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.
De Leon, Samuel Ponce, and Richard P. Wenzel. "Hospital-acquired bloodstream infections with Staphylococcus epidermidis: review of 100 cases."The American journal of medicine 77.4 (1984): 639-644.
Haslett, T. M., et al. "Microbiology of indwelling central intravascular catheters."Journal of clinical microbiology 26.4 (1988): 696-701.
Stohl, Sheldon, et al. "Blood cultures at central line insertion in the intensive care unit: comparison with peripheral venipuncture." Journal of clinical microbiology 49.7 (2011): 2398-2403.
Beekmann, Susan E., Daniel J. Diekema, and Gary V. Doern. "Determining the clinical significance of coagulase-negative staphylococci isolated from blood cultures." Infection control and hospital epidemiology 26.6 (2005): 559-566.
Raad, Issam, et al. "Impact of central venous catheter removal on the recurrence of catheter-related coagulase-negative staphylococcal bacteremia."Infection control and hospital epidemiology (1992): 215-221.
Raad, Issam, et al. "Management of the catheter in documented catheter-related coagulase-negative staphylococcal bacteremia: remove or retain?."Clinical infectious diseases 49.8 (2009): 1187-94.
Raad, Issam, et al. "Differential time to positivity: a useful method for diagnosing catheter-related bloodstream infections." Annals of Internal Medicine 140.1 (2004): 18-25.
Chu, Vivian H., et al. "Emergence of coagulase-negative staphylococci as a cause of native valve endocarditis." Clinical infectious diseases 46.2 (2008): 232-242.
Blot, François, et al. "Earlier positivity of central-venous-versus peripheral-blood cultures is highly predictive of catheter-related sepsis." Journal of clinical microbiology 36.1 (1998): 105-109.
DesJardin, Jeffrey A., et al. "Clinical utility of blood cultures drawn from indwelling central venous catheters in hospitalized patients with cancer."Annals of internal medicine 131.9 (1999): 641-647.
Hall, Keri K., and Jason A. Lyman. "Updated review of blood culture contamination." Clinical microbiology reviews 19.4 (2006): 788-802.
Bates, David W., Lee Goldman, and Thomas H. Lee. "Contaminant blood cultures and resource utilization: the true consequences of false-positive results." JAMA 265.3 (1991): 365-369.
Souvenir, David, et al. "Blood cultures positive for coagulase-negative staphylococci: antisepsis, pseudobacteremia, and therapy of patients." Journal of clinical microbiology 36.7 (1998): 1923-1926.
Bates, David W., and Thomas H. Lee. "Rapid classification of positive blood cultures: prospective validation of a multivariate algorithm." Jama 267.14 (1992): 1962-1966.
Weinstein, Melvin P., et al. "The clinical significance of positive blood cultures in the 1990s: a prospective comprehensive evaluation of the microbiology, epidemiology, and outcome of bacteremia and fungemia in adults." Clinical Infectious Diseases 24.4 (1997): 584-602.
Gowardman, J. R., et al. "Central venous catheter-related bloodstream infections: an analysis of incidence and risk factors in a cohort of 400 patients." Intensive care medicine 24.10 (1998): 1034-1039.
Beekmann, Susan E., Daniel J. Diekema, and Gary V. Doern. "Determining the clinical significance of coagulase-negative staphylococci isolated from blood cultures." Infection Control 26.06 (2005): 559-566.
Tokars, Jerome I. "Predictive value of blood cultures positive for coagulase-negative staphylococci: implications for patient care and health care quality assurance." Clinical infectious diseases 39.3 (2004): 333-341.