Tag Archives: antimicrobial stewardship

“To err is human”

Those that know me, will be aware that I am a passionate believer in having clinical rationale and clinical context as pre-requisite for all microbiology samples that are processed by the laboratory.

Exactly the same principles should apply for antibiotic prescriptions…

There are various reasons why a clinician might prescribe an antibiotic:

  • Fear: That if an antibiotic is not prescribed, then any suspected infection might increase in severity or even be potentially life threatening.
  • Pressure: Pressure to prescribe an antibiotic from the patient or their relatives.
  • Action: To be seen to be doing something positive for the patient.
  • Justification: That prescribing an antibiotic justifies the cost or time of the consultation.
  • Loyalty: If an antibiotic is not prescribed then the patient may go elsewhere to get what they want.
  • Bacterial infection: That there is a genuine suspicion of a bacterial infection where the evidence shows that antibiotics are indicated in that particular clinical scenario.

It would be foolish to think that the real prescribing reason is always the last one on this list.

Humans are subject to all sorts of internal biases, and external pressures. We are in essence, fundamentally flawed. It is therefore wrong to expect us to always prescribe antibiotics for the right reasons as opposed to the “not so right” ones.

In other words we need tight controls on our decision making behaviours.

At the moment a clinician can write a prescription for most antibiotics without including any indication as to why the antibiotic was prescribed.

This needs to change.

It is my belief that all antibiotic prescriptions should have the clinical indication for prescribing included on the prescription form as a pre-requisite for dispensing, in both community and hospital settings.

Otherwise the pharmacist is essentially dispensing blindly.

Once such a system is in place, then specific criteria can start to be applied for certain infections in order for an antibiotic prescription to be valid/approved.

Then we can start getting some real controls in place for the purposes of antibiotic stewardship.

The days of clinicians being able to request laboratory tests and prescribe antibiotics without providing a clinical rationale are numbered.

I hope…


“The Antibiotic Free Period”

The patients who get the most courses of antibiotics are as expected, the ones who get the most infections, and these infections are often recurrent at the one site. A few examples are the elderly person who gets recurrent urinary tract infections, the toddler who gets recurrent otitis media, or the patient with chronic obstructive pulmonary disease (COPD), who gets recurrent bouts of bronchitis.

The antibiotic selection pressure on such patients is often intense, and one can often see by observing their microbiology results over time, that the infecting organisms become increasingly resistant, until multi-drug resistant organisms (MDROs) appear, and the clinician is forced to resort to less routine and more exotic antibiotics to treat the infection.

Whilst some of these “infections” will absolutely require antibiotics, many don’t, and many more were probably not bacterial infections in the first place.

What these patients really need is “An Antibiotic Free Period” . A period where the playing field is level. When MDROs have to compete against their susceptible counterparts in the absence of selection pressure, the increased fitness of the susceptible bacteria will win in the end. (This may take a while, and varies from patient to patient, and from organism to organism, but it will happen eventually.)

MDROs really don’t like level playing fields, they much prefer the odds slanted in their favour…

How can the microbiology laboratory assist in creating antibiotic free periods for patients?

Well we can add a comment to the result, for example “Uncomplicated otitis media does not routinely require antibiotic therapy” or “The isolation of pseudomonas from a patient with COPD does not imply acute infection.”, etc., etc.

or we can simply withold susceptibilities. For example an E. coli in a urine from an elderly Rest Home patient could have a comment along the lines of: “No clinical details have been provided with this sample. Asymptomatic bacteruria occurs in a significant proportion of elderly patients. If this patient has urinary symptoms, and they are continuing, please contact the laboratory for antimicrobial susceptibilities.”

It is my experience that the presence of an MDRO on a microbiology result report causes a reflex reaction from the requestor and increases the chance that the patient will be treated with antibiotics.

However the exact opposite should really apply. The threshold for treating an infection caused by an MDRO, as opposed to a susceptible one, should go up, not down.

One of the roles of microbiology laboratories, and clinical microbiologists, should be to facilitate antibiotic free periods where the opportunity arises…


There were seven new subscribers last week during the “Purple Cow Giveaway”. Rather than draw 5 from 7, I will ensure all seven new subscribers get a copy of my book. 🙂

“Too much knowledge…”


A little bit of knowledge can be a bad thing. So can too much…

The acronym  ESCHAPPM ( or something similar) will be familiar to most microbiologists. (a similar acronym SPICE, is sometimes used instead)

  • Enterobacter spp.
  • Serratia spp.
  • Citrobacter freundii
  • Hafnia spp.
  • Aeromonas spp.
  • Proteus spp.
  • Providencia spp.
  • Morganella morganii

Because we are clever microbiologists, we know this group of organisms may have inducible beta-lactamase activity, and we advise the clinicians of this, often provoking a reflex switch in anti-microbial therapy to carbapenems. Not only clinicians, but there are plenty of ID physicians who make this automatic transfer to carbapenems the moment the word ESCHAPPM is mentioned, my hospital included.

The thing is however, do all patients with infections by an ESCHAPPM organism require a carbapenem?

Almost certainly not…

If we use a carbapenem for every infection due to one of these organisms, then this amounts to a significant amount of carbapenems. This is therefore an important an important antimicrobial stewardship issue. We are supposed to be trying to decrease the use of broad spectrum antibiotics, not increase them.

But we have read the textbooks, and we are clever…

And yet, if we look at the literature, there is very little evidence to support the theoretical dangers of using a beta-lactam in such patients. In fact, there are several small studies out there that support the non-inferiority of beta-lactams in such patients, particularly in non-life threatening illnesses.

Not to mention there are other options out there, fluoroquinolones, sulphonamides, etc.

We are simply scared.

Here is what I generally do (rightly or wrongly):

  • In a patient with bacteraemia due to an ESCHAPPM organism, as long as they are clinically improving I am happy to continue therapy based on the phenotypic susceptibility results.
  • In patients with UTIs due to ESCHAPPM organisms, even if in hospital, I feel no need  whatsoever to move to carbapenems.
  • I reserve carbapenem use in “ESCHAPPM” patients to bacteraemic patients who are getting worse, and also for patients with chronic infections, e.g. prosthetic joint infection, on the rationale that the longer the treatment, the more chance you have of getting clinically relevant inducible beta-lactamase activity.

We need to take a more pragmatic approach to ESCHAPPM organisms and their treatment. We also need larger scale trials so we can be more confident in our decisions and adopt such approaches into guidelines.

and we need to be brave…