in house haematology

Re: in house haematology

Christopher Saul — Thu, 18 Jul 2013 20:44:46 GMT

Wow OK fair enough, I would suggest an IDEXX procyte as the least bad option

As a quick point though I would always check a manual PCV; if the machine cannot get the PCV right then you can hardly trust the rest of it! Also you can look at a smear for platelets as the automated analysers tend to struggle most with platelets.

I like this article in the september 2011 issue of 'in practice'

Clinical practice: Companion animal practice: Practical assessment of blood smears in dogs and cats

Rand Wilson

In Practice 2011;33:8 402-409

Hope this helps

Chris

Re: in house haematology

Mark Hedberg — Thu, 18 Jul 2013 19:32:14 GMT

[quote user="Zoe Luxton"]

Thanks everyone:) I perhaps should have mentioned that I am in the Falkland Islands in a truely mixed practice and no easy access to a reference lab. I dont really have the time to become hugely competant or confident in interpreting my own slides so we do rely on an in house machine to some extent. We do often send smears away to a UK based lab and they are amazing with the turn around (thank you FINN pathologists!) but of course sometimes you dont have 10 days to play with for a confirmed result. My new years vet resolution is always to do more heamatology slides and intpretation (i do do manual PCVs often) and i need to stick to that! Does anyone have any good reference guides for preparing and reading blood slides yourself? thanks again.

[/quote]

Haha! :) Fair step and a hard job - my hat is off, you get lazy when you get back to Blighty with all these referral bods hanging around!

That said, if you have trouble with slides and smears, stick a camera phone over the eyepiece, the resolution is surprisingly good! Email the picture off to your pathologist or slap it up here.

Re: in house haematology

Zoe Luxton — Thu, 18 Jul 2013 18:54:06 GMT

Re: in house haematology

Rob Loxley — Fri, 12 Jul 2013 22:40:32 GMT

Maybe the important point is to separate reliability and financial viability

Re: in house haematology

Francisco Gomez — Thu, 11 Jul 2013 11:55:21 GMT

[quote user="Neil Wheadon"]

[quote user="Clive Ansell"]Some OOH providers would suffer without a machine though[/quote]

It's of interest that Vets Now have lots of analysers, including a vetest, EPOC and lactate analyser, but we don't have a haematology machine. We are encouraged to do a PCV and blood smear which in an emergency setting is deemed adequate and I don't disagree with this.

In locum work if in any doubt get a pathologist to look at the smear as the turnaround is really fast these days and is so much more helpful.

Neil

[/quote] I think Clive agrees w you (I think). He was being sarcastic 'quoting' a bit from one of my posts in another thread.... http://www.vetsurgeon.org/forums/p/15772/93138.aspx#93138 hence his 'cheeky face'

Re: in house haematology

Bob Russell — Thu, 11 Jul 2013 11:20:32 GMT

We have a HM5 (replaced the older QCR machine) and find it gives fairly reliable results from a good sample. It does correlate pretty well with external lab samples.

The older vetscan HMT you took pot luck, guessed and crossed fingers and toes IMO!

Re: in house haematology

Neil Wheadon — Thu, 11 Jul 2013 10:38:41 GMT

[quote user="Clive Ansell"]Some OOH providers would suffer without a machine though[/quote]

In locum work if in any doubt get a pathologist to look at the smear as the turnaround is really fast these days and is so much more helpful.

Neil

Re: in house haematology

Anthony Todd — Thu, 11 Jul 2013 09:27:51 GMT

[quote user="John Flynn"]I question the use of in-house haematology machines.[/quote]

Me too,for all sorts of reasons, the worst of my many poor business and veterinary decisions.

Will expand at length if anyone disagrees.

Re: in house haematology

Graham Bilbrough — Thu, 11 Jul 2013 08:24:59 GMT

Good morning, All

I'd normally avoid replying to this one for fear of red stars--my vested interest in this topic is obvious. But, I cannot resist making some points:

1. I'd argue that the automated differential from an in-clinic analyser may be MORE reliable than that from a reference lab! For example, the 'guts' inside the ProCyte Dx are the same as that in the XT-V found at many of the veterinary commercial reference labs in the UK and beyond. IDEXX sells them both. And, generally speaking, the fresher the sample, the better the automated differential. The key difference between in-clinic and the reference lab is the person who looks at the blood film. It is not rocket surgery [pun intended], but if you don't want to do it yourself, or want a second opinion, send the glass slides out to the ref lab.

