Change Of Cerebral Glucose Metabolism In Geriatric Patients With Postoperative Delirium And Effect Of Dexmedetomidine On Postoperative Delirium

Purpose:To investigate the change of cerebral glucose metabolism in geriatric patients with postoperative delirium following general anesthesia and the effect of dexmedetomidine on postoperative delirium patients using the PET/CT imaging technology.Method:Patients, age65to85were admitted to ICU postoperatively following major abdominal surgeries, and were divided into three groups dependent on whether the patients developed postoperative delirium or not within48hours postoperatively:Group A, patients with postoperative delirium (N=13); Group B, patients with postoperative delirium treated with dexmedetomidine (N=16); and Group C, patients without postoperative delirium (N=13). All patients were subjected to18fluorine-fluorodeoxyglucose (18F-FDG) cerebral glucose metabolism PET imaging study within48hours after surgery. Cerebral glucose metabolism was evaluated with visual analyzing method and semi-quantitative method by calculating cerebral glucose uptake value (SUV)Result:Patients who developed postoperative delirium (A and B) had lower cerebral glucose metabolism in general and in the parietal, temporal and frontal cerebral cortex areas particularly as compared to patients without postoperative delirium (C) based on visual analysis of the PET images. Semi-quantitative glucose standard uptake value (SUV) analysis further confirmed that patients with post-operative delirium (A and B) had significantly lower cerebral SUV in their parietal, temporal and front cerebral lobes than patients without postoperative delirium (C)(P<0.05). Patients with postoperative delirium but subsequently treated with dexmedetomidine (B) has significantly higher SUV values in each and every analyzed cerebral regions than untreated patients with postoperative delirium (A)(P<0.05).Conclusion:1. The cerebral glucose metabolism of Patients with postoperative delirium was lower than that of patients without postoperative delirium, suggesting that reduced cerebral glucose metabolism might be related to postoperative delirium.2. Dexmedetomidine could not only relieve the symptoms of delirium, but also could minimize the degree of cerebral glucose metabolism reduction seen in postoperative delirium patients.