Blood culture sampling for diagnosis of bloodstream infection in adults: A scoping review

Project overview 

This project is intended to help inform NHS best practice when identifying bloodstream infections and sepsis in adults through identifying, categorising, and summarising evidence related to the collection of two or more sets of blood culture samples versus collecting one set.

If feasible, the project will be extended to conduct a fuller systematic review and an economic analysis on the clinical implications and cost-benefits of using a single blood culture set rather than two or more sets when identifying bloodstream infections and sepsis in adults.

Status: ongoing

Contact: mark.simmonds@york.ac.uk 

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What is the problem?

Sepsis and other bloodstream infections are a major risk to health. In the UK, around 245,000 people are affected by sepsis every year, of which there are 48,000 related deaths. Blood infection is normally diagnosed by a prompt blood test, which is sent to a laboratory to test for presence of bacteria. This is called a blood culture. The current guidance recommends collecting two complete “sets” of blood culture bottles. However, recent evidence suggests that collecting from a single site may be superior to samples collected from two or more sites. Transitioning to collecting two blood culture sets rather than one carries substantial cost and capacity implications for NHS pathology services, which could lead to processing delays.

Rapid and accurate diagnosis of BSI is a national priority and the identification of evidence in this area will support the implementation of best practice on how best to collect blood cultures for the diagnosis of bloodstream infections and sepsis. Findings from this review will also be used to inform the upcoming national audit on the “two-set usage” metric across the NHS.

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What are we doing? 

This project will review all the available literature on how many “sets” of blood cultures to take in adults to detect blood stream infections. This review will take the form of a scoping review initially, intended to identify and broadly categorise and summarise the available clinical and economic evidence on the topic. We will search medical databases to identify all relevant studies. The identified studies will be presented and summarised in an online “Evidence Map” which will categorise studies by theme, population and other characteristics so the range of evidence can be seen.

The intention of this scoping review and evidence map is to inform a subsequent systematic review and economic analysis. This scoping review will be used to determine if there is sufficient evidence to proceed to a fuller systematic review and economic analysis, and what further analysis is most appropriate and useful in the NHS context. A full systematic review would examine those studies of most relevance to NHS practice in greater detail. If feasible, an economic analysis will investigate the costs, benefits, and implications of using a single blood culture set instead of multiple sets in the NHS.