Remote Ischemic Preconditioning Attenuates Oxidative Stress during Cardiopulmonary Bypass

Background: Deep hypothermic circulatory arrest (DHCA) is used to overcome the threat of cerebral ischemia during complex surgical operations of the heart and the aortic arch. Remote ischemic preconditioning (RIPC) has been shown to mitigate neurological damage. Methods: We analyzed blood samples in a consecutive series of 52 piglets that underwent a 60-min period of DHCA with RIPC (the RIPC group) or without (the control group), to reveal whether the protective effect to oxidative stress could be seen by measuring serum 8-hydroxydeoxyguanosine (8-OHdG). The piglets were cannulated and cooled to 18 degrees C using a heart-lung machine, for the DHCA. The piglets were then rewarmed to normothermic temperature. Blood sampling was taken at baseline, after 30 minutes of cooling, 2 hours postoperatively, and 8 hours postoperatively, and analyzed. 8-hydroxydeoxyguanosine (8-OHdG) from blood samples was analyzed by using Enzyme Linked Immunosorbent Assay (ELISA). Results: The serum 8-OHdG concentration was lower in the RIPC group after the cooling phase, 1.84 (1.44-2.17) ng/mL, and at 8 hours after HCA 1.48 (1.39-1.69) ng/mL, when compared with the control group, where the values were 2.14 (1.81-2.56) and 1.84 (1.62-2.44) ng/mL, respectively (P=.025) and (P=.004). Conclusion: Remote ischemic preconditioning lowers oxidative stress during cardiopulmonary bypass.