Prevention of Postoperative Delirium in Elderly Patients

Within the framework of a six-month observation period, the investigators intend to identify risk factors of the patient collective for the development of postoperative delirium. For this purpose, a preoperative risk assessment is performed, which includes cognitive and physical performance as well as premedication and concomitant diseases. Included are patients of at least 65 years of age of defined specialties. Postoperatively, patients who have undergone the assessment are tested for delirium once per shift until the third postoperative day and severity and duration are documented. After completion of the observation period, risk factors favoring the development of postoperative delirium will be identified. In the subsequent intervention period, patients from the age of 65 years with an additional identified risk factor will receive standardized, targeted perioperative care. This includes both adherence to preventive measures in accordance with guidelines and the recommendation of therapeutic measures if a delirium is diagnosed. Through the standardized, interprofessional and interdisciplinary application of the described approach, the investigator aim to reduce the incidence, duration and severity of postoperative delirium. Furthermore, the evaluation of the identification of the weighting of risk factors as well as the identification of risk factors by the tests performed, length of hospital stay, three-month mortality and daily living skills after three months. In addition, a baseline EEG (standardized awake EEG before initiation) is recorded in a subgroup to determine whether patients at risk for delirium can be identified and whether intraoperative EEG parameters support the delirium risk assessment.

• duration of postoperative delirium [Time frame: for three days postoperatively and if the patient has delirium on the last day for the period until he is delirium negative or discharged from inpatient care, up to the day 90 visit at the latest]
• Severity of the postoperative delirium [Time frame: for three days postoperatively and if the patient has delirium on the last day for the period until he is delirium negative or discharged from inpatient care, up to the day 90 visit at the latest]
• Which parameters and tests detect patients at risk for postoperative delirium? [Time frame: From the time of premedication until three days postoperatively]
• Can baseline and intraoperative EEG parameters be used to identify patients at risk? Does intraoperative burst suppression EEG represent a risk factor for delirium? [Time frame: From the patient's arrival in the operating room to three days postoperatively]
• When is the diagnosis of postoperative delirium most commonly made? [Time frame: for three days postoperative]
• The implementation of a delirium management protocol during the intervention period serves to improve the three-month outcome of patients at risk in terms of maintaining their autonomy or daily living skills. [Time frame: One-time interview three months postoperatively]
• Implementation of a delirium management protocol reduces the length of hospital stay of risk patients [Time frame: from the date of hospitalisation to the date of discharge from hospital, up to the day 90 visit at the latest]
• Implementation of a delirium management protocol reduces three-month mortality in high-risk patients [Time frame: Query of the patients' death data three months postoperatively]