Erythroblastosis Fetalis | Donor Blood Volume Calculator for Transfusion

Parameters:

(1) fetal hemoglobin

(2) donor blood hemoglobin (as packed red blood cells)

(3) adjusted fetoplacental blood volume based on week of gestation

where:

• The equation for estimating the fetoplacental blood volume is described in Chapter 2.

• The donor hemoglobin is between 15 and 30 g/dL.

• The fetal hemoglobin is from 0 to 15 g/dL.

(fetal blood volume) / (donor blood volume) =

= (15 - (donor blood hemoglobin)) / ((fetal hemoglobin) - 15)

where:

• 15 is the mean normal fetal hemoglobin value at 40 weeks gestation.

volume of donor blood to transfuse in mL =

= (fetoplacental blood volume in mL) / ((15 - (donor blood hemoglobin)) / ((fetal hemoglobin) - 15))

where:

• Nicolaides provides a nomogram for a term "F". This is the inverse of ((15 - (donor blood hemoglobin)) / ((fetal hemoglobin) - 15)), which is multiplied by the fetal blood volume.