Current and future applications of target-controlled infusions

Target-controlled infusions (TCI) aim to provide constant, user-defined blood concentrations of a drug. The infusion device of such a system is controlled by a microprocessor that uses population pharmacokinetic data and the individual patient's weight and age to continuously calculate required drug infusion rate to replace losses from the blood compartment due to drug distribution and metabolism. This technology has several exciting applications in anesthesia where stable blood concentrations of drugs are of benefit. TCI of propofol for general anesthesia and sedation are now widely used, but the technology is also being extended to the fields of intra- and postoperative analgesia and to patient-maintained sedation and analgesia. Early work on targeting the effect site (brain) is under way and target-controlled propofol infusions are being used in experimental the closed-loop anesthesia systems. (C) 1999 Prous Science. All rights reserved