Pharmacokinetics and concentration-effect relationship after propofol infusion.
BACKGROUND
We investigated the pharmacokinetics (PK) and concentration-effect relationship after an infusion of propofol in order to obtain a model which can predict the time to eye opening.


METHODS
Anaesthesia was induced and maintained with propofol in 34 patients using a Computer Controlled Infusion Pump. Arterial blood samples were taken during recovery and a new model describing the PK was derived. The model was then used to predict the concentration of propofol at the time of eye opening to command.


RESULTS
The central volume of distribution was 0.228 L/kg, and the inter-compartment transfer rate constants (min-1) were: k10 0.166, K12 0.091, k13 0.124, k21 0.045, and k31 0.0098. The predicted concentration at which 50% of the patients responded to command was 0.98 microgram/ml.


CONCLUSIONS
PK parameters predicting propofol concentration during anaesthesia differ from those describing recovery. The PK of propofol during recovery following an infusion are similar to those following a bolus dose. Real time estimation of blood propofol concentration serves as a useful additional monitor of recovery from anaesthesia.
Lim
T A
TA
Department of Anaesthesia and Intensive Care, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
Tam
Y H
YH
Short
T G
TG
D000328:Adult; D018686:Anesthetics, Intravenous / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015742:Propofol / Q000493:pharmacokinetics* / Q000494:pharmacology
D018686:Anesthetics, Intravenous; D015742:Propofol