From Postoperative Delirium to Falls: Investigating Prevention, Long-Term Effects and Predictive Tools for Delirium and Falls in the Perioperative Setting

• Applicant: Dr. Justus Student
• Subject Area: Anaesthesiology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 567508647

Postoperative delirium (POD) is a frequent and serious complication following major surgical procedures, particularly among patients of advanced age. Furthermore, it significantly increases the risks of other postoperative adverse outcomes, including prolonged in-hospital length of stay, higher risks of postoperative emergency department visits, hospital readmissions, as well as mortality within one year. While a growing body of evidence describes measures to predict and treat POD, there remains a lack of comprehensive preventive strategies. The protective effect of ketamine application on POD is subject of controversial debate. However, recent data shows a protective effect by application of low-dose ketamine intraoperatively. Critically ill patients who were admitted to the intensive care unit (ICU) following surgery often remain in the ICU-setting for a longer period of time and occasionally need to be sedated during their stay. It remains unclear whether there is also an effect of ketamine administration in the ICU on delirium. (I) Together, we hypothesize that the neuroprotective effects of ketamine at lower doses may reduce the risk of POD. In Addition, POD is associated with long-term cognitive decline. Current research shows that individuals with mild cognitive impairment (MCI) are more prone to falls at home. While both MCI and delirium are characterized by disordered cognition, delirium mainly affects attention and awareness of patients. Whether the occurrence of POD puts patients at increased risk of falls following discharge from the hospital remains unclear. (II) Therefore, we hypothesize that the risk of readmission or presentation to the emergency room due to a fall in the postoperative course after surgery is increased in patients who developed POD during their initial hospitalization. Overall, falls after hospital discharge represent a significant hazard, impairing quality of life and independence for those affected. To prevent falls, it is important to identify those at high risk. To date there is no model available that includes variables that are available at the time of a patient’s discharge from the hospital to evaluate the patient’s post-discharge fall risk. (III) We aim to develop a machine-learning supported tool to create a perioperative screening system that recognizes patients who have an increased risk of subsequent falls within the first 365 days after surgery as a result of their hospital stay. During my research stay of 18 months a retrospective cohort study based on an established, comprehensive database at the Center for Anesthesia Research Excellence at Beth Israel Deaconess Medical Center (BIDMC) will be conducted to investigate all these research questions. This database comprises data from 74,200 patients admitted to the ICU and 115,218 who underwent a surgical or interventional procedure from 2011 to 2024.

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Privatdozent Dr. Maximilian Schaefer, Ph.D.