Target-controlled infusions (TCI) aim to provide constant, user-defined blo
od concentrations of a drug. The infusion device of such a system is contro
lled 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 dis
tribution and metabolism. This technology has several exciting applications
in anesthesia where stable blood concentrations of drugs are of benefit. T
CI of propofol for general anesthesia and sedation are now widely used, but
the technology is also being extended to the fields of intra- and postoper
ative analgesia and to patient-maintained sedation and analgesia. Early wor
k on targeting the effect site (brain) is under way and target-controlled p
ropofol infusions are being used in experimental the closed-loop anesthesia
systems. (C) 1999 Prous Science. All rights reserved.