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Antibody Screen before Issuing RhIg


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On ‎3‎/‎23‎/‎2017 at 3:49 PM, BldBnker said:

AABB Standards only apply to AABB accredited facilities

This is from The Joint Commission 2011. I don't think it has changed, but, I don't have the latest edition of the Laboratory Accreditation Program for Blood Transfusion Service.

"The laboratory has written policies and procedures for the blood transfusion service that are consistent with AABB standards."

 

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On ‎5‎/‎28‎/‎2017 at 1:52 PM, seraph44 said:

At my prior facility we used to constantly get patients with positive antibody screens due to antepartum RhIG. In order to help differentiate between passive and active immunization, we performed a 1:4 titer on the patient's plasma. If the titer was greater than 4, we would suspect active vs passive. We never had one over 4 as far as I can remember. I don't recall were they obtained the reference material, but they are AABB, FDA, CAP, and JC accredited. 

Hope this helps.

The AABB TM, 18th edition, states in Chapter 22, Perinatal Issues in Transfusion Practice, Serology and Mechanism, "Administration of RhIG during pregnancy may produce a positive antibody screening result in the mother, but the titer is rarely greater than 4 and thus poses no risk to the fetus."

If we ID anti-D in prenatal sample, we perform a 1:4 dilution and if the results are non-reactive we have two statements in our report, "The antibody demonstrated a titer of less than 4 in saline at AGT indicating that it may be due to recent administration of RhIG."  and "Due to the recent administration of RhIG, the antibody may have been passively acquired. To establish this as the sole cause of the antibody's presence, repeat testing six months post-delivery should demonstrate a negative antibody screen."

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On ‎3‎/‎23‎/‎2017 at 11:27 AM, BldBnker said:

According to AABB Standard 5.30.2 part 2; "the woman is not known to be actively immunized to the D antigen."  We perform an antibody screen, along with an  ABO/Rh on a current sample before issuing a Rhogam. This is for ED patients and LD patients.

So how do you know if the antibody you are detecting is antenatal RhIg or active sensitization?  Just because it reacts weakly doesn't seem to me to be a valid criteria.  We do not do absc to release RhIg post partum. 

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We are AABB accredited and don't do an antibody screen for RhIG.  We have never been cited. We are proving that the mom doesn't have immune anti-D by showing that her Rh pos baby does not have a positive DAT.  This is probably a better indicator of "clinically significant" anti-D than how strongly it reacts.  Antenatal RhIG is given by the doctor's office or comes from pharmacy so we have nothing to do with it.  Some OBs order an antibody screen at the time of giving 28 week RhIG but I understand that is not a requirement in ACOG guidelines.  Even if they order it they give the RhIG while the patient is there and get the results of the screen a day or so later.  If you are going to do the same thing (give RhIG) regardless of the test results, why are you doing the test?  If the mom has a significant anti-D at delivery you should have an affected baby.  We did find one significant anti-D at the 28 week screen which resulted in an affected baby (but no exchange) so I am in favor of them doing those screens so they can better prepare for the delivery.  If the titer is high enough they follow with ultrasound, not titers, so having given the RhIG isn't such a big deal either.  

All of that said, we try to take note of any blood type on an ED female who is Rh neg and contact the office to see if they want to order a screen run on the sample so they have a baseline.  If the miscarriage is complete they probably won't.

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We will run a type and screen on patients with no history with us. Usually these are ER visits. Other than that we just run a Fetal Bleed Screen if the gestation is >14 weeks or the baby has been delivered and is Rh positive.

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On ‎6‎/‎2‎/‎2017 at 9:06 PM, Mabel Adams said:

All of that said, we try to take note of any blood type on an ED female who is Rh neg and contact the office to see if they want to order a screen run on the sample so they have a baseline.  If the miscarriage is complete they probably won't

We always get or have an historical Blood Type and frequently get the (roughly) 28 week antibody screens from our outpatients, but we do not require the antibody screen results before giving antenatal RhIG.   On any of the numerous(!) positive antibody screens on Rh Neg moms, we always have to call and ask about the last known RhIG injections.  With an ECHO - you can detect RhIG for months.  We almost always get a Type and Screen for all new admits on L&D too - almost all of them who are Rh Neg have a positive antibody screen for anti-D.  Much of our Rhig is now given in the Dr's offices and clinics. 

