A phase II study of ramelteon for the prevention of postoperative delirium in elderly patients undergoing gastrectomy.

The growing number of cases of gastric cancer being diagnosed in elderly patients highlights the importance of preventing postoperative delirium. This phase II study aimed to evaluate the efficacy of perioperative treatment with ramelteon for preventing postoperative delirium in elderly patients undergoing gastrectomy. This study was designed as a single-institute prospective phase II study. Patients ≥ 75 years old were eligible. Ramelteon 8 mg/day was administered from 8 days before the operation until discharge. Postoperative delirium was evaluated using the Confusion Assessment Method-Intensive Care Unit flow sheet. Between September 2015 and July 2017, a total of 83 patients were enrolled, 76 of whom were eligible and included in the analysis. Postoperative delirium was observed in four patients (5%) (60% confidence interval: 3.0-8.7). The upper margin of the confidence interval was lower than the prespecified threshold of 13%; therefore, the null hypothesis was rejected. This phase II study suggested that the perioperative administration of ramelteon is safe and feasible for preventing postoperative delirium in elderly patients undergoing gastrectomy. Trial registration This study was registered at UMIN (UMIN 000018697).