Hello,

This is our first post and we would like to say hello. Angel Med is not just one person but several of us who have been viewing the forums for a few months now. We have found it very helpful and would like to thank you all for allowing us to quietly view. A little about us. We are a small hospital in North Carolina approximately 55 beds with a small blood bank.

Now we have a question for you guys in the know. The AABB standards state that a weak D is unnecessary when testing the patient. It also states that a weak D is not necessary when retyping the units. My question is: When crossmatching blood for an Rh negative patient, should the weak D be included on the units before transfusion?

No - weak D on units is performed by the blood supplier. You verify D= upon receipt/retype. No need to recheck weak D.

Welcome all of angelmed, and like David said.

We have our own donor center at our Blood Bank. We check all negative donors immediately for weak D. We don't have a supplier in the whole country.

Welcome to this great place!!!

Liz

The reasoning is this: Any weak D units must be considered positive for RH as there is a slight possibility of the recipient making antibody to even a portion of the D antigen, if it was given to an RH negative recipient. For the same reason, Baby cords are testing for weak D and the mother is given Rhogam even in those cases.

Yes that is what we do.

We are a teaching institution, so we also run it on the patients at times for the students. Of course patients Du are documented as negative.

It then becomes an exam question for them.

Liz

never should a weak D considered to be chosen for Rh NEG pt....it has every chance to produce antibodies ,we test all negative donors with RhD(vi+) cards

Angelmed, are you working in a transfusion hospital? If the answer is yes, then weak D test only perform on baby cord blood to determine Rh negative mom need further RhoGam injection after the baby is born. Perform weak D test on donor blood is not necessary.

Hope that helps.

CK Cheng, MSc, SBB(ASCP), CQS(ASQ)

Hong Kong

Oct 13, 2009

Angelmed, are you working in a transfusion hospital? If the answer is yes, then weak D test only perform on baby cord blood to determine Rh negative mom need further RhoGam injection after the baby is born. Perform weak D test on donor blood is not necessary.

Hope that helps.

CK Cheng, MSc, SBB(ASCP), CQS(ASQ)

Hong Kong

Oct 13, 2009

Weak D MUST be performed on Donor blood.

Weak D MUST be performed on Donor blood.

I agree entirely with you Liz.

If you are working in a transfusion hospital, weak D test on Rh-negative donor blood is not necessary cuz already done in Blood Center before labeled as [Rh Negative]. Of course individual hospital or transfusion center may choose to do it. Follow your institute's SOP.

However, if you are working in a Blood Center or Donor Center, weak D test must be done before the unit labeled as [Rh Negative].

Hope that helps.

CK Cheng, MSc, SBB(ASCP), CQA(ASQ)

Oct 14, 2009

If you are working in a transfusion hospital, weak D test on Rh-negative donor blood is not necessary cuz already done in Blood Center before labeled as [Rh Negative]. Of course individual hospital or transfusion center may choose to do it. Follow your institute's SOP.

However, if you are working in a Blood Center or Donor Center, weak D test must be done before the unit labeled as [Rh Negative].

Hope that helps.

CK Cheng, MSc, SBB(ASCP), CQA(ASQ)

Oct 14, 2009

Yes, with those provisos, I agree with you.

Weak D testing of donor blood BY A HOSPITAL who receives blood from outside source (actually a retype) is not necessary

My understanding is that donor facilities are required to do weak D testing on blood units. Hospitals are not. If the donor facility detects a weak D the unit is considered Rh positive and labeled as such.

The only circumstance in which we perform weak D testing is on an Rh negative infant (usually cord blood) of an Rh negative mother. This is to verify whether or not Rhogam is needed.

Angelmed, are you working in a transfusion hospital? If the answer is yes, then weak D test only perform on baby cord blood to determine Rh negative mom need further RhoGam injection after the baby is born. Perform weak D test on donor blood is not necessary.

Hope that helps.

CK Cheng, MSc, SBB(ASCP), CQS(ASQ)

Hong Kong

Oct 13, 2009

I believe that it is necessary to read the entire post as opposed to the last sentence. When I read this post I assumed that the reference to a transfusion hospital meant that they are not a donor center. Therefore the weak D testing is not needed when verifying the donor blood type.