Washed red cell haematocrit

In early 2018 NHSBT changed the method of production of washed red cells from an automated system to a manual system in order to improve the haemoglobin (Hb) content of units.  Hospitals were informed of the change at the time in the January 2018 Update. 

This update is to highlight that the Washed Red Cell component currently has a higher mean haematocrit (0.68) than standard Red Cells in Additive (0.58) although both are compliant with specification.  This may have clinical implications, for example if washed red cell units are used for automated red cell exchanges. 

It has been noted that the NHSBT Portfolio of Blood Components and Guidance for their Clinical Use (SPN233/9) does not currently include information on the Hct of Washed Red Cells. 

Summary of the current component quality monitoring data:

This work is already in progress and should be rolled out in the next few months. Once a go live date has been approved a further update will be communicated to hospitals and the NHSBT Portfolio of Blood Components and Guidance for their Clinical Use (SPN233/9) will be amended once there is sufficient quality monitoring data.NHSBT is undertaking validation work in order to reduce the mean Hct of Washed Red Cells which will bring it more in to line with a standard Red Cell in Additive Solution component.  This validation work should not change the haemoglobin yield for the washed components.  

Until a further update is received by hospitals the mean Hct of Washed Red Cells received by hospitals will remain at 0.68. Please disseminate this information to Hospital Transfusion Teams and clinicians who undertake red cell exchange transfusions.  

Jane Davies - Lead Specialist Manufacturing Development Team