Risk Factors Of Postoperative Delirium And The Preventive Effect Of Metformin

ObjectiveTo explore the risk factors of postoperative delirium in elderly patients receiving hip fracture surgery and investigate the preventive effect of metformin on postoperative cognitive dysfunction in high-fat diet rats.Methods286 patients with hip fracture and receiving hip replacement,were included in the investigation.Demographic data,comorbidity,laboratory examinations,intraoperative variables were collected.Different tests were used to compare variates between two groups.Logistic regression analyses were used to identify the impact of various factors on the development of postoperative delirium.30 adult rats were randomized into three groups: high-fat diet group(HF),high fat and splenectomy group(HF+Surg)and high fat and metformin and splenectomy group(HF+Met+Surg).HF+Met+Surg group was fed with metformin for two weeks after two months high-fat diets.The HF+Surg and HF+Met+Surg group received splenectomy after the gavage.The Morris water maze was used to study the cognitive function of rats.The escape latency,distances of swimming,and speed of swimming were recorded during 5 days after operation;on the 6th day,the time spent in target quadrant was recorded.ResultsRegression analysis showed that age,total bilirubin,blood glucose,C-reactive protein,and volume of red blood cells transfusion were different statistically.On the first day after surgery,HF+Surg group had a longer escape latency and swimming distance than other groups;HF+Met+Surg group had a shorter escape latency and swimming distance than HF+Surg group but had no statistical difference with HF group.The escape latency had no statistical difference in the rest of time ConclusionThe age,total bilirubin,blood glucose,C-reactive protein,volume of red blood cells transfusion are independent risk factors of postoperative delirium in elderly patients receiving hip replacement.The high fat diet rats have a cognitive decline after splenectomy.Metformin may prevent postoperative cognitive dysfunction in rats receiving high-fat diet.