Pharmacokinetic simulation of an anesthetic with target-controlled infusion (TCI)
(A) Pharmacokinetic simulation of an anesthetic with TCI (Marsh pharmacokinetic model)[1]. Note that there is no propofol bolus dose, an infusion of 1% propofol at 10 mL/hour for 10 minutes then 30 mL/hour for 10 minutes then 20 mL/hour for 10 minutes (see bottom white panels). The blue line is the calculated blood concentration and the green line the calculated brain or effect-site concentration. Note the very gradual rise in concentrations that for a period, may lie below anesthetic concentrations.
(B) Pharmacokinetic simulation of an anesthetic with TCI (Marsh pharmacokinetic model). Note that the TCI algorithm generates a bolus dose then an infusion that maintains plasma levels above putative anesthetic concentrations. The blue line is the calculated blood concentration and the green line the calculated brain or effect site concentration.
Reproduced with permission from: 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland: Accidental awareness during general anaesthesia in the United Kingdom and Ireland: Report and findings, September 2014. Pandit JJ, Cook TM (Eds). Copyright © 2014 The Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland. Available at:
https://www.nationalauditprojects.org.uk/NAP5report (Accessed on June 24, 2021).
Reference:
- Coppens M, Van Limmen JG, Schnider T, et al. Study of the time course of the clinical effect of propofol compared with the time course of the predicted effect-site concentration: Performance of three pharmacokinetic-dynamic models. Br J Anaesth 2010; 104:452.
