Blood Culture
Collection Guidelines

Association for Vascular Access (AVA)

Recommendation 1: Use of Blood Culture Diversion Devices

It is reasonable to use blood culture diversion devices (BCDDs) during specimen collection when contamination is possible.

‍

Summary of Evidence

Authors of a prospective, quasi-experimental study assessed contamination rates among intensive care unit (ICU) and non-ICU patients where phlebotomists used either traditional veni­puncture or a BCDD. Use of the BCDD resulted in a 0% con­tamination rate across 11,202 samples compared with a 2.3% contamination rate from 4,759 traditional samples. The authors also reported a significant reduction in false-positive central line–associated bloodstream infection (CLABSI) diagnoses when BCDD were used, supporting their utility in improving diagnostic accuracy and avoiding unnecessary treatment.

Since early 2020, the CMS Conditions of Participation have required hospitals to “demonstrate adherence to nationally recognized infection prevention and control guidelines for reducing the transmission of infections, as well as best practices for improving antibiotic use where applicable, and for reducing the development and transmission of HAIs and antibiotic-resistant organisms.” CMS Compliance will require:

1. A hospital’s infection prevention and control and antibiotic stewardship programs be active and hospital-wide for the surveillance, prevention, and control of [hospital acquired infections] and other infectious diseases.
2. Optimization of antibiotic use through stewardship.

‍

In December 2022, a Centers for Medicare & Medicaid Services (CMS) Consensus-Based Entity (CBE) endorsed the CDC's proposal to establish a national patient safety measure focused on BCC. (10.1093/jalm/jfae132)

In offering guidance, the CDC references a study by Doern GV et al, which calls for the use of diversion devices saying, “There are devices that are commercially available that have shown promise in further reducing blood culture contamination rates. These devices initially divert a small amount of potentially contaminated blood and then collect blood for the blood culture.”

Source: Blood Culture Contamination: An Overview for Infection Control and Antibiotic Stewardship Programs Working with the Clinical Laboratory

This 2022 CLSI guideline provides comprehensive recommendations for blood culture collection, transport, processing, and result interpretation to enhance the detection of bacteremia and fungemia. M47 supports improved laboratory practices for detecting bloodstream infections, helping clinicians make informed treatment decisions.

Recommendation: Consider the use of a waste tube or diversion device as a strategy for reducing blood culture contamination rates when blood culture contamination rates are higher than expected despite high compliance with appropriate collection technique. Further research is necessary to understand the relationship between initial specimen diversion and bloodstream infection.

PQM Recommendations for Blood Culture Collection‍

1. Blood Culture Contamination Rate (BCC)

• PQM sets a benchmark maximum contamination rate of 3% for adult blood cultures. However, many hospitals report wide variation, ranging from 0.6% up to 12.5% in some settings.
• Institutions should track and report this rate monthly, calculating it as:
  
  (Number of contaminated blood culture sets ÷ Total number of blood culture sets collected) × 100

• While 3% is the established standard, PQM notes that some systems achieve rates well below this threshold. The ideal goal, per PQM, is to drive contamination rate as close to 0% as possible.

2. Single-Set Blood Culture Rate (Inadequate Volume)

• PQM also emphasizes the importance of monitoring the rate of single-set blood cultures, which are defined as instances where only one culture set is collected within a 24-hour period. This typically yields insufficient diagnostic volume and impairs the ability to distinguish true bacteremia from contamination.
• The single-set rate is similarly calculated monthly as:
  
  (Number of single set blood cultures without another set collected within 24 hours ÷ Total blood culture sets collected) × 100

3. Recommended Blood Culture Practices

• For adult patients with suspected bloodstream infections, PQM endorses collecting two to four blood culture sets per septic episode (defined as a 24-hour period) to ensure adequate detection of bacteremia and proper differentiation of contaminants.
• PQM supports the inclusion of blood volume as a future required measure, with a target of 40–60 mL per septic episode, to strengthen diagnostic accuracy.

4. PQM Timeline for Implementation

By 2026–2029, PQM plans to:

• Review and update the measure based on ongoing literature and practice.
• Begin collecting and monitoring both contamination and volume data, including the proportion of single sets.
• By 2029, PQM aims to make these measures—BCC rate and blood volume collected—required reporting components for hospital accreditation and CMS quality programs.

