Risk factors for postoperative delirium after colorectal surgery for carcinoma

Data regarding the incidence and risk factors for postoperative delirium (PD) after gastrointestinal surgery are heterogeneous because they include both benign and malignant disease. The aim of this study was to investigate the incidence and risk factors for PD in 100 consecutive patients over 65 years who underwent colorectal surgery for carcinoma.Pre-operative cognitive function was assessed using the Mini Mental State Examination. The onset of PD was diagnosed by the Confusion Assessment Methods administered to the patients every 12 h starting from the first postoperative day to discharge. The severity of PD was also evaluated with the Delirium Rating Scale. Different parameters: pre-, intra- and postoperative, were analyzed. Univariate and multivariate analyses were performed.PD developed in 18% of patients. Univariate analysis revealed that advanced age, a history of PD, alcohol abuse, lower blood albumin concentration, intra-operative hypotension, elevated infusion volume and excessive blood loss were significantly related to the development of PD. On multivariate analysis, only lower levels of albumin, alcohol abuse, and hypotension were independent risk factors for PD.These findings suggest that PD is a frequent complication after colorectal surgery for carcinoma. A model based on pre, intra and postoperative risk factors allows prediction of the patient's risk for developing PD in order to implement preventive measures for this complication.