2. We should not regard the manual differential as a gold-standard as it is inherently imprecise. I you doubt me, send a blood film from the same EDTA pot to three reference labs and compare what you get back. This is especially true if you are only looking at 100 WBCs. Sometimes, however, it is the differential of last resort.

3. The dot plots (a.k.a. 'scatterplots') are key to knowing more about your sample, At a glance, you can tell if the subpopulations of WBC are separated. Put simply, if the clouds are on top of each other, ANY automated analyser will struggle and you will have to resort to a manual differential. If the clouds are well separated, I don't think a manual differential will help you (you still need an examination of the blood film, just not the differential). The subpopulations can become indistinct for a variety of reasons, including pathology and sample degradation.

Thanks

Graham

Re: in house haematology

John Flynn — Thu, 11 Jul 2013 07:21:05 GMT

[quote user="Clive Ansell"]I prefer a haematologist looking at and commenting on cell morphology, and an interpretation. Many external labs now provide results within 24 hours.[/quote]

You can get expert rbc morphology assessment within a couple of hours if you expend the time and energy, for a cost of £9 / time from www.televetdx.com

Obviously only as good as the representative photos you take down the microscope, but then that's not much different from the situation where you make blood smears and send them externally without looking at them - only as good as the slide that is made and submitted. OOH on a Saturday evening when post won't go until Monday can be of use,

Also provides a learning experience where you can learn from the smears you're assessing and improve your own inhouse assessment. I do think I make and submit MUCH better blood smears since I started looking at them routinely myself.

Re: in house haematology

Clive Ansell — Thu, 11 Jul 2013 07:10:17 GMT

I wouldn't bother with a haematology machine, particularly in a smaller practice.

I prefer a haematologist looking at and commenting on cell morphology, and an interpretation. Many external labs now provide results within 24 hours.

A simple PCV in house will suffice for the occasional emergency or pre op assessment.

Some OOH providers would suffer without a machine though, how would they run emergency haematology on that young healthy cat with a cat bite abscess?

Re: in house haematology

John Flynn — Thu, 11 Jul 2013 07:09:36 GMT

[quote user="Andrew Kent"]The problem with them is when results are taken at face value and not questioned.[/quote]

The problem with them is the cost which is then passed on to the client either directly or indirectly.

They represent poor value.

If they were free (or cheap) to purchase, maintain, fix and run, then I wouldn't question their diagnostic utility.

Re: in house haematology

Andrew Kent — Thu, 11 Jul 2013 07:02:01 GMT

You get out of the machines what you put in, especially if you get used to looking at the scatter plots they produce you can learn to validate the results rapidly. The problem with them is when results are taken at face value and not questioned.

Re: in house haematology

Rob Loxley — Thu, 11 Jul 2013 00:02:44 GMT

[quote user="John Flynn"]Overall, I think sending blood and good quality smears to a properly-validated external lab haematology service is more cost effective, and as long as you can do a blood smear and manual PCV in house I really don't think missing anything by skipping on the in-house haematology analyser.[/quote]

We recently had our old machine fixed and serviced; having looked at the price of a replacement it made no sense to upgrade. We can get properly validated results and an experiences pathologist's comment next day (or even same day at a push), so spending lots of money on a in-house lab equipment is very hard to justify.

Re: in house haematology

Christopher Saul — Wed, 10 Jul 2013 23:30:27 GMT

I'm with John on this.

Even with a laser flow cytometer type machine, I am very sceptical about the reliability of the differentials. We have a lasercyte and have had some quite worryingly poor correlation with manual counts. Twice before now I have delayed chemotherapy on a patient because of suspected myelosupression only to find perfectly normal haemograms from the reference laboratory on blood taken at the same time.

Many labs now offer a reasonably priced courier service and to be honest I would say this is a better value option, especially as you're likely to need to request a smear to give you an idea of morphology anyway - and I wouldn't say doing an in-house and a reference lab haematology is a good use of owners' money.

Patient side, you can get haemoglobin fairly reliably from a blood gas machine, you can of course do a manual PCV and you can do an in house smear to give you an idea of platelet count, as well as an idea of cellular morphology.

Vet Clin Pathol. 2006 Sep;35(3):295-302.

Comparison of white blood cell differential percentages determined by the in-house LaserCyte hematology analyzer and a manual method.

Papasouliotis K, Cue S, Crawford E, Pinches M, Dumont M, Burley K.

