The Clinical Study Of Cognitive Dysfunction After Coronary Artery Bypass Graft

Objective 1. To evaluate whether off-pump coronary artery bypass grafting(CABG) could decrease the incidence of postoperative cognitive dysfunction(POCD) of middle-aged patients through compare with traditional on-pump CABG.2. To discuss the feasible anesthesia method of off-pump coronary artery bypass grafting(OPCABG) through compare the postoperative cognitive function of OPCABG between total intravenous anesthesia with propoful complex lidocaine and inhaled anesthesia with sevoflurane.Methods 1. Sixty undergoing elective CABG patients aged 40-64,heart functionⅠorⅡ,left ventricular ejection fraction≥45%,were randomly divided into two groups:off-pump group(Ⅰ,n=30) and on-pump group(Ⅱ,n-30).All patients did not have heart operation and nervous system disease history.The liver,kidney and pulmonary function were also normal.Right internal jugular vein was punctured and the catheter was advanced regressively up to the bulb of internal jugular vein after anesthesia induction.The blood samples of internal jugular vein were taken for determination of serum S-100 protein,neuronspecific enolase(NSE),tumor necrosis factor-a(TNF-a),interleukin-1(IL-1) and interleukin-6(IL-6) content at the moment after anesthesia induction(baseline value,To),the process of operation(T1),the end of operation(T2),6 h after operation(T3) and 24 h after operation(T4).The blood samples of radial artery and internal jugular vein were taken for blood gas analysis to determination of arterial oxygen saturation(SaO2),arterial partial pressure of oxygen(PaO2),internal jugular venous oxygen saturation(SjvO2), internal jugular venous partial pressure of oxygen(PjvO2) and haemoglobin(Hb) at above time point.Cerebral arterial venous oxygen content difference(Ca-jvO2) and cerebral blood flow/cerebral metabolic rate of oxygen(CBF/CMRO2) were calculated base on Fick formula.A mini-mental state examination (MMSE) was performed 1 day before and 3,7 days after operation by an experienced psychometrician.The total scores of MMSE was 30 points.Those scores not reach 24 points were defined as postoperative cognitive dysfunction (POCD).2. Sixty undergoing elective OPCABG patients aged 40-64,heart functionⅠorⅡ,left ventricular ejection fraction≥45%,were randomly divided into two groups:sevoflurane group(S,n=30) and propoful complex lidocaine group(P+L,n=30). All patients did not have heart operation and nervous system disease history.The liver,kidney and pulmonary function were also normal.Right internal jugular vein was punctured and the catheter was advanced regressively up to the bulb of internal jugular vein after anesthesia induction.The blood samples of internal jugular vein were taken for determination of serum S-100 protein,neuronspecific enolase(NSE) content at the moment after anesthesia induction(baseline value,To),the end of operation(T1),6 h after operation(T2) and 24 h after operation(T3).A mini-mental state examination (MMSE) was performed 1 day before and 3,7 days after operation by an experienced psychometrician.The total scores of MMSE was 30 points.Those scores not reach 24 points were defined as postoperative cognitive dysfunction(POCD).Results 1. The incidence of POCD within 7 days after operation in guoupⅡ(37%) was higher than that in groupⅠ(13%)(P<0.05).The scores of MMSE at 3,7 day after operation were lower than that at 1 day before operation in both groups(P<0.05).The score of MMSE at 7 day after operation in guoupⅡwas lower than that in groupⅠ(P<0.05).The contents of serum S-100 protein and NSE increased at T1(P<0.05),reached peak at T2(P<0.05),then decreased at T3 in both groups(P<0.05).The contents of serum S-100 protein and NSE returned to baseline level at T4 in groupⅠ(P>0.05),while in guoupⅡ, the contents of serum S-100 protein and NSE were higher than baseline level at T4(P<0.05). The contents of serum S-100 protein and NSE were higher in guoupⅡthan those in groupⅠat T1～T4(P<0.05). The PaO2 of two groups were lower than baseline level of each group at T3 and T4 (P<0.05). The PaO2 was higher in groupⅡthan that in groupⅠat Tj (P<0.05).The SjvO2 and PjvO2 of two groups were lower than baseline level of each group at T1 (P<0.05),while returned to baseline level of each group at T2 (P>0.05). The SjvO2 and PjvO2 were lower in groupⅡthan those in groupⅠat Tj (P<0.05).The Hb of two groups were lower than baseline level of each group at T3 and T4(P<0.05). The Hb was lower in groupⅡthan that in groupⅠat T) (P<0.05).The Ca-jvO2 of two groups was higher than baseline level of each group at T1 (P<0.05),while lower than baseline level of each group at T3 and T4(P<0.05). The Ca-jvO2 was higher in groupⅡthan that in group I at T1 (P<0.05).The CBF/CMRO2 of two groups was lower than baseline level of each group at T1 (P<0.05),while higher than baseline level of each group at T3 and T4(P<0.05). The CBF/CMRO2 was lower in groupⅡthan that in groupⅠat T1 (P<0.05).The levels of serum TNF-α,IL-1 and IL-6 were higher in groupⅡthan those in group I at Tj-T4 (P<0.05).The levels of serum IL-1 and IL-6 at T3 in groupⅠ, T1～T4 in groupⅡwere higher than those at To (P<0.05).2. The incidence of POCD within 7 days after operation in guoup S (27%) was higher than that in group P+L (7%)(P<0.05).The scores of MMSE at 3,7 day after operation were lower than that at 1 day before operation in both groups(P<0.05). The score of MMSE at 7 day after operation in guoup S was lower than that in group P+L (P<0.05).The contents of serum S-100 protein and NSE increased at the prime of operation(P<0.05),reached peak at T1 (P<0.05),then decreased at T2 (P<0.05),and returned to baseline level at T3in both groups(P>0.05).The contents of serum S-100 protein and NSE were lower in group P+L than those in group S at T1 and T2 (P<0.05).Conclusion 1. On-pump CABG can cause cerebral blood flow-metabolism disorder and serious inflammatory reaction,which may be the main reason of POCD that happened on middle-aged patients.Off-pump CABG improve the state of postoperative cognitive function,which contribute to decrease the risk of POCD that happened on middle-aged patients who undergoing heart operation.2. Intravenous anesthesia with propoful complex lidocaine can cause slighter cerebral injury and lower incidence of POCD than inhaled anesthesia with sevoflurane during OPCABG,which is a recommendable anesthesia method that could be used for prevent cognitive dysfunction after heart operation.