Why is recon. whole blood required for neonatal exchange transfusion?

[studenttttttt 0]

We have a case of severe hyperbilirubinemia secondary to HDFN due to Rh incompatability between mother and a pre-term, moderately underweight (2000g) baby.

What are the precise reasons a recon. whole blood is required in neonatal exchange transfusion?

Is it still common to wash the red cells? 

Is there a procedure/SOP anyone can share as to how the recon is made and how the hematocrit is calculated??

[Malcolm Needs ★ 4,771]

In the UK we do not use reconstituted blood for this process.  We use fresh as possible, irradiated blood, with a higher than normal haematocrit, as some of the plasma is expressed prior to the exchange.

[Neil Blumberg 217]

Most transfusion practices in neonatalogy, including this one, are not evidence based, but rather empirical expert opinion.  The use of reconstituted whole blood is more historical than anything else.  A unit or two of recently collected (perhaps 7-14 days) whole blood would probably be as rational.  One might check the potassium before using to make sure it isn't super high.  That is the rationale for washing a red cell.  It removes potassium from hemolysis during collection and storage, and makes the red cells more likely to absorb potassium once transfused.  It's definitely more useful if the baby is hyperkalemic to begin with.  Otherwise, whole blood would be fine.  The reason for using plasma is fear of hypocoagulability, which is probably mostly mumbo jumbo for small exchanges, but might be more of an issue for larger exchanges (2 or more blood volumes).  There is no real proof that any of these approaches is superior or inferior.

Calculating the hematocrit is a case of weighing the red cells and measuring their hematocrit and then diluting accordingly with plasma or albumin solution (5%).  You don't want a hematocrit higher than 40 in the exchange as normal neonates do not have high hematocrits and oxygen delivery is actually worse at hematocrits much above 30 in experimental models.  In this case, more is not better as far as anyone knows.  Once again, this is expert opinion not evidence based.

[YorkshireExile 20]

For our hospital the donation center does not provide whole blood so we have to reconstitute PRBC with plasma to make an exchange unit. I would like to ask Malcolm what type of red cells are used for exchange transfusions in the UK? Is it CPD-SAGM or just CPD units?

We get CPD-SAGM units from our supplier and have to centrifuge the unit to remove the SAGM, then we add plasma to achieve a HCT of around 45 to 50%.

[Baby Banker 77]

If kernicterus is a consideration, you might want to dilute your  RBC unit for the first exchange with albumin.  

[srichar3 19]

When performing double exchange is the additive solution and anticoagulants not an issue? Plus removal of any potential residual AB antibodies if using group O unit with non group O patient? This was always my understanding of the justification for reconstituting.

 

[srichar3 19]

20 hours ago, Malcolm Needs said:

In the UK we do not use reconstituted blood for this process.  We use fresh as possible, irradiated blood, with a higher than normal haematocrit, as some of the plasma is expressed prior to the exchange.

Hi Malcolm, according to the red book whole blood is used in the UK for exchange TX with removal of some plasma to increase the HCT. Is this not the reason why reconstituted PRBC are not been used as the end product is the same? But for labs that don't have access to whole blood reconstitution would be required to remove the additives and correct the HCT.

 

 

[srichar3 19]

22 hours ago, studenttttttt said:

We have a case of severe hyperbilirubinemia secondary to HDFN due to Rh incompatability between mother and a pre-term, moderately underweight (2000g) baby.

What are the precise reasons a recon. whole blood is required in neonatal exchange transfusion?

Is it still common to wash the red cells? 

Is there a procedure/SOP anyone can share as to how the recon is made and how the hematocrit is calculated??

If you PM me your e-mail address I would be happy to share our SOP with you. We don't wash the red cells though we only remove the supernatant then reconstitute with FFP.

Edited April 11, 2019 by srichar3

[Malcolm Needs ★ 4,771]

1 hour ago, srichar3 said:

Hi Malcolm, according to the red book whole blood is used in the UK for exchange TX with removal of some plasma to increase the HCT. Is this not the reason why reconstituted PRBC are not been used as the end product is the same? But for labs that don't have access to whole blood reconstitution would be required to remove the additives and correct the HCT.

This is true, but ALL hospitals have access to such blood as it is prepared on an ad hoc basis from whole blood, taken specifically for neonatal exchange by the four national blood services.

[srichar3 19]

42 minutes ago, Malcolm Needs said:

This is true, but ALL hospitals have access to such blood as it is prepared on an ad hoc basis from whole blood, taken specifically for neonatal exchange by the four national blood services.

Hi Malcolm I was aiming my comment at blood centers in other countries where PRBC's may be the only option, I don't believe we can order whole blood from our center here in the UAE and reconstituting PRBC's is the only option we have. I wish every blood service was a capable as NHSBT. 

[Malcolm Needs ★ 4,771]

5 hours ago, srichar3 said:

Hi Malcolm I was aiming my comment at blood centers in other countries where PRBC's may be the only option, I don't believe we can order whole blood from our center here in the UAE and reconstituting PRBC's is the only option we have. I wish every blood service was a capable as NHSBT. 

My apologies!

[simret 19]

This is how we calculate our volume:

Volume reduced RBC~ =150cc (g) =70% hct

X= total volume

Goal HCT= 45% 

(Volume reduced RBC * Volume reduced RBC HCT) = (Total Volume * Needed HCT)

 

                  (150g)                 *      (70%)                               =       (X ml)         *     (45%)

= (150g) (70/45)

X ml= 233ml total volume

233-150=83 plasma

∴      - Plasma needed = 83ml

-        Total volume = 233 ml

 Simret G.