Evaluation of Marsh's Pharmacokinetic Parameter Set for Target Controlled Infusion of Propofol in Korean

Jeon, Soon Young; Kil, Ho Yeong; Kim, Kwang Min

Abstract

BACKGROUND: Marsh's pharmacokinetic parameter set is the most widely used parameter for target controlled infusion for propofol. However, Marsh's model was derived from a European population, and it is uncertain whether this model is accurate for Koreans.
METHODS
Thirty ASA 1 or 2 adult patients undergoing orthopedic surgery participated in this study. Atropine 0.5 mg was injected for premedication. Anesthesia was induced by a TCI of propofol with a target concentration of 6 microgram/ml and maintained around 3 - 5 microgram/ml according to the bispectral index (35 - 45). In the middle of surgery, target concentrations were increased to 6 microgram/ml and maintained until effect site concentration was the same concentration. Three minutes after equilibration, 3 ml of blood was drawn from the radial artery and contralateral antecubital cephalic vein for measuring blood concentration using HPLC. Target concentrations were gradually decreased at the interval of 1 microgram/ml until the end of surgery and a blood sample was drawn as described in the method. A sample for every 1 microgram/ml was collected in the recovery room. Performance error of the predicted concentration of blood was calculated.
RESULTS
The performance error was -12.86 - 16.55% for 1 - 6 microgram/ml of predicted concentration. Measured concentrations were higher than predicted at higher concentrations, but lower at lower concentrations. Measured cardiac output and arteriovenous concentration differences at 1 - 6 microgram/ml showed no difference.
CONCLUSIONS
Marsh's pharmacokinetic model was accurate for propofol TCI in Koreans in terms of relatively low performance error (< 20%) in the concentration range of 1 - 6 microgram/ml.