct a national VHA data dashboard to display the data from this query that could be used in VHA quality improvement projects aimed at reducing blood culture contamination.

METHODS

A VHA microbiology expert work group was formed to generate a standardized definition and oversee the validation studies. The standardized definition was used to generate data for calendar year 2021 using a Structured Query Language data query. Twelve VHA hospital microbiology laboratories compared the data from the query against their own locally derived contamination data and recorded those data in a data collection worksheet that all sites used. Data were collated and presented to the work group.

RESULTS

More than 50,000 blood culture accessions were in the validation data set, with more than 1,200 contamination events. The overall blood culture contamination rate for the 12 facilities participating was 2.56% with local definitions and data and 2.43% with the standardized definitions and data query. The main differences noted between the 2 data sets were deemed to be issues in local definitions. The query and definition were then converted into a national data dashboard that all VHA facilities can now access.

CONCLUSIONS

A standardized definition for blood culture contamination and a national data query were validated for enterprise-wide VHA use. To our knowledge, this represents the first reported standardized, validated, and automated approach for calculating and tracking blood culture contamination. This tool will be key in quality initiatives aimed at reducing contamination events in VHA.

Identification of the main contributors to blood culture contamination at a tertiary care academic medical center

Background

Blood culture contamination poses an issue to all hospital systems worldwide because of the associated costs of extended length of stays, unnecessary antibiotic therapy, and additional laboratory testing that are preventable with proper handling and collection techniques.

Methods

In our study, multiple units, staff, and collection methods were compared to determine the primary culprits of contamination from a tertiary care academic medical center, which includes a pediatric hospital and both adult and pediatric emergency departments.

Results

Over 33 months, 2,083 out of 88,322 total blood cultures collected were contaminated, with an overall contamination rate of 2.4%. A moderate positive correlation was found between the monthly total number of cultures and monthly contamination rate (r = 0.411 P < .01). The most notable factors associated with contamination were found to be phlebotomy teams (2.7%) (P < .01), peripheral draws (2.3%) (P <.01), adult emergency departments (2.6%) (P < .01), and pediatric intensive care units (2.7%) (P < .01). A positive correlation was present between the number of hospital beds per unit and unit contamination rates (r = 0.429 P < .01).

Conclusion

Our results were used to make recommendations for decreasing the rate of blood culture contamination in this institution, which includes acknowledgement of an overwhelmed staff and mandatory periodic training on acceptable aseptic technique and contamination awareness. Understanding the factors contributing to blood culture contamination can aid efforts to reduce contamination rates.

The Diagnostic Yield of Routine Admission Blood Cultures in Critically Ill Patients

OBJECTIVES

Although the Surviving Sepsis Campaign bundle recommends obtaining blood cultures within 1 hour of sepsis recognition, adherence is suboptimal in many settings. We, therefore, implemented routine blood culture collection for all nonelective ICU admissions (regardless of infection suspicion) and evaluated its diagnostic yield.

DESIGN

A before-after analysis.

SETTING

A mixed-ICU of a tertiary care hospital in the Netherlands.

PATIENTS

Patients acutely admitted to the ICU between January 2015 and December 2018.

MEASUREMENTS AND MAIN RESULTS

Automatic orders for collecting a single set of blood cultures immediately upon ICU admission were implemented on January 1, 2017. Blood culture results and the impact of contaminated blood cultures were compared for 2015-2016 (before period) and 2017-2018 (after period). Positive blood cultures were categorized as bloodstream infection or contamination. Blood cultures were obtained in 573 of 1,775 patients (32.3%) and in 1,582 of 1,871 patients (84.5%) in the before and after periods, respectively (p < 0.0001), and bloodstream infection was diagnosed in 95 patients (5.4%) and 154 patients (8.2%) in both study periods (relative risk 1.5; 95% CI 1.2-2.0; p = 0.0006). The estimated number needed to culture for one additional patient with bloodstream infection was 17. Blood culture contamination occurred in 40 patients (2.3%) and 180 patients (9.6%) in the before period and after period, respectively (relative risk 4.3; 95% CI 3.0-6.0; p < 0.0001). Rate of vancomycin use or presumed episodes of catheter-related bloodstream infections treated with antibiotics did not differ between both study periods.

CONCLUSIONS

Implementation of routine blood cultures was associated with a 1.5-fold increase of detected bloodstream infection. The 4.3-fold increase in contaminated blood cultures was not associated with an increase in vancomycin use in the ICU.

Reducing Blood Culture Contamination Rates: Experiences of Four Hospital Systems

INTRODUCTION

Blood cultures (BCs) frequently become contaminated during the pre-analytic phase of collection leading to downstream ramifications. We present a summary of performance improvement (PI) interventions provided by four hospital systems and common factors that contributed to decreased blood culture contamination (BCC) rates.

METHODS

Each hospital independently formed a multidisciplinary team and action plan for implementation of their intervention, focusing on the use of educational and training tools. Their goal was to significantly decrease their BCC rates. Pre- and post-intervention data were compared during the sustainment period to determine their success.

RESULTS

All hospitals met their goals of post-intervention BCC rates and with most achieving and sustaining BCC rates ≤ 1.0-2.0%.

CONCLUSION

Our report highlights how four hospitals independently achieved their objective to decrease their BCC rate with the support of a multidisciplinary team. We propose a benchmark for BCC rates of 1.5 to < 2.0% as achievable and sustainable.

