What is a clinically significant coagulase-negative staph bacteraemia? This has exam relevance. Question 14 from the second paper of 2017 asked various detailed questions about coagulase-negative staphylococci, and Question 23.1 from the first paper of 2013 asks the candidate how they would react to a S.epidermidis growing from a culture which was drawn from a central line in the process of insertion. For a coherent answer, the time-poor exam candidate is redirected to the LITFL article on CRBSI and CLABSI. That is what you call a "brief summary". In contrast, what follows here may represent spontaneous prose.
So, your CVC culture is positive. What could this mean?
Positive cultures collected from the CVC could mean one of three things:
Generally speaking, the practice of taking cultures from CVCs is discouraged by guideline-makers (eg. the American College of Physicians).
A recent (2006) review article suggests some strategies to help you tell which CVC culture warrants CVC removal, and which does not.
Coagulase-negative staphylococci represent an area of uncertain twilight between these two groups. For most, these are benign contaminants. For some, they are horrific valve-eating pathogens. Practically speaking, it does not matter to the intensivist whether the blood culture represents systemic bacteraemia or catheter colonisation; rather it is more important to determine whether the clinical scenario warrants concern. If you're concerned, you will remove the line and start antibiotics.
Question 23.1 from the first paper of 2013 asks the candidate how they would react to a S.epidermidis growing from a culture which was drawn from a central line in the process of insertion.
In other words, people with the above risk factors are much more likely to have a serious problem if they really do have S.epidermidis in their blood; which means that the risk-benefit balance favours the removal of the CVC and the commencement of antibiotics.