How many times have you heard that arterial lines do not become infected. In a recent discussion I was informed that the reason these types of catheters are not a source of infection is that the blood flow is too fast; bacteria are not strong enough to hang on! Is this true?
To offer an insight into a possible answer to this question I decided to reverse the question. Which practices associated with arterial lines may result in an increased risk of contamination? I’m sure you can think of many. The main issues that I am concerned with are that arterial lines remain in place for many days, I assume they are not immune to biofilm formation (or are they) and the most important factor is that they are often accessed multiple times for blood sampling.
I’m beginning to think that the comment that arterial lines do not become infected is an urban myth. What about the literature? Makii, Kluger and Crinch (2006) Completed a systematic review of 200 published prospective studies that examined the risk of bloodstream infection in adults with different intravascular devices. Maki et al (2006) present the data in a variety of forms and I recommend that you read the full study. However, for the purpose of this discussion the arterial catheter blood stream infection rate per thousand catheter days is 1.3 (based on studies requiring microbial concordance between catheter and blood cultures).
Finally, we have an answer. Arterial lines can and do become infected. However, the opposite is also true, arterial line bacteraemia can be prevented.
MAKI, D.G, KLUGER, D.M. and CRINCH, C.J. (2006) The Risk of Bloodstream Infection in Adults With Different Intravascular Devices: A Systematic Review of 200 Published Prospective Studies. Mayo Clinic Proceedings. 81(9), 1159-1171.