Abstract: Objective To investigate the effect of individualized dosing regimen of dexmedetomidine based on multimodal anesthetic depth monitoring in preventing postoperative cognitive dysfunction (POCD) in the elderly patients undergoing non-cardiac surgery. Methods This prospective randomized controlled study enrolled 240 elderly patients undergoing non-cardiac surgery. All the patients were randomly assigned to group A (individualized dexmedetomidine administration guided by multimodal monitoring), group B (conventional anesthesia guided by multimodal monitoring), and group C (conventional anesthesia with routine monitoring), with 80 cases in each group. Mini-Mental State Examination (MMSE) was assessed and serum levels of S100β, neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) were measured to evaluate neuronal injury and oxidative stress before and 1, 3, 7 d after the operation. Meanwhile, adverse events in the three groups were also recorded. Results Compared with group B and group C, group A showed a significantly lower incidence of POCD 3 d and 7 d after operation (P<0.05), with a faster recovery of MMSE scores. At all postoperative time points, the serum levels of S100β, NSE, GFAP, MDA and GSH-Px were significantly lower while the level of SOD was higher in group A than those in group B and group C (P<0.01). The incidence rates of excessive sedation/somnolence, hypotension, and bradycardia were significantly lower in group A than those in group C(P<0.05). Conclusions The individualized dosing regimen of dexmedetomidine based on multimodal anesthetic depth monitoring has significant advantages in preventing POCD in the elderly patients undergoing non-cardiac surgery.    

Key words: dexmedetomidine, postoperative cognitive dysfunction, multimodal anesthetic depth monitoring, individualized dosing, neuroprotection