I am doing a bit of research on KB stains and I was wondering what is the current practice.  In the past I've worked at facilities where they were performed in-house (by BB or another department) and also where they were sent out.  What are most hospital labs doing currently?

Primary benefit of referral seem to be that you do not have to maintain competency, which can be difficult when the test is performed infrequently.  I see TAT as the main drawback of referral, considering the recommendation to administer RhIg within 72 hours of delivery. 

Any other thoughts on referral vs. in-house testing?  Anyone using KB as first test for routine FMH, i.e. not performing a "rosette" test fetal screen?

 

Labs in the UK don't use the rosette - we KB all samples where the cord blood is positive. We have national QA to ensure competency (multiple times a year). We are a medium sized maternity hospital and we do 3-4 a day

1 hour ago, Auntie-D said:

Labs in the UK don't use the rosette - we KB all samples where the cord blood is positive. We have national QA to ensure competency (multiple times a year). We are a medium sized maternity hospital and we do 3-4 a day

Agreed, but, where necessary, we will also perform testing by flow cytometry using FITC-labelled anti-D.

Ours are done for trauma patients only, so we do not perform fetal screens at all and they are not sent out. We do them in blood bank and get maybe 2 a year, max.

 

We had so much trouble with our CAP survey this year, once it was submitted we repeated it quite a few times trying to get a decent looking slide and just got nowhere. It's an incredibly frustrating test for us.

27 minutes ago, Teristella said:

Ours are done for trauma patients only, so we do not perform fetal screens at all and they are not sent out. We do them in blood bank and get maybe 2 a year, max.

 

We had so much trouble with our CAP survey this year, once it was submitted we repeated it quite a few times trying to get a decent looking slide and just got nowhere. It's an incredibly frustrating test for us.

Whose stain are you running?  I use Simmler and it always works fine.  My staff is all generalists - maybe 1-2/month.

How on earth do you get away with not doing them in the US, with it being such a litigious society? We do several every day...

1 hour ago, David Saikin said:

Whose stain are you running?  I use Simmler and it always works fine.  My staff is all generalists - maybe 1-2/month.

Sigma-Aldrich. We used to use Simmler and were told we could no longer purchase the stain from them as they were not a contracted vendor. Surprise, we never had any issues with them.

I sent Sigma-Aldrich's technical support an email asking for suggestions and was told to add a rinse step (?????) at a point in the procedure... when I checked the package insert again, there is ALREADY a rinse step at that point. Considering that our problem is that we cannot distinguish the edges of the maternal cells (with Simmler they stained a nice pale pink, the Sigma stain leaves basically no color in them), adding an extra rinse didn't seem to make much sense to me. We could not tell if we were reading an appropriate field because we couldn't see if cells were overlapping or too far apart.

We got frustrated and stopped messing with it for this go-around. Next time maybe the staff will play with it more, but hopefully I'll be at another facility by then and won't have to touch KBs ever again.

We are sending out our KB stains, which amounts to maybe 6-8 a year. We delivered approx 940 babies last year. At that rate we would be doing more survey samples than patient samples and you can't maintain competency doing that. Our TAT from the reference lab is 24 to 36 hours depending on when mom delivers. All patients with KBs automatically get one vial of RhoGAM. If the report says they need more, we notify the Dr and floor accordingly. We've been doing it this way for maybe 6 years and haven't had any problems.

WE use the Sure-Tech kit and ~ 2 specimens per month are tested.  The test is time and technique dependent, but competency is not an issue in our lab.  The patient specimen results are usually clear and easily read by the techs.

The positive CAP survey specimens are not easy to process, and the Limits of Acceptability are quite wide - attesting to the challenge of this survey.

We send ours out to a hospital not too far away.  We do so few it's not worth cost or pain of competency. 

Edited May 24, 20169 yr by amym1586

14 minutes ago, amym1586 said:

We send ours out a hospital not too far away.  We do so few it's not worth cost or pain of competency. 

Someone please tell our administration this!

We used Sure-Tech and liked the ease of reading, but we do so few that last fall, we upgraded our procedure to send ours out to a larger hospital about 30 minutes away. Like AMcCord, we will give one vial Rhogam until we get the results back, and give additional   vials if needed. (We haven't had to send one out yet!!!)

We do fetal screens on the Rh negative moms. If positive, our LIS will reflex a KB. We then send to a local reference lab here in town. We usually get a 6 to 8 hour turnaround time which I think is pretty decent. Occasionally, we will get an order for just a KB for trauma cases. We only get one or two a month so it wouldn't be worth the effort to bring them in house. Besides, most techs hate doing them. At my previous employer, we did briefly look into the Tosoh HPLC method but nixed that due to cost. We also looked at sending them to another area hospital that was doing them by flow cytometry. However, they only performed them 3 days a week which wouldn't have helped with STAT TAT requirements. I hope this gives you "food for thought."

As someone who has never done one - how is a foetal screen easier than a KB? KBs are so so simple I am finding it harder to envisage a simpler test.

3 hours ago, Auntie-D said:

As someone who has never done one - how is a foetal screen easier than a KB? KBs are so so simple I am finding it harder to envisage a simpler test.

A fetal screen is essentially adding a weak anti-D to patient cells and incubating; the Immucor kit is a 5 minute RT incubation now, I believe. Then wash and add indicator cells to form rosettes, if the test is positive, and count them.

