A retrospective analysis of propofol use following a guideline change from syringe- to in-fusion pump-induction for elective surgery

This retrospective cohort study aims to evaluate the clinical and operational impact of a departmental guideline change from syringe-bolus to infusion pump–based propofol induction during elective surgery under total intravenous anaesthesia at Copenhagen University Hospital, Bispebjerg and Frederiksberg. Using data from the validated TRIPLE-A perioperative database, adult patients treated before and after implementation in 2025 will be compared, excluding a predefined transitional washout period. The primary outcome is total peri-induction propofol dose, defined as administration within 15 minutes before and after induction. Secondary exploratory outcomes include remifentanil use, vasopressor requirements, lowest mean arterial pressure, time to airway management, difficult mask ventilation, and estimated propofol waste-related carbon footprint. Between-group comparisons will be performed using two-sided t-tests, while adjusted associations for the primary outcome will be examined using multivariable linear regression including relevant covariates such as age, sex, BMI, and ASA classification. Temporal changes in practice patterns and outcomes will additionally be assessed using statistical process control methods with run and control charts