The Effect Of Lidocaine On Systemic Inflammatory Response And Early Postoperative Cognitive Dysfunction In Elderly Patients Following Spine Surgery

Objective:Postoperative cognitive dysfunction (POCD) which means the disturbance of the ability of focusing, attention, learning and solving problems, often occurs after operation. At present, the pathogenesis of POCD is not clear.A large number of studies imply that inflammatory mediators are involved in the occurrence of POCD, and anti-inflammatory strategies are effective for the prevention and treatment of POCD. Another study shows that lidocaine can inhibit inflammatory mediators release, inhibit inflammatory response, and maybe has the role of brain protection,but whether it can reduce the incidence of postoperative systemic inflammation and early cognitive dysfunction in elderly patients with general anesthesia needs further investigation. This study intends to investigate the effect of lidocaine on postoperative systemic inflammatory response and early cognitive dysfunction in elderly patients undergoing general anesthesia, and to provide clinical basis for the treatment and prevention of POCD. Methods: 80 cases of elderly patients with lumbar internal fixation under general anesthesia were enrolled in this study.The patients, ASA Ⅰ～Ⅱ, older than 65 years, were randomly divided into lidocaine (L) group and saline (C) group,40 cases in each group. All patients were anesthetized with total intravenous anesthesia.After inserting Tracheal tube,the patients in L group were injected with 1mg/kg lidocaine, and maintained with 1.5mg/kg/h lidocaine till the end of the operation, and the patients in C group were injected with the same amount of normal saline. MMSE was used to determine whether POCD occurred ond day before surgery and third days after surgery, and the incidence rate of POCD was recorded. NSE, S100β protein, IL-6 and TNF-α in serum were measured before and after operation and the third day after operation.Results:MMSE was not significantly different between the two groups before operation. (P>0.05); compared with the preoperative MMSE score, the score in L group was not significantly changed, but the score in C group was significantly decreased (P<0.05);the incidence of POCD in L group was 7.5%(3/40),which is significantly lower than the C group 27.5%(11/40) (P<0.05) (POCD). There was no significant difference in serum S100β protein, IL-6, NSE and TNF-α(p>0.05) before operation. Compared with T1, NSE was significantly increased at T3, IL-6 and S100β protein were significantly increased at T2 and T3 in C group(p<0.05),but IL-6, NSE and S100β protein in L group had no significant change at T2 and T3 (P>0.05). Compared with the C group, NSE at T3, IL-6 and S100β protein at T2 and T3,in L group were significantly lower (P<0.05). There was no significant change in the content of TNF-α at T1, T2, T3 in the two groups (P>0.05).Conclusion:Lidocaine can reduce the production and release of inflammatory mediators effectively which were caused by spinal surgery in elderly patients. Lidocaine can reduce the incidence of postoperative cognitive dysfunction, so it can be used as neuroprotective agents to prevent postoperative cognitive dysfunction.