A Prospective Randomized Study of the Herbal Medicine Yokukansan for Preventing Delirium After Gastrointestinal Cancer Surgery.

Background: Yokukansan, the Chinese Herbal Medicine, may be effective for treating postoperative delirium. However, there is no sufficient evidence supporting this notion. This study aimed to investigate whether yokukansan was effective for preventing delirium after gastrointestinal cancer surgery by the prospective randomized study. Methods: This was a double-blind, randomized, controlled trial. Patients aged 75 years or older who underwent surgery between May 2017 and December 2019 were randomized to the yokukansan or anchusan (another Herbal Medicine) group. They received treatments with oral intake of assigned medicine from the day before surgery until postoperative day 3. Then, the incidence of postoperative delirium was compared. A psychiatrist diagnosed patients with postoperative delirium. Results: Seventy-seven patients were enrolled in this study, and the full analysis set comprised 68 patients. In total, 25 of 68 (36.8%) patients presented with postoperative delirium. Specifically, 13 (37.1%) patients in the control group and 12 (36.4%) in the yokukansan group were diagnosed with postoperative delirium. However, the results did not differ significantly in both groups. Moreover, there was no remarkable difference in terms of delirium severity, and adverse events correlated with the medications were not observed. Conclusion: Yokukansan was ineffective in preventing delirium after gastrointestinal cancer surgery.