Anaemia during cardiopulmonary bypass (CPB) is strongly associated with acute kidney injury in clinical studies however reversal of anaemia with red blood cell (RBC) transfusions is associated with further renal injury. To understand this paradox we evaluated the effects of reversal of anaemia during CPB with allogenic RBC transfusion in a novel large animal model of post cardiac surgery acute kidney injury that shows significant homology to that observed in cardiac surgery patients. Adult pigs undergoing general anaesthesia were allocated to Sham procedure, CPB alone, Sham + RBC Transfusion or CPB + RBC Transfusion, with recovery and reassessment at 24 hours. CPB was associated with dilutional anaemia and caused acute kidney injury in swine characterised by renal endothelial dysfunction, loss of NO bioavailability, vasoconstriction, medullary hypoxia, cortical ATP depletion, glomerular sequestration of activated platelets and inflammatory cells and proximal tubule epithelial cell stress. RBC transfusion in the absence of CPB also resulted in renal injury. This was characterised by endothelial injury, microvascular endothelial dysfunction, platelet activation and equivalent cortical tubular epithelial phenotypic changes to those observed in CPB pigs, but occurred in the absence of severe intrarenal vasoconstriction, ATP depletion or reductions in creatinine clearance. In contrast, reversal of anaemia during CPB with RBC Transfusion prevented the reductions in creatinine clearance, loss of NO bioavailability, platelet activation, inflammation and epithelial cell injury attributable to CPB although it did not prevent the development of significant intrarenal vasoconstriction and endothelial dysfunction. In conclusion, contrary to the findings of observational studies in cardiac surgery RBC transfusion during CPB protects pigs against acute kidney injury. Our study underlines the need for translational research into indications for transfusion and prevention strategies for acute kidney injury.
|Translated title of the contribution||Reversal of anemia with allogenic RBC transfusion prevents post-cardiopulmonary bypass acute kidney injury in swine|
|Pages (from-to)||F605 - F614|
|Number of pages||10|
|Journal||AJP - Renal Physiology|
|Publication status||Published - Sep 2011|