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.

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.

The effectiveness of an online training program in a nursing unit: extraction of blood cultures

OBJECTIVE

To assess the effectiveness of an online training platform for procedures among nurses in an internal medicine unit to reduce the number of contaminated blood cultures.

METHOD

This was a quasi-experimental pre-post intervention parallel group study. The sample consisted of internal medicine nurses in a tertiary hospital who participated in an online training program about blood culture extraction technique. Knowledge about the technique was measured pre- and post-intervention. Additionally, the study compared the number of blood cultures taken 6 months before and 3 months after the intervention.

RESULTS

Forty-eight nurses participated. Pre-intervention knowledge was homogeneous among both groups, improving significantly after the online training program (p=0.0001). The blood cultures taken prior to the training showed contamination levels above international standards; post-intervention, contamination levels fell by up to 3% in the intervention group.

CONCLUSION

The educational intervention using the digital platform increased knowledge about the procedure and its application in clinical practice.

Establishing a Long-Term Model for Analysis and Improvement of Underfilled Blood Culture Volumes

Objectives

Underfilling of blood culture bottles decreases the sensitivity of the culture. We attempt to increase average blood culture fill volumes (ABCFVs) through an educational program.

Methods

Partnerships were established with four hospital units (surgical intensive care unit [SICU], medical intensive care unit [MICU], medical intermediate care unit [MIMCU], and hematology and oncology unit [HEME/ONC]). ABCFVs were continuously tracked and communicated to each unit monthly. Educational sessions were provided to each unit.

Results

ABCFVs for the SICU, MICU, MIMCU, and HEME/ONC were 4.8, 5.0, 5.0, and 6.3 mL/bottle, respectively. After the final education session, the SICU, MICU, MIMCU, and HEME/ONC were able to maintain an ABCFV of 6.8, 8.1, 7.9, and 8.2 mL/bottle, respectively.

Conclusions

Partnering with a specific unit and providing monthly volume reports with educational sessions has a direct positive correlation on increasing ABCFVs. Increasing ABCFVs has the potential to decrease false-negative blood cultures, time to detection of positive blood cultures, and time to appropriate and specific antimicrobial therapy, as well as improve patient outcomes in high-acuity patient care units.

A Quality Improvement Initiative: Reducing Blood Culture Contamination in a Children's Hospital

BACKGROUND AND OBJECTIVE

Blood culture contamination is a safety and quality concern in children's hospitals; it leads to increased unnecessary testing, admissions, antibiotic exposure, and cost. The standard benchmark for blood culture contamination is 3%. Our aim with the quality improvement project was to reduce the contamination rate at our children's hospital from a mean of 2.85% to <1.5% in 2 years.

METHODS

After initial unit-specific efforts, we formed a multidisciplinary team, created a process map and a cause-and-effect analysis, sent out surveys to nurses, and created observation sheets used to identify problem areas and record the most common deviations during the collection process. We also standardized the blood culture collection protocol and reemphasized nurse education in person and with online modules. During our project, we noted that nurses were collecting 1 to 3 mL of blood on all children regardless of weight. We developed optimal weight-based blood volumes and, after educating ordering providers, we updated our electronic medical record to reflect appropriate volumes in the order.

RESULTS

Despite a steady increase in the number of blood cultures collected at our children's hospital, we were able to decrease the average contamination rate from 2.85% to 1.54%, saving the hospital an estimated average of $49 998 per month.

CONCLUSIONS

By standardizing blood culture collection methods, optimizing blood volume, creating checklists, and reinforcing nurse education, we were able to develop a best practice for pediatric blood culture collection and reduce blood culture contamination to a sustainable low rate at our children's hospital.

Reduction in Blood Culture Contamination Through Use of Initial Specimen Diversion Device

Background

Blood culture contamination is a clinically significant problem that results in patient harm and excess cost.

Methods

In a prospective, controlled trial at an academic center Emergency Department, a device that diverts and sequesters the initial 1.5-2 mL portion of blood (which presumably carries contaminating skin cells and microbes) was tested against standard phlebotomy procedures in patients requiring blood cultures due to clinical suspicion of serious infection.

Results

In sum, 971 subjects granted informed consent and were enrolled resulting in 904 nonduplicative subjects with 1808 blood cultures. Blood culture contamination was significantly reduced through use of the initial specimen diversion device™ (ISDD) compared to standard procedure: (2/904 [0.22%] ISDD vs 16/904 [1.78%] standard practice, P = .001). Sensitivity was not compromised: true bacteremia was noted in 65/904 (7.2%) ISDD vs 69/904 (7.6%) standard procedure, P = .41. No needlestick injuries or potential bloodborne pathogen exposures were reported. The monthly rate of blood culture contamination for all nurse-drawn and phlebotomist-drawn blood cultures was modeled using Poisson regression to compare the 12-month intervention period to the 6 month before and after periods. Phlebotomists (used the ISDD) experienced a significant decrease in blood culture contamination while the nurses (did not use the ISDD) did not. In sum, 73% of phlebotomists completed a post-study anonymous survey and widespread user satisfaction was noted.

Conclusions

Use of the ISDD was associated with a significant decrease in blood culture contamination in patients undergoing blood cultures in an Emergency Department setting.

Clinical Trials Registration

NCT02102087.

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.