Risk Factors for Postoperative Delirium After Gastrectomy in Gastric Cancer Patients

Purpose: The incidence of postoperative delirium is reported to range from 9 to 87%; however, no report has focused on cases of postoperative delirium in gastric cancer surgery alone. Therefore, we investigated the incidence of and risk factors for postoperative delirium after gastrectomy in patients with gastric cancer. Methods: A total of 1037 patients who underwent surgery were included in the study. Patients were divided into two groups—those with (delirium group) or without (non-delirium group) postoperative delirium—and their backgrounds were compared. The short-term outcomes and the overall survival were also investigated. Results: Postoperative delirium was observed in 47 of 1037 patients (4.5%). A multivariate analysis revealed that male gender, age ≥ 75 years, a history of cerebrovascular disease, and the habitual use of sleeping pills were independent predictive factors for postoperative delirium. The postoperative hospital stay was significantly longer in the postoperative delirium group than in the non-delirium group. Postoperative delirium was significantly associated with postoperative complications. The 3-year overall survival was 74.3% in the delirium group and 85.5% in the non-delirium group (log-rank p = 0.006). A multivariate analysis revealed that postoperative delirium was an independent prognostic factor, along with the age and cancer stage. Conclusion: The incidence of postoperative delirium was 4.5% in gastric cancer patients. Male gender, age ≥ 75 years, a history of cerebrovascular disease, and the habitual use of narcoleptic agents were risk factors for postoperative delirium after gastrectomy in gastric cancer patients. Postoperative delirium was strongly associated with other postoperative complications and a poor survival after surgery.