The protective effect of remote ischemic preconditioning on the brain injury of patients treated with cardiac valve replacement under cardiopulmonary bypass

Objective:To investigate the protective effects of remote ischemic preconditioning(RIPC) on the brain injury of patients treated with cardiac valve replacement under cardiopulmonary bypass(CPB).Methods:Forty patients treated with cardiac valve replacement under CPB were randomly divided into the RIPC group and control group(CON group)(20 cases each group).After induction of anesthesia and before cardiopulmonary bypass, the pressure of left upper arm in RIPC group was increased by cerclage with orthopedic inflatable pressure tourniquet, loop 3 times, 5 min each time, and an interval of 5 min.The treatment of the CON group was the same as the RIPC group, but the tourniquet was not inflated.The levels of S-100β protein and NSE in internal carotid artery bulb were detected after 5 min of the induction of anaesthesia stability(T₀), at the end of operation(T₁), and at postoperative 1 h(T₂), 6 h(T₃) and 24 h(T₄).The neuropsychology in all operation patients were tested and assessed before 1 day of operation and after 3 and 8 days of operation.Results:The levels of S-100β and NSE in two groups at T₂ to T₄ were significantly higher than those at T₀(P<0.01), but the levels of S-100β at T₂ and T₃, and the levels of NSE at T₂ to T₄ in RIPC group were significantly lower than those in CON group(P<0.01).The MMSE and MoCA scores in RIPC group after 3 days of operation were lower than those in CON group(P<0.05 to P<0.01).Conclusions:The RIPC can decrease the levels of S-100β and NSE in the patients treated with cardiac valve replacement under CPB, and the incidence of cognitive impairment of patients, which can play a role on protecting brain.