Recently the editors of Lab Medicine received a request for information regarding referral of sensitivities from one site to another or to the same site within three days. Here are a few examples of what I mean so we’re all on the same page:
- A pan-sensitive Staphylococcus aureus is recovered from a left ankle wound on 1/28; the same organism is recovered from the same site on 1/31.
- An E. coli with a typical susceptibility pattern is recovered from a right knee incision on 2/3; the same organism is recovered from the right ankle on the same date.
Referring sensitivities can streamline processes; thereby saving time and money (for the lab as well as the patient). According to the CLSI guideline M100-S23 (January 2013), Enterobacter, Citrobacter, and Serratia may develop resistance within three to four days of treatment with third-generation cephalosporin; Staphylococcus spp. may develop resistance to during prolonged therapy with quinolones. Since resistance can develop over the course of the same disease occurrence, it’s advisable to retest the susceptibility after three days so therapy can be adjusted if needed.
As for referring one site to another—such a left ankle to a left knee—I couldn’t find any source that advocated this practice. However, I am aware of facilities that have implemented such policies. What policies does your microbiology department follow when referring one sensitivity result to another?
–Kelly Swails, MT(ASCP), is a laboratory professional, recovering microbiologist, and web editor for Lab Medicine.