Breath Monitoring of Propofol (Observational Study)

Propofol is a hypnotic drug commonly used for induction and maintenance of general anesthesia. Propofol is adiministered intravenously and has a comfortable side effect profile. Patients recover fast after propofol anesthesia and are less likely to suffer from post-operative nausea and vomiting compared to general anesthesia with inhalational anesthetics. However, titration of propofol can be challenging and patients may suffer from over- or underdosing during propofol anesthesia. Recent work has demonstrated that propofol is exhaled during anesthesia. Monitoring of propofol concentrations in breath gas during anesthesia may help to titrate propofol anesthesia more effectively. Yet, it is unclear how propofol concentrations vary among patients. This study aims to investigate this variation in a cohort of patients undergoing general anesthesia for elective surgical procedures. Propofol will be measured in breath gas continuously from the induction of anesthesia until recovery. Blood samples will be drawn from the start of anesthesia up to 24 h after the end of the anesthesia procedure and assayed for propofol blood concentrations. We will built a pharmacokinetic model from breath and blood measurements in order to describe the variability of propofol breath concentrations among study participants.