The project QV-POD-2 is a prolongation based on QV-POD-1, which was a quality contract program of the IQTIG - Institute for Quality and Transparency in Health Care. The aim is to improve inpatient care for older patients who are undergoing inpatient surgery and thus to specifically reduce the postoperative risk of delirium. This is achieved through the implementation of evidence-based and consensus-based measures to prevent postoperative delirium in a comprehensive structured concept in routine care. The transparent documentation in an electronic patient file enables the relationships between the symptoms to be depicted in accordance with the clinical circumstances and the genesis of the postoperative delirium to be recorded and treated at an early stage. The content of the additional elements from the routine data (see primary and secondary outcome measures) in QV-POD-2 is analysed internally. Subproject Retro-Pressure started in August 2022: Retrospective, exploratory cohort study using electronic anesthesia and hospital records from Jan 1, 2016 to Jan 1, 2020, including patients ≥70 years undergoing surgery with anesthesia. The objective is to quantify associations between intraoperative blood pressure dynamics-variability, rate of change, relative hypo-/hypertension versus baseline, and time-integrated BP (area under/above reference)-and postoperative organ dysfunction Primary endpoints: Emergence delirium incidence (PACU/ITS) based on Nu-DESC scores and CAM-ICU scores; incidence of postoperative acute renal failure (creatinine and urea levels, as well as urine output); intraoperative blood pressure variation\*; intraoperative blood pressure variation rate\*; intraoperative blood pressure integral\* Secondary endpoints: Blood count (hemoglobin and hematocrit values); intraoperative transfusions of blood reserves Addendum from the ethics amendment vote of 25/07/2022 Subproject Delta-Scan started in August 2022: Evaluation of brain function using Delta Scan Primary objective: Evaluation of the prognostic significance of Delta Scan measurements in relation to postoperative delirium Secondary objectives: Examination of the delirium-related predictive relevance of individual influencing factors (directly but also indirectly through Delta Scan values) and examination of the effect of Delta Scan measurements on standard delirium screening methods. Study and control group's Inclusion criteria: Age \>= 70 years and major surgery with anesthesia; additional exclusion criterion in the control group: Inclusion in the QV-POD-1 project (receipt of postoperative preventive measures) Addendum from the ethics amendment vote of 25/07/2022