Risk factors for postoperative delirium in elderly patients undergoing non-major oral and maxillofacial surgery-a retrospective chart study

Background/purpose: Recently, postoperative delirium (POD) has become a major problem in the perioperative management of general anesthesia in elderly patients. In this study, the general anesthesia and perioperative management of elderly patients aged 75 years or older undergoing non-major oral and maxillofacial surgery, and the incidence of POD, were retrospectively investigated, and the risk factors associated with them were determined. Materials and methods: The study was performed by retrospectively investigating patients’ medical records. The items investigated included: patient characteristics, dental diagnosis, concomitant general diseases, including dementia, preoperative laboratory data, anesthesia method (induction and maintenance of anesthesia), changes in blood pressure during anesthesia, duration of anesthesia, duration of surgery, perioperative complications, dose of anesthetics at induction, use of hemodynamic agents, and changes in pre- and postsurgical cognitive function. The Mann-Whitney U test and logistic regression analysis were used for statistical analysis. A significance level of p<0.05 was set for each test. Results and conclusions: The participants were 42 patients (15 males and 27 females) with a median age of 81 years. Six patients were preoperatively diagnosed with dementia. The risk factors for POD identified were preoperative diagnosis of dementia, higher age and longer duration of anesthesia. No other factors were significantly related to the risk of POD. Logistic regression analysis demonstrated that a preoperative diagnosis of dementia correlated with postoperative delirium. Six patients developed POD within several hours or 1 day after the end of anesthesia; five of the six patients were diagnosed with dementia preoperatively