Comparison of plasma compartment versus two methods for effect compartment--controlled target-controlled infusion for...

Area of Science:

• Anesthesiology and pharmacology.
• Pharmacokinetics and pharmacodynamics.
• Medical device technology.

Background:

• Target-controlled infusion (TCI) systems offer precise drug delivery by managing plasma or effect-site concentrations.
• Accurate prediction of drug effect time course is crucial for effect-site controlled TCI.
• This study compares plasma-controlled TCI with two effect-site controlled TCI algorithms.

Purpose of the Study:

• To evaluate the performance of different TCI control algorithms in predicting propofol's effect-site concentration.
• To assess the clinical safety and efficacy of effect-site controlled TCI.

Main Methods:

• One hundred twenty healthy women received propofol via TCI.
• Three groups were studied: plasma-controlled TCI, effect-site controlled TCI with a 3.5-min equilibration half-life, and effect-site controlled TCI with a 1.6-min time to peak effect.
• Propofol effect was monitored using the bispectral index, alongside measurements of blood pressure, ventilation, and loss of consciousness.

Main Results:

• Effect-site controlled TCI, particularly with a 1.6-min time to peak effect, provided the most accurate prediction of propofol's drug effect.
• Targeting effect-site concentration reduced time to loss of consciousness without inducing hypotension.
• Apnea incidence was lower in the group with a 1.6-min time to peak effect compared to the 3.5-min group.

Conclusions:

• Effect-site controlled TCI is a safe and effective clinical practice.
• A biophase model incorporating Marsh kinetics and a 1.6-minute time to peak effect accurately predicts propofol's drug effect time course.