Washed RBCs or Washed red cells transfusion is performed to reduce allergic reactions due to contaminating plasma proteins or to reduce the concentration of potassium accumulating in the supernatant of red cells during storage as an alternative to transfusion of fresher red cells in patients at risk of hyperkalaemia.

Indication of Washed RBCs Transfusion:

• The main indication for washed red cells is for patients that have repeated severe reactions to standard red cells. The rationale is that plasma proteins in the supernatant of the red cell in combination with recipient factors may be responsible for causing these reactions, and that washing removes the majority of plasma.
• Recurrent severe allergic transfusion reactions such as anaphylaxis or severe urticarial reactions not prevented by pre-transfusion antihistamine and corticosteroid administration.
• Depletion of potassium and anticoagulants prior to transfusion to a fetus or to a neonate with renal failure or when large amount of RBC component needed for neonate (RBC exchange, dialysis, ECMO etc.) when fresh RBCs are not available.
• IgA deficiency with documented anti-IgA antibodies when IgA deficient donors are not available to prevent anaphylactic transfusion reactions.
• Recurrent febrile non-hemolytic transfusion reactions not prevented by leukocyte reduction and antipyretics.

Preparation of Washed RBCs:

1. Under take the washing procedure after the compatibility test is over.
2. If single bag is used attach transfer bag by using sterile connecting device.
3. Balance the blood bag in centrifuge bucket along with another empty bucket. Spin at 3500r.p.m. for 10 minutes at 4ºC.
4. Remove supernatant plasma completely in the transfer bag using plasma expresser under the laminar flow.
5. The washing procedure is undertaken only after proposed unit is found to be compatible with recipient.
6. The proposed unit is balance in centrifuge bucket with another empty bucket. The buckets are centrifuge as per program.
7. The bag is removed, the supernatant plasma is completely removed in transfer bag using plasma expresser in laminar flow connect bag with bag containing 0.9% saline using transfer set.
8. Record the batch no. and expiry date of saline.
9. Introduce approximately 200 ml of saline in the Packed cell bag and mix thoroughly and centrifuge again.
10. Transfer supernatant saline with some plasma in transfer bag. Disconnect transfer bag, seal and discard.
11. Repeat the washing procedure with saline twice more (total three times) in exactly same manner as describe above.
12. Kept 20-30 ml saline I n Red cell bag. Seal the thrice washed red cell unit, weight the bags and record the details in register.
13. Store the Washed packed cell unit at 4°C (2ºC - 6ºC) temperature in the refrigerator and use within 24 hours.