Effect of warming and infusion of red blood cell concentrates on markers of haemolysis: An ex vivo simulation study

Transfusion of red blood cell (RBC) concentrates is a common procedure to restore blood volume and tissue oxygen delivery in patients with trauma. Although RBC warmers may prevent hypothermia, some warming or infusion equipment may lead to haemolysis and patient injury. The aim of this study was to test the effect of (i) RBC warming and (ii) administration via manual vs. pump infusion on haemolysis. This experimental ex vivo study studied haemolysis markers of RBC injury. The sample consisted of 90 RBC infusions in two simulations, randomly, 45 warmed RBC infusions and 45 nonwarmed RBC infusions, in two or three stages: before the intervention (baseline—warming, N= 45; nonwarming, N= 45), after water bath warming at 42 °C (warmed, N= 45), and then after the warmed or nonwarmed RBCs were infused by manual or pump infusion at a rate of 100 mL/h (infusion—warming, N= 45; nonwarming, N= 45). Warmed RBCs showed significantly lower total haemoglobin (Hb) and haematocrit levels and increase in free Hb levels, haemolysis levels, and lactate dehydrogenase (LDH) activity (all p