Re: In House Haematology

Anthony Todd — Wed, 10 Mar 2010 08:30:23 GMT

Graham,

A couple of comments.

I think it should be pointed out that lab values are not like accounts, in that the exact value or amount of a parameter is there, not to "balance" , but to indicate a clinical state. eg if the Hb is down by less than 10%,say, then probably this is not significant whereas in accounting you'd want to ask where the 10% had gone!

What is important is that the analyser will give a value which is close to the same value and whether it is slightly higher or lower doesn't really matter because, clinically you are looking for a ball-park figure to give you clinical information.

Secondly the exam. of a blood film by someone who is not doing large numbers for a long time is almost certainly a waste of time; experience is everything. I would say if the machine isn't happy send of a smear to an experienced haematologist.

How often is a significant film abnormality picked up when the lasercyte says the blood is normal and how easy would it be for your common or garden vet to pick up that abnormality??

Re: In House Haematology

Graham Bilbrough — Thu, 04 Dec 2008 10:36:42 GMT

Dear Andy

Thanks for the message.

You are quite correct our latest haematology analyser is the LaserCyte. How does if perform when compared to the reference laboratory analysers? Well, there are numerous scientific papers and I would be happy to share these with you via email. Typically, these compare the LaserCyte and other in-clinic haematology analysers to a manual leukocyte differential and/or one of the analysers commonly used at the reference labs (e.g. a Siemens ADVIA).

In some of the papers the LaserCyte performs very well indeed and in others, it is fair to say, that it would appear to not do so well. I could talk for hours about each of the papers in turn, but that would get to be rather boring for the reader. I will say briefly that a manual diff is far from the "gold standard" - if you are looking at 100 WBCs down your microscope, and you find one instead of two eosinophils, the concentration will have apparently halved. Futhermore, in some of the papers the authors have admitted that the LaserCyte was alerting them to the fact that it was working at a too high ambient temperature.

Anyway, with all this literature you can find situations where two competitor companies throw papers at each other and the bemused vet wanders off to buy an endoscope! For what it is worth, here is my opinion: the LaserCyte is every bit as good, or to think of it another way, as bad as the some of the analysers used at the reference laboratory. The difference is at the lab, there is someone looking at a blood smear and they will intervene if analyser gets into a muddle with the diff.

To my mind there are many medical benefits to running haematology "cage side". However, a full blood count is not complete without someone looking at a blood smear. As vets (and indeed nurses) we should all be able to look down a microscope and get some information from a blood smear. I accept I live in something of an ivory tower, but there are no excuses.

When I suggest that to most vets there is a look of absolute horror - "I don't have time to do that, I have to earn a living". I would suggest that it is quite possible to train the practice staff to do a three to four minute blood smear. There is no expectation that we will all become haematologists, rather we should all be able to spot normality and identify some of the more common abnormalities.

We will still be reliant on haematologists at a reference lab to help us with more complex cases. However, I do not think it is acceptable to send all blood films to the lab - e.g. I want to know if there are lots of band neuts now, not 6 to 24 hours later. Honestly, it is not "rocket surgery" (my favourite mixed metaphor) to get some basic information from a blood smear. In practice, there is rarely the time available to use oil-immersion.

For those that doubt this is possible, we have an on-line presentation on the subject that can be found by following this link:

Evaluate Your Blood Film in Less than 3 Minutes
http://idexx.na3.acrobat.com/p96174723/

You may be required to install/update Adobe Flash to view the seminar.

Remember, a blood smear gives complimentary information to the numbers from the analyser and allows you to confirm some of the details. The analyser should flag when it has struggled to distinguish between various populations of cells, but I would still recommend this 3 to 4 minute blood smear with every run of the analyser.

So, what is the bottom line? I think the LaserCyte is great, but it does not remove the need to look at blood smears. If someone tries to sell you any haematology analyser on the grounds that you no longer need a microscope then they are telling you fibs. There is nothing to stop you using the analyser in-house and sending the smears to a reference lab - but this rather removes the benefit of immediate information.

Hope that has helped.

All the best

Graham