eeagan

Everything that Malcom wrote is true for explaining why no carry over was seen in the reverse typings. As an interesting note though, the first specimen that made the staff realize that there was possibly carry over contamination had a back type discrepancy due to anti-c. Her anti-c was capable of reacting with the Rh negative c positive A1 cells. This happened on the ProVue and in manual tube testing. There wasn't extra reactivity in the back type with the specimens that did have carry over in the antibody screen. I'd still like to know if anyone else experienced this problem.

I would like to add that we did not see any carry over in the ABO/Rh typing.

I don't know if Ortho has said so in words, but I'm sure that they realize the implications. I've yet to do a detailed search of patient results, but so far I am not aware of any false negatives due to the carry over. We're only aware of false positives which caused extra testing and some delay of completing crossmatches.

We have just resolved a problem with carry over on the ProVue and I'd like to know if anyone else has experienced the same thing. The carry over was only seen on the antibody screen and with strongly positive specimens. We were fortunate in that 2 of the specimens involved were prenatal specimens. So titers were done on them. One specimen had anti-c (128), anti-E (128) and anti-K (8). Carry over was seen with the anti-c and anti-E but not with anti-K. The other specimen had anti-D (128) and anti-C (2). Carry over was seen with anti-D on both Rh positive cells. The last specimen contained anti-D, titer unknown and carry over was seen on both Rh positive cells. The problem turned out to be caused by a reversal of the tubing of the wash solutions. At some point in the system, the tubing for solution A was connected to the hook up for solution B and vise versa. This was not the connection at the wash bottle but further back in the system and was done by the Ortho repair tech. While it seems likely that the problem occurred because of an error on the part of the repair tech, I'd like to know if anyone else ever encountered carry over on the ProVue.

Yes, when blood products are urgently needed before both specimens can be processed, we give O negative RBC and AB FFP. It's not often that we have to do this. But we do not hesitate to offer the emergency release (uncrossmatched) O negative RBC.

This incident also points out the need for a second specimen to verify the ABO/Rh. At our hospital, we do not issue any blood product until there are 2 ABO/Rh types in our computer system and the types agree. Granted, this does not detect patient identification errors at any level if both patients have the same ABO/Rh. It also doesn't avoid patient identification errors at the phlebotomy level if both tubes were drawn at the same time but submitted to the blood bank at different times. But it has detected labeling errors that happened at the phlebotomy stage and in the blood bank.

That's a very good question and I don't have an answer for it. It still may work out that the order is placed after the actual emergency release has been done. But I do know that there is an option in the computer for the physician to request emergency release blood.

We are in the process of switching to physician ordering through UCare computer system. Part of this process will include an electronic signature by the physician for emergency release blood. Because we have not gone live with it, I cannot comment on how well it is working. But I look forward to having this option as it will be easier than getting a piece of paper. If an electronic signature is valid for medical records and on line review fo procedure,s I see no reason why it isn't valid for emergency release.

Sandy, You are not missing anything. Ortho does not have a Rh control for their Bioclone anti-D.

We always do a AHG crossmatch on patients with anti-M. We also always do a prewarm screen on M+ cells that reacted at AHG. We use PEG for our manual antibody screens. If the prewarm screen is negative, we rely on the crossmatches for compatible units. If the prewarm screen is positive, we crossmatch (PEG to AHG) M negative units. This policy was started recently by our medical director who feels that the results of the prewarm screen will show if the anti-M is IgG or IgM. So far, I cannot recall one patient whose anti-M was prewarm positive.

For those of you who use the Ortho Rh control, be aware that this control is only for the Ortho human based anti-D. It is not for the Ortho monoclonal anti-D. If you are using the monoclonal anti-D, you should use 6% albumin, saline or the patien'ts serum/plasma for the control. We use a Rh control (6% albumin) only for AB positive patients when they are typed manually. We use the Ortho ProVue. So all patients typed on that have a Rh control as part fo the typing.

Does saline work as a control as well as the 6% albumin? Ellen Eagan

I would like to purchase albumin already diluted to 6% instead of diluting 22% albumin to 6%. I have been unable to find a source for this but have been told that it's available. Does anyone know where I can purchase 6% albumin that's acceptable as a blood bank reagent? Ellen Eagan