Development of a pharmacokinetic model-based infusion system for ketamine analgesia.

Model-driven infusion systems in anaesthesia overcome the difficulties in obtaining on-line measurements of controlled variables. A linear pharmacokinetic model for ketamine was used to achieve target blood concentrations and was implemented using a palmtop PC. Although the use of ketamine for analgesia in total intravenous anaesthesia with propofol has been reported, this is the first such application to spontaneously breathing patients. Preliminary results show this to be a useful system, which may easily be applied to other intravenous anaesthetic agents.