Washed red cell haematocrit
Our work to reduce the mean haematocrit of washed red cells
In May 2019 we informed you that due to a change in the production method of washed red cells from an automated system to a manual system the mean haematocrit (0.68) of the washed red cell component was currently higher than that of standard Red Cells in Additive Solution (0.58) although both are compliant with specification.
We have been undertaking work to reduce the mean haematocrit of Washed Red Cells and bring it more in to line with a standard Red Cell in Additive Solution component. This work has now been completed and may have clinical implications, for example if washed red cell units are used for automated red cell exchanges.
Summary of the component quality monitoring data for the reduced Hct component:
|
Component |
Specification |
Mean |
SD |
-3SD |
+3SD |
|
Washed Red Cells |
Volume (200-320mL) |
277.3 |
12.8 |
238.8 |
315.8 |
|
Washed Red Cells |
Hb per Unit (>40g) |
53.3 |
3.82 |
41.9 |
64.8 |
|
Washed Red Cells |
HCT (0.5-0.7) |
0.60 |
0.02 |
0.52 |
0.67 |
|
Red Cells in Additive Solution (Routine) |
HCT (0.5-0.7) |
0.58 |
0.03 |
0.50 |
0.66 |
The reduced haematocrit is due to an increase in the volume of SAGM in which the final component is suspended. The new suspension volume is 100mL. The component label will be updated to reflect the new volume on the go live date.
We intend to go live with this new process on Monday 29 July 2019 and our Portfolio of Blood Components and Guidance for their Clinical Use (SPN223) will be amended once there is sufficient quality monitoring data (currently a limited data set).
The mean Hct of Washed Red Cells will now remain at 0.60. Please disseminate this information to Hospital Transfusion Teams and clinicians who undertake red cell exchange transfusions.
Jane Davies - Lead Specialist, Manufacturing Development Team