Table V.
Instructions for calculating the volume of donor red cells necessary to obtain the desired final haematocrit and residual concentration of haemoglobin S after a three-step red cell exchange
| Cell | Text to be entered |
|---|---|
| A1 | Kinetics of continuous flow red cell exchange – non-isovolumetric |
| A3 | Patient’s blood volume (mL) |
| A4 | Patient’s initial venous haematocrit (%) |
| A5 | Correction factor for the body haematocrit |
| A6 | Haematocrit of the removed blood (%) |
| A7 | Haematocrit of the transfused blood (%) |
| A8 | Initial concentration of HbS (%) |
| A9 | Desired final concentration of HbS (%) |
| A10 | Desired final haematocrit (%) |
| A11 | Minimum allowed haematocrit (%) |
| A13 | Patient’s initial red cell volume (mL) |
| A14 | Volume of patient’s red cells to be removed in the first phase (mL) |
| A15 | Volume of donor red cell concentrate to be exchanged in the second phase (mL) |
| A16 | Volume of donor red cell concentrate to be transfused at the end (mL) |
| A17 | Total volume of donor red cell concentrate needed for the exchange (mL) |
| Value to be entered | |
| B3 | Blood volume of the patient (mL), e.g. 4,500 |
| B4 | Initial haematocrit of the patient, e.g. 30 |
| B5 | Correction factor for body haematocrit: 0.91 |
| B6 | Haematocrit of the removed blood (%), e.g. 80 |
| B7 | Haematocrit of the transfused blood (%), e.g. 60 |
| B8 | Initial concentration of HbS (%), e.g. 70 |
| B9 | Desired final concentration of HbS (%), e.g. 30 |
| B10 | Desired final haematocrit (%), e.g. 33 |
| B11 | Minimum allowed haematocrit (%), e.g. 25 |
| Formula to be entered | |
| B13 | =B3*B4/100*B5 |
| B14 | =B3*B5/B6*100*(B4/100−B11/100) |
| B15 | = − B3*B5*B11/B7*LN(B10/B11*B9/B8) |
| B16 | =B3*B5/B7*100*(B10/100−B11/100) |
| B17 | =B3*B5/B7*100*(B10/100−B11/100*(1+LN(B10/B11*B9/B8))) |