It is only 6/5 and we have already done 7 KB stains.  Does this seem excessive to anyone?  How many are routinely done in other institutions?  We are not a high risk OB facility or a trauma center.  Does anyone have any references on the usefulness of KB stains?  It seems like such a subjective (questionable) test to me.

Are you doing the KBs because they meet a criteria for doing them or simply because the physicians are ordering them? 

We are like you, pbaker..... not a high risk OB facility.  We did so few Kleihauer-Betke Stains that we discontinued doing them and started sending them out to a nearby hospital  around 3 or 4 years ago.  I don't have statistics on how many we send out, but I have noticed that there has been a significant increase during the last couple years.  Apparently our Maternal Fetal Medicine Physician now orders a battery of tests on OB patients who have experienced a fetal demise, and a KB Stain is one of those tests.

 

Donna

There are different reasons for doing KBs:  positive fetal screen, abdominal trauma to the mother, versions.  The number does seem excessive.  I do 1-3/month and am a referral for 3 other hospitals.  I like the question from John - Are the docs just ordering them?  Get your medical director involved.

We do them because the physician orders them.  Most come through the ER as "fall".  Many are only 10 or 11 weeks pregnant.  I have asked our medical director and he is afraid to confront the OBs because of law suits.  That's why I am trying to get ammunition that we do waaaaaaaay too many for no real reason.

The docs are looking for a compromised placental circulation which could end up in a fetal demise (I think).  A tough nut to crack for you . . . good luck.  I guess you could always send them out.

We send them out to our Blood Center reference lab, where they are actually done by flow cytometry now instead of the actual KB staining.

We send them out to our Blood Center reference lab, where they are actually done by flow cytometry now instead of the actual KB staining.

 

I am insanely jealous - I keep trying to get one of those but it is futile.  That is the way fetal bleed calculations should be done.

This is going to send you way over the top then David!

 

In the UK, if the KB test comes out as an estimate of 2mL or more, it is mandatory to send samples for estimation by flow.

 

SORRY!!!!!!!!!!!!!!!!!!

Don't be sorry.  In the USA flow is the preferred method.  Unfortunately most hospitals do not have access to one so are forced to perform the KB stain or send the spec to a refererral lab (hospital or commercial).

I prefer to let the reference lab do them. I have been in the situation where you are the ONLY lab doing KB's, so you get all the stats from all the surrounding hospitals. That 2 am KB on a busy Saturday night with multiple traumas including "gun and knife club" business really makes one thank your lucky stars for reference labs that have a flow cytometer.

I have been told that we have to do KB because of turn around time.  The OB/ER want to know now and do not want to wait a day or so for the flow results...

If they sent up the samples in sufficient time, then you have 72 hours before the anti-D immunoglobulin has to be given.  I would make that plain to them in words of one syllable (maybe even a half a syllable)!

Malcolm, a fair number of KBs have nothing to do with RhIG.  There are emergent situations where they need to know if the blood they are dealing with is mom's of baby's.  I know you know this but thought I would point it out anyway.  That's what friends are for. 

This is probably a stupid question...........So if the KB Stain indicates that the baby has bled into the mother, exactly what action is the doc going to take?

 

(Assuming the baby is not mature enough to allow the induction of early labor and assuming that the situation does not involve RhIG.)

 

 

Donna

L106

That is my biggest question since the majority of my KB moms are not anywhere close to term.

One of our sister hospitals does hundreds a year because the the doctors order them.  At our hospital the lab orders them based on fetal screens and we only do a handful a year.  BTW- we both have large OB/L&D services.

One of our sister hospitals does hundreds a year because the the doctors order them.  At our hospital the lab orders them based on fetal screens and we only do a handful a year.  BTW- we both have large OB/L&D services.

For the emergent situations the fetal screen is only going to detect the Rh Pos baby/Rh neg mom scenario. If the fetus is Rh neg or mom and baby are both Rh pos, it's not going to detect a bleed. We actually don't get very many orders for this. We do see a rare request for the KB for fetal demise cases.

 

We send our KB stains out - thankfully  we get very few emergency requests because the reference lab that does them for us is150 miles away.

For the emergent situations the fetal screen is only going to detect the Rh Pos baby/Rh neg mom scenario. If the fetus is Rh neg or mom and baby are both Rh pos, it's not going to detect a bleed.

 

I'm sorry AMcCord, but I would dispute this.

 

The KB test is based on the detection of HbF, rather than on the D antigen type of the nother or foetus.  I would agree that flow would not help, as this is based on the D type, as this is based on using a FITC-anti-D.

 

Mind you, if the mother has a high HbF, such as a thalassaemia, then the KB wouldn't help either!

 

For the emergent situations the fetal screen is only going to detect the Rh Pos baby/Rh neg mom scenario. If the fetus is Rh neg or mom and baby are both Rh pos, it's not going to detect a bleed.

 

I'm sorry AMcCord, but I would dispute this.

 

The KB test is based on the detection of HbF, rather than on the D antigen type of the nother or foetus.  I would agree that flow would not help, as this is based on the D type, as this is based on using a FITC-anti-D.

 

Mind you, if the mother has a high HbF, such as a thalassaemia, then the KB wouldn't help either!

 

I think this is a case of difference in nomenclature.....  .   Yes, the KB is going to detect the HbF (unless mom has persistent HbF) and that is the test that should be ordered for the case where mother has fallen or been in a car accident.  The fetalscreen (rosette) test is only going to detect the D antigen and will not work for the kind of emergent situation where they are looking for fetal bleed for the baby's safety/wellbeing or for a case of fetal demise. For the rosette test to be useful we would have to know that mom is Rh pos and the fetus is Rh neg - therein lies the problem as we don't know the type of the fetus.

This is probably a stupid question...........So if the KB Stain indicates that the baby has bled into the mother, exactly what action is the doc going to take?

 

(Assuming the baby is not mature enough to allow the induction of early labor and assuming that the situation does not involve RhIG.)

 

 

Donna

Donna, I'm afraid you will have to consult a neonatologist on this.  They probably can't do much for the baby but if it's mom who is bleeding the OB/ ER docs can probably do quite a bit to save her. 

Edited June 13, 201411 yr by John C. Staley

How do you prepare your specimen for KB and Fetal Bleed competency? For direct observation or for blinded specimen?

How do you prepare your specimen for KB and Fetal Bleed competency? For direct observation or for blinded specimen?

 

Both. (We don't do KB anymore, though.) I make blinded samples - 2 or 3 - then observe them perform testing on those samples.

We do most of our KB's from the ED for auto wrecks. 

Today an ER physician asked us to perform flow on the mothers urine to detect fetal hemoglobin in the case of fetal demise. Is there a scenario where urine will give them answers where the maternal blood sample won't?