Source

Langford Veterinary Diagnostics, School of Clinical Veterinary Science, University of Bristol, Langford, Bristol, UK. kos.papasouliotis@bristol.ac.uk

Abstract

BACKGROUND:

The LaserCyte hematology analyzer (IDEXX Laboratories, Chalfont St. Peter, Bucks, UK) is the first in-house laser-based single channel flow cytometer designed specifically for veterinary practice. The instrument provides a full hematologic analysis including a 5-part WBC differential (LC-diff%). We are unaware of published studies comparing LC-diff% results to those determined by other methods used in practice.

OBJECTIVE:

To compare LC-diff% results to those obtained by a manual differential cell count (M-diff%).

METHODS:

Eighty-six venous blood samples from 44 dogs and 42 cats were collected into EDTA tubes at the Forest Veterinary Centre (Epping, UK). Samples were analyzed using the LaserCyte within 1 hour of collection. Unstained blood smears were then posted to Langford Veterinary Diagnostics, University of Bristol, and stained with modified Wright's stain. One hundred-cell manual differential counts were performed by 2 technicians and the mean percentage was calculated for each cell type. Data (LC-diff% vs M-diff%) were analyzed using Wilcoxon signed rank tests, Deming regression, and Bland-Altman difference plots.

RESULTS:

Significant differences between methods were found for neutrophil and monocyte percentages in samples from dogs and cats and for eosinophil percentage in samples from cats. Correlations (r) (canine/feline) were .55/.72 for neutrophils, .76/.69 for lymphocytes, .05/.29 for monocytes and .60/.82 for eosinophils. Agreement between LC-diff% and Mdiff% results was poor in samples from both species. Bland-Altman plots revealed outliers in samples with atypical WBCs (1 cat), leukocytosis (2 dogs, 9 cats), and leukopenia (16 dogs, 11 cats). The LaserCyte generated error flags in 28 of 86 (32.6%) samples, included 7 with leukopenia, 8 with lymphopenia, 7 with leukocytosis, 1 with anemia, and 1 with erythrocytosis. When results from these 28 samples were excluded, correlations from the remaining nonflagged results (canine/feline) were .63/.65 for neutrophils, .67/.65 for lymphocytes, .11/.33 for monocytes, and .63/.82 for eosinophils.

CONCLUSION:

Although use of a 100-cell (vs 200-cell) M-diff% may be a limitation of our study, good correlation between WBC differentials obtained using the LaserCyte and the manual method was achieved only for feline eosinophils.

Re: in house haematology

John Flynn — Wed, 10 Jul 2013 22:25:29 GMT

I question the use of in-house haematology machines.

I have one (a lasercyte), but I don't think they tend to be good value for diagnostic yield.

They might have a place for quick screening of "normality", but how useful is that really?

Normally if I'm interested in haematology, it's for one of 3 reasons:

1) Platelets - look at blood smear, wouldn't trust in-house automated count.

2) Anaemia - will need to do manual PCV and blood smear anyway, all I get extra from expensive machine is haemoglobin (big whoop)

3) WBCs - will get a wbc count and I do consider that useful, but how useful? If elevated, then need a smear to see what cells are and any signs of inflammatory-shift to neutrophils etc. If 'normal', would still need to look at smear for inflammatory shift. Probably single biggest advantage could be checking for low neutrophils prior to chemo? How often do I change treatment in a case for first 24hrs based on a wbc count??

Overall, I think sending blood and good quality smears to a properly-validated external lab haematology service is more cost effective, and as long as you can do a blood smear and manual PCV in house I really don't think missing anything by skipping on the in-house haematology analyser.

Re: in house haematology

Andrew Kent — Wed, 10 Jul 2013 21:10:47 GMT

If you want something you can trust then go for a machine that has a laser flow cytometer ( which I think means lasercyte or procyte). The differentials are much more reliable than the impedance machines, particularly if you look at the scatter plots. Do you have other machines it needs to be compatible with?

Re: in house haematology

Francisco Gomez — Wed, 10 Jul 2013 20:22:53 GMT

Main practice I work for uses Lasercyte http://www.idexx.co.uk/view/xhtml/en_us/smallanimal/inhouse/vetlab/lasercyte-hematology.jsf

It is very good. It gives your % of each WBC, even with 'suspected presence ' of band neutrophils and it is quite quick but...

As far as I know, all machines can confuse cells (band or segmented neutrophils, RBC with platelets, etc...) so be sure to always have a drop ready for a blood smear...

Re: in house haematology

CatherineThomas — Wed, 10 Jul 2013 20:17:42 GMT

We have a Menarini machine - it is fine when it works but it seems to have some kind of problem at least every other day. So I would suggest you avoid Menarini.