Frequency of postoperative delirium and associated factors among consultation-liaison psychiatry patients with schizophrenia spectrum disorders undergoing surgery: a retrospective cohort study.

Patients with schizophrenia spectrum disorders (SSDs) have a high risk of physical illnesses that require surgery. Postoperative delirium (POD) is an important postoperative complication that may be difficult to manage in patients with SSDs and may require psychiatric expertise. This study aimed to investigate the frequency of POD and its associated factors among patients with SSDs who were referred to consultation-liaison psychiatry during surgical hospitalization. A retrospective study was conducted at three tertiary hospitals in Japan, including 200 patients with SSDs who underwent surgery between April 2017 and March 2022 and were referred to consultation-liaison psychiatry during their surgical hospitalization. Patients admitted due to psychiatric crises were excluded. Data on demographics, psychiatric history, surgical details, and POD development were collected. Statistical analysis included chi-square or Fisher's exact tests and logistic regression to identify factors associated with POD. POD occurred in 10.5% of patients with SSDs, and only one patient required transfer to a psychiatric ward. Most patients had schizophrenia (90.5%), and the mean age was 57.4 years. In the exploratory multivariable analysis, age ≥ 65 years and smoking before admission showed associations with POD. Antipsychotic medication use or dose was not associated with POD. Most POD cases in this consultation-liaison psychiatry cohort were managed with psychotropic drug adjustments. These findings suggest that POD in psychiatrically managed surgical patients with SSDs may often be manageable in general hospitals when psychiatric liaison expertise is available, although further studies are needed to determine generalizability to broader populations of surgical patients with SSDs.