Monthly Archives: April 2015

“Discharged, deteriorating or deceased?”

The Art of Microbiology

I have always been a big believer in the philosophy that the importance of a microbiological result is inversely proportional to the time taken to produce that result. (check out this post).

On occasion extra work and time does need to go into a sample in order to produce a “complete report”. But how do we decide when such work is necessary? A large part of this decision should depend on the current status of the patient.

There is not much point in doing a viral PCR panel on the CSF of a patient who has recovered from his meningitis and has gone home.

On the other hand it may well be worthwhile working up that Klebsiella spp. in the sputum of a patient who has gone downhill and is heading towards ICU.

…and there probably is not much point sweating over the borderline susceptibility of an E.coli to co-amoxyclav when the patient has unfortunately passed on.

The clinical status of a patient often changes from day to day. The more the scientists know about the current condition of the patient whose sample they are working on, the more appropriate the laboratory work-up will be.

The laboratory/clinical interface needs to be as seamless as possible….

Michael

“Nothing lasts forever”

The Art of Microbiology, The Science of Microbiology, , ,

routine_swab_small_500x94

Take a look at the picture above. It is the traditional wound swab. It seems to have been around since the beginning of time.

But not for much longer…. Why?

These swabs are slowly but surely being replaced by swabs that are not only better, but are also adapted/designed to be placed on automated platforms.

The new swabs look something like this:

ecouvillon-milieu-transport-amies-68105-7752837

So what are the differences?

  • The transport medium is liquid. This allows a more standardised concentration of bacteria throughout the transport medium. It also allows the sample to be pipetted out (either manually or on an automated platform) onto the plates, again more standardised than taking the swab out of the gel and directly inoculating onto a plate. In addition, the liquid media allows fastidious organisms such as N. gonorrhoeae to survive for longer.
  • The swab has a screw top cap: This allows automated de-capping in a de-capping instrument.
  • The swab is the same size as a blood collection tube. This is intentional so that such swabs can be placed on automated tracks and automated inoculation platforms.
  • The swab is “flocked”. This means it is made of 1000’s of perpendicular strands of nylon or some other synthetic material. This allows better pick-up and adherence of bacteria compared to traditional cotton swabs.
"Flocked" swab
“Flocked” swab

This change to the “new” swabs may already have happened in your area or region. As automated microbiology processing platforms become increasingly common over the next few years, the trickle towards the new swabs will become a flood.

Adding this to the quality benefits of the new swabs, I would not be surprised if the traditional wound swab becomes extinct in the next 10 years or so.

Rest in peace.

Michael

 

“Old Habits Die Hard”

Confessions of a Microbiologist,

We all like to have a bit of a grumble when a request form has no clinical details on it. I assume it must make us feel a bit better. It is also incredibly frustrating.

Clinical details are important and paticularly for microbiological requests for several reasons. As well as giving clinical justification to the test order, clinical details allow us to decide what tests to perform, what media to put up, how long to incubate the sample for. They are also important for determining the clinical significance of any isolates or results. It allows us to decide what antibiotic  susceptibilities are required to be tested and reported, and so on. In other words, clinical details for microbiology tests are very important.

Clinical details do not have to be an essay. A couple of lines usually suffices, which should include the clinical rationale for testing, current treatment, any allergies, and a mention of travel, pregnancy, animal contact etc etc where necessary.

Traditionally, the laboratory worked very much in isolation from the clinical aspect of patient care. Samples were received, and processed indiscriminately regardless of cost, quality of specimen, reason for testing, how long the sample took to arrive at the lab etc. Things have moved on from this and the lab is slowly becoming more pro-active and involved in which specimens should be tested, and when they should be rejected. However, despite this, the provision of brief but pertinent clinical details remains stubbornly low. 

Old habits die hard…

There are some potential reasons why lab users may not include clinical details:

  • The requestor may not believe that the inclusion of clinical details will make a clinical difference and therefore may not feel the need to include them.
  • The time used to include clinical details on the request form could be used for something else.
  • The clinical reasons for testing may not meet standard testing or funding criteria for the test so the requestor may not wish to disclose them.

However the main reason that so many request forms come with no clinical details included, is because we allow it to happen. We might grumble, but in the vast majority of labs, we go on to perform the test, because if we didn’t we could potentially cause harm to the patient….

But in contrast, and paradoxically, best quality patient care requires the provision of clinical details to the laboratory.

In fact, they are so important, that we should really insist on them….

If you made clinical details mandatory on a request form, then non-critical samples with no clinical details could be reported with a comment to the effect that the sample will be stored but not tested until appropriate clinical details are included (sterile site samples and blood cultures would be the exceptions here).

If such a policy were implemented, then I think you would find that the percentage of forms arriving with appropriate clinical details would increase dramatically, and quickly.

It is just getting there that is the difficult bit.

The major problem is in the implementation. Communicating to all lab users about major changes can be difficult, and dealing with the inevitable queries if samples are rejected can be time consuming. There may also be a proportion of lab users who may just simply dislike the fact that they have to include clinical details in order to get the test performed.

I think that in the future all clinical microbiology labs will insist on the provision of clinical details in order for testing to take place, much in the same way that most radiology departments now insist on clinical details before the patient is imaged.

When electronic request forms become more commonplace, I think it should alleviate this problem to a certain extent. An electronic system can be set up in order to not allow the request to be completed without the provision of appropriate clinical details.

The road to best practice and the changing of current habits can be a long and painful one. Maybe we need to develop a thicker skin, keep communicating, keep justifying our reasoning, and just get on with it!

Michael