Preoperative identification of patients at risk for delirium after major head and neck cancer surgery.

This study was performed to determine preoperative criteria for identifying patients at risk for delirium after major head and neck cancer surgery. The authors prospectively evaluated 138 consecutive patients undergoing head and neck cancer surgery lasting more than 2 hours at the Arthur G. James Cancer Hospital and Research Institute, Ohio State University, Columbus, from July 1993 through May 1994. Postoperative delirium developed in 24 of 138 patients (17%; 95% confidence interval 11% to 24%). The strongest univariate predictors of delirium were living alone (P = .005), the American Society of Anesthesiologists class (P = .003), and the preoperative white blood cell count (P < .0001). A predictive model for delirium using five criteria--age of 70 or more years, alcohol abuse, poor cognitive status, poor functional status, and markedly abnormal serum sodium, potassium, or glucose level--stratified the patients into three cohorts with an increasing risk of postoperative delirium (i.e., 9%, 19%, and 25%).