If I have a case needed Exchange Transfusion, both mother and baby blood group are A. How much plasma should i remove from whole blood to make the final haematocrit around 50? Is there any special formula? I want to refrain myself from using Reconstituted blood as this may expose to 2 donors. 

you will need to know the hct of your unit.  Example:

WB of 500mL w a 45% hct =  225 ml or rbcs and 275 ml of plasma.

remove 50 mL of plasma giving you  225 mL rbc and 225 mL of plasma and a hct of 50%.

 

Edited February 16, 20187 yr by David Saikin
I can't add or subtract

To questions just out of idle curiosity.  What's the antibody and where on earth are you getting whole blood?

 

It is anti-c. In my country, hospital blood bank still do the blood procurement, not by agency like Red Cross etc, so getting the whole blood is not a problem. We usually standby few pints of whole blood in our inventory.

Edited February 16, 20187 yr by Kandahlawi

Good luck with the exchange.  The worst case of HDN I ever saw was caused by anti-c.

 

V1  x C1 = V2  x C2  where V1 is volume of initial unit in mL, C1 = hematocrit (%) of initial unit, C2 = desired hematocrit (%), and V2 = final volume in mL

V1 - V2 =  volume of plasma to remove in mL

1.06 g/mL is approximate specific gravity of whole blood.  You will need to subtract the tare weight of empty collection bag and convert weight to volume using specific gravity.