Postoperative delirium in patients undergoing tumor resection with reconstructive surgery for oral cancer

Many attempts have been made to identify the risk factors for postoperative delirium, but this has proved difficult due to its complex morbidity. Furthermore, there is little information on postoperative delirium in patients undergoing tumor resection and reconstructive surgery for oral cancer. The aim of the current study was to investigate the incidence of and risk factors for postoperative delirium in patients undergoing resection and reconstructive surgery for oral cancer. The present study included 104 patients with pedicle or free flap reconstruction. Postoperative delirium developed in 22 (21.2%) of these patients. The mean time to onset of postoperative delirium was 2.5±1.0 days and the duration of delirium was 1.9±1.2 days. Univariate analysis demonstrated that the occurrence of postoperative delirium was significantly correlated with operating time (P=0.033), duration of anesthesia (P=0.039), amount of blood loss (P=0.027), method of reconstruction (P=0.008), type of flap used (P=0.009) and time until postoperative ambulation (P=0.0008). Low postoperative red blood cell count (P=0.004), hemoglobin (P=0.004) and hematocrit (P=0.004) were significantly associated with delirium, but preoperative blood test results were not. The multiple logistic regression analysis of these risk factors revealed that the only significant correlation that remained was between postoperative delirium and the time to ambulation after surgery (P=0.005). Since 2009, the Department of Oral and Maxillofacial Surgery, Kumamoto University Hospital has promoted ambulation after the first two postoperative days for patients with oral cancer undergoing tumor resection with reconstruction, and the occurrence of postoperative delirium has decreased from 29.2 to 14.0%. The results of the current study suggest that early postoperative ambulation in patients who undergo reconstructive surgery for oral cancer is effective for preventing postoperative delirium.