Our lab at times, ran out of PRBC units intended for neonates, now what we do is just centrifuge SAGM units, take it out and retain the 21-day expiry. The new circular of information says that the shelf life of volume reduced components should be no more than 24 hours at 1 to 6C, but there's no explanation. Do you do this in your lab?thanks

BB03,

What is a SAGM unit? Is it Irradiated, CMV-Neg, HbS-Neg, and less than 7 days old when initialy used for aliquot prep? Are you using a sterile docking device for preparation of aliquots?

A SAG-M unit is unit of packed red cells that have been resuspended in the additive solution sucrose, adenine, glucose and mannitol. This is a "cell preservative" that "preserves" the red cells by allowing them to metabolise (if I remember correctly, and this is going back decades, via the Rappaport-Luberen shunt of the citric acid cycle - not too sure of the spelling).

The problem is the the mannitol is supposed to be hepatotoxic to babies.

It will be CMV-, HbS-, but it can be used up to 35 days (I think it's 35 days anyway), but it will not necessarily be irradiated.

Thank you Malcolm. I would ask then why is this product even in use for neonates if the manitol is hapatotoxic? At our facility and at other BB's I have worked the policies for Neonatal transfused state a requirement that PRBC's be less than seven days old (avoids hyperkalemia), Irradiated (avoids GVHD), CMV-Neg and HbS-Neg (for avoidence of passive aquisition). What are your practices and why if you don't mind me asking?

An additive, and I mean volume reduction not aliquoting. I just got confused with the AABB's circular of info. So the shelf life still remains dependent on the anticoagulant used and not 24 hours whether it's done aseptically or otherwise. thanks.

Thank you bb03.

thanks

Thank you Malcolm. I would ask then why is this product even in use for neonates if the manitol is hapatotoxic? At our facility and at other BB's I have worked the policies for Neonatal transfused state a requirement that PRBC's be less than seven days old (avoids hyperkalemia), Irradiated (avoids GVHD), CMV-Neg and HbS-Neg (for avoidence of passive aquisition). What are your practices and why if you don't mind me asking?

You have to remember that I am talking purely from a UK point of view here. I don't know what goes on in the rest of the world.

The answer is that SAG-M blood is never used for neonates, except in extremis.

I know of one case where we had to supply SAG-M blood for an exchange transfusion on a bay whose mother had an anti-k, and the only fresh liquid blood available (it was too urgent for frozen blood to be reconstituted) that was K+k- was a SAG-M unit. Actually, the baby showed no sign wahtsoever of hepatotoxicity.

In other words, SAG-M blood is reserved for children over a certain age (which escapes me at the moment I'm afraid) and adults. It would only be used for babies when the hospital is completely out of packed red cells, and they are too far away from their Blood Centre to get more too them, even using "blues and twos". It hardly ever happens, I might add.

When we are using packed red cells, the expiry date is much shorter (like you, I think it is 7 days), it has to be CMV- and has to be HbS-. If it is being used for a top-up, rather than an exchange or an IUT, it does not have to be irradiated in the UK unless the baby has had an IUT before birth, is extremely premature, or, of course, the donor is a close relative (although some hospitals do prefer to have it irradiated at all times).

:)

The addtive solution (in addition to the primary anticoagulant solution used at the time of collection) is what fuels the cells during the storage period and determines the acceptable length of storage. If you remove the fuel, the cells will not survive normally. Hence the requirement for the 24 hour expiration date if volume reducing 1-6 degree products (regardless if done in open or closed system). If you're simply aliquoting, you're removing the cells as well as the storage medium in the same proportions so original expiration date remains (if aliquoted in closed system) since adequate fuel remains for remaining cells.