Tag Archives: antimicrobial stewardship

“Reporting susceptibilities on UTIs, not urinary isolates…”

Antimicrobial Resistance, Antimicrobial Stewardship, , , ,

Urines arrive at diagnostic microbiology laboratories in considerable numbers. My own lab in New Zealand processes a couple of thousand urines a week. A significant proportion of these will have positive cultures. Therefore, the potential for the laboratory to promote good antimicrobial stewardship with respect to urinary tract infection is considerable.

My mantra on this is as follows: “The microbiology lab should never release antibiotic susceptibilities on a positive culture from a urine sample unless there is reasonable evidence accompanying the request that the patient has a UTI.”

The fact that the urine sample has turned up at the microbiology lab is insufficient evidence per se that the patient has a UTI. Urines get sent to microbiology laboratories for all sorts of spurious reasons, see below for a few examples:

  • Urines often get sent “automatically” from acute receiving wards as part of a blanket laboratory screen, where the patient may have a diverse spectrum of symptoms such as chest pain, shortness of breath, collapse, etc.
  • Urines can get sent from Long Term Care Facilities when someone decides to dipstick all their patients and send the urine samples with positive dipsticks to the lab for culture. Yes, it happens, and a lot more often than you might think!
  • Urine from indwelling catheters can get sent when the patient has a blocked catheter, or the catheter bag is cloudy.
  • Urines from patients attending outpatient clinics should also raise a flag. With the exception of urology clinics, patients who attend a pre-planned elective clinic appointment generally do not have an acute UTI. The same principle can apply for patients who are in hospital wards for other reasons.
  • Urines where the clinicians are looking for other tests, i.e. albumin/creatinine ratio, and due to laboratory processes the urine ends up getting cultured as well…

So, my argument is that if a urine sample turns up at the laboratory without any clinical details or with inappropriate clinical details, the lab is under no obligation whatsoever to release antibiotic susceptibilities on any organisms grown. 

The best approach of course is not to process the sample at all unless relevant clinical details are received. I would regard all of the following clinical details as being unacceptable to justify proceeding to urine culture:

  • No clinical details
  • Cloudy urine
  • Concentrated urine
  • Dark urine
  • Smelly urine
  • Urine dipstick urinalysis results only
  • Routine/monitoring/screening urine
  • Fatigue
  • Increased CRP
  • Lots of other non-specific symptoms!

The easy option for the lab of course is just to accept the sample, report the organisms, and the accompanying susceptibilities. However, this is almost certainly not the best way…

Michael

“Antimicrobial Stewardship and the Problem of Unsolicited Advice”

Antimicrobial Stewardship, The Art of Microbiology,

“I would stop that fluoroquinolone…”

A good proportion of my job as a clinical microbiologist is being an antimicrobial steward. i.e. giving antibiotic advice based on microbiology results. And a good chunk of this advice is “unsolicited”, in that nobody has specifically asked for it. One could argue that the advice is “semi-solicited” in that it is given under the auspices or framework of an Antimicrobial Stewardship Program.

Being on-call over the Christmas period has made me reflect on the difference between giving solicited and unsolicited antibiotic advice. When someone specifically asks for your advice, they are genuinely interested in what you have to say and for the most part listen and act on your recommendations. However, when the advice is unsolicited, regardless of whether it is given by phone or in-person, it may not always be welcomed with open arms…

It is not that the prescriber necessarily disagrees with your advice. They know it is generally correct in purist terms. It is just that there are (several) other agendas at play for the attending clinician.

Taking it from the clinician’s perspective, antibiotic advice from an antimicrobial steward on occasion may prevent early discharge and may create logistical issues in terms of organising outpatient antibiotics, arranging further investigations, or arranging clinic follow-up. Put in simpler terms, more work. Such factors are accentuated during the Christmas break where the (laser) focus is on getting patients out of hospital, and minimising any admin work that is required during the holiday season.

A classical example of this is advising on a Staphylococcus aureus bacteraemia. (2 weeks IV abx, Echocardiogram, repeat blood cultures, etc.) Sometimes the attending clinician just doesn’t want to know…

Of course, sometimes our advice can be beneficial to the patient workflow & pathway. For example, early oral switches, and promotion of short course antibiotic therapy. I think it is really important to focus on documenting & highlighting such “wins”, as a counterbalance for when “bad news” needs to be given.

Personally, I am a little fatalistic when it comes to whether my advice is accepted, whether it solicited or unsolicited. I believe in the principle that the final management decision always rests with the attending clinician and they can choose whether to take my advice or not. There is only so much that you can do…

Building up relationships and trust is key in getting people to listen to your unsolicited advice. Some prescribers are more receptive than others. And some specialties are more receptive than others.

So, is unsolicited advice more about the giver than the receiver? Is it essentially self-serving in nature? Or is it a necessary evil of being a good antimicrobial steward? These are difficult questions, and ones that I do not have the answers for.

The other approach is to have a more passive approach to antimicrobial stewardship, to only give advice when it is specifically asked for, or at least to issue clear guidelines as to when advice should be sought.

My children often complain when I give them unsolicited advice on how to live their lives. I hope that my clinician colleagues do not feel the same way!

Michael

Check out this interesting article on the psychology of antimicrobial stewardship, published in CID

“Vanquishing VRE”

Confessions of a Microbiologist, ,

I am the master of false assumptions…

When a hospital close by was affected by a VanB VRE outbreak, I suspected that my local hospital would be relatively immune, due to its smaller size, different patient cohort and relatively strict antimicrobial stewardship policies.

Of course, my assumptions were wrong! It didn’t take long for the VRE to gain a foothold locally as well. (I am simply carrying my poor form on from the COVID pandemic, where I also made several false assumptions…)

MDRO rates in NZ are relatively low compared to many parts of the world. Even though I work in a reasonably big laboratory covering a population of approximately 500,000, up until recently we could go a whole year between VRE isolates! It has therefore been a bit of a shock to see them appear on an almost daily basis over the past few months, fortunately all from rectal screening samples.

Enterococci are hardy bugs and survive well in the environment, necessitating meticulous cleaning with high-level disinfectant to minimise the risk of onward transmission. Despite our best efforts to date, we have struggled to get on top of the outbreak.

However, the news is not all gloomy. All our isolates so far have been from screening samples, and we have yet to see any clinical infections. Can you really call it an outbreak if you don’t have any clinical infections? Personally, I find it difficult to get excited about something like this unless the patients are clearly unwell.

The laboratory I work in serves secondary level care hospitals and we don’t have many of those highly immunocompromised patients with lots of lines in-situ who tend to run into problems with VRE. Our annual number of Enterococcus faecium bacteraemias is low and it may be that we will not end up with many VRE clinical infections even if it does become endemic.

VanB VREs are still amenable to several different treatment options such as linezolid, teicoplanin, daptomycin, etc. In terms of the MDRO spectrum, VanB VREs are on the milder end, at least on a population level. I would be a lot more worried about a CPE outbreak in the hospital.

It is also a good reminder to us that we cannot afford to relax in the field of antimicrobial stewardship. VREs are in particular selected out by the “3Cs”, namely (3rd generation) Cephalosporins, Ciprofloxacin and Carbapenems. We do well in controlling usage of the first two, maybe not so hot on the carbapenem front.

At the moment we are still trying to “stamp out” VRE from our local hospital. The financial cost and staff time involved in managing a VRE outbreak are not insignificant by any means. At some point, one needs to weigh up the cost-benefit analysis of an eradication approach…

Michael