When do you use PRBC and when do you use whole blood? (And some other questions)

[studenttttttt]

1. Especially for a neonatal exchange transfusion (for hyperbilirubinemia), isn't there more of a danger of polycythemia if you use PRBC?  Am I understanding it correctly?: A specific volume of donor PRBC is being transfused in exchange for the same volume of baby's whole blood.  (So the baby's hematocrit is increasing, but the relative plasma volume is being depleted).

2. What is the liquid in PRBC bag? Is it saline?

3. Other than reducing hyperkalemia risk, why do the PRBCs have to be washed for neonatal ET?

4. Why does PRBC prep take ten hours?

[carolyn swickard]

On ‎1‎/‎19‎/‎2019 at 10:15 PM, studenttttttt said:

1. Especially for a neonatal exchange transfusion (for hyperbilirubinemia), isn't there more of a danger of polycythemia if you use PRBC?  Am I understanding it correctly?: A specific volume of donor PRBC is being transfused in exchange for the same volume of baby's whole blood.  (So the baby's hematocrit is increasing, but the relative plasma volume is being depleted).

Exchange transfusions are usually done with reconstituted RBCs - in other words - the PRBCs are diluted to the physician desired hct with thawed FFP so the hct stays where you want it and the baby's coagulation values are not depleted.  If you are in a hospital that is using solely RBCs for an exchange transfusion (and not just a small volume transfusion) - that is different and I have no idea why they would be doing it.

2. What is the liquid in PRBC bag? Is it saline?

The liquid in most RBCs is one of the current anti-coagulants (CP2D, etc) and a RBC liquid food such as ADSOL (usually about 100 cc).  This mixture allows most of our units to last 42 days.  Almost all of the original plasma is removed.  Only a Whole Blood unit contains plasma.  None contain saline.

3. Other than reducing hyperkalemia risk, why do the PRBCs have to be washed for neonatal ET?

If the only units available to your hospital are ADSOL units - they are washed to remove the ADSOL because otherwise the hct is already too low to add FFP to the unit and ADSOL contains chemicals (such as mannitol) that are too much for babies when you are doing an exchange transfusion.  Also, ADSOL does not help with coagulation, so you need to get it out so you can replace it with FFP.  

If the units being used are not leukocyte reduced originally - they would also be washed to remove white cells and all remaining plasma.

4. Why does PRBC prep take ten hours?

There is a good chance that prep alone does not take 10 hours - sometimes just getting a suitable unit is what takes the time.  In our region, because the Drs still want CMV neg units (not just leukocyte reduced) - we can get caught looking for a units quite a while.  It also depends on how far away your hospital's blood distribution center is and what their availability is for O neg units (if that is what your hospital is trying to supply).  Between the need for CMV neg and O neg RBCs, it can be very hard to come up with additional units.  If the Mommy has an odd antibody on top of all that (that you must find antigen neg units for...) well, things can get complicated.

Exchange transfusion is a very complex procedure for the Blood Bank.  It is not at all like the small volume transfusion aliquots that are supplied more frequently.  Training and availability of competent personnel can be a real challenge, especially in the middle of the night when these things always seem to get ordered.

Does this help?