In Table 10. Examples of Relevant Supporting Metrics for HOB Management, (pg. 48), NQF includes a supporting metric for HOB management that states, "Use of blood culture diversion device or waste tubes to reduce contamination, unless drawing through device to identify suspected source of infection." In Phase 4 – Continuous Improvement, the Playbook identifies several metrics tied to blood culture practices:

• Number of blood cultures collected as contaminants
• Blood culture contamination rate
• Number of common commensals identified from contaminated cultures
• Days of therapy avoided as a result of identifying contaminated cultures

The 2024 ASM guidelines include the following excerpt:

Key action statement: institutions (facilities) that draw BCs should consider implementing a diversion device as part of the procedure for drawing peripheral BCs (evidence quality: II, recommendation strength: moderate).

Aggregate evidence quality: II

Benefits: diversion devices reduce BCC by an average of 64% and may lead to more appropriate therapy for bloodstream infections.

Risk, harm, and cost: there is a potential to contribute to iatrogenic anemia in patients with prolonged hospital stays with frequent phlebotomy to obtain BCs if large amounts of blood are discarded. Diversion tubes must be labeled with patient information as with any other specimen tube to avoid unlabeled or mislabeled tubes being processed for other lab studies. The cost of using a non-commercial diversion tube should keep additional costs to a minimum.

Benefit–harm assessment: preponderance of benefit.

The Subcommittee report includes the following excerpt:

"Recent attention has been given to lowering the acceptable threshold to ≤ 1%, as it has been noted that this rate is achievable even without blood diversion devices. In large studies, high-performing (90th percentile and above) laboratories have reported contamination rates of ≤ 1%. Therefore, this threshold may be considered aspirational by some. Conversely, a BCC rate of ≤ 1% may not always be achievable due to an expected baseline of transient bacteremia and true bacteremia that qualify as contamination based on laboratory criteria. Some investigators have reported that even with the use of initial blood diversion devices, rates lower than 1% may not be attained in some environments. In any case, institutions may choose to lower the acceptable threshold from the standard ≤ 3% to a level that is practically achievable while ensuring the highest quality BC collections."

The Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases was updated in 2024 by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM).

‍The update includes a section entitled "Bloodstream infections and infections of the cardiovascular system" (page 6) which includes the following recommendation: "To minimize the risk of contamination of the blood culture with commensal skin microbiota, meticulous care should be taken in skin preparation prior to venipuncture. In addition, products are available that allow diversion and discard of the first few milliliters of blood that are most likely to contain skin contaminant."

The 2024 INS Guidelines on Blood Culture Diversion includes Section 41: Blood Sampling – Practice Recommendations Comment G, Part C, which suggests: “Consider the costs and benefits in implementing a consistent process to divert and discard the initial blood sample when drawing blood cultures. Studies have demonstrated reduction in blood culture contamination with use of a diversion device.”

While CAP does not formally mandate diversion, it acknowledges that diversion devices can help reduce contamination and may be considered as part of improvement strategies. CAP publications highlight the effectiveness of diversion:

• A laboratory stewardship case presented via CAP’s executive insights reported how diversion reduced contamination rates from about 3% to ≤ 1%, providing significant clinical and financial benefits. (info.cap.org)
• In CAP Today (2017), diversion was described as a simple yet powerful method to reduce contamination—with studies showing up to 85% reduction in skin flora contamination. captodayonline.com

The ENA guidelines highlight blood culture diversion in Recommendation 13:

"The ENA advises that when drawing blood culture specimens via peripheral venipuncture, practitioners should divert the initial 1–2 mL of blood into a sterile receptacle—i.e., perform specimen diversion as part of the collection process. This recommendation is graded as Level B – Moderate evidence."

NICE has made this recommendation because although there is uncertainty around the evidence of cost effectiveness for Kurin Lock, antimicrobial resistance is an area of high unmet need in the NHS.

Adopting Kurin Lock would need no change to standard practice. Clinical experts report that it is easy to use and needs minimal training compared with other methods to reduce contamination.

Evidence generation alongside using Kurin Lock in the NHS should give an opportunity to collect resource impact data to inform the economic modelling.

These recommendations will be reviewed within 3 years, or sooner if new evidence becomes available. Take this and the uncertainty around pricing into account when negotiating lengths of contracts.