Abstract:

Objective To determine the incidence of post-operative delirium after oral and maxillofacial surgery under general anesthesia in elderly patients, and to examine its association with plasma concentrations of beta amyloid protein 1-40（Aβ1-40）. Methods Fifty patients underwent elective oral and maxillofacial surgery were divided into two groups: Group C（n=20） aged from 20 to 60 years old, and Group T（n=30） aged from 62 to 78 years old. The two group received the same general anesthesia. Delirium rating scale-revised-98（DRS-R-98） was used as an instrument to diagnose and access the postoperative delirium of the two groups. The scores of DRS-R-98 were recorded before operation（T0） and at 24 h（T1）, 48 h（T2）, 72 h（T3） and 96 h（T4） after the operation. Serial measurements of serum concentrations of Aβ1-40 were also performed at the same time. Results The incidence of post -operative delirium after oral and maxillofacial surgery in Group T was 20.0%. The concentrations of plasma Aβ1-40 in group T were much higher than group C at T0, T1, T2 and T3 significantly（P＜0.01）. The concentrations of plasma Aβ1-40 at T1 and T2 were higher than those at T0 in the same group（P＜0.05）. The scores of DRS-R-98 in Group T at T3 and T4 were much higher than those at T1 and Group C significantly（P＜0.01）. Conclusion The constant increase of plasma Aβ1-40 may be one of the important factors related to post-operative delirium in elderly patients underwent oral and maxillofacial surgery.

Key words: delirium, beta amyloid protein 1-40, delirium rating scale-revised-98