Comparison of the Incidences of Anesthesia-Related Adverse Events in Patients Undergoing Surgery in the Daytime, Care Transition, and After-Hours Period

Background: The timing of surgery might affect anesthesia-related adverse events due to limited personnels, inadequate supervision, and/or lack of equipment, especially after-hours period. Objective: To compare the incidence of adverse anesthesia events in patients undergoing surgery in different periods of the day. Materials and Methods: A retrospective cohort study was performed in adult patients who undergone surgery under anesthesia at Siriraj Hospital in 2020. Patients were randomly selected and categorized into three groups according to the time of anesthesia, Group 1, daytime anesthesia group (8 a.m. to 4 p.m.), Group 2, anesthesia with care transition between the daytime and after-hours period, and Group 3, after-hours anesthesia group (4 p.m. to 8 a.m.). The patients’ demographic data, surgical-related, anesthesia data, and anesthesia-related adverse events were reviewed from the hospital electronic medical records. Analysis was performed to compare the incidence and determine the risk factors associated with adverse anesthesia events. Results: One thousand two hundred patients were included in the present study with 600, 400, and 200 patients in groups 1, 2, and 3, respectively. The overall incidence of adverse anesthesia events was 5.3% with 6.7%, 3.5%, and 5.0% in groups 1, 2, and 3, respectively (p=0.090). The most common adverse anesthesia event was difficult intubation at 1.5%. The factor found to be significantly associated with anesthesia-related adverse events was the non-operating room anesthesia (OR 5.97, 95% CI 2.94 to 12.13, p<0.001). Conclusion: The present study was unable to demonstrate a significant difference in the incidences of anesthesia-related adverse events among the various anesthesia periods.