Objectives: To determine whether intraoperative blood transfusion, a known trigger and amplifier of inflammation, is an independent risk factor for early postoperative delirium (POD), an acute state of confusion with fluctuating consciousness and inattention after surgery, in older adults undergoing surgery.
Design: Secondary analysis using a database created for a prospective cognitive outcomes study.
Setting: University hospital.
Participants: Four hundred seventy-two individuals aged 65 and older undergoing major noncardiac surgery.
Measurements: Perioperative data were examined for association with POD on the first postoperative day. Multivariable logistic regression analysis was conducted to determine whether intraoperative blood transfusion independently predicts POD after adjusting for covariates known to be associated with onset of delirium and blood transfusions.
Results: One hundred thirty-seven individuals (29%) developed delirium on the first postoperative day. The multivariable logistic regression model identified age, sex, history of central nervous system disorder, preoperative cognitive dysfunction, and pain, as well as blood transfusions, as independent risk factors for POD. Intraoperative administration of more than 1,000 mL of red blood cells (RBCs) was the strongest predictor of POD on the first postoperative day (odds ratio = 3.68; 95% confidence interval = 1.32–10.94; P < .001).
Conclusion: Intraoperative blood transfusion of more than 1,000 mL of RBCs increases the risk of delirium on the first postoperative day in older adults undergoing noncardiac surgery.