Neuroprotective effects of intravenous lidocaine on early postoperative cognitive dysfunction in elderly patients following spine surgery

Abstract

Background: This study aimed to evaluate the effects of lidocaine treatment on cognitive impairment in aged patients undergoing spine surgery and to explore the underlying mechanism.

Material/methods: Patients were randomly divided into 2 treatment groups: (1) saline (control) and (2) lidocaine. After induction of anesthesia, the lidocaine group received lidocaine as a bolus of 1 mg/kg over 5 minutes, followed by a continuous infusion at 1.5 mg/kg/h until the end of the surgery. We examined the effects of lidocaine treatment on the improvement of cognitive function using the Mini-Mental State Examination (MMSE) at preoperation and 3 days postoperation. Serum samples were collected to assess the levels of IL-6, TNF-α, MDA, S100β, and NSE before inducing anesthesia, at the end of surgery, and 3 days after the end of surgery.

Results: We found that the MMSE scores in the lidocaine group were markedly higher than those in the control group at 3 days after surgery. Moreover, lidocaine treatment markedly suppressed the release of IL-6, S100β, and NSE into the serum at the end of surgery and 3 days after the end of surgery. In the control group, serum MDA levels increased by 3 days after the end of surgery. The lidocaine group had lower serum MDA levels than those in the control group.

Conclusions: Lidocaine may be an effective neuroprotective agent in treating early postoperative cognitive dysfunction in elderly patients undergoing spine surgery.

Figure 1

MMSE scores in the 80 patients prior to and 3 days after surgery. All data are expressed as the means ±SD. n= 40 per group. * p<0.05 compared with preoperative MMSE scores; ** p<0.05 compared with control group.

Figure 2

Serum IL-6 (A) and TNF-α (B) concentrations (pg/ml) at different time points. All data are expressed as the means ±SD. n=40 per group. * p<0.05 compared with preoperative IL-6 or TNF-α levels; ** p<0.05 compared with control group.

Figure 3

Serum MDA concentrations (nmol/ml) at different time points. All data are expressed as the means ±SD. n=40 per group. * p<0.05 compared with preoperative MDA levels; ** p<0.05 compared with control group.

Figure 4

Serum S100β (A, pg/ml) and NSE (B, ng/ml) concentrations at different time points. All data are expressed as the means ±SD. n=40 per group. * p<0.05 compared with preoperative S100β or NSE levels; ** p<0.05 compared with control group.