We previously highlighted this topic nearly a year ago. A crucial topic, as we are seeing a war of attrition with more microbes reported to be capable of side-stepping an increasing array of antibiotics.
About two months ago our hospital isolated its first pan-resistance Pseudomonas strain. This was a bit of a wake up call for our sleepy community, who had already long gotten over the initial angst of seeing community acquired MRSA. Odd to say, but few truly get excited about MRSA anymore. Just another routine medical problem to treat...
To-date, we have maintained 264 pathogen-antibiotic forecast lines and made a few discoveries:
- That agreement between the "old standard", the Sanford Guide, and our forecast library-informed recommendations ranged between 60-100%, depending on the pathogen. What this implied was physicians not using antibiograms and relying on Sanford to make their decisions ran a tremendous risk of choosing an antibiotic for which the pathogen was resistant.
- That the forecast lines challenged our prior assumptions based on the last antibiogram, where agreement between the a forecast-informed versus last antibiogram-informed recommendation to use a particular drug for a particular pathogen ranged between 67 and 100%. In other words, if you relied on the last antibiogram, you ran a tremendous risk of continuing to use an antibiotic that may not be available for use within the next 5 years. Kind of like trying to drive a car forward by looking into the rearview mirror.
- That the largest discrepancies noted between use of the last antibiogram versus being informed by forecast was associated with E. faecium, P. aeroginosa, MSSA, E. faecalis, and E. coli... yet not so for Klebsiella or MRSA, regardless of whether isolated systemically or from urine. In other words, we were seeing faster apparent changes in antimicrobial resistance patterns for these pathogens. A bit counterintuitive when we have all been bombarded with concern about MRSA.
As with all forecasts in our domain, we are now challenged with the question of how to exploit this information to maximum benefit for the community. The answer is not as simple as pulling the given antibiotic off the list of available drugs within the hospital. You have to contend with:
- "cat herding" among the private commercial pharmacies in the community
- "cat herding" among physicians who are set in their behavioral patterns of prescribing
- differences of engagment between hospital versus independent private outpatient physicians
- ongoing resistance to observe proper dispensing of antibiotics in the agricultural, veterinary, and human medical communities
- whether one should instead pick a group of antibiotics and randomly select and rotate antibiotics used for a given type of infection versus picking the one antibiotic favored by the analysis... until that drug becomes unavailable due to evolutionary selection for resistance strains
The problem is a fascinating one as we continue to tease the pieces apart...