Risk factors for postoperative delirium in patients undergoing head and neck cancer surgery.

This study was carried out to determine risk factors for delirium after major head and neck cancer surgery. The postoperative experience of 38 patients who underwent major head and neck cancer surgery and were managed in the high care unit was retrospectively examined by reviewing their medical records. Delirium was defined as confusion and abnormal behavior that interfered with postoperative recovery. Postoperative delirium occurred in 10 patients (26.3%) who all had stage IV cancer, flap reconstruction, an operative time of more than 10 h, blood transfusion of more than 4 units or infusion of more than 5000 ml, which together suggested the risk of delirium increased significantly with extensive surgery. Delirium occurred less frequently in patients with minor tranquilizer use for postoperative sleep disorder. Multivariative analyses showed an operative time of >10 h and no use of minor tranquilizer as significant factors for increasing the incidence of delirium, with odds ratios (95% confidence interval) of 11.4 (1.5-83.8) and 9.8 (1.5-66.0), respectively.