Background: Experimental studies suggest that mechanical cell washing to remove pro-inflammatory components that accumulate in the supernatant of stored donor red blood cells (RBCs) might reduce inflammation and organ injury in transfused patients.
Methods: Cardiac surgery patients at increased risk of large-volume RBC transfusion were eligible. Participants were randomized to receive either mechanically washed allogenic RBCs or standard care RBCs. The primary outcome was serum interleukin-8 measured at baseline and at four postsurgery time points. A mechanism substudy evaluated the effects of washing on stored RBCs in vitro and on markers of platelet, leucocyte, and endothelial activation in trial subjects.
Results: Sixty adult cardiac surgery patients at three UK cardiac centres were enrolled between September 2013 and March 2015. Subjects received a median of 3.5 (interquartile range 2-5.5) RBC units, stored for a mean of 21 ( sd 5.2) days, within 48 h of surgery. Mechanical washing reduced concentrations of RBC-derived microvesicles but increased cell-free haemoglobin concentrations in RBC supernatant relative to standard care RBC supernatant. There was no difference between groups with respect to perioperative serum interleukin-8 values [adjusted mean difference 0.239 (95% confidence intervals -0.231, 0.709), P =0.318] or concentrations of plasma RBC microvesicles, platelet and leucocyte activation, plasma cell-free haemoglobin, endothelial activation, or biomarkers of heart, lung, or kidney injury.
Conclusions: These results do not support a hypothesis that allogenic red blood cell washing has clinical benefits in cardiac surgery.
Clinical trial registration: ISRCTN 27076315.
Bibliographical noteNational Institute for Health Research Programme Grant for Applied Research (RP-PG-0407-10384 for The REDWASH trial); British Heart Foundation (RG/13/6/29947, CH/12/1/29419, and PG/11/95/29173 to G.J.M., M.W., W.D., T.K. and N.S.); Leicester Cardiovascular Biomedical Research Unit (G.J.M., M.W., W.D., T.K. and N.S.).
- Aged, 80 and over
- Blood Preservation
- Cardiac Surgical Procedures/adverse effects
- Endothelium, Vascular
- Erythrocyte Transfusion/adverse effects
- Leukocytes/drug effects
- Middle Aged
- Platelet Activation
- Postoperative Complications/prevention & control
- Single-Blind Method
- Treatment Outcome