Abstract: Objective To explore and analysis the relationship between preoperative hemoglobin level and postoperative delirium in elderly patients undergoing abdominal surgery. Methods From August 2021 to March 2022, 216 elderly patients who underwent abdominal surgery in the General Hospital of Ningxia Medical University were retrospective selection as the research subjects. According to whether delirium occurred, they were divided into delirium group(n=32) and non-delirium group(n=184). Investigate and record the general information of all patients, including gender, age, anesthesia ASA classification, anesthesia time, operation time, intraoperative blood loss, fasting blood glucose, albumin, etc. The hemoglobin levels were monitored in all patients 1 day before surgery and the day after surgery. Postoperative delirium was assessed by the Confusion Assessment Method(CAM), and Pearson analysis was used for correlation analysis. Multivariate Logistic stepwise regression analysis was used for influencing factor analysis, and ROC curve analysis was used for predictive value analysis. Results There was no significant difference in sex, age, ASA grade, anesthesia time, operation time, intraoperative bleeding and albumin compared between delirium group and non delirium group (P>0.05). The hemoglobin level of delirium group was significantly lower than that of non delirium group (P<0.05). In the 216 patients, Pearson analysis showed that there was correlation between hemoglobin level on the 1st day before operation and delirium on the 5th day after operation (P<0.05). Multivariate logistic stepwise regression analysis showed that the level of hemoglobin 1 day before operation was an important factor leading to delirium 5 days after operation (P<0.05). Receiver operating characteristic (ROC) curve analysis showed that the area under the curve of hemoglobin level 1 day before operation to predict delirium 5 days after operation was 0.670. Conclusion Elderly patients with abdominal surgery are prone to postoperative delirium. There is positive correlation between preoperative hemoglobin level and postoperative delirium. It is also an important factor leading to delirium and can also predict the occurrence of postoperative delirium.

Key words: elderly patients, delirium, hemoglobin, abdominal surgery, relevance, influencing factors, predictive value