The CDC issued new guidelines as to the time a primary set should remain in use in 2011, this is the conflicting information in the cited article. Also it is noted in the 2010 Lynn Hadaway Associates Inc. link r.e. backpriming "Unfortunately, this is an area of clinical practice that has received no attention and no research." (First line of author's response). And further down in the authors response to a post "Of course there are no studies to refer to about this practice. I would recommend that your practice council consult with a pharmacist knowledgeable about IV drug compatibility information just to be sure. I just checked some recent compatibility information on Vancomycin and found conflicting compatibility information when given with ampicillin, several of the cephalosporins, nafcillin, piperacillin, ticarcillin and tigecycline. I would recommend that you assess the common combinations prescribed by physicians in your facility and then assess the compatibility of those combinations."
Additionally, per the 2011 CDC guidelines, "No recommendation can be made regarding the frequency for replacing intermittently used administration sets.Unresolved issue " (#2 under Replacement of Administration Sets).
Hence, the use of backpriming cannot be claimed to be evidence based, therefore, how can it be best practice? I don't see it as not wanting to change habits, but in following the protocols established. It seems to boil down to using the practice that your hospital or agency establishes as best practices. If your agency says a new secondary for each drug and 24 hour use for each secondary and you wanted to argue the issue, what evidence would you present? What research could be presented? At this point, per Lynn Hadaway, "The absence of studies means that we are left to base practices on general principles of infection prevention." (Paragraph 3, author's response).
It would be extremely interesting to look at the rates of blood stream infections in hospitals with varying practices to see if there is a greater incidence of infection when multiple secondaries are used vs limited access for secondaries. Perhaps a good research topic?