Perioperative Cerebral Protective Effect Of Nicorandil, A Mitochondrial K_ATP Channel Opener, On Patients Undergoing Double Valvular Replacement

Objective:To investigate whether different doses of nicorandil, a mitochondrial KATP channel opener have perioperative cerebral protective effects in patients undergoing Double Valve Replacement by measuring MMSE scores and serum NSE concentrations.Materials and methods:From March to October in 2009,a total of 30 patients with Rheumatic Heart Disease were collected in the Second Xiangya Hospital.The patients undergoing double valve replacement surgery were randomized to 3 groups:nicorandil first group (N1 group, n=10), nicoradil second group (N2 group,n=10) and the control group (C group,n=10). Patients in N1 group received 5mg nicorandil 30 min before anesthesia; patients in N2 group received 10mg nicorandil 30 min before anesthesia, and patients in C group did not receive nicoradil. Any Patient was scored with the Mini-mental state examination (MMSE) 24h before and after the cardiac surgery. Blood serum NSE concentrations were tested by ELISA method precisely before induction (T1),30 mins after termination of CPB (T2),6h after the surgery (T3) and 24h after the surgery (T4)Results:The three groups'postoperative MMSE scores were all lower than before, the differences in N1 and N2 groups were all statistically significant (P<0.05), C group differences were statistically significant (P<0.01). Preoperative and postoperative score difference of N1, N2 groups were less than C group,between N1 and C, the difference was statistically significant (p<0.05), between N2 and C, the difference was statistically significant (p<0.01), N1 and N2 was statistically significant difference between each other (p<0.05). T2, T3, T4 of three groups were significantly higher in serum NSE levels than T1 (P<0.01), Compared to the same time point of serum NSE concentration in three groups,the difference was statistically significant (P<0.05). The increasing amplitude of N1,N2 serum NSE concentration in T2,T3 was significantly lower than that of N1 group (P<0.05). The increasing amplitude of N2 serum NSE concentration in T2,T3 was significantly lower than that of N1 group (P<0.05) Conclusion:It could relieve the range of MMSE scores and the amplitude of serum NSE,when taking oral dose of nicorandil before the undergoing CPB Double Valve Replacement surgery.Compared with the lower dose,the higer dose of nicorandil effected better.It suggestted that nicorandil had cerebral protective effect.