Far easier than a KB. A lot of things are simple that aren't easy.  I'd take a 15 minute process over a 30 minute one any day, and skip staring through a scope for very long.

Edit: That said, they definitely test for different things! We dumped fetal screens because they too situational for us to stock the kits.

Edited May 25, 20169 yr by Teristella
Addition

A KB doesn't take 30 minutes - 5 minutes to dry, 3 minutes to fix, 30 seconds to leach and 2 minutes to stain.

How sensitive is the foetal kit? Can you judge the volume of bleed accurately from it?

On ‎5‎/‎27‎/‎2016 at 0:17 PM, Auntie-D said:

A KB doesn't take 30 minutes - 5 minutes to dry, 3 minutes to fix, 30 seconds to leach and 2 minutes to stain.

How sensitive is the foetal kit? Can you judge the volume of bleed accurately from it?

For us it ends up taking that long, considering we do not have the stain out, the buffer has to warm, we have techs who work blood bank only trying to make decent smears and everyone has to pull out the procedure because we do them maybe once a year.

The fetal screen kit is not a quantitative test.

20 hours ago, Teristella said:

For us it ends up taking that long, considering we do not have the stain out, the buffer has to warm, we have techs who work blood bank only trying to make decent smears and everyone has to pull out the procedure because we do them maybe once a year.

The fetal screen kit is not a quantitative test.

Why do you keep your buffer in the fridge? It is supposed to be stored at room temp.

Decent smears - it doesn't really matter if they are decent or not (unlike for a diff). 2 drops of saline and one of cells will 99% of the time make a prep that is a uniform monolayer.

Lastly - if the foetal screen kit isn't quantitative how do you ensure you are giving sufficient anti-D?

48 minutes ago, Auntie-D said:

Why do you keep your buffer in the fridge? It is supposed to be stored at room temp.

Decent smears - it doesn't really matter if they are decent or not (unlike for a diff). 2 drops of saline and one of cells will 99% of the time make a prep that is a uniform monolayer.

Lastly - if the foetal screen kit isn't quantitative how do you ensure you are giving sufficient anti-D?

We keep it in the fridge because the storage temperature is 2-8C on the package insert. It is diluted and warmed to 37C when time to use it... I think you are incorrectly assuming every fetal stain kit is the same.

You seem to be misinterpreting the use of the screening kit. The fetal screen kit does not tell you how much anti-D to give at all, it simply screens for the presence of a bleed. As I said, they are used for two different situations.

 

Here, I will attach the package inserts for the two tests. Based on the times for each step in the stain kit, it can easily take 30 minutes.

Fetal stain kit - 285.pdf

Fetal screen kit - 3047.pdf

Edited June 1, 20169 yr by Teristella
Attachment

1 hour ago, Teristella said:

You seem to be misinterpreting the use of the screening kit. The fetal screen kit does not tell you how much anti-D to give at all, it simply screens for the presence of a bleed. As I said, they are used for two different situations.

I just can't get my head round how any hospital can only be doing one a year.

 

ETA - it seems an awfully faffy stain that you are using! If it isn't following the actual KB staining regime (which every other kit I have ever used does) then I'd be revalidating it.

Edited June 1, 20169 yr by Auntie-D

Well, as I said, we do not have OB, and we do not take OB traumas except to stabilize them, there is another trauma center about 45 minutes away that does OB, so they take those patients.

On 6/1/2016 at 8:18 AM, Auntie-D said:

I just can't get my head round how any hospital can only be doing one a year.

 

ETA - it seems an awfully faffy stain that you are using! If it isn't following the actual KB staining regime (which every other kit I have ever used does) then I'd be revalidating it.

A positive fetal bleed screen tells you if you might need to give more than one dose RhoGAM. The fetal bleed screen is designed to be negative when only a small bleed has occurred (insert says 'usually less than 2 mL'), which is easily covered by one dose of RhoGAM (which covers 30 mL whole blood in the US). Since the vast majority of fetal bleeds are small, the vast majority of fetal bleed screens are negative, thus very few Kleihauer-Betke stains are needed. Almost all of the Kleihauer-Betkes we send out are also negative.  We had about 950 deliveries last year, so figure approx. 150 Rh negative patients - we sent out 3 Kleihauer-Betke stains. That's not worth doing in house.

On 6/6/2016 at 1:34 PM, AMcCord said:

A positive fetal bleed screen tells you if you might need to give more than one dose RhoGAM. The fetal bleed screen is designed to be negative when only a small bleed has occurred (insert says 'usually less than 2 mL'), which is easily covered by one dose of RhoGAM (which covers 30 mL whole blood in the US). Since the vast majority of fetal bleeds are small, the vast majority of fetal bleed screens are negative, thus very few Kleihauer-Betke stains are needed. Almost all of the Kleihauer-Betkes we send out are also negative.  We had about 950 deliveries last year, so figure approx. 150 Rh negative patients - we sent out 3 Kleihauer-Betke stains. That's not worth doing in house.

I understand now - in the UK it is required that it is quantified as guaranteed less than 2ml so KB for us for all pos babies.

ETA - doesn't the manufacturer instructions state that the rosette test is only for antenatal use, not postnatal? I remember a thread quite recently...

Edited June 21, 20169 yr by Auntie-D

The rosette test, or fetal screen, is only for use after delivery of all products of conception, and then a venous sample is collected 1 hour later (or it can be longer).  We use the FMH RapidScreen by Immucor, which is the same one Teristella mentioned.