In the ER, we have a computer reflex test that adds the Antibody screen to any ABORh ordered in the ER that comes out Rh Neg.   This has worked out well for our OBs because otherwise, by the time they see the pt and ask for the antibody screen - it is positive from the RhIG given in ER.  We went to the hospital OB committee and asked to do this (once we could get the computer programmed to guarantee it would happen) and they happily agreed.

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  • 4 weeks later...
On ‎6‎/‎6‎/‎2017 at 0:08 PM, cswickard said:

On any of the numerous(!) positive antibody screens on Rh Neg moms, we always have to call and ask about the last known RhIG injections.  With an ECHO - you can detect RhIG for months.  We almost always get a Type and Screen for all new admits on L&D too - almost all of them who are Rh Neg have a positive antibody screen for anti-D.  Much of our Rhig is now given in the Dr's offices and clinics. 

 

What do you call the passive anti-D in the computer?  Do you have a special comment you add?  We use gel and the OB docs do not like all the "Anti-D possible result of RhIG" results they are getting.  We do perform an antibody screen before issuing RhoGAM, which we could eliminate, but that doesn't help the type and screen orders prior to delivery.

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If the mother is a possible miscarriage of 12 weeks or less, we do a blood type or go by the patient's history. If she is Rh negative by history, or if she types as Rh negative on a current specimen, she is a candidate for 1 - 300 mcg dose of RhIG.  No further workup is needed.  A patient who is 13+ weeks pregnant and bleeding would have the ABO/Rh, antibody screen, and fetal bleed screen tested prior to administration of the RhIG. 

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On ‎7‎/‎1‎/‎2017 at 6:13 AM, BBfuntimes said:

What do you call the passive anti-D in the computer?  Do you have a special comment you add?  We use gel and the OB docs do not like all the "Anti-D possible result of RhIG" results they are getting.  We do perform an antibody screen before issuing RhoGAM, which we could eliminate, but that doesn't help the type and screen orders prior to delivery.

We have a canned comment that says " Anti-D detected is presumed (you might want to make that "possibly" or something less) to be due to Rh immune globulin given...." and then we input whatever date is given to us from phone calls, computer searches, questions to the pt, etc.  Some of my techs are now also putting in the source we receive the information from ("chart", "computer", RN's or clerk"s name, etc.)  The computer puts the comment on the chart.

hope this helps.  

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  • 8 months later...

if you have a patient present at 15 week in the ED and perform the type and screen, administer rhogam.  At 20 weeks they come in for an amnio - do you perform any testing?  Or because you have the Type and screen previously you just administer the Rhogam?

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On 6/5/2017 at 9:14 AM, Darren said:

We will run a type and screen on patients with no history with us. Usually these are ER visits. Other than that we just run a Fetal Bleed Screen if the gestation is >14 weeks or the baby has been delivered and is Rh positive.

Our fetal bleed screen kit (Immucor Rapid Screen) is only approved for postpartum testing with known infant type.  Antenatal bleeds and losses > 20 weeks require a KB in our facility.  Which screening kit do you use?

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  • 3 weeks later...
On 3/22/2018 at 10:35 AM, Carrie Easley said:

Our fetal bleed screen kit (Immucor Rapid Screen) is only approved for postpartum testing with known infant type.  Antenatal bleeds and losses > 20 weeks require a KB in our facility.  Which screening kit do you use?

We use the FetalScreen II from Ortho/Quotient. Reading through the instructions for use makes me wonder if it's useful at all. I think we may consider some send out options for KHB or flow cytometry and relieve the bench staff of the effort altogether.

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On ‎3‎/‎22‎/‎2018 at 9:35 AM, Carrie Easley said:

Our fetal bleed screen kit (Immucor Rapid Screen) is only approved for postpartum testing with known infant type.  Antenatal bleeds and losses > 20 weeks require a KB in our facility.  Which screening kit do you use?

In my experience I think a lot of Blood Banks don't know or know but continue to use fetal bleed screens on prenatal specimens.   Big pet peeve of mine. 

 

 

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9 hours ago, Darren said:

We use the FetalScreen II from Ortho/Quotient. Reading through the instructions for use makes me wonder if it's useful at all. I think we may consider some send out options for KHB or flow cytometry and relieve the bench staff of the effort altogether.

The fetal screen definitely has its place...just not for antepartum bleeds (at least the kits I’m familiar with).  I keep hoping our Hematology department will bring flow in so we can ditch the K-B!!!

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