Tag Archives: MDROs

Anti-microbial Stewardship in the Hospital Setting: “The Vicious Circles of Resistance”

Here are a few vicious circles that make the job of anti-microbial stewardship even more difficult than it already is:

1) Increasing rates of Multi-Drug Resistant Organisms (MDROs) increases the use of broad spectrum anti-microbials, which in turn increases further the MDRO rate. This is probably the main vicious circle at play. To break it requires a lot of work put into predicting which patient cohorts absoulutely need broad spectrum antimicrobials, and which cohort can “get away with” a narrower spectrum anti-microbial in the first instance.

2) Increasing availability of broad spectrum anti-microbials on the hospital formulary increases use of broad spectrum antimicrobials, which increases the resistance rates, which in turn encourages more broad spectrum antimicrobials being placed on the formulary. The premise behind this vicious circle is that if something is available, it is used. Institutions need to think very carefully what broad spectrum anti-microbials it has on their formulary. “just in case” or “personal preference” for me are poor arguments in the bigger scheme of things.

3) Increasing numbers of patients with MDROs on a ward increases chances of patients on the ward without MDROs being colonised with an MDRO, thus increasing tranmission risk further. The cascade effect. If I was lying in ICU with 7 other patients, and 5 of them have MDRO colonisation, then regardless of how good Infection Control is, I don’t fancy my chances of staying MDRO free.

4) Increasing MDRO rates leads to less chance of properly isolating patients, thus increases chances of MDRO transmission, which increases the MDRO rate. Not dissimilar to 3). We know some institutions have “run out” of isolation facilities, and thus have to prioritise Isolation Facilities to the highly Multi Resistant Drug Organisms (hMDROs)

 5) Higher MDRO rates, leads to antibiotic policies which include more broad spectrum antimicrobials which in turn further increases MDRO rates. If you have a hospital with very low MDRO rates, then it is much easier to omit antimicrobials like tigecycline, meropenem, daptomycin, linezolid etc etc, from your “admission antimicrobial policies”.

(If I was an artist I would illustrate these vicious circles as circles. Alas it was not to be..!)

There are almost certainly more vicious circles at play but I think these are the main ones.

I think these vicious circles go some way to explaining the vast differences in MDRO rates that we see between different institutions.

And the solution? I don’t think there is any miracle solution here. I certainly do not like defeatist attitudes as I have encountered in some hospitals with high MDRO rates. I.e. “No point in shutting the stable door after the horse has bolted.” I think the UK’s recent impact on MRSA rates shows that these vicious circles can be broken. However it requires a combination of strong leadership, co-operation between different stakeholders, and political will.

Food for thought…..


See also “Anti-microbial stewardship in the Hospital Setting: The dilemma.”


“Antimicrobial Stewardship in the Hospital Setting: The Dilemma….”

The Dilemma (or is it dilemna!)

The individual patient v the population: Potentially every patient that walks in the door of the hospital with clinical sepsis could be given the broadest spectrum antimicrobial available on the formulary. This might give the individual the best chance of survival from their sepsis but such management will have the potential to select out Multi Drug Resistant Organisms (MDROs) and cause/store up problems on a population basis.

Antibiotic Stewardship policies are often based on balancing treating the individual patient against minimising MDRO selection in the population.

One could argue that in the making of such policies, general physicians would be most focused on treating the individual patient, clinical microbiologists would be most focused on minimising MDROs in the population, and ID physicians are somewhere in between. A generalisation and an assumption of course but I suspect there may be an element of truth in it. I guess this is why we have stewardship committees with representatives from all these groups.

Communities/cultures may exist where the importance of treating the individual is prioritised; i.e if there is a low threshold for legal action should the patient suffer as a consequence of not receiving the “correct” antimicrobial. This in turn leads to broader spectrum antimicrobial policies and in turn MDRO selection.

And of course there can be micro-cohorts of patients within the hospital setting such as ICU patients. In such cohorts the severity of sickness tips the balance towards treating the patient with the best possible antimicrobial and MDRO minimisation takes a relative back seat. This is why ICUs often become micro-environments within the hospitals for MDROs.

Antimicrobial Stewardship is a (very) complex area and it’s implementation often becomes very political, often because of The Dilemma. The one good thing from my point of view is that it often involves lots of concepts rather than facts. There is a lot out there on the Internet on Antimicrobial Stewardship, most of which is fairly dull reading. To read some more on the varying elements of antimicrobial stewardship click here for a readable and relatively concise article.


See also Anti-microbial Stewardship in the Hospital Setting: “The Vicious Circles of Resistance”