Incidence and risk factor analysis of the postoperative delirium after gastrointestinal surgery: An exploratory analysis of a prospective, randomized phase II trial.

30 Background: The postoperative complications, delirium are a particularly common morbidity after gastrointestinal surgery. Postoperative delirium makes patient management much more difficult, increases costs, and causes severe discomfort to the patient. The aim of this study was to evaluate the incidence of the postoperative delirium and a predictor for postoperative delirium using phase II clinical trial data. Methods: We analyzed the cases that were enrolled to randomized clinical trials of the efficacy and safety of TJ-54 (Yokukansan; a traditional Japanese medicine [Kampo]) for the prevention and/or treatment of postoperative delirium in a randomized phase II trial of patients receiving surgery for gastrointestinal and lung malignancies (UMIN000005423). The American Psychiatric Association’s the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) was used to assess. A uni- and multivariate logistic regression analyses was performed to identify risk factors for morbidity. Results: Between October 2009 and July 2011, a total of 186 patients were registered to the Yokukansan trial. Among them, 167 patients received surgery for gastrointestinal malignancy and were eligible for the present study. The incidence of postoperative delirium was 9.0% (15 patients) and postoperative delirium was the most common postoperative complication in the study. Risk factors for postoperative delirium were analyzed by uni- and multi-variate analyses using clinical factors determined before the enrollment of the study. Among these, high patients’ age ( > 80 years) and low MMSE score ( < 27) were identified as significant independent risk factor for postoperative delirium (Odds ratio: 3.90, 95% CI; 1.25-12.16, p = 0.013 and Odds ratio: 0.24, 95% CI; 0.08-0.73, p = 0.013). Conclusions: The major of the findings were that high patients’ age (≥ 80 years) and low MMSE score ( < 27) were significant independent risk factors for predicting postoperative delirium. Careful attention for postoperative delirium is required in patients with high patients’ age and MMSE score when surgeons perform surgery for gastrointestinal malignancies. Clinical trial information: 000005423.