Predictive performance of computer-controlled infusion of remifentanil during propofol/remifentanil anaesthesia

Background. The predictive performance of the available pharmacokineticparameter sets for remifentanil, when used for target-controlledinfusion (TCI) during total i.v. anaesthesia, has not been determinedin a clinical setting. We studied the predictive performanceof five parameter sets of remifentanil when used for TCI ofremifentanil during propofol anaesthesia in surgical patients. Methods. Remifentanil concentration–time data that hadbeen collected during a previous pharmacodynamic interactionstudy in 30 female patients (ASA physical status I, aged 20–65 yr)who received a TCI of remifentanil and propofol during lowerabdominal surgery were used in this evaluation. The remifentanilconcentrations predicted by the five parameter sets were calculatedon the basis of the TCI device record of the infusion rate–timeprofile that had actually been administered to each individual.The individual and pooled bias [median performance error (MDPE)],inaccuracy [median absolute performance error (MDAPE)], divergenceand wobble of the remifentanil TCI device were determined fromthe pooled and intrasubject performance errors. Results. A total of 444 remifentanil blood samples were analysed.Blood propofol and remifentanil concentrations ranged from 0.5to 11 µg ml^–1 and 0.1 to 19.6 ng ml^–1respectively. Pooled MDPE and MDAPE of the remifentanil TCIdevice were –15 and 20% for the parameter set of Mintoand colleagues (Anesthesiology 1997; 86: 10–23), 1 and21%, –6 and 21%, and –6 and 19% for the three parametersets described by Egan and colleagues (Anesthesiology 1996;84: 821–33, Anesthesiology 1993; 79: 881–92, Anesthesiology1998; 89: 562–73), and –24 and 30% for the parameterset described by Drover and Lemmens (Anesthesiology 1998; 89:869–77). Conclusions. Remifentanil can be administered by TCI with acceptablebias and inaccuracy. The three pharmacokinetic parameter setsdescribed by Egan and colleagues resulted in the least biasand best accuracy. Br J Anaesth 2003; 90: 132–41