The Mechanism Of Cognitive Dysfunction After OP-CABG Perioperatively

Objective:To investigate if propofol and hidocaine—propofol can decreasethe incidence of cognitive dysfunction in the early postoperativeperiod after off-pump coronary artery bypass graft (OPCABG),analyse the intelligence and their influence factors with theMini-Mental State Examimation (MMSE). To observe the changes of serumlevel of S-100 protein and neuronspecific enolase(NSE) and theeffects on the oxygen metabolism during the early period after OPCABG.Methods:Fourty-five ASAâ…¡-â…¢patients undergoing elective OPCABG wererandomly divided into three groups: isoflurane group (â… ,n=15),propofol group (â…¡,n=15) and Lidocaine-propofol group(â…¢,n=15).Patients with neurologic diseases were excluded.Anesthesia was induced with midazolam 0.05-0.1mg/kg, sufentanyl 8-15μg/kg and vecuronium 0.1-0.2 mg/kg. Sufentanyl 250-300μg wascontinously infused after tracheal intubation and during operation.Vecuronium was given intermittently to maintain musclerelaxation, Internal jugular vein was canulated and the catheter wasadvanced retrogressly up to jugular bulb. Jugular venous bloodsamples were taken for determination of S-100 protein and NSEcontent. Under a state, the arterial and jugular oxygen content(CaO₂)were monitored at different time points. The arterial-venous oxygencontent difference (Ca-jvO₂),total body oxygen up take rate(CEO₂)ofthe cerebrum were calculated. Abattery ofneutropsychological testswas performed and scored preoperative and 7 days after surgery.Result:The three groups did not differ with respect to preoperative, operative and postoperative general data, and had no obvious influenceonhemodynamicparameters. 45 cases with clinical data were subjectedto the m ini-mental state exam ination(MMSE).The mean score andstandard deviation of each test were calculated. No patient wasfound to have postoperative cognitive dysfunction. There were nosignificant changes of CaO₂, CjvO₂ in the three groups during allstages(p＞0.05). SjvO₂ of the three groups increased, while Ca-jvO₂ andCEO₂ decreased during operative period, and then they returned tobaseline level postoperation. In groupâ…¢, SjvO₂ were higher thanthose in groupâ… , while Ca-jvO₂ and CEO₂ were lower than those inâ… group 24h after surgery (p＜0.05). Ca-jvO₂ were decreasedsingnificantly than that of groupâ… at the same stage. Afterintubation, Sera S-100 protein and NSE level increasedsignificantly(p＜0.01) and got to highest level on the time of skinincision and then returned to baseline level 24h after operation. Theserum S-100 protein concentrations ofâ…¡,â…¢groups and the serum NSElevel ofâ…¢group were significantly higher thanâ… group (p＜0.05)6h after the operation.Conclusion:The interference of OPCABG on cerebral oxgen metabolism is light.The present study demonstrates that perioperative intravenousinfusion with proper dose of propofol or lidocaine and propofol couldhave some protective effects on cognitive dysfunction in the earlypostoperative period after